Re: How do nerve cells regenerate?

Nerve cells or neurons regenerate differently in different parts of the 
nervous system.  In the central nervous system (CNS), your brain and spinal 
cord, they typically do not regenerate.  In the peripheral nervous system 
they are able to regenerate.  This is why spinal cord injuries leave people 
paralyzed for life, whereas a severed hand or foot can be re-attached and 
regain a great deal of function after several months.  Peripheral nerves 
are known to grow along the path of the severed nerves.  The supporting 
cells (Schwaan cells) of the peripheral nerves are also known to release 
substances called growth factors that let the growing nerve cells continue 
to the appropriate location an support its regrowth.  For a good and 
concise tutorial on this visit:

http://www.physiol.usyd.edu.au/daved/teaching/injury.html


Admin Note:  Also, see these previous MadSci Answers by Annette Lewis and James Goss.  -- RJS