I have heard that acetylcholine can be excitatory or inhibitory, but I am confused as to which it is when it comes to muscles. On the one hand, I believe that muscle atonia during REM sleep is associated with an abundance of acetylcholine in the brain stem, suggesting it has an inhibitory response on the motor neurons. On the other hand I know that the illness myasthenia gravis is caused by antibodies blocking acetylcholine receptors, which suggests to me that acetylcholine is excitatory. Could it be that with myasthenia gravis, the effect occurs at the neuromuscular junction where acetylcholine is excitatory, but it has an inhibitory effect on the motor neurons in the brain stem?

Thank you in advance.

  • $\begingroup$ I can write a full answer later if you wish, but quoting this source: ebi.ac.uk/interpro/potm/2005_11/Page1.htm - "Acetylcholine release can be either excitatory (promoting a signal), or inhibitory depending upon the type of receptor on the adjoining cell." So yes, you are correct in that it depends on what type of neuron is receiving the signal and where it is located. $\endgroup$ – CDB Nov 12 '15 at 6:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.