DIFFUSE THALAMIC PROJECTION SYSTEM IN MONKEY

Abstract

The diffuse thalamic projection system has been studied in the monkey by observing the recruiting wave responses recorded from cortical and subcortical structures during low frequency thalamic stimulation. The thalamic origins of this system include the central median, intralaminar, inferior part of the medial, ventralis anterior and anterior reticular nuclei. These form a functional unit, excitation of any part of which sets the whole into activity and induces recruiting responses in the associational thalamic nuclei-medial, anