Tonic vibration reflex in human and monkey subjects.

Abstract

1. Both in human subjects and monkeys, the tonic vibration reflex, TVR, was observed during vibratory stimulation of the muscle. In the latter, TVR reaches its maximum soon after vibratory application.2. In the monkey, unitary EMG was recorded during vibratory stimulation and nonsequential interspike interval histograms were obtained. Intervals of unitary EMG were shown to occur on the principle of integer multiplication of the vibratory cyclic time.3. A gradual increase or decrease of TVR during vibratory stimulation in the human subject or the monkey is effected by the EMG discharges of shorter or longer firing intervals which occur on this principle.4. Both in human subjects and monkeys, the TVR becomes larger with the higher range of vibratory frequency. Beyond a certain vibratory frequency the TVR shows a gradual decrease. The relationship between the TVR and the vibratory frequency was called the TVR-f relation. There is an optimal frequency of vibratory stimulation for producing the largest TVR tension.5. The size of the reflex tension from TVR-f relation depends on the discharge frequency of the unitary EMG, which occurs according to the principle of the integer multiplication of original vibratory cyclic time.