Редактирование: DCX (раздел)

==Publications==

{{medline-entry
|title=GSK-3β activation accelerates early-stage consumption of Hippocampal Neurogenesis in senescent mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/32863953
|abstract=Adult hippocampal neurogenesis (AHN) deficits contribute to the progression of cognitive impairments during accelerated senescence, with the mechanistic causes poorly understood. Glycogen synthase kinase-3β (GSK-3β) is a critical regulator in prenatal neurodevelopment. The present study aims to study whether and how GSK-3β regulates AHN during the accelerated senescence.   AHN and AHN-dependent cognition and GSK-3β were evaluated in 3- and 6-month senescence-accelerated mice prone 8 (SAM-P8) and senescence resistant 1 (SAM-R1) mice, respectively. GSK-3β was selectively overexpressed in wild-type mice using adeno-associated virus, or knocked-out by crossbreeding with GSK-3β floxed mice in the neural stem cells (NSCs) of Nestin-Cre mice, or pharmacologically inhibited with SB216763 in SAM-P8 mice. AHN was evaluated by BrdU-, [[DCX]]-staining and retrovirus-labeling.   AHN transiently increased at 3-month, but dramatically dropped at 6-month of age in SAM-P8 mice with a simultaneous activation of GSK-3β at 3-month. Selective overexpression of GSK-3β in hippocampal NSCs of wildtype mice induced long-term AHN deficits due to an accelerated depletion of NSC pool, although it transiently increased the proliferation and survival of the newborn neurons. Pharmacologically inhibiting GSK-3β by SB216763 efficiently preserved AHN and improved contextual memory in 6-month SAM-P8 mice, while conditional knock-out of GSK-3β in NSCs impaired AHN.   Early-stage activation of GSK-3β in NSCs impairs AHN by accelerating the depletion of NSC pool, and pharmacological inhibition of GSK-3β is efficient to preserve AHN during the accelerated aging. These results reveal novel mechanisms underlying the AHN impairments during accelerated senescence and provide new targets for pro-neurogenic therapies for related diseases.

|keywords=* Adult hippocampal neurogenesis
* Glycogen synthase kinase-3β
* Senescence
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7449917
}}
{{medline-entry
|title=Doublecortin and IGF-1R protein levels are reduced in spite of unchanged DNA methylation in the hippocampus of aged rats.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/32236698
|abstract=The aim of the current study was to investigate whether doublecortin ([[DCX]]), insulin-like growth factor receptor 1 (IGF-1R) and metabotropic glutamate receptor 5 (mGluR5) levels are indeed modified in the aging rat hippocampal individual subareas (rather than total hippocampal tissue as in previous reports) at the protein and mRNA level and whether the methylation status contributes to these changes. Since the aging population is not homogeneous in terms of spatial memory performance, we examined whether changes in [[DCX]], IGF-1R and mGluR5 are linked to cognitive aging. Aged (22 months) male Sprague Dawley rats were trained in the hole-board, a spatial memory task, and were subdivided according to performance to aged impaired and aged unimpaired groups. Age- and memory performance-dependent changes in mRNA steady-state levels, protein levels and DNA methylation status of [[DCX]], IGF-1R and mGluR5 were evaluated by RT-PCR, immunoblotting and bisulfite pyrosequencing. Extending previous findings, we detected decreased [[DCX]] protein and mRNA levels in dentate gyrus (DG) of aged animals. IGF-1 signaling is a key event and herein we show that mRNA levels for IGF-1R were unchanged although reduced at the protein level. This finding may simply reflect that these protein levels are regulated at the level of protein synthesis as well as protein degradation. We provide evidence that promoter methylation is not involved in regulation of mRNA and protein levels of [[DCX]], IGF-1R and mGluR5 during aging. Moreover, there was no significant difference between aged rats with impaired and aged rats with unimpaired memory at the protein and mRNA level. Findings propose that changes in the abovementioned protein levels may not be relevant for performance in the spatial memory task used in aged rats.

