[ExI] Another step towards uploading

[Anders Sandberg]

On 2013-10-06 16:33, John Clark wrote:
>
> http://www.nbcnews.com/science/human-brain-cut-7-400-slices-then-reconstructed-digitally-3-6C10413680
>
> Using an automated process a woman's brain was cut into 7400 slices 20 
> micrometers thick, a human hair is about 50 micrometers thick. Then 
> they mounted the slices on glass slides, stained them and took very 
> high resolution photographs that almost reached the cellular level. 
> This is 50 times better resolution in all 3 directions than ever made 
> of a human brain before. I can't help but wonder if more information 
> has been preserved about this women, that is to say she has a better 
> chance of resurrection, than any current patient of Alcor. I'm not 
> saying she does but I wonder.

While a tour-de-force of what we can do today in the lab, the scanned 
images are not enough to reconstruct her network topology. First, they 
used Nissl stains, so we can mainly see cell nuclei rather than 
dendrites and synapses. Second, the scan was optical resolution: we know 
there are fine branches below optical resolution. And third, 20 microns 
is too wide to get the topology. Looking at the cube here
http://connectomethebook.com/?portfolio=atum-cortex-reconstructions
http://connectomethebook.com/?portfolio=atum-cortex-reconstructions-2
shows just how much stuff there is in a ~3x3x3 micron cube. The slices 
are seven times thicker! EM approaches are great in resolution, but 
overload our data storage methods and lack the big field optical methods 
have.

Now, we can hope the stained sections are stored safely and retain the 
information for the future methods.

-- 
Dr Anders Sandberg
Future of Humanity Institute
Oxford Martin School
Oxford University