Extraocular Proprioceptive Responses in the Vi Nerve of the Cat

Proprioceptive responses, produced by stretch of the lateral rectus muscle, were studied in the VI nerve of twenty‐one cats. Responses were recorded from slips teased from the nerve at its emergence from the pons; thus it is a mixed nerve in the cat. The responses from in‐series (tendon organ type) and in‐parallel (muscle spindle type) receptors were differentiated by observing the effect of electrically‐induced muscle contraction. A number of inhibitory and long latency responses to stretch were noted. A stretch reflex was noted in the VI nerve only when the eyeball and all muscles were intact.