|keywords=* Aging
* DNA methylation
* Doublecortin
* Hippocampus
* IGF-1R
* mGluR5
|full-text-url=https://sci-hub.do/10.1007/s00726-020-02834-3
}}
{{medline-entry
|title=Human Hippocampal Neurogenesis Persists in Aged Adults and Alzheimer's Disease Patients.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/31130513
|abstract=Whether hippocampal neurogenesis persists throughout life in the human brain is not fully resolved. Here, we demonstrate that hippocampal neurogenesis is persistent through the tenth decade of life and is detectable in patients with mild cognitive impairments and Alzheimer's disease. In a cohort of 18 participants with a mean age of 90.6 years, Nestin Sox2  neural progenitor cells (NPCs) and [[DCX]]  neuroblasts and immature neurons were detected, but their numbers greatly varied between participants. Nestin  cells localize in the anterior hippocampus, and NPCs, neuroblasts, and immature neurons are evenly distributed along the anterior to posterior axis. The number of [[DCX]] [[PCNA]]  cells is reduced in mild cognitive impairments, and higher numbers of neuroblasts are associated with better cognitive status. The number of [[DCX]] [[PCNA]]  cells correlates with functional interactions between presynaptic SNARE proteins. Our results suggest that hippocampal neurogenesis persists in the aged and diseased human brain and that it is possibly associated with cognition.
|mesh-terms=* Aged, 80 and over
* Aging
* Alzheimer Disease
* Cells, Cultured
* Cognition
* Cohort Studies
* Female
* Hippocampus
* Humans
* Male
* Microtubule-Associated Proteins
* Nestin
* Neural Stem Cells
* Neurogenesis
* Neurons
* Neuropeptides
* Proliferating Cell Nuclear Antigen
* SNARE Proteins
* SOXB1 Transcription Factors
|keywords=* Alzheimer’s disease
* adult neurogenesis
* aging
* cognitive dysfunction
* human neurogenesis
* neural stem cells
* neurogenesis in aging
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6608595
}}
{{medline-entry
|title=Age-related changes in Ki-67 and [[DCX]] expression in the BALB/ c mouse (Mus Musculus) brain.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/30472241
|abstract=Several studies have identified age as one of the strongest regulators of neurogenesis in the mammalian brain. However, previous age-related studies focused mainly on changes in neurogenesis during different stages of adulthood and did not describe changes in neurogenesis through the different life history stages of the animal. The aim of this study was therefore to determine time course changes in neurogenesis in the male BALB/c mouse brain at postnatal ages 1 week to 12 weeks, spanning juvenile, sub adult and adult life history stages. To achieve this, Ki-67 and [[DCX]] immunohistochemistry was used to assess changes in cell proliferation and neuronal incorporation respectively. Ki-67 expression was mainly observed in the olfactory bulb, rostral migratory stream, sub ventricular zone of lateral ventricle and the sub granular zone of the dentate gyrus. In addition, fewer Ki-67 positive cells were also observed in the neocortex, cerebellum and tectum. [[DCX]] was expressed in similar regions as Ki-67 except for the cerebellum and tectum. Expression of both Ki-67 and [[DCX]] sharply decreased with advancing age or life history stages in the sub ventricular zone, rostral migratory stream and sub granular zone of the BALB/c mouse brain. Neurogenesis therefore persists throughout all life history stages in the BALB/c mouse brain although it decreases with age.
|mesh-terms=* Age Factors
* Aging
* Animals
* Animals, Newborn
* Brain
* Cell Movement
* Cell Proliferation
* Gene Expression Regulation, Developmental
* Ki-67 Antigen
* Male
* Mice
* Mice, Inbred BALB C
* Microtubule-Associated Proteins
* Neurogenesis
* Neurons
* Neuropeptides
|keywords=* Age
* BALB/c mouse
* Brain
* DCX
* Ki-67
* Life-history stage
|full-text-url=https://sci-hub.do/10.1016/j.ijdevneu.2018.11.005
}}
{{medline-entry
|title=Inflammation-induced Gro1 triggers senescence in neuronal progenitors: effects of estradiol.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/30201019
|abstract=Inflammation has been proposed to contribute to the decline in adult hippocampal neurogenesis. Proinflammatory cytokines activate transcription of chemokine growth-regulated oncogene α (Gro1) in human and murine hippocampal neuronal progenitor cells (NPC). The goal of this study was to investigate the effects of Gro1 on hippocampal neurogenesis in the presence of inflammation. Human hippocampal NPC were transfected with lentivirus expressing Gro1, and murine NPC and hippocampal neuronal HT-22 cells were treated with Gro1 protein. A plasmid expressing mGro1 was electroporated in the hippocampus of newborn mice that were sacrificed 10 days later. Adult male and female mice were injected with lipopolysaccharide (LPS; 1 mg/kg, i.p in five daily injections) or normal saline. Adult male mice were implanted with pellets releasing 17-β estradiol (E2; 2.5 mg/pellet, 41.666 μg/day release) or placebo for 6 weeks and challenged with LPS or normal saline as above. In both experiments, mice were sacrificed 3 h after the last injection. Hippocampal markers of neurogenesis were assessed in vitro and in vivo by Western blot, real-time PCR, and immunohisto/cytochemistry. Gro1 induced premature senescence in NPC and HT-22 cells, activating senescence-associated β-galactosidase and the cell cycle inhibitor p16 and suppressing neuroblast proliferation and expression of doublecortin ([[DCX]]) and neuron-specific class III beta-tubulin (Tuj-1), both neuroblast markers, while promoting proliferation of neural glial antigen 2 (Ng2)-positive oligodendrocytes. Gro1 overexpression in the hippocampus of newborn mice resulted in decreased neuroblast development, as evidenced by decreased [[DCX]] expression and increased expression of platelet-derived growth factor α receptor (PDGFαR), a marker of oligodendrocyte precursors. In adult mice, Gro1 was induced in response to LPS treatment in male but not in female hippocampus, with a subsequent decrease in neurogenesis and activation of oligodendrocyte progenitors. No changes in neurogenesis were observed in females. Treatment with E2 blunted LPS-induced Gro1 in the male hippocampus. Inflammation-induced Gro1 triggers neuroblast senescence, thus suppressing new neuron development in the hippocampus. Sex-dependent differences in Gro1 response are attributed to estradiol, which blunts these changes, protecting the female hippocampus from the deleterious effects of inflammation-induced Gro1 on neurogenesis.
|mesh-terms=* Adult
* Animals
* Cell Proliferation
* Cells, Cultured
* Chemokine CXCL1
* Cytokines
* Epilepsy
* Estradiol
* Estrogens
* Female
* Galactose
* Gene Expression Regulation
* Humans
* Inflammation
* Lipopolysaccharides
* Male
* Mice
* Mice, Inbred C57BL
* Middle Aged
* Neural Stem Cells
* SOXB1 Transcription Factors
|keywords=* Chemokines
* Gro1
* Hippocampus
* LPS-induced inflammation
* Neuronal progenitor cells
* Senescence
* Sex dimorphism
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6131894
}}
{{medline-entry
|title=Neuroprotective Effects of the Multitarget Agent AVCRI104P3 in Brain of Middle-Aged Mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/30181440
|abstract=Molecular factors involved in neuroprotection are key in the design of novel multitarget drugs in aging and neurodegeneration. AVCRI104P3 is a huprine derivative that exhibits potent inhibitory effects on human AChE, BuChE, and BACE-1 activities, as well as on AChE-induced and self-induced Aβ aggregation. More recently, cognitive protection and anxiolytic-like effects have also been reported in mice treated with this compound. Now, we have assessed the ability of AVCRI104P3 (0.43 mg/kg, 21 days) to modulate the levels of some proteins involved in the anti-apoptotic/apoptotic processes (pAkt1, Bcl2, pGSK3β, p25/p35), inflammation ([[GFAP]] and Iba1) and neurogenesis in C57BL/6 mice. The effects of AVCRI104P3 on AChE-R/AChE-S isoforms have been also determined. We have observed that chronic treatment of C57BL/6 male mice with AVCRI104P3 results in neuroprotective effects, increasing significantly the levels of pAkt1 and pGSK3β in the hippocampus and Bcl2 in both hippocampus and cortex, but slightly decreasing synaptophysin levels. Astrogliosis and neurogenic markers [[GFAP]] and [[DCX]] remained unchanged after AVCRI104P3 treatment, whereas microgliosis was found to be significantly decreased pointing out the involvement of this compound in inflammatory processes. These results suggest that the neuroprotective mechanisms that are behind the cognitive and anxiolytic effects of AVCRI104P3 could be partly related to the potentiation of some anti-apoptotic and anti-inflammatory proteins and support the potential of AVCRI104P3 for the treatment of brain dysfunction associated with aging and/or dementia.
|mesh-terms=* Acetylcholinesterase
* Aging
* Aminoquinolines
* Animals
* Brain
* GPI-Linked Proteins
* Gene Expression Regulation
* Gene Regulatory Networks
* Glycogen Synthase Kinase 3 beta
* Male
* Mice
* Mice, Inbred C57BL
* Neuroprotective Agents
* Phosphorylation
* Proto-Oncogene Proteins c-akt
* Proto-Oncogene Proteins c-bcl-2
* Synaptophysin
|keywords=* AVCRI104P3
* acetylcholinesterase inhibitors
* apoptosis
* huprine derivatives
* neuroinflammation
* neuroprotection
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6165152
}}
{{medline-entry
|title=Differential effects of adolescent and adult-initiated voluntary exercise on context and cued fear conditioning.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/29793890
|abstract=Adolescence is a critical period for postnatal brain maturation and a time during which there is increased susceptibility to developing emotional and cognitive-related disorders. Exercise during adulthood has been shown to increase hippocampal plasticity and enhance cognition. However, the impact of exercise initiated in adolescence, on brain and behaviour in adulthood is not yet fully explored or understood. The aim of this study was to compare the impact of voluntary exercise that was initiated either during adolescence or early adulthood on cognitive performance in hippocampal and amygdala-dependent fear conditioning tasks in adulthood. Adult (eight weeks old) and adolescent (four weeks old) male Sprague Dawley rats had access to a running wheel (exercise) or were left undisturbed (sedentary control) for seven weeks. Adult-initiated exercise enhanced both contextual and cued fear conditioning, while conversely, exercise that began in adolescence did not affect performance in these tasks. These behaviours were accompanied by differential expression of plasticity-related genes in the hippocampus and amygdala in adulthood. Specifically, adolescent-initiated exercise increased the expression of an array of plasticity related genes in the hippocampus including [[BDNF]], synaptophysin, Creb, [[PSD]]-95, Arc, TLX and [[DCX]], while adult-initiated exercise did not affect hippocampal plasticity related genes. Together results show that exercise initiated during adolescence has a differential effect on hippocampal and amygdala-dependent behaviour and neuronal plasticity compared to when exercise was initiated in adulthood. These findings reinforce adolescence as a period during which environmental influences have a distinct impact on neuronal plasticity and cognition. This article is part of the Special Issue entitled "Neurobiology of Environmental Enrichment".
|mesh-terms=* Aging
* Amygdala
* Animals
* Conditioning, Psychological
* Cues
* Fear
* Gene Expression Regulation, Developmental
* Hippocampus
* Male
* Mental Recall
* RNA, Messenger
* Rats, Sprague-Dawley
* Running
|keywords=* Adolescence
* Amygdala
* Fear conditioning
* Hippocampus
* Plasticity
* Running
|full-text-url=https://sci-hub.do/10.1016/j.neuropharm.2018.05.007
}}
{{medline-entry
|title=Hippocampal neurogenesis in the C57BL/6J mice at early adulthood following prenatal alcohol exposure.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/29164372
|abstract=We examined the effect of chronic prenatal alcohol exposure (PAE) on the process of adult neurogenesis in C57BL/6J mice at early adulthood (PND 56). Pregnant mice, and their in utero litters, were exposed to alcohol, through oral gavage, on gestational days 7-16, with recorded blood alcohol concentrations averaging 184 mg/dL (CA group). Two control groups, sucrose (CAc) and non-treated (NTc) control groups were also examined. The brains of pups at PND 56 from each experimental group were sectioned in a sagittal plane, and stained for Nissl substance with cresyl violet, and immunostained for Ki-67 which labels proliferative cells and doublecortin ([[DCX]]) for immature neurons. Morphologically, the neurogenic pattern was identical in all three groups studied. Populations of Ki-67 immunopositive cells in the dentate gyrus were not statistically significantly different between the experimental groups and there were no differences between the sexes. Thus, the PAE in this study does not appear to have a strong effect on the proliferative process in the adult hippocampus. In contrast, the numbers of immature neurons, labeled with [[DCX]], was statistically significantly lower in the prenatal alcohol exposed mice compared with the two control groups. Alcohol significantly lowered the number of [[DCX]] hippocampal cells in the male mice, but not in the female mice. This indicates that the PAE appears to lower the rate of conversion of proliferative cells to immature neurons and this effect of alcohol is sexually dimorphic. This lowered number of immature neurons in the hippocampus appears to mirror hippocampal dysfunctions observed in FASD children.
|mesh-terms=* Aging
* Animals
* Dentate Gyrus
* Ethanol
* Female
* Hippocampus
* Mice, Inbred C57BL
* Microtubule-Associated Proteins
* Neural Stem Cells
* Neurogenesis
* Neurons
* Pregnancy
* Prenatal Exposure Delayed Effects
|keywords=* Adult hippocampal neurogenesis
* Adult neurogenesis
* Fetal alcohol spectrum disorder
* Immature neurons
* Memory dysfunction
* Proliferation
|full-text-url=https://sci-hub.do/10.1007/s11011-017-0156-4
}}
{{medline-entry
|title=Puerarin and Amlodipine Improvement of D-Galactose-Induced Impairments of Behaviour and Neurogenesis in Mouse Dentate Gyrus: Correlation with Glucocorticoid Receptor Expression.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/28831640
|abstract=Glucocorticoid receptors (GRs) exert actions on the hippocampus that are important for memory formation. There are correlations between vascular dysfunctions and GR-related gene expression. Both vascular dysfunction and GR gene expression decline occur during the ageing process. Therefore, hypotensors, which have effects on improving vascular dysfunction, may be able to ameliorate GR gene expression decline in ageing mice and improve ageing-mediated memory deficits. In this study, we hypothesized that hypotensors could alleviate the decline of GR gene expression and ameliorate age-induced learning and memory deficits in a D-gal-induced ageing mice model. In line with our hypothesis, we found that chronic D-gal treatment decreased GR and [[DCX]] expression in the hippocampus, leading to learning and memory deficits. Amlodipine (AM) and puerarin (PU) treatment improved GR gene expression decline in the hippocampus and ameliorated the learning and memory deficits of D-gal-treated mice. These changes correlated with enhanced [[DCX]] expression and brain-derived neurotrophic factor (BDNF) expression in the hippocampus. Furthermore, PU treatment conveyed better effects than AM treatment, but combination therapy did not enhance the effects on improving GR expression. However, we did not find evidence of these changes in non-D-gal-treated mice that lacked GR gene expression decline. These results suggest that AM and PU could improve D-gal-induced behavioural deficits in correlation with GR gene expression.
|mesh-terms=* Aging
* Amlodipine
* Animals
* Dentate Gyrus
* Drug Therapy, Combination
* Female
* Galactose
* Gene Expression
* Isoflavones
* Maze Learning
* Mice
* Mice, Inbred BALB C
* Neurogenesis
* Receptors, Glucocorticoid
* Vasodilator Agents
|keywords=* Amlodipine
* CREB-BDNF pathway
* Glucocorticoid receptors
* Learning
* Locomotor
* Puerarin
|full-text-url=https://sci-hub.do/10.1007/s11064-017-2366-x
}}
{{medline-entry
|title=Evidence for reduced neurogenesis in the aging human hippocampus despite stable stem cell markers.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/28766905
|abstract=Reduced neurogenesis in the aging mammalian hippocampus has been linked to cognitive deficits and increased risk of dementia. We utilized postmortem human hippocampal tissue from 26 subjects aged 18-88 years to investigate changes in expression of six genes representing different stages of neurogenesis across the healthy adult lifespan. Progressive and significant decreases in mRNA levels of the proliferation marker Ki67 ([[MKI67]]) and the immature neuronal marker doublecortin ([[DCX]]) were found in the healthy human hippocampus over the lifespan. In contrast, expression of genes for the stem cell marker glial fibrillary acidic protein delta and the neuronal progenitor marker eomesodermin was unchanged with age. These data are consistent with a persistence of the hippocampal stem cell population with age. Age-associated expression of the proliferation and immature neuron markers [[MKI67]] and [[DCX]], respectively, was unrelated, suggesting that neurogenesis-associated processes are independently altered at these points in the development from stem cell to neuron. These data are the first to demonstrate normal age-related decreases at specific stages of adult human hippocampal neurogenesis.
|mesh-terms=* Adolescent
* Adult
* Aged
* Aged, 80 and over
* Cell Differentiation
* Cell Proliferation
* Female
* Gene Expression Regulation, Developmental
* Glial Fibrillary Acidic Protein
* Healthy Aging
* Hippocampus
* Humans
* Ki-67 Antigen
* Male
* Microtubule-Associated Proteins
* Middle Aged
* Neural Stem Cells
* Neurogenesis
* Neurons
* Neuropeptides
* T-Box Domain Proteins
|keywords=* Ki67
* cognition
* doublecortin
* healthy aging
* hippocampus
* neurogenesis
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5595679
}}
{{medline-entry
|title=Early-life decline in neurogenesis markers and age-related changes of TrkB splice variant expression in the human subependymal zone.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/28612959
|abstract=Neurogenesis in the subependymal zone (SEZ) declines across the human lifespan, and reduced local neurotrophic support is speculated to be a contributing factor. While tyrosine receptor kinase B (TrkB) signalling is critical for neuronal differentiation, maturation and survival, little is known about subependymal TrkB expression changes during postnatal human life. In this study, we used quantitative PCR and in situ hybridisation to determine expression of the cell proliferation marker Ki67, the immature neuron marker doublecortin ([[DCX]]) and both full-length (TrkB-TK ) and truncated TrkB receptors (TrkB-TK-) in the human SEZ from infancy to middle age (n = 26-35, 41 days to 43 years). We further measured TrkB-TK  and TrkB-TK- mRNAs in the SEZ from young adulthood into ageing (n = 50, 21-103 years), and related their transcript levels to neurogenic and glial cell markers. Ki67, [[DCX]] and both TrkB splice variant mRNAs significantly decreased in the SEZ from infancy to middle age. In contrast, TrkB-TK- mRNA increased in the SEZ from young adulthood into ageing, whereas TrkB-TK  mRNA remained stable. TrkB-TK- mRNA positively correlated with expression of neural precursor (glial fibrillary acidic protein delta and achaete-scute homolog 1) and glial cell markers (vimentin and pan glial fibrillary acidic protein). TrkB-TK  mRNA positively correlated with expression of neuronal cell markers ([[DCX]] and tubulin beta 3 class III). Our results indicate that cells residing in the human SEZ maintain their responsiveness to neurotrophins; however, this capability may change across postnatal life. We suggest that TrkB splice variants may differentially influence neuronal and glial differentiation in the human SEZ.
|mesh-terms=* Adolescent
* Adult
* Aged
* Aged, 80 and over
* Aging
* Caudate Nucleus
* Cohort Studies
* Female
* Humans
* Infant
* Ki-67 Antigen
* Lateral Ventricles
* Male
* Membrane Glycoproteins
* Microtubule-Associated Proteins
* Middle Aged
* Neurogenesis
* Neuropeptides
* Protein Isoforms
* RNA, Messenger
* Receptor, trkB
* Stem Cell Niche
* Young Adult
|keywords=* doublecortin
* neurogenesis
* proliferation
* subventricular zone
* truncated TrkB
|full-text-url=https://sci-hub.do/10.1111/ejn.13623
}}
{{medline-entry
|title=Dehydroepiandrosterone increases the number and dendrite maturation of doublecortin cells in the dentate gyrus of middle age male Wistar rats exposed to chronic mild stress.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/28062256
|abstract=Aging increases the vulnerability to stress and risk of developing depression. These changes have been related to a reduction of dehydroepiandrosterone (DHEA) levels, an adrenal steroid with anti-stress effects. Also, adult hippocampal neurogenesis decreases during aging and its alteration or impaired is related to the development of depression. Besides, it has been hypothesized that DHEA increases the formation of new neurons. However, it is unknown whether treatment with DHEA in aging may stimulate the dendrite maturation of newborn neurons and reversing depressive-like signs evoked by chronic stress exposure. Here aged male rats (14 months old) were subjected to a scheme of chronic mild stress (CMS) during six weeks, received a treatment with DHEA from the third week of CMS. Changes in body weight and sucrose preference (SP) were measured once a week. DHEA levels were measured in serum, identification of doublecortin-([[DCX]])-, BrdU- and BrdU/NeuN-labeled cells was done in the dentate gyrus of the hippocampus. CMS produced a gradual reduction in the body weight, but no changes in the SP were observed. Treatment enhanced levels of DHEA, but lack of recovery on body weight of stressed rats. Aging reduced the number of [[DCX]]-, BrdU- and BrdU/NeuN- cells but DHEA just significantly increased the number of [[DCX]]-cells in rats under CMS and controls, reaching levels of young non-stressed rats (used here as a reference of an optimal status of health). In rats under CMS, DHEA facilitated dendritic maturation of immature new neurons. Our results reveal that DHEA improves neural plasticity even in conditions of CMS in middle age rats. Thus, this hormone reverted the decrement of [[DCX]]-cells caused during normal aging.
|mesh-terms=* Aging
* Animals
* Antigens, Nuclear
* Body Weight
* Bromodeoxyuridine
* Cell Survival
* Chronic Disease
* Dehydroepiandrosterone
* Dendrites
* Dentate Gyrus
* Dietary Sucrose
* Male
* Microtubule-Associated Proteins
* Nerve Tissue Proteins
* Neurogenesis
* Neuropeptides
* Psychotropic Drugs
* Random Allocation
* Rats, Wistar
* Stress, Psychological
|keywords=* Adult neurogenesis
* Aging
* Chronic mild stress
* Dehydroepiandrosterone
* Doublecortin
* Middle age
|full-text-url=https://sci-hub.do/10.1016/j.bbr.2017.01.007
}}
{{medline-entry
|title=Neurogenesis upregulation on the healthy hemisphere after stroke enhances compensation for age-dependent decrease of basal neurogenesis.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/28007584
|abstract=Stroke is a leading cause of death and disability worldwide with no treatment for the chronic phase available. Interestingly, an endogenous repair program comprising inflammation and neurogenesis is known to modulate stroke outcome. Several studies have shown that neurogenesis decreases with age but the therapeutic importance of endogenous neurogenesis for recovery from cerebral diseases has been indicated as its ablation leads to stroke aggravation and worsened outcome. A detailed characterization of the neurogenic response after stroke related to ageing would help to develop novel and targeted therapies. In an innovative approach, we used the [[DCX]]-Luc mouse, a transgenic model expressing luciferase in doublecortin-positive neuroblasts, to monitor the neurogenic response following middle cerebral artery occlusion over three weeks in three age groups (2, 6, 12months) by optical imaging while the stroke lesion was monitored by quantitative MRI. The individual longitudinal and noninvasive time profiles provided exclusive insight into age-dependent decrease in basal neurogenesis and neurogenic upregulation in response to stroke which are not accessible by conventional BrdU-based measures of cell proliferation. For cortico-striatal strokes the maximal upregulation occurred at 4days post stroke followed by a continuous decrease to basal levels by three weeks post stroke. Older animals effectively compensated for reduced basal neurogenesis by an enhanced sensitivity to the cerebral lesion, resulting in upregulated neurogenesis levels approaching those measured in young mice. In middle aged and older mice, but not in the youngest ones, additional upregulation of neurogenesis was observed in the contralateral healthy hemisphere. This further substantiates the increased propensity of older brains to respond to lesion situation. Our results clearly support the therapeutic relevance of endogenous neurogenesis for stroke recovery and particularly in older brains.
|mesh-terms=* Aging
* Animals
* Brain Ischemia
* Cerebral Cortex
* Corpus Striatum
* Disease Models, Animal
* Disease Progression
* Functional Laterality
* Immunohistochemistry
* Longitudinal Studies
* Magnetic Resonance Imaging
* Male
* Mice, Inbred C57BL
* Mice, Transgenic
* Neurogenesis
* Optical Imaging
* Stroke
|keywords=* Age dependence of neurogenesis after stroke
* Bioluminescence imaging
* Doublecortin
* Magnetic resonance imaging
* Neurogenesis
* Stroke
|full-text-url=https://sci-hub.do/10.1016/j.nbd.2016.12.015
}}
{{medline-entry
|title=Postnatal maturation of mouse medullo-spinal cerebrospinal fluid-contacting neurons.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/27939302
|abstract=The central canal along the spinal cord (SC.) and medulla is characterized by the presence of a specific population of neurons that contacts the cerebrospinal fluid (CSF). These medullo-spinal CSF-contacting neurons (CSF-cNs) are identified by the selective expression of the polycystin kidney disease 2-like 1 ionic channel (PKD2L1 or polycystin-L). In adult, they have been shown to express doublecortin ([[DCX]]) and Nkx6.1, two markers of juvenile neurons along with the neuron-specific nuclear protein (NeuN) typically expressed in mature neurons. They were therefore suggested to remain in a rather incomplete maturation state. The aim of this study was to assess whether such juvenile state is stable in postnatal animals or whether CSF-cNs may reach maturity at older stages than neurons in the parenchyma. We show, in the cervical SC. and the brainstem that, in relation to age, CSF-cN density declines and that their cell bodies become more distant from the cc, except in its ventral part. Moreover, in adults (from 1month) by comparison with neonatal mice, we show that CSF-cNs have evolved to a more mature state, as indicated by the increase in the percentage of cells positive for NeuN and of its level of expression. In parallel, CSF-cNs exhibit, in adult, lower [[DCX]] immunoreactivity and do not express PSA-NCAM and TUC4, two neurogenic markers. Nevertheless, CSF-cNs still share in adult characteristics of juvenile neurons such as the presence of phospho-CREB and [[DCX]] while NeuN expression remained low. This phenotype persists in 12-month-old animals. Thus, despite a pursuit of neuronal maturation during the postnatal period, CSF-cNs retain a durable low differentiated state.
|mesh-terms=* Aging
* Animals
* Animals, Newborn
* Cell Count
* Cervical Cord
* DNA-Binding Proteins
* Female
* Fluorescent Antibody Technique
* Male
* Medulla Oblongata
* Mice, Transgenic
* Microtubule-Associated Proteins
* Nerve Tissue Proteins
* Neural Cell Adhesion Molecule L1
* Neurons
* Neuropeptides
* Nuclear Proteins
* Prosencephalon
* Sialic Acids
|keywords=* CSF-contacting neurons
* PKD2L1
* brainstem
* central canal
* cervical spinal cord
* maturity markers
|full-text-url=https://sci-hub.do/10.1016/j.neuroscience.2016.11.028
}}
{{medline-entry
|title=Topiramate Improves Neuroblast Differentiation of Hippocampal Dentate Gyrus in the D-Galactose-Induced Aging Mice via Its Antioxidant Effects.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/27734244
|abstract=Some anticonvulsant drugs are associated with cognitive ability in patients; Topiramate (TPM) is well known as an effective anticonvulsant agent applied in clinical settings. However, the effect of TPM on the cognitive function is rarely studied. In this study, we aimed to observe the effects of TPM on cell proliferation and neuronal differentiation in the dentate gyrus (DG) of the D-galactose-induced aging mice by Ki-67 and doublecortin ([[DCX]]) immunohistochemistry. The study is divided into four groups including control, D-galactose-treated group, 25 and 50 mg/kg TPM-treated plus D-galactose-treated groups. We found, 50 mg/kg (not 25 mg/kg) TPM treatment significantly increased the numbers of Ki-67  cells and [[DCX]] immunoreactivity, and improved neuroblast injury induced by D-galactose treatment. In addition, we also found that decreased immunoreactivities and protein levels of antioxidants including superoxide dismutase and catalase induced by D-galactose treatment were significantly recovered by 50 mg/kg TPM treatment in the mice hippocampal DG (P < 0.05). In conclusion, our present results indicate that TPM can ameliorate neuroblast damage and promote cell proliferation and neuroblast differentiation in the hippocampal DG via increasing SODs and catalase levels in the D-galactose mice.
|mesh-terms=* Aging
* Animals
* Antioxidants
* Catalase
* Cell Differentiation
* Cell Proliferation
* Dentate Gyrus
* Fructose
* Galactose
* Mice
* Microtubule-Associated Proteins
* Neurons
* Neuropeptides
* Superoxide Dismutase
* Topiramate
|keywords=* Aging
* Antiepileptic
* Antioxidants
* Hippocampus
* Neuroblast differentiation
|full-text-url=https://sci-hub.do/10.1007/s10571-016-0424-6
}}
{{medline-entry
|title=Adenosine A1 receptor antagonist mitigates deleterious effects of sleep deprivation on adult neurogenesis and spatial reference memory in rats.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/27623393
|abstract=Sleep deprivation (SD) upsurges intracellular levels of adenosine, impairs adult neuronal cell proliferation (NCP) and cognition while caffeine, a non-selective adenosine A1 receptor (A1R) antagonist improves cognition and adult NCP during SD. We examined the selective antagonistic effects of adenosine A1R using 8-cyclopentyl-1,3-dimethylxanthine (8-CPT) on impairment of spatial reference memory and adult NCP during 48h SD. Adult male Sprague Dawley rats were sleep deprived for 48h, using an automatic cage vibrating stimulus based on animal activity. Spatial reference memory was tested as a measure of cognitive performance employing Morris Water Maze. Rats were given 8-CPT dissolved in 50% dimethyl sulfoxide (DMSO), twice daily (10mg/kg, i.p.) along with 5-bromo-2-deoxyuridine (BrdU) (50mg/kg/day, i.p.). The rats treated with 8-CPT showed significantly short mean latency and path-length to reach the platform compared to the SD rats. Consistent with these findings, 8-CPT-treated group was found to have significantly increased the number of BrdU, Ki-67 and doublecortin ([[DCX]]) positive cells. However, no significant difference was seen in NeuN expression in the Dentate Gyrus (DG). Brain-derived neurotropic factor ([[BDNF]]) expression in the DG and [[CA1]] region was observed to decrease significantly after SD and be rescued by 8-CPT treatment. Furthermore, latency to reach platform showed a negative correlation with number of BrdU, [[DCX]] type-1 cells and [[BDNF]] expression in DG. Thus, it may be concluded that treatment with 8-CPT, an adenosine A1R antagonist during SD mitigates SD induced decline in spatial reference memory and adult NCP possibly via up regulation of [[BDNF]] levels in DG and [[CA1]] regions.
|mesh-terms=* Adenosine A1 Receptor Antagonists
* Aging
* Animals
* Caffeine
* Hippocampus
* Male
* Neurogenesis
* Rats, Sprague-Dawley
* Receptor, Adenosine A1
* Sleep Deprivation
* Spatial Memory
|keywords=* adenosine A1R antagonist
* adult neurogenesis
* brain-derived neurotropic factor
* sleep deprivation
* spatial reference memory
|full-text-url=https://sci-hub.do/10.1016/j.neuroscience.2016.09.007
}}
{{medline-entry
|title=Sex-Specific Effects of Prenatal Stress on Memory and Markers of Neuronal Activity in Juvenile Rats.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/27372837
|abstract=Stress during pregnancy can increase the incidence of emotional problems, learning and language difficulties in human infants and pre-adolescents. Most preclinical studies in rats that attempted to find experimental support for these observations were performed in adult male offspring, but the results are inconsistent. The aim of the current study was to examine the effect of prenatal stress on novel object recognition (NOR) and spatial learning and memory in the Morris water maze (MWM) of juvenile rats of both sexes. By the use of fluorescence immunohistochemistry and protein measurements by Western blot, we measured the expression of markers of neurogenesis (doublecortin, [[DCX]]) and neuronal activity that are important for synaptic plasticity and learning (c-fos, GluR1, nNOS). Since neuronal activity in the developing and adult brain can be regulated by astrocytes, we also measured the number of astrocytes and the expression of two astroglial proteins ([[GFAP]] and [[S100B]]) in the stress-responsive hippocampal dentate gyrus (DG). Experiments were performed on littermates of rats in which its effects on behavior were measured. We found for the first time that juvenile females performed better than males in the NOR and MWM tests. They also had higher densities of [[DCX]] and c-fos in the DG, together with the expression of nNOS and GluR1 in the subgranular zone (SGZ) of the DG. There were no sex differences in the expression of [[GFAP]] and [[S100B]] in astrocytes. Prenatal stress did not affect NOR in females, but improved it in males, together with an increase in [[DCX]]  and c-fos, the number of [[GFAP]]-expressing astrocytes and the intensity of [[GFAP]] and [[S100B]] immunofluorescence in the DG. Staining intensity of GluR1 and nNOS in the hilus and SGZ of the DG, and protein expression in the whole DG, was unchanged in prenatally stressed males. Thus, prenatal stress changed the behavior and expression of key proteins in the DG to resemble that in females. A reduction in plasma testosterone, which although not attaining statistical significance was associated with that in anogenital distance, may contribute to the effect of prenatal stress in males. In females, prenatal stress had no effect on c-fos, [[DCX]] or the number of astrocytes but reduced the staining intensity of GluR1 and nNOS. Protein expression of nNOS was also significantly lower than that in prenatally stressed males. The differential effects of prenatal stress on hippocampal neuronal and glial markers may help to explain the sex-dependent effect on spatial learning in prepubertal rats.
|mesh-terms=* Aging
* Animals
* Astrocytes
* Dentate Gyrus
* Female
* Hippocampus
* Memory
* Neurogenesis
* Neuronal Plasticity
* Neurons
* Pregnancy
* Prenatal Exposure Delayed Effects
* Rats, Wistar
* Sex Characteristics
* Stress, Physiological

