[Role of the caudate nucleus in the development of evoked synchronized activity]

Evoked spindles, recruitment and augmention to thalamic stimulation were studied in chronic cats after lesions of the caudate nuclei. The duration of spindles in the frontal cortex, thalamic and striatal sites were reduced to 3-4 oscillations. Their amplitude significantly decreased up to 50-10% in the thalamic and striatal sites. In the frontal cortex this decrease was not constant and sometimes was insignificant. Unilateral lesion of the caudate nucleus suppressed the synchronous activity evoked only by the ipsilateral thalamic stimulation. Lesion of the striatum (n. caudatus, globus pallidum, n. entopeduncularis, putamen) did not abolish the synchronous activity. It is suggested that the caudate nucleus produces ipsilateral facilitatory effect on the nonspecific thalamic system during the evoked synchronous activity.