[Participation of muscle spindles in the mechanism of peripheral inhibition].

A relaxed deefferented muscle of an anesthetized cat has spindles with long-lasting impulse activity. The receptors with spontaneous activity are more sensitive to an alteration in the muscle condition than inactive ones. Stimulation of the muscle nerve entails inhibition of discharges not only in the spindles of a contracting muscle but in spontaneously active receptors of the synergic muscles which do not actively contract. The conditions for inhibition of spontaneous activity of the synergic muscles' receptors arise during natural locomotion in rats. The mechanism of peripheral inhibition in motor coordination seems to have an unspecific character and maintains the aiming of motor command at a small number of executive units in the course of the control.