|full-text-url=https://sci-hub.do/10.1159/000446981
}}
{{medline-entry
|title=MeHg Suppressed Neuronal Potency of Hippocampal NSCs Contributing to the Puberal Spatial Memory Deficits.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/26743863
|abstract=Hippocampal neurogenesis-related structural damage, particularly that leading to defective adult cognitive function, is considered an important risk factor for neurodegenerative and psychiatric diseases. Normal differentiation of neurons and glial cells during development is crucial in neurogenesis, which is particularly sensitive to the environmental toxicant methylmercury (MeHg). However, the exact effects of MeHg on hippocampal neural stem cell (hNSC) differentiation during puberty remain unknown. This study investigates whether MeHg exposure induces changes in hippocampal neurogenesis and whether these changes underlie cognitive defects in puberty. A rat model of methylmercury chloride (MeHgCl) exposure (0.4 mg/kg/day, PND 5-PND 33, 28 days) was established, and the Morris water maze was used to assess cognitive function. Primary hNSCs from hippocampal tissues of E16-day Sprague-Dawley rats were purified, identified, and cloned. hNSC proliferation and differentiation and the growth and morphology of newly generated neurons were observed by MTT and immunofluorescence assays. MeHg exposure induced defects in spatial learning and memory accompanied by a decrease in number of doublecortin ([[DCX]])-positive cells in the dentate gyrus (DG). [[DCX]] is a surrogate marker for newly generated neurons. Proliferation and differentiation of hNSCs significantly decreased in the MeHg-treated groups. MeHg attenuated microtubule-associated protein-2 (MAP-2) expression in neurons and enhanced the glial fibrillary acidic protein (GFAP)-positive cell differentiation of hNSCs, thereby inducing degenerative changes in a dose-dependent manner. Moreover, MeHg induced deficits in hippocampus-dependent spatial learning and memory during adolescence as a consequence of decreased generation of DG neurons. Our findings suggested that MeHg exposure could be a potential risk factor for psychiatric and neurodegenerative diseases. 
|mesh-terms=* Aging
* Animals
* Cell Differentiation
* Cell Proliferation
* Hippocampus
* Memory Disorders
* Methylmercury Compounds
* Neural Stem Cells
* Neurogenesis
* Rats
* Rats, Sprague-Dawley
* Risk Factors
* Spatial Learning
|keywords=* Hippocampal neurogenesis
* Methylmercury
* Neural stem cells
* Proliferation and differentiation
* Spatial learning and memory defect
|full-text-url=https://sci-hub.do/10.1007/s12011-015-0609-8
}}
{{medline-entry
|title=Hypercrosslinked Additives for Ageless Gas-Separation Membranes.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/26749173
|abstract=The loss of internal pores, a process known as physical aging, inhibits the long-term use of the most promising gas-separation polymers. Previously we reported that a porous aromatic framework (PAF-1) could form a remarkable nanocomposite with gas-separation polymers to stop aging. However, PAF-1 synthesis is very onerous both from a reagent and reaction-condition perspective, making it difficult to scale-up. We now reveal a highly dispersible and scalable additive based on α,α'-dichloro-p-xylene (p-[[DCX]]), that inhibits aging more effectively, and crucially almost doubles gas-transport selectivity. These synergistic effects are related to the intimately mixed nanocomposite that is formed though the high dispersibility of p-[[DCX]] in the gas-separation polymer. This reduces particle-size effects and the internal free volume is almost unchanged over time. This study shows this inexpensive and scalable polymer additive delivers exceptional gas-transport performance and selectivity. 

