Редактирование: Whole brain emulation (раздел)

==== SBFSEM ====

One way of reducing the problems of sectioning is to place the microtome inside 
the microscope chamber (Leighton, 1981)

for further contrast, plasma etching was used 
(Kuzirian and Leighton, 1983)

(Denk and Horstmann, 2004) demonstrated that 
backscattering contrast could be used instead in a SEM, simplifying the technique. 

 They 
produced stacks of 50‐70 nm thick sections using an automated microtome in the microscope 
chamber, with lateral jitter less than 10 nm. The resolution and field size was limited by the 
commercially available system. They estimated that tracing of axons with 20 nm resolution 
and S/N ratio of about 10 within a 200 μm cube could take about a day (while 10 nm x 10 nm 
x 50 nm voxels at S/N 100 would require a scan time on the order of a year). 


Reconstructing volumes from ultrathin sections faces many practical challenges. Current 
electron microscopes cannot handle sections wider than 1‐2 mm. Long series of sections are 
needed but the risk of errors or damage increase with the length, and the number of specimen 
holding grids becomes excessive (unless sectioning occurs inside the microscope (Kuzirian 
and Leighton, 1983)). Current state of the art for practical reconstruction from tissue blocks is 
about 0.1 mm3 , containing about 107‐108 synapses (Fiala, 2002).