Effect of botulinum toxin on NMJ?

[James Reed]

Hi All,

I am a 1st year Medical Student, and I have been set an essay on the 
effects of the botulinum toxins. I have been able to gather some info 
from books, but what I am really lacking is info on what actually happens 
at the neuromuscular junction, and how this affects the muscle itself. I 
know that the toxin disables ACh release at the synapse, but I am not 
clear on how this affects the NMJ - is there Wallerian degeneration of 
the nerve fibre or something? Or is the effect felt in a different way? 
The other thing I would like to know (I know this is not strictly 
neuroscience, but I couldn't find any other newsgroups that seemed 
relevant) is what effects there are on the muscle itself. We have been 
asked to outline 'morphological and physiological changes in the muscle 
which occur if recovery takes place'. Can anyone give me any clues on this?

I would be very grateful for any replies!

Thanks in advance, James