Monosynaptic Reflex (H Wave) in Evoked Muscle Potential of the Cow

Abstract

The reflex-evoked muscle potential (REMP) was examined in normal cows. The common peroneal nerve was stimulated with rectangular pulses, and muscle potentials were recorded in the peroneus tertius muscle with needle electrodes. REMP appeared after the M wave (direct-evoked muscle potential) had a lower threshold but was obliterated by increasing the intensity of the stimulus before the appearance of the maximal M wave. The latency increased as the stimulation point was moved from proximal to distal. T wave in the same muscle was similar in the wave form and the duration as REMP but the latency was slightly longer. When thb nerve was blocked proximally to the stimulation site, REMP was obliterated. These results indicate that REMP is due to a monosynaptic reflex (H wave).