|keywords=* Davankov polymers
* gas separation
* hypercrosslinked polymers
* membranes
* physical aging
|full-text-url=https://sci-hub.do/10.1002/anie.201508070
}}
{{medline-entry
|title=Fibroblast Growth Factor 14 Modulates the Neurogenesis of Granule Neurons in the Adult Dentate Gyrus.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/26687232
|abstract=Adult neurogenesis, the production of mature neurons from progenitor cells in the adult mammalian brain, is linked to the etiology of neurodegenerative and psychiatric disorders. However, a thorough understanding of the molecular elements at the base of adult neurogenesis remains elusive. Here, we provide evidence for a previously undescribed function of fibroblast growth factor 14 ([[FGF14]]), a brain disease-associated factor that controls neuronal excitability and synaptic plasticity, in regulating adult neurogenesis in the dentate gyrus (DG). We found that [[FGF14]] is dynamically expressed in restricted subtypes of sex determining region Y-box 2 (Sox2)-positive and doublecortin ([[DCX]])-positive neural progenitors in the DG. Bromodeoxyuridine (BrdU) incorporation studies and confocal imaging revealed that genetic deletion of Fgf14 in Fgf14   mice leads to a significant change in the proportion of proliferating and immature and mature newly born adult granule cells. This results in an increase in the late immature and early mature population of [[DCX]] and calretinin (CR)-positive neurons. Electrophysiological extracellular field recordings showed reduced minimal threshold response and impaired paired-pulse facilitation at the perforant path to DG inputs in Fgf14   compared to Fgf14   mice, supporting disrupted synaptic connectivity as a correlative read-out to impaired neurogenesis. These new insights into the biology of [[FGF14]] in neurogenesis shed light into the signaling pathways associated with disrupted functions in complex brain diseases.
|mesh-terms=* Aging
* Animals
* Animals, Newborn
* Apoptosis
* Cell Count
* Cell Differentiation
* Cell Survival
* Cytoplasmic Granules
* Dentate Gyrus
* Female
* Fibroblast Growth Factors
* Gene Deletion
* Gene Expression Profiling
* Male
* Mice, Inbred C57BL
* Microtubule-Associated Proteins
* Neural Stem Cells
* Neurogenesis
* Neurons
* Neuropeptides
* Synapses
|keywords=* Adult neurogenesis
* Ataxia
* Axon initial segment
* FGF14
* Growth factors
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4916041
}}
{{medline-entry
|title=Effects of Ginko biloba leaf extract on the neurogenesis of the hippocampal dentate gyrus in the elderly mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/26297531
|abstract=Aging is associated with reduced hippocampal neurogenesis, which may in turn contribute to cognitive impairment. We assessed the effect of Ginkgo biloba (Gb) on hippocampal neurogenesis in elderly male mice using immunohistochemistry. We used anti-caspase-3 as a marker of apoptosis, anti-[[GFAP]] as a marker of neural stem cells, anti-Ki-67 as a specific marker for cellular proliferation and anti-doublecortin ([[DCX]]) to detect newly born neurons in the hippocampal dentate gyrus (DG) of aged male mice. The 24-month-old male mice were divided into two groups: a control group treated with distilled water and a group fed with Gb at a dose of 100 mg/kg once daily for 28 days. A sharp decrease in apoptotic cells in Gb-treated compared to nontreated mice was observed by anti-csapase-3 immunostaining. A large number of [[GFAP]] ve cells was found in the subgranular zone of the DG of Gb-treated mice, suggesting an increase in the pool of neural stem cells by Gb treatment. There was also an increase in Ki-67 immunoreactive cells, indicating increased cell proliferation in the DG in the Gb-treated compared to nontreated group. A significant increase in newborn [[DCX]] ve neurons with well-developed tertiary dendrites was also found in the Gb-treated compared to nontreated group. Using Western blot analysis, the expression of [[DCX]] protein in the Gb group was also significantly increased compared to the control. The results support a beneficial role of Gb on hippocampal neurogenesis in the context of brain aging. 
|mesh-terms=* Administration, Ophthalmic
* Aging
* Animals
* Cell Proliferation
* Dentate Gyrus
* Ginkgo biloba
* Male
* Mice
* Neurogenesis
* Plant Extracts
* Plant Leaves
* Stimulation, Chemical
|keywords=* Ginkgo biloba leaf extract
* Immunohistochemistry
* Neurogenesis
* Old-aged mice
|full-text-url=https://sci-hub.do/10.1007/s12565-015-0297-7
}}
{{medline-entry
|title=Persistent loss of hippocampal neurogenesis and increased cell death following adolescent, but not adult, chronic ethanol exposure.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/24993092
|abstract=Although adolescence is a common age to initiate alcohol consumption, the long-term consequences of exposure to alcohol at this time of considerable brain maturation are largely unknown. In studies utilizing rodents, behavioral evidence is beginning to emerge suggesting that the hippocampus may be persistently affected by repeated ethanol exposure during adolescence, but not by comparable alcohol exposure in adulthood. The purpose of this series of experiments was to explore a potential mechanism of hippocampal dysfunction in adults exposed to ethanol during adolescence. Given that disruption in adult neurogenesis has been reported to impair performance on tasks thought to be hippocampally related, we used immunohistochemistry to assess levels of doublecortin ([[DCX]]), an endogenous marker of immature neurons, in the dentate gyrus (DG) of the hippocampus 3-4 weeks after adolescent (postnatal day, PD28-48) or adult (PD70-90) intermittent ethanol exposure to 4 g/kg ethanol administered intragastrically. We also investigated another neurogenic niche, the subventricular zone (SVZ), to determine if the effects of ethanol exposure were region specific. Levels of cell proliferation and cell death were also examined in the DG via assessing Ki67 and cleaved caspase-3 immunoreactivity, respectively. Significantly less [[DCX]] was observed in the DG of adolescent (but not adult) ethanol-exposed animals about 4 weeks after exposure when these animals were compared to control age-mates. The effects of adolescent ethanol on [[DCX]] immunoreactivity were specific to the hippocampus, with no significant exposure effects emerging in the SVZ. In both the DG and the SVZ there was a significant age-related decline in neurogenesis as indexed by [[DCX]]. The persistent effect of adolescent ethanol exposure on reduced [[DCX]] in the DG appears to be related to significant increases in cell death, with significantly more cleaved caspase-3-positive immunoreactivity observed in the adolescent ethanol group compared to controls, but no alterations in cell proliferation when indexed by Ki67. These results suggest that a history of adolescent ethanol exposure results in lowered levels of differentiating neurons, probably due at least in part to increased cell death of immature neurons. These effects were evident in adulthood, weeks following termination of the chronic exposure, and may contribute to previously reported behavioral deficits on hippocampal-related tasks after chronic ethanol exposure in adolescence.
|mesh-terms=* Aging
* Animals
* Body Weight
* Caspase 3
* Cell Death
* Central Nervous System Depressants
* Dentate Gyrus
* Ethanol
* Hippocampus
* Ki-67 Antigen
* Male
* Microtubule-Associated Proteins
* Neurogenesis
* Neuropeptides
* Rats
* Rats, Sprague-Dawley

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4125431
}}
{{medline-entry
|title=Lactobacillus pentosus var. plantarum C29 ameliorates memory impairment and inflammaging in a D-galactose-induced accelerated aging mouse model.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/24657159
|abstract=Aging is associated with Alzheimer's disease (AD), cardiovascular disease and cancer. Oxidative stress is considered as a major factor that accelerates the aging process. To understand the ability of lactic acid bacteria to ameliorate memory impairment caused by aging, we investigated the effect of Lactobacillus pentosus var. plantarum (C29), which is known to protect against scopolamine-induced memory impairment, on oxidative stress (D-galactose)-induced memory impairment in mice. D-Galactose was subcutaneously injected to 20-week old male C57BL/6J mice for 10 weeks, with oral administration of C29 for the final 5 weeks. Excessive intake of D-galactose not only impaired memory, which was indicated by passive avoidance, Y-maze, and Morris water-maze tasks, but also reduced the expression of brain-derived neurotrophic factor ([[BDNF]]) and hippocampal doublecortin ([[DCX]]) and the activation of cAMP response element-binding protein (CREB). C29 treatment ameliorated D-galactose-induced memory impairment and reversed the suppression of [[BDNF]] and [[DCX]] expression and CREB activation. Moreover, C29 decreased the expression of a senescence marker p16 and inflammation markers p-p65, p-FOXO3a, cyclooxygenase (COX)-2, and inducible NO synthase (iNOS). C29 treatment inhibited D-galactose-induced expression of M1 polarization markers tumor necrosis factor-α and arginase II, and attenuated the d-galactose-suppressed expression of M2 markers IL-10, arginase I and CD206. Taken together, these findings suggest that C29 may ameliorate memory impairment and M1 macrophage-polarized inflammation caused by aging.
|mesh-terms=* Aging
* Animals
* Biomarkers
* Galactose
* Inflammation
* Lactobacillus
* Male
* Memory Disorders
* Mice, Inbred C57BL
* Models, Animal
* Oxidative Stress
* Probiotics
|keywords=* Inflammaging
* Lactobacillus pentosus var. plantarum C29
* Memory
* d-Galactose
|full-text-url=https://sci-hub.do/10.1016/j.anaerobe.2014.03.003
}}
{{medline-entry
|title=Notch1 signaling modulates neuronal progenitor activity in the subventricular zone in response to aging and focal ischemia.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/23834718
|abstract=Neurogenesis diminishes with aging and ischemia-induced neurogenesis also occurs, but reduced in aged brain. Currently, the cellular and molecular pathways mediating these effects remain largely unknown. Our previous study has shown that Notch1 signaling regulates neurogenesis in subventricular zone (SVZ) of young adult brain after focal ischemia, but whether a similar effect occurs in aged normal and ischemic animals is unknown. Here, we used normal and ischemic aged rat brains to investigate whether Notch1 signaling was involved in the reduction of neurogenesis in response to aging and modulates neurogenesis in aged brains after focal ischemia. By Western blot, we found that Notch1 and Jagged1 expression in the SVZ of aged brain was significantly reduced compared with young adult brain. Consistently, the activated form of Notch1 (Notch intracellular domain; NICD) expression was also declined. Immunohistochemistry confirmed that expression and activation of Notch1 signaling in the SVZ of aged brain were reduced. Double or triple immunostaining showed that that Notch1 was mainly expressed in doublecortin ([[DCX]])-positive cells, whereas Jagged1 was predominantly expressed in astroglial cells in the SVZ of normal aged rat brain. In addition, disruption or activation of Notch1 signaling altered the number of proliferating cells labeled by bromodeoxyuridine (BrdU) and [[DCX]] in the SVZ of aged brain. Moreover, ischemia-induced cell proliferation in the SVZ of aged brain was enhanced by activating the Notch1 pathway and was suppressed by inhibiting the Notch1 signaling. Reduced infarct volume and improved motor deficits were also observed in Notch1 activator-treated aged ischemic rats. Our data suggest that Notch1 signaling modulates the SVZ neurogenesis in aged brain in normal and ischemic conditions. 
|mesh-terms=* Aging
* Animals
* Behavior, Animal
* Brain Ischemia
* Calcium-Binding Proteins
* Cell Proliferation
* Cerebral Infarction
* Cerebral Ventricles
* Intercellular Signaling Peptides and Proteins
* Jagged-1 Protein
* Male
* Membrane Proteins
* Neural Stem Cells
* Protein Structure, Tertiary
* Rats
* Rats, Inbred F344
* Receptors, Notch
* Serrate-Jagged Proteins
* Signal Transduction
|keywords=* Notch1 signaling pathway
* aged rat brain
* focal cerebral ischemia
* neurogenesis
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3838489
}}
{{medline-entry
|title=Age-dependent changes in the subcallosal zone neurogenesis of mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/22417727
|abstract=There are several known neurogenic areas including subventricular zone and subgranular layer in the dentate gyrus of the hippocampus. Both germinal centers exhibit an age-dependent decline in cell proliferation and neurogenesis, which may be associated with age-related decline in brain function. We recently identified the subcallosal zone (SCZ) as a novel neural stem cell niche with a potential to spontaneously produce new neuroblasts. We examined whether SCZ neurogenesis is also regulated by the age of mice. The number of newly generated neuroblasts was reduced in the SCZ with age, and only marginal number of [[DCX]]-labeled neuroblasts was found in 6-month-old SCZ, which is most likely due to reduced proliferation of progenitor cells and loss of neural stem cells (NSCs). This age-dependent changes in the SCZ occurred earlier than that of other neurogenic brain regions. The neurosphere assay in vitro confirmed the depletion of NSCs within the SCZ of young adults. However, marked induction of neuroblast production in the SCZ was seen in 6-month-old mice after traumatic brain injury. Taken together, these results indicate that a rapid decline in SCZ neurogenesis in mice is due to depletion of NSCs and reduced capacity to produce neuroblasts.
|mesh-terms=* Aging
* Animals
* Corpus Callosum
* Male
* Mice
* Mice, Inbred C57BL
* Neurogenesis

