STIMULATION OF PERIPHERAL NERVE TERMINATIONS BY ACTIVE MUSCLE

Abstract

When muscles were activated indirectly by motor volleys (stimulation of ventral roots) centripetal volleys reflected from the periphery into the stimulated ventral root and into neighboring ventral and dorsal roots. The latency of these centripetal volleys was equal to the sum of conduction time from the stimulating electrodes to the muscle, neuromuscular delay, a short utilization period, and conduction time from the muscle to the recording leads. In the case of centripetal discharges into a stimulated ventral root, the consequences of refractoriness added to the total latency. The centripetal discharges reflected faithfully the intervention of neuromuscular transmission and muscle action as steps in their causal sequence, and were initiated by muscular processes coincident with the rising phase of the muscle action potential at or near the junctional region.