Effects of electrical stimulation of the caudate nucleus on functionally identified neurons of the sensorimotor cortex in the cat brain.

Paired stimulation was used to study the effects of the caudate nucleus on the specific and nonspecific responses of projection neurons of the sensorimotor cortex in the cat brain. Caudal influences on the neurons being studied had insignificant effects on specific peripheral evoked responses. Nonspecific peripherally evoked activity was in most cases inhibited by caudate spike activity, and the pattern of evoked activity underwent significant modulation in conditions of a constant type of peripherally evoked response. It is suggested that the caudate nucleus acts as a filter of proprioceptive information in the cortex or in pathways to the cortex: specific corticopetal information is passed unchanged, while nonspecific signals are predominantly inhibited or significantly modulated.