|full-text-url=https://sci-hub.do/10.1016/j.neuint.2012.02.027
}}
{{medline-entry
|title=Comparison of neurogenesis in the dentate gyrus between the adult and aged gerbil following transient global cerebral ischemia.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/22215251
|abstract=In the present study, we compared differences in cell proliferation, neuroblast differentiation and neuronal maturation in the hippocampal dentate gyrus (DG) between the adult and aged gerbil induced by 5 min of transient global cerebral ischemia using Ki-67 and BrdU (markers for cell proliferation), doublecortin ([[DCX]], a marker for neuroblast differentiation) and neuronal nuclei (NeuN, a marker for mature neuron). The number of Ki-67-immunoreactive (⁺) cells in the DG of both the groups peaked 7 days after ischemia/reperfusion (I/R). However, the number in the aged DG was 40.6 ± 1.8% of that in the adult DG. Thereafter, the number decreased with time. After ischemic damage, [[DCX]] immunoreactivity and its protein level in the adult and aged DG peaked at 10 and 15 days post-ischemia, respectively. However, [[DCX]] immunoreactivity and its protein levels in the aged DG were much lower than those in the adult. [[DCX]] immunoreactivity and its protein level in the aged DG were 11.1 ± 0.6% and 34.4 ± 2.1% of the adult DG, respectively. In addition, the number of Ki-67⁺ cells and [[DCX]] immunoreactivity in both groups were similar to those in the sham at 60 days postischemia. At 30 days post-ischemia, the number of BrdU⁺ cells and BrdU⁺/NeuN⁺ cells in the adult-group were much higher (281.2 ± 23.4% and 126.4 ± 7.4%, respectively) than the aged-group (35.6 ± 6.8% and 79.5 ± 6.1%, respectively). These results suggest that the ability of neurogenesis in the ischemic aged DG is much lower than that in the ischemic adult DG.
|mesh-terms=* Age Factors
* Aging
* Animals
* Cell Differentiation
* Dentate Gyrus
* Gerbillinae
* Ischemic Attack, Transient
* Male
* Neurogenesis
* Neurons

|full-text-url=https://sci-hub.do/10.1007/s11064-011-0675-z
}}
{{medline-entry
|title=Adult neurogenesis in the short-lived teleost Nothobranchius furzeri: localization of neurogenic niches, molecular characterization and effects of aging.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/22171971
|abstract=We studied adult neurogenesis in the short-lived annual fish Nothobranchius furzeri and quantified the effects of aging on the mitotic activity of the neuronal progenitors and the expression of glial fibrillary acid protein ([[GFAP]]) in the radial glia. The distribution of neurogenic niches is substantially similar to that of zebrafish and adult stem cells generate neurons, which persist in the adult brain. As opposed to zebrafish, however, the N. furzeri genome contains a doublecortin ([[DCX]]) gene. Doublecortin is transiently expressed by newly generated neurons in the telencephalon and optic tectum (OT). We also analyzed the expression of the microRNA miR-9 and miR-124 and found that they have complementary expression domains: miR-9 is expressed in the neurogenic niches of the telencephalon and the radial glia of the OT, while miR-124 is expressed in differentiated neurons. The main finding of this paper is the demonstration of an age-dependent decay in adult neurogenesis. Using unbiased stereological estimates of cell numbers, we detected an almost fivefold decrease in the number of mitotically active cells in the OT between young and old age. This reduced mitotic activity is paralleled by a reduction in [[DCX]] labeling. Finally, we detected a dramatic up-regulation of [[GFAP]] in the radial glia of the aged brain. This up-regulation is not paralleled by a similar up-regulation of [[S100B]] and Musashi-1, two other markers of the radial glia. In summary, the brain of N. furzeri replicates two typical hallmarks of mammalian aging: gliosis and reduced adult neurogenesis.
|mesh-terms=* Aging
* Animals
* Cell Survival
* Fishes
* Neurogenesis
* Neurons

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3437507
}}
{{medline-entry
|title=Properties of doublecortin-([[DCX]])-expressing cells in the piriform cortex compared to the neurogenic dentate gyrus of adult mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/22022443
|abstract=The piriform cortex receives input from the olfactory bulb and (via the entorhinal cortex) sends efferents to the hippocampus, thereby connecting the two canonical neurogenic regions of the adult rodent brain. Doublecortin ([[DCX]]) is a cytoskeleton-associated protein that is expressed transiently in the course of adult neurogenesis. Interestingly, the adult piriform cortex, which is usually considered non-neurogenic (even though some reports exist that state otherwise), also contains an abundant population of [[DCX]]-positive cells. We asked how similar these cells would be to [[DCX]]-positive cells in the course of adult hippocampal neurogenesis. Using BAC-generated transgenic mice that express GFP under the [[DCX]] promoter, we studied [[DCX]]-expression and electrophysiological properties of [[DCX]]-positive cells in the mouse piriform cortex in comparison with the dentate gyrus. While one class of cells in the piriform cortex indeed showed features similar to newly generated immature granule neurons, the majority of [[DCX]] cells in the piriform cortex was mature and revealed large Na  currents and multiple action potentials. Furthermore, when proliferative activity was assessed, we found that all [[DCX]]-expressing cells in the piriform cortex were strictly postmitotic, suggesting that no [[DCX]]-positive "neuroblasts" exist here as they do in the dentate gyrus. We conclude that [[DCX]] in the piriform cortex marks a unique population of postmitotic neurons with a subpopulation that retains immature characteristics associated with synaptic plasticity. [[DCX]] is thus, per se, no marker of neurogenesis but might be associated more broadly with plasticity.
|mesh-terms=* Aging
* Animals
* Biomarkers
* Cell Membrane
* Cell Proliferation
* Dentate Gyrus
* Electrophysiological Phenomena
* Green Fluorescent Proteins
* Mice
* Microtubule-Associated Proteins
* Neurogenesis
* Neuropeptides
* Phenotype
* Recombinant Fusion Proteins

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3192736
}}
{{medline-entry
|title=Distinct structural plasticity in the hippocampus and amygdala of the middle-aged common marmoset (Callithrix jacchus).
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/21605555
|abstract=Adult neurogenesis in the primate brain is generally accepted to occur primarily in two specific areas; the subgranular zone (SGZ) of the hippocampal dentate gyrus (DG) and the subventricular zone (SVZ) of the lateral ventricles. Hippocampal neurogenesis is well known to be downregulated by stress and aging in rodents, however there is less evidence documenting the sensitivity of neuroblasts generated in the SVZ. In primates, migrating cells generated in the SVZ travel via a unique temporal stream (TS) to the amygdala and entorhinal cortex. Using adult common marmoset monkeys (Callithrix jacchus), we examined whether i) adult-generated cells in the marmoset amygdala differentiate into doublecortin-positive ([[DCX]] ) neuroblasts, and ii) whether lasting changes occur in [[DCX]]-expressing cells in the DG or amygdala when animals are exposed to 2 weeks of psychosocial stress. A surprisingly large population of [[DCX]]  immature neurons was found in the amygdala of these 4-year-old monkeys with an average density of 163,000 [[DCX]]  cells per mm(3). Co-labeling of these highly clustered cells with PSA-NCAM supports that a subpopulation of these cells are migratory and participate in chain-migration from the SVZ to the amygdala in middle-aged marmosets. Exposure to 2 weeks of isolation and social defeat stress failed to alter the numbers of BrdU , or [[DCX]]  cells in the hippocampus or amygdala when evaluated 2 weeks after psychosocial stress, indicating that the current stress paradigm has no long-term consequences on neurogenesis in this primate.
|mesh-terms=* Aging
* Amygdala
* Animals
* Callithrix
* Cell Count
* Hippocampus
* Immunohistochemistry
* Microtubule-Associated Proteins
* Neurogenesis
* Neuronal Plasticity
* Neurons
* Neuropeptides

|full-text-url=https://sci-hub.do/10.1016/j.expneurol.2011.05.008
}}
{{medline-entry
|title=Comparison of newly generated doublecortin-immunoreactive neuronal progenitors in the main olfactory bulb among variously aged gerbils.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/20607603
|abstract=In the present study, we investigated age-related differences in neuronal progenitors in the gerbil main olfactory bulb (MOB) using doublecortin ([[DCX]]), a marker for neuronal progenitors which differentiate into neurons in the brain. No difference in the number of neuronal nuclei (NeuN)-immunoreactive neurons was found in the MOB at variously aged gerbils. At postnatal month (PM) 1, [[DCX]] immunoreaction was detected in all layers of the MOB except for the olfactory nerve layer. At this time point, [[DCX]]-immunoreactive cells (neuronal progenitors) were very abundant; however, they did not have fully developed-processes. From PM 3, the number of [[DCX]]-immunoreactive neuronal progenitors was decreased with age. At PM 6, [[DCX]]-immunoreactive cells showed very well-developed processes. In western blot analysis, [[DCX]] protein level in the MOB was highest at PM 1. Thereafter, levels of [[DCX]] protein were decreased with age. In the subventricular zone of the lateral ventricle, the number of Ki-67-immunoractive cells (proliferating cells) was also significantly decreased with age. In addition, increases of α-synuclein-immunoreactive structures were observed in the MOB with age. These results suggest that decrease in [[DCX]]-immunoreactive neuronal progenitors and its protein levels in the MOB with age may be associated with reduction of cell proliferation in the SVZ and with an increase in α-synuclein in the MOB.
|mesh-terms=* Aging
* Animals
* Antigens, Nuclear
* Cell Proliferation
* Gerbillinae
* Immunohistochemistry
* Male
* Microtubule-Associated Proteins
* Nerve Tissue Proteins
* Neural Stem Cells
* Neurons
* Neuropeptides
* Olfactory Bulb
* alpha-Synuclein

|full-text-url=https://sci-hub.do/10.1007/s11064-010-0220-5
}}
{{medline-entry
|title=Astrocytic endogenous glial cell derived neurotrophic factor production is enhanced by bone marrow stromal cell transplantation in the ischemic boundary zone after stroke in adult rats.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/20468049
|abstract=Bone marrow stromal cells (BMSCs) facilitate functional recovery in rats after focal ischemic attack. Growing evidence suggests that the secretion of various bioactive factors underlies BMSCs' beneficial effects. This study investigates the expression of glial cell derived neurotrophic factor ([[GDNF]]) in the ischemic hemisphere with or without BMSC administration. Adult male Wistar rats were subjected to 2 h of middle cerebral artery occlusion followed by an injection of 3 x 10(6) BMSCs (n = 11) or phosphate-buffered saline (n = 10) into the tail vein 24 h later. Animals were sacrificed seven days later. Single and double immunohistochemical staining was performed to measure [[GDNF]], Ki67, doublecortin, and glial fibrillary acidic protein expression as well as the number of apoptotic cells along the ischemic boundary zone (IBZ) and/or in the subventricular zone (SVZ). BMSC treatment significantly increased [[GDNF]] expression and decreased the number of apoptotic cells in the IBZ (P < 0.05). [[GDNF]] expression was colocalized with [[GFAP]]. Meanwhile, BMSCs increased the number of Ki-67 positive cells and the density of [[DCX]] positive migrating neuroblasts (P < 0.05). [[GDNF]] expression was significantly increased in single astrocytes collected from animals treated with BMSCs, and in astrocytes cocultured with BMSCs after OGD (P < 0.05). Our data suggest that BMSCs increase [[GDNF]] levels in the ischemic hemisphere; the major source of [[GDNF]] protein is reactive astrocytes. We propose that the increase of [[GDNF]] in response to BMSC administration creates a hospitable environment for local cellular repair as well as for migrating neuroblasts from the SVZ, and thus contributes to the functional improvement.
|mesh-terms=* Aging
* Animals
* Apoptosis
* Astrocytes
* Bone Marrow Transplantation
* Brain
* Brain Ischemia
* Glial Cell Line-Derived Neurotrophic Factor
* Infarction, Middle Cerebral Artery
* Male
* Neurons
* Random Allocation
* Rats
* Rats, Wistar
* Stem Cell Niche
* Stroke
* Stromal Cells

