[gibbonsrcool]

I've always wondered... and so far have been unable to Google this: Does the non-nucleus part of a severed nerve cell die? If so, that would mean we only have a small window to "rejoin" severed CNS nerve cells, right? Nerve cells can be very long, I think up to a meter. I'd assume this includes spinal nerve cells of the CNS, which don't regrow. If the cells are severed, like in a spinal injury, that means there's a half-cell fragment with a nucleus, and the other half is the axon that's been cut away without a nucleus. Wouldn't the fragment without a nucleus shrivel up and die? That would be my intuition because I'd assume the nucleus is necessary to keep a cell alive.

[tryptophan]

Yep. The nerve soma(the cell body) does not die when the nerve is cut. The axon distal to the cut dies. The living axon tries to grow into the 'scaffold' of the axon part that died. This can take months and doesn't always restore full functionality.

[mattlondon]

I would assume that the entire cell would die without the membrane to hold everything together.

https://en.wikipedia.org/wiki/Lysis

[gibbonsrcool]

PNS nerve cells regenerate axons: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2846285/

[bawana]

so we just have to inject stem cells into the area where there are a lot of damaged nerve cells without nuclei and have these cells fuse with the damaged remnants. Just throw some PEG in there with the stem cells?