The effect of denervation on the skeletal muscle resting membrane potential (RMP) was studied in the soleus muscle of the intact rat. The RMP decreased much later than reported in previous in vitro studies. With a very short nerve stump (less than 2 mm), the RMP began to decrease 18 h after denervation and 4 h after miniature end-plate potentials ceased. With a longer nerve stump (39 to 43 mm) the decrease in RMP was delayed about 3 h. Our findings in vivo fail to confirm previous arguments against a role for acetylcholine in regulating the muscle RMP. The influence of usage and the possible effects of spontaneous quantal and nonquantal acetylcholine release or other hypothetical factors are discussed.
- miniature end-plate potential
- resting membrane potential
ASJC Scopus subject areas
- Developmental Neuroscience