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3096459
}}
{{medline-entry
|title=Deafferentation enhances neurogenesis in the young and middle aged hippocampus but not in the aged hippocampus.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/20333732
|abstract=Increased neurogenesis in the dentate gyrus (DG) after brain insults such as excitotoxic lesions, seizures, or stroke is a well known phenomenon in the young hippocampus. This plasticity reflects an innate compensatory response of neural stem cells (NSCs) in the young hippocampus to preserve function or minimize damage after injury. However, injuries to the middle-aged and aged hippocampi elicit either no or dampened neurogenesis response, which could be due to an altered plasticity of NSCs and/or the hippocampus with age. We examined whether the plasticity of NSCs to increase neurogenesis in response to a milder injury such as partial deafferentation is preserved during aging. We quantified DG neurogenesis in the hippocampus of young, middle-aged, and aged F344 rats after partial deafferentation. A partial deafferentation of the left hippocampus without any apparent cell loss was induced via administration of Kainic acid (0.5 μg in 1.0 μl) into the right lateral ventricle of the brain. In this model, degeneration of [[CA3]] pyramidal neurons and dentate hilar neurons in the right hippocampus results in loss of commissural axons which leads to partial deafferentation of the dendrites of dentate granule cells and [[CA1]]-[[CA3]] pyramidal neurons in the left hippocampus. Quantification of newly born cells that are added to the dentate granule cell layer at postdeafferentation days 4-15 using 5'-bromodeoxyuridine (BrdU) labeling revealed greatly increased addition of newly born cells (∼three fold increase) in the deafferented young and middle-aged hippocampi but not in the deafferented aged hippocampus. Measurement of newly born neurons using doublecortin ([[DCX]]) immunostaining also revealed similar findings. Analyses using BrdU-[[DCX]] dual immunofluorescence demonstrated no changes in neuronal fate-choice decision of newly born cells after deafferentation, in comparison to the age-matched naive hippocampus in all age groups. Thus, the plasticity of hippocampal NSCs to increase DG neurogenesis in response to a milder injury such as partial hippocampal deafferentation is preserved until middle age but lost at old age.
|mesh-terms=* Age Factors
* Aging
* Animals
* Bromodeoxyuridine
* Cell Count
* Cell Differentiation
* Cell Proliferation
* Dentate Gyrus
* Fluorescent Antibody Technique
* Humans
* Kainic Acid
* Male
* Microtubule-Associated Proteins
* Models, Animal
* Neural Stem Cells
* Neurogenesis
* Neurons
* Neuropeptides
* Rats
* Rats, Inbred F344

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2927723
}}
{{medline-entry
|title=Slow age-dependent decline of doublecortin expression and BrdU labeling in the forebrain from lesser hedgehog tenrecs.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/20298680
|abstract=In addition to synaptic remodeling, formation of new neurons is increasingly acknowledged as an important cue for plastic changes in the central nervous system. Whereas all vertebrates retain a moderate neuroproliferative capacity, phylogenetically younger mammals become dramatically impaired in this potential during aging. The present study shows that the lesser hedgehog tenrec, an insectivore with a low encephalization index, preserves its neurogenic potential surprisingly well during aging. This was shown by quantitative analysis of 5-bromo-2'-deoxyuridine (BrdU) immunolabeling in the olfactory bulb, paleo-, archi-, and neocortices from 2- to 7-year-old animals. In addition to these newly born cells, a large number of previously formed immature neurons are present throughout adulthood as shown by doublecortin ([[DCX]]) immunostaining in various forebrain regions including archicortex, paleocortex, nucleus accumbens, and amygdala. Several ventricle-associated cells in olfactory bulb and hippocampus were double-labeled by BrdU and [[DCX]] immunoreactivity. However, most [[DCX]] cells in the paleocortex can be considered as persisting immature neurons that obviously do not enter a differentiation program since double fluorescence labeling does not reveal their co-occurrence with numerous neuronal markers, whereas only a small portion coexpresses the pan-neuronal marker HuC/D. Finally, the present study reveals tenrecs as suitable laboratory animals to study age-dependent brain alterations (e.g., of neurogenesis) or slow degenerative processes, particularly due to the at least doubled longevity of tenrecs in comparison to mice and rats.
|mesh-terms=* Aging
* Animals
* Brain
* Bromodeoxyuridine
* Cell Differentiation
* Female
* Fluorescent Antibody Technique
* Immunoenzyme Techniques
* Insectivora
* Male
* Microtubule-Associated Proteins
* Neurogenesis
* Neurons
* Neuropeptides
* Prosencephalon
* Time Factors

|full-text-url=https://sci-hub.do/10.1016/j.brainres.2010.03.026
}}
{{medline-entry
|title=Murine features of neurogenesis in the human hippocampus across the lifespan from 0 to 100 years.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/20126454
|abstract=Essentially all knowledge about adult hippocampal neurogenesis in humans still comes from one seminal study by Eriksson et al. in 1998, although several others have provided suggestive findings. But only little information has been available in how far the situation in animal models would reflect the conditions in the adult and aging human brain. We therefore here mapped numerous features associated with adult neurogenesis in rodents in samples from human hippocampus across the entire lifespan. Such data would not offer proof of adult neurogenesis in humans, because it is based on the assumption that humans and rodents share marker expression patterns in adult neurogenesis. Nevertheless, together the data provide valuable information at least about the presence of markers, for which a link to adult neurogenesis might more reasonably be assumed than for others, in the adult human brain and their change with increasing age. In rodents, doublecortin ([[DCX]]) is transiently expressed during adult neurogenesis and within the neurogenic niche of the dentate gyrus can serve as a valuable marker. We validated [[DCX]] as marker of granule cell development in fetal human tissue and used [[DCX]] expression as seed to examine the dentate gyrus for additional neurogenesis-associated features across the lifespan. We studied 54 individuals and detected [[DCX]] expression between birth and 100 years of age. Caveats for post-mortem analyses of human tissues apply but all samples were free of signs of ischemia and activated caspase-3. Fourteen markers related to adult hippocampal neurogenesis in rodents were assessed in [[DCX]]-positive cells. Total numbers of [[DCX]] expressing cells declined exponentially with increasing age, and co-expression of [[DCX]] with the other markers decreased. This argued against a non-specific re-appearance of immature markers in specimen from old brains. Early postnatally all 14 markers were co-expressed in [[DCX]]-positive cells. Until 30 to 40 years of age, for example, an overlap of [[DCX]] with Ki67, Mcm2, Sox2, Nestin, Prox1, PSA-NCAM, Calretinin, NeuN, and others was detected, and some key markers (Nestin, Sox2, Prox1) remained co-expressed into oldest age. Our data suggest that in the adult human hippocampus neurogenesis-associated features that have been identified in rodents show patterns, as well as qualitative and quantitative age-related changes, that are similar to the course of adult hippocampal neurogenesis in rodents. Consequently, although further validation as well as the application of independent methodology (e.g. electron microscopy and cell culture work) is desirable, our data will help to devise the framework for specific research on cellular plasticity in the aging human hippocampus.
|mesh-terms=* Aging
* Animals
* Biomarkers
* Blotting, Western
* Hippocampus
* Humans
* Immunohistochemistry
* In Situ Hybridization
* Mice
* Microtubule-Associated Proteins
* Neurogenesis
* Neuropeptides
* Rats

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2813284
}}
{{medline-entry
|title=Effects of age and treadmill exercise in chronic diabetic stages on neuroblast differentiation in a rat model of type 2 diabetes.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/20005869
|abstract=In the present study, we investigated the effects of type 2 diabetes and treadmill exercise in chronic diabetic stages on neuroblast differentiation using doublecortin ([[DCX]]) in the subgranular zone of the dentate gyrus (SZDG) in Zucker diabetic fatty (ZDF) rats. Four-, 12-, 20- and 30-week-old Zucker lean control (ZLC) and ZDF rats were used to elucidate age-dependent changes of [[DCX]]-immunoreactive neuroblasts. [[DCX]]-immunoreactive neuroblasts were significantly decreased with age in the SZDG. This reduction was prominent in the age-matched ZDF rats compared to that in the ZLC rats. To investigate the effects of treadmill exercise, ZLC and ZDF rats at 23 weeks of age were put on the treadmill with or without running for 1 h/day/5 consecutive days at 12-16 m/min for 7 weeks. Treadmill exercise significantly increased the tertiary dendrites of [[DCX]]-immunoreactive neuroblasts in both ZLC and ZDF rats. In addition, exercise significantly increased the number of [[DCX]]-immunoreactive neuroblasts in the ZLC rats, but not in the ZDF rats. These results suggest that diabetes significantly decreases neuroblast differentiation and treadmill exercise in chronic diabetic animals has limitation to increase neuroblast differentiation although it increases neural plasticity.
|mesh-terms=* Aging
* Animals
* Cell Differentiation
* Chronic Disease
* Diabetes Complications
* Diabetes Mellitus, Type 2
* Disease Models, Animal
* Exercise Test
* Female
* Male
* Neurogenesis
* Neurons
* Physical Conditioning, Animal
* Rats
* Rats, Zucker
* Treatment Outcome

|full-text-url=https://sci-hub.do/10.1016/j.brainres.2009.12.009
}}
{{medline-entry
|title=Age effects on the regulation of adult hippocampal neurogenesis by physical activity and environmental enrichment in the APP23 mouse model of Alzheimer disease.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/19219917
|abstract=An active lifestyle is to some degree protective against Alzheimer's disease (AD), but the biological basis for this benefit is still far from clear. We hypothesize that physical and cognitive activity increase a reserve for plasticity by increasing adult neurogenesis in the hippocampal dentate gyrus (DG). We thus assessed how age affects the response to activity in the murine APP23 model of AD compared with wild type (WT) controls and studied the effects of physical exercise (RUN) and environmental enrichment (ENR) in comparison with standard housing (CTR) at two different ages (6 months and 18 months) and in both genotypes. At 18 months, both activity paradigms reduced the hippocampal human Abeta1-42/Abeta1-40 ratio when compared with CTR, despite a stable plaque load in the hippocampus. At this age, both RUN and ENR increased the number of newborn granule cells in the DG of APP23 mice when compared with CTR, whereas the levels of regulation were equivalent to those in WT mice under the same housing conditions. At 6 months, however, neurogenesis in ENR but not RUN mice responded like the WT. Quantifying the number of cells at the doublecortin-positive stage in relation to the number of cells on postmitotic stages we found that ENR overproportionally increased the number of the [[DCX]]-positive "late" progenitor cells, indicative of an increased potential to recruit even more new neurons. In summary, the biological substrates for activity-dependent regulation of adult hippocampal neurogenesis were preserved in the APP23 mice. We thus propose that in this model, ENR even more than RUN might contribute to a "neurogenic reserve" despite a stable plaque load and that age affects the outcome of an interaction based on "activity."
|mesh-terms=* Adult Stem Cells
* Aging
* Alzheimer Disease
* Amyloid beta-Peptides
* Amyloid beta-Protein Precursor
* Animals
* Disease Models, Animal
* Environment
* Female
* Hippocampus
* Housing, Animal
* Mice
* Mice, Inbred C57BL
* Mice, Transgenic
* Neurogenesis
* Neurons
* Peptide Fragments
* Physical Conditioning, Animal
* Plaque, Amyloid
* Protease Nexins
* Receptors, Cell Surface

