Effects of reinnervation upon electrical membrane properties of normal and paralyzed muscles

Resting membrane potentials (RMP) and resistance to tetrodotoxin (TTX) have been compared in denervated rat soleus muscles and muscles reinnervated with tetrodotoxin-inactive nerves for periods of 15-18 days. RMP's of the two muscle groups exhibited the same low values typical of denervated muscles. Similarly, comparable values of TTX-resistance were found in the two muscle groups, although exceptions with slightly lower values in the innervated-paralyzed muscles were noted. It is concluded that muscle reinnervation restores to normal the membrane properties altered by denervation essentially through the return of muscle activity.