Shawn Mikula on Brain Preservation Protocols and Extensions

oge

Recently published article in Nature Methods on a new protocol for preserving mouse brains that allows the neurons to be traced across the entire brain, something that wasn't possible before. This is exciting because in as little as 3 years, the method could be extended to larger mammals (like humans), and pave the way for better neuroscience or even brain uploads. From the abstract:

Here we describe a preparation, BROPA (brain-wide reduced-osmium staining with pyrogallol-mediated amplification), that results in the preservation and staining of ultrastructural details throughout the brain at a resolution necessary for tracing neuronal processes and identifying synaptic contacts between them. Using serial block-face electron microscopy (SBEM), we tested human annotator ability to follow neural ‘wires’ reliably and over long distances as well as the ability to detect synaptic contacts. Our results suggest that the BROPA method can produce a preparation suitable for the reconstruction of neural circuits spanning an entire mouse brain

http://blog.brainpreservation.org/2015/04/27/shawn-mikula-on-brain-preservation-protocols/

Here we describe a preparation, BROPA (brain-wide reduced-osmium staining with pyrogallol-mediated amplification), that results in the preservation and staining of ultrastructural details throughout the brain at a resolution necessary for tracing neuronal processes and identifying synaptic contacts between them. Using serial block-face electron microscopy (SBEM), we tested human annotator ability to follow neural ‘wires’ reliably and over long distances as well as the ability to detect synaptic contacts. Our results suggest that the BROPA method can produce a preparation suitable for the reconstruction of neural circuits spanning an entire mouse brain

http://blog.brainpreservation.org/2015/04/27/shawn-mikula-on-brain-preservation-protocols/

No - it's just an observation from my experience (CS degree in the 90's).

Just to be clear, he is making a clear conceptual mistake that indicates he does not understand universal computability:

... the reason for this is simulating the neural activity on a Von Neumann (or related computer) architecture does not reproduce the causal structure of neural interactions in wetware. Using a different computer architecture may avert this problem ...

If there is some other weird computer architecture that can reproduce the causal structure of neural interactions in wetware, then a universal computer (such as a Von Neumann machine) can also reproduce the causal structure of neural interactions simply by simulating the weird computer. This really is theory of computation 101.

"He does not understand universal computability" seems an overstatement, universal computability doesn't logically imply functionalism, although I agree that it tends to imply that definitions of consciousness which are not invariant under simulation have little epistemic usefulness.

-2Lumifer11y

In theory there is no difference between theory and practice. In practice there is. A physical Turing machine can simulate an iPhone, in theory. Would you like to try to build one? :-D