|full-text-url=https://sci-hub.do/10.1002/hipo.20560
}}
{{medline-entry
|title=Status epilepticus during old age is not associated with enhanced hippocampal neurogenesis.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/18493929
|abstract=Increased production of new neurons in the adult dentate gyrus (DG) by neural stem/progenitor cells (NSCs) following acute seizures or status epilepticus (SE) is a well known phenomenon. However, it is unknown whether NSCs in the aged DG have similar ability to upregulate neurogenesis in response to SE. We examined DG neurogenesis after the induction of continuous stages III-V seizures (SE) for over 4 h in both young adult (5-months old) and aged (24-months old) F344 rats. The seizures were induced through 2-4 graded intraperitoneal injections of the excitotoxin kainic acid (KA). Newly born cells in the DG were labeled via daily intraperitoneal injections of the 5'-bromodeoxyuridine (BrdU) for 12 days, which commenced shortly after the induction of SE in KA-treated rats. New cells and neurons in the subgranular zone (SGZ) and the granule cell layer (GCL) were analyzed at 24 h after the last BrdU injection using BrdU and doublecortin ([[DCX]]) immunostaining, BrdU-[[DCX]] and BrdU-NeuN dual immunofluorescence and confocal microscopy, and stereological cell counting. Status epilepticus enhanced the numbers of newly born cells (BrdU( ) cells) and neurons ([[DCX]]( ) neurons) in young adult rats. In contrast, similar seizures in aged rats, though greatly increased the number of newly born cells in the SGZ/GCL, failed to increase neurogenesis due to a greatly declined neuronal fate-choice decision of newly born cells. Only 9% of newly born cells in the SGZ/GCL differentiated into neurons in aged rats that underwent SE, in comparison to the 76% neuronal differentiation observed in age-matched control rats. Moreover, the number of newly born cells that migrate abnormally into the dentate hilus (i.e., ectopic granule cells) after SE in the aged hippocampus is 92% less than that observed in the young adult hippocampus after similar SE. Thus, SE fails to increase the addition of new granule cells to the GCL in the aged DG, despite a considerable upregulation in the production of new cells, and SE during old age leads to much fewer ectopic granule cells. These results have clinical relevance because earlier studies have implied that both increased and abnormal neurogenesis occurring after SE in young animals contributes to chronic epilepsy development.
|mesh-terms=* Age Factors
* Aging
* Animals
* Cell Differentiation
* Cell Proliferation
* Hippocampus
* Neurons
* Rats
* Rats, Inbred F344
* Status Epilepticus

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3612499
}}
{{medline-entry
|title=Early age-related changes in adult hippocampal neurogenesis in C57 mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/18455269
|abstract=Strong age-related declines in conjunction with comparatively easy experimental manipulations of adult hippocampal neurogenesis have generated considerable public and scientific interest in the prospect of "new neurons for old brains". Only few studies addressed the time course of the natural changes, which are the substrate for interventions that may realize this prospect. We provide a monthly or bimonthly account of cell proliferation, neurogenesis and cell death during the first 9 months of the life of C57Bl/6J mice. Ki67- and [[DCX]]-positive cell numbers declined exponentially without an intermittent plateau ( approximately 40% per month). Cell death in relation to cell proliferation was lowest at 1 month, increased at 2 months to remain constant until 4 months, and decreased again at 5 months to remain stable until 9 months. Granule cell number did not change with age. Our results suggest that manipulations of proliferation and neurogenesis may, at any time, interact with strong natural changes of these processes. Mediators of their age-related decline may be studied over periods much shorter than those typically used.
|mesh-terms=* Aging
* Animals
* Biomarkers
* Cell Count
* Cell Death
* Cell Proliferation
* Female
* Hippocampus
* Ki-67 Antigen
* Male
* Memory Disorders
* Mice
* Mice, Inbred C57BL
* Microtubule-Associated Proteins
* Neurogenesis
* Neuronal Plasticity
* Neuropeptides
* Time Factors

|full-text-url=https://sci-hub.do/10.1016/j.neurobiolaging.2008.03.002
}}
{{medline-entry
|title=Distribution and localization of pituitary adenylate cyclase-activating polypeptide-specific receptor (PAC1R) in the rostral migratory stream of the infant mouse brain.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/17900711
|abstract=Pituitary adenylate cyclase-activating polypeptide (PACAP) is known to participate in the regulation of neuronal proliferation and differentiation. While these processes are considered to be mediated via PACAP's actions on the PACAP-specific receptor, PAC1R, the precise distribution of PAC1R during neurodevelopment has not yet to be elucidated in detail. The purpose of this study is to examine the distribution of PAC1R in the neurogenic region of the rostral migratory stream (RMS) from the apical subventricular zone (SVZa) to the olfactory bulb (OB) in infant mice using immunostaining. Co-immunostaining for PAC1R in a variety types of cell were carried out using different markers. These included the neural stem cell markers, nestin and glial fibrillary acidic protein ([[GFAP]]), a marker for migrating neuroblasts (doublecortin, [[DCX]]), a marker for immature neurons betaIII-tubulin, (Tuj1), and a marker for mature neurons, neuronal nuclei (NeuN). PAC1R-like immunoreactivity (LI) was observed in the RMS. However, the intensity of PAC1R- LI was different depending on the regions which were investigated. PAC1R-LI was strong in nestin- and [[GFAP]]-positive cells in the SVZa and was also observed in NeuN-positive cells in the OB. However, the intensities of PAC1R-LI in [[DCX]]- and Tuj1-positive cells were weaker than the other markers. These results suggest that PACAP may participate in the neurodevelopment with the stage-specific expression of PAC1R and that PACAP plays important roles in neurons as well as in glial cells.
|mesh-terms=* Aging
* Animals
* Biological Transport
* Brain
* Mice
* Mice, Inbred ICR
* Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I

|full-text-url=https://sci-hub.do/10.1016/j.regpep.2007.08.016
}}
{{medline-entry
|title=Neurogenesis decreases with age in the canine hippocampus and correlates with cognitive function.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/17587610
|abstract=New neurons are continually produced in the adult mammalian brain from progenitor cells located in specific brain regions, including the subgranular zone (SGZ) of the dentate gyrus of the hippocampus. We hypothesized that neurogenesis occurs in the canine brain and is reduced with age. We examined neurogenesis in the hippocampus of five young and five aged animals using doublecortin ([[DCX]]) and bromodeoxyuridine (BrdU) immunostaining. The total unilateral number of new neurons in the canine SGZ and granule cell layer (GCL) was estimated using stereological techniques based upon unbiased principles of systematic uniformly random sampling. Animals received 25mg/kg of BrdU once a day for 5 days and were euthanized 9 days after the last injection. We found evidence of neurogenesis in the canine brain and that cell genesis and neurogenesis are greatly reduced in the SGZ/GCL of aged animals compared to young. We further tested the hypothesis that an antioxidant fortified food or behavioral enrichment would improve neurogenesis in the aged canine brain and neurogenesis may correlate with cognitive function. Aged animals were treated for 2.8 years and tissue was available for six that received the antioxidant food, five that received the enrichment and six receiving both treatments. There were no significant differences in the absolute number of [[DCX]] or [[DCX]]-BrdU neurons or BrdU nuclei between the treatment groups compared to control animals. The number of [[DCX]]-positive neurons and double-labeled [[DCX]]-BrdU-positive neurons, but not BrdU-positive nuclei alone, significantly correlated with performance on several cognitive tasks including spatial memory and discrimination learning. These results suggest that new neurons in the aged canine dentate gyrus may participate in modulating cognitive functions.
|mesh-terms=* Aging
* Animals
* Antioxidants
* Cognition Disorders
* Dentate Gyrus
* Dogs
* Food, Fortified
* Hippocampus
* Immunohistochemistry
* Neurons

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2173881
}}
{{medline-entry
|title=Differences in doublecortin immunoreactivity and protein levels in the hippocampal dentate gyrus between adult and aged dogs.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/17514419
|abstract=Doublecortin ([[DCX]]), a microtubule-associated protein, specifically expresses in neuronal precursors. This protein has been used as a marker for neuronal precursors and neurogenesis. In the present study, we observed differences in [[DCX]] immunoreactivity and its protein levels in the hippocampal dentate gyrus between adult and aged dogs. In the adult dog, [[DCX]] immunoreactive cells with well-stained processes were detected in the subgranular zone of the dentate gyrus. Numbers of [[DCX]] immunoreactive cells in the dentate gyrus of the aged dog were significantly decreased compared to those in the adult dog. [[DCX]] immunoreactive cells in both adult and aged dog did not show NeuN (a marker for mature neurons) immunoreactivity. NeuN immunoreactivity in the aged dog was poor compared to that in the adult dog. [[DCX]] protein level in the aged dentate gyrus was decreased by 80% compared to that in the adult dog. These results suggest that the reduction of [[DCX]] in the aged hippocampal dentate gyrus may be involved in some neural deficits related to the hippocampus.
|mesh-terms=* Aging
* Animals
* Dentate Gyrus
* Dogs
* Immunohistochemistry
* Male
* Microtubule-Associated Proteins
* Neuropeptides

|full-text-url=https://sci-hub.do/10.1007/s11064-007-9366-1
}}
{{medline-entry
|title=Postnatal expression pattern of doublecortin ([[DCX]]) in some areas of the developing brain of mouse.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/17451056
|abstract=We have investigated the spatio-temporal expression pattern of doublecortin ([[DCX]]) protein from postnatal day (P) 2 to postnatal day (P) 22 in the brain of developing mouse. We compared the expression of [[DCX]] in the rostral migratory stream (RMS) and dentate gyrus of the hippocampus (DG). Weak expression of [[DCX]] was detected in the RMS at P5, it became gradually stronger during the second postnatal week and reached its strongest expression by P18-P22. Moderate [[DCX]] immunostaining was present in the DG at P11, its marked expression--characteristic of newly generated neurons in the adult DG -appeared only after P22. Morphological and functional maturation was different in the RMS and DG, continuous neurogenesis appeared earlier in the RMS than in the DG.
|mesh-terms=* Aging
* Animals
* Cell Movement
* Dentate Gyrus
* Gene Expression Regulation, Developmental
* Hippocampus
* Immunohistochemistry
* Mice
* Mice, Inbred C57BL
* Microtubule-Associated Proteins
* Neuropeptides
* Time Factors


}}
{{medline-entry
|title=Environmental lead exposure during early life alters granule cell neurogenesis and morphology in the hippocampus of young adult rats.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/17276012
|abstract=Exposure to environmentally relevant levels of lead (Pb(2 )) during early life produces deficits in hippocampal synaptic plasticity in the form of long-term potentiation (LTP) and spatial learning in young adult rats [Nihei MK, Desmond NL, McGlothan JL, Kuhlmann AC, Guilarte TR (2000) N-methyl-D-aspartate receptor subunit changes are associated with lead-induced deficits of long-term potentiation and spatial learning. Neuroscience 99:233-242; Guilarte TR, Toscano CD, McGlothan JL, Weaver SA (2003) Environmental enrichment reverses cognitive and molecular deficits induced by developmental lead exposure. Ann Neurol 53:50-56]. Other evidence suggests that the performance of rats in the Morris water maze spatial learning tasks is associated with the level of granule cell neurogenesis in the dentate gyrus (DG) [Drapeau E, Mayo W, Aurousseau C, Le Moal M, Piazza P-V, Abrous DN (2003) Spatial memory performance of aged rats in the water maze predicts level of hippocampal neurogenesis. Proc Natl Acad Sci U S A 100:14385-14390]. In this study, we examined whether continuous exposure to environmentally relevant levels of Pb(2 ) during early life altered granule cell neurogenesis and morphology in the rat hippocampus. Control and Pb(2 )-exposed rats received bromodeoxyuridine (BrdU) injections (100 mg/kg; i.p.) for five consecutive days starting at postnatal day 45 and were killed either 1 day or 4 weeks after the last injection. The total number of newborn cells in the DG of Pb(2 )-exposed rats was significantly decreased (13%; P<0.001) 1 day after BrdU injections relative to controls. Further, the survival of newborn cells in Pb(2 )-exposed rats was significantly decreased by 22.7% (P<0.001) relative to control animals. Co-localization of BrdU with neuronal or astrocytic markers did not reveal a significant effect of Pb(2 ) exposure on cellular fate. In Pb(2 )-exposed rats, immature granule cells immunolabeled with doublecortin ([[DCX]]) displayed aberrant dendritic morphology. That is, the overall length-density of the [[DCX]]-positive apical dendrites in the outer portion of the DG molecular layer was significantly reduced up to 36% in the suprapyramidal blade only. We also found that the area of Timm's-positive staining representative of the mossy fibers terminal fields in the [[CA3]] stratum oriens (SO) was reduced by 26% in Pb(2 )-exposed rats. These findings demonstrate that exposure to environmentally relevant levels of Pb(2 ) during early life alters granule cell neurogenesis and morphology in the rat hippocampus. They provide a cellular and morphological basis for the deficits in synaptic plasticity and spatial learning documented in Pb(2 )-exposed animals.
|mesh-terms=* Aging
* Animals
* Brain
* Bromodeoxyuridine
* Environmental Exposure
* Female
* Hippocampus
* Lead Poisoning
* Nerve Fibers
* Neurons
* Phenotype
* Rats
* Rats, Inbred Lew

