On the Firing Pattern of Spinal Neurones Activated from the Secondary Endings of Muscle Spindles

Abstract

Abstract Some properties of a group of spinal neurones with axons ascending in the dorsolateral funicle are reported. They are excited by muscle stretch, and pause during muscle contraction. Their threshold to electrical stimulation of the muscle nerve is in the group II range. Their latencies are greater than that of the group I activated units. Their firing frequency increases approximately linearly with muscle length. Their discharge pattern is characterizcd by a relatively high degree of regularity. It is suggested that they represent a system relaying information on the length of individual muscles or synergistic muscle groups to the brain.