Early Effects of Denervation Upon Response of Muscle to Continuous Stimulation

Abstract

SummaryMale rats (310 to 350 g) were subjected to direct faradic stimulation of the gastrocnemius muscle following the cutting of the sciatic nerve, and their work performance was compared to that of sham-operated controls. When stimulation was started immediately following the operation the rate of work of denervated muscle was normal for several hours but was depressed below normal by 24 hours and continued to decrease rapidly, whereas the control animals sustained a high rate of work. When stimulation was delayed for 24 and 48 hours following denervation, the initial contractions were subnormal and decreased rapidly during continued stimulation. When the intensity of the pulse was increased from 12 to 20 milliamperes, at the end of each experiment there was a striking recovery in the rate of work of denervated muscle but it remained below that of the sham-operated controls.