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1892316
}}
{{medline-entry
|title=The window and mechanisms of major age-related decline in the production of new neurons within the dentate gyrus of the hippocampus.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/17129216
|abstract=While it is well known that production of new neurons from neural stem/progenitor cells (NSC) in the dentate gyrus (DG) diminishes greatly by middle age, the phases and mechanisms of major age-related decline in DG neurogenesis are largely unknown. To address these issues, we first assessed DG neurogenesis in multiple age groups of Fischer 344 rats via quantification of doublecortin-immunopositive ([[DCX]] ) neurons and then measured the production, neuronal differentiation and initial survival of new cells in the subgranular zone (SGZ) of 4-, 12- and 24-month-old rats using four injections (one every sixth hour) of 5'-bromodeoxyuridine (BrdU), and BrdU-[[DCX]] dual immunostaining. Furthermore, we quantified the numbers of proliferating cells in the SGZ of these rats using Ki67 immunostaining. Numbers of [[DCX]]  neurons were stable at 4-7.5 months of age but decreased progressively at 7.5-9 months (41% decline), 9-10.5 months (39% decline), and 10.5-12 months (34% decline) of age. Analyses of BrdU( ) cells at 6 h after the last BrdU injection revealed a 71-78% decline in the production of new cells per day between 4-month-old rats and 12- or 24-month-old rats. Numbers of proliferating Ki67  cells (putative NSCs) in the SGZ also exhibited similar (72-85%) decline during this period. However, the extent of both neuronal differentiation (75-81%) and initial 12-day survival (67-74%) of newly born cells was similar in all age groups. Additional analyses of dendritic growth of 12-day-old neurons revealed that newly born neurons in the aging DG exhibit diminished dendritic growth compared with their age-matched counterparts in the young DG. Thus, major decreases in DG neurogenesis occur at 7.5-12 months of age in Fischer 344 rats. Decreased production of new cells due to proliferation of far fewer NSCs in the SGZ mainly underlies this decline.
|mesh-terms=* Aging
* Animals
* Bromodeoxyuridine
* Cell Count
* Cell Differentiation
* Cell Proliferation
* Cell Survival
* Dentate Gyrus
* Immunohistochemistry
* Ki-67 Antigen
* Male
* Microtubule-Associated Proteins
* Models, Biological
* Neurons
* Neuropeptides
* Rats
* Rats, Inbred F344
* Stem Cells
* Telencephalon

|full-text-url=https://sci-hub.do/10.1111/j.1474-9726.2006.00243.x
}}
{{medline-entry
|title=The distribution of expression of doublecortin ([[DCX]]) mRNA and protein in the zebra finch brain.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/16814268
|abstract=Using in situ hybridization, we measured the distribution of expression of doublecortin ([[DCX]]), a microtubule-associated protein, in zebra finch adult and nestling (P9-11) brains. In adult brain, [[DCX]] mRNA was detected mainly in the mesopallium (M), medial striatum (MSt), septum, Area X, diencephalon, telencephalic subventricular zone (SVZ), and Purkinje cells in the cerebellum. The expression at posthatch day 9 (P9) was heavy in almost the entire telencephalon and showed heavier expression in SVZ and song regions such as the high vocal center (HVC) and the robust nucleus of arcopallium (RA). Outside of the telencephalon at P9, we found distinct label in nucleus ovoidalis (OV), nucleus spiriformis lateralis (SpL), and nucleus subpretectalis (SP) in the midbrain, almost the entire diencephalon including nucleus dorsomedialis posterior thalami (DMP), stratum griseum et fibrosum superficiale (SGF) in optic tectum, and Purkinje cells in cerebellum. Most of the heavily labeled areas by in situ hybridization overlapped with immunohistochemical staining for [[DCX]], indicating that [[DCX]] mRNA is probably translated into protein in those regions. No sex difference was found in [[DCX]] expression at P9 or in the adult except that Area X was labeled only in the adult male. The intensity of expression in the adult was significantly lower than that at P9, which suggests a particular role for [[DCX]] in early song bird brain development. If [[DCX]] is predominantly expressed in migrating neurons, as suggested from studies in mammals, the present results offer no evidence for a sex difference in neuronal migration.
|mesh-terms=* Aging
* Animals
* Brain
* Brain Mapping
* Cell Differentiation
* Cell Movement
* Cerebellum
* Female
* Finches
* Gene Expression
* Immunohistochemistry
* Male
* Mesencephalon
* Microtubule-Associated Proteins
* Neural Pathways
* Neurons
* Neuropeptides
* RNA, Messenger
* Sex Characteristics
* Sexual Behavior, Animal
* Stem Cells
* Telencephalon
* Vocalization, Animal

|full-text-url=https://sci-hub.do/10.1016/j.brainres.2006.05.080
}}
{{medline-entry
|title=The doublecortin and doublecortin-like kinase 1 genes cooperate in murine hippocampal development.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/16766710
|abstract=The doublecortin (Dcx) and doublecortin-like kinase 1 (Dclk) genes are developmentally expressed neuronal microtubule-associated proteins. Humans with [[DCX]] mutations show a severe defect in hippocampal development, but targeted deletion in mouse shows only a defect in pyramidal neuron lamination. There is significant sequence overlap between Dcx and Dclk, suggesting functional redundancy. Here we show that the two genes display overlapping expression patterns in developing mouse hippocampus. Targeted deletion of Dclk shows no appreciable developmental defect in the hippocampus, but removal of both genes shows severe hippocampal lamination defects involving the entire cornu ammonis and dentate gyrus fields that mimic the human phenotype. These results suggest these genes are partially functionally redundant in the formation of the murine hippocampus.
|mesh-terms=* Aging
* Animals
* Animals, Newborn
* Body Patterning
* Cell Aggregation
* Cell Differentiation
* Cell Movement
* Hippocampus
* In Vitro Techniques
* Mice
* Mice, Knockout
* Microtubule-Associated Proteins
* Nerve Net
* Neurons
* Neuropeptides
* Organogenesis
* Protein-Serine-Threonine Kinases

|full-text-url=https://sci-hub.do/10.1093/cercor/bhk005
}}
{{medline-entry
|title=Newly born cells in the ageing dentate gyrus display normal migration, survival and neuronal fate choice but endure retarded early maturation.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/15673445
|abstract=Addition of new granule cells to the dentate gyrus (DG) from stem or progenitor cells declines considerably during ageing. However, potential age-related alterations in migration, enduring survival and neuronal fate choice of newly born cells, and rate of maturation and dendritic growth of newly differentiated neurons are mostly unknown. We addressed these issues by analysing cells that are positive for 5'-bromodeoxyuridine (BrdU), doublecortin ([[DCX]]), BrdU and [[DCX]], and BrdU and neuron-specific nuclear antigen (NeuN) in the DG of young adult, middle-aged and aged F344 rats treated with daily injections of BrdU for 12 consecutive days. Analyses performed at 24 h, 10 days and 5 months after BrdU injections reveal that the extent of new cell production decreases dramatically by middle age but exhibits no change thereafter. Interestingly, fractions of newly formed cells that exhibit appropriate migration and prolonged survival, and fractions of newly born cells that differentiate into neurons, remain stable during ageing. However, in newly formed neurons of the middle-aged and aged DG, the expression of mature neuronal marker NeuN is delayed and early dendritic growth is retarded. Thus, the presence of far fewer new granule cells in the aged DG is not due to alterations in the long term survival and phenotypic differentiation of newly generated cells but solely owing to diminished production of new cells. The results also underscore that the capability of the DG milieu to support neuronal fate choice, migration and enduring survival of newly born cells remains stable even during senescence but its ability to promote rapid neuronal maturation and dendritic growth is diminished as early as middle age.
|mesh-terms=* Age Factors
* Aging
* Analysis of Variance
* Animals
* Bromodeoxyuridine
* Cell Count
* Cell Differentiation
* Cell Enlargement
* Cell Movement
* Cell Survival
* Dendrites
* Dentate Gyrus
* Gene Expression Regulation
* Immunohistochemistry
* Male
* Microtubule-Associated Proteins
* Neurons
* Neuropeptides
* Phosphopyruvate Hydratase
* Rats
* Rats, Inbred F344
* Stem Cells
* Time Factors

|full-text-url=https://sci-hub.do/10.1111/j.1460-9568.2005.03853.x
}}
{{medline-entry
|title=Transient expression of doublecortin during adult neurogenesis.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/14574675
|abstract=During development of the central nervous system, expression of the microtubule binding protein doublecortin ([[DCX]]) is associated with migration of neuroblasts. In addition to this developmental role, expression of [[DCX]] remains high within certain areas of the adult mammalian brain. These areas, mainly the dentate gyrus and the lateral ventricle wall in conjunction with the rostral migratory stream and olfactory bulb, retain the capacity to generate new neurons into adulthood. Adult neurogenesis is typically detected by incorporation of bromodeoxyuridine (BrdU) into dividing cells and colabeling of BrdU-positive cells with markers for mature neurons. To elucidate whether [[DCX]] could act as an alternative indicator for adult neurogenesis, we investigated the temporal expression pattern of [[DCX]] in neurogenic regions of the adult brain. Analysis of newly generated cells showed that [[DCX]] is transiently expressed in proliferating progenitor cells and newly generated neuroblasts. As the newly generated cells began expressing mature neuronal markers, [[DCX]] immunoreactivity decreased sharply below the level of detection and remained undetectable thereafter. The transient expression pattern of [[DCX]] in neuronal committed progenitor cells/neuroblasts indicates that [[DCX]] could be developed into a suitable marker for adult neurogenesis and may provide an alternative to BrdU labeling. This assumption is further supported by our observation that the number of [[DCX]]-expressing cells in the dentate gyrus was decreased with age according to the reduction of neurogenesis in the aging dentate gyrus previously reported.
|mesh-terms=* Aging
* Animals
* Blotting, Western
* Bromodeoxyuridine
* Cell Differentiation
* Cell Movement
* Central Nervous System
* Dentate Gyrus
* Electrophoresis, Polyacrylamide Gel
* Female
* Fluorescent Antibody Technique
* Hippocampus
* Lateral Ventricles
* Microtubule-Associated Proteins
* Mitosis
* Neurons
* Neuropeptides
* Olfactory Bulb
* Rats
* Rats, Wistar
* Stem Cells
* Time Factors

|full-text-url=https://sci-hub.do/10.1002/cne.10874
}}
{{medline-entry
|title=Doublecortin expression in the adult rat telencephalon.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/11556888
|abstract=Doublecortin ([[DCX]]) is a protein required for normal neuronal migration in the developing cerebral cortex, where it is widely expressed in both radially and tangentially migrating neuroblasts. Moreover, it has been observed in the adult rostral migratory stream, which contains the neuronal precursors traveling to the olfactory bulb. We have performed [[DCX]] immunocytochemistry in the adult rat brain to identify precisely the neuronal populations expressing this protein. Our observations confirm the presence of [[DCX]] immunoreactive cells with the characteristic morphology of migrating neuroblasts in the subventricular zone, rostral migratory stream and the main and accessory olfactory bulbs. We have also found putative migratory cells expressing [[DCX]] in regions were no adult neuronal migration has been described, as the corpus callosum, the piriform cortex layer III/endopiriform nucleus and the striatum. Surprisingly, many cells with the phenotype of differentiated neurons were [[DCX]] immunoreactive; e.g. certain granule neurons in the hilar border of the granular layer of the dentate gyrus, some neuronal types in the piriform cortex layer II, granule and periglomerular neurons in the main and accessory olfactory bulbs, and isolated cells in the striatum. Almost all [[DCX]] immunoreactive cells also express the polysialylated form of neural cell adhesion molecule and have a similar distribution to rat collapsin receptor-mediated protein-4, two molecules involved in neuronal structural plasticity. Given these results, we hypothesize that [[DCX]] expression in differentiated neurons could be related to its capacity for microtubule reorganization and that this fact could be linked to axonal outgrowth or synaptogenesis.
|mesh-terms=* Aging
* Animals
* Cell Differentiation
* Cell Movement
* Corpus Striatum
* Hippocampus
* Immunohistochemistry
* Intermediate Filament Proteins
* Lateral Ventricles
* Male
* Microtubule-Associated Proteins
* Nerve Tissue Proteins
* Nestin
* Neural Cell Adhesion Molecule L1
* Neural Cell Adhesion Molecules
* Neurons
* Neuropeptides
* Olfactory Bulb
* Olfactory Pathways
* Rats
* Rats, Sprague-Dawley
* Sialic Acids
* Stem Cells
* Telencephalon

|full-text-url=https://sci-hub.do/10.1046/j.0953-816x.2001.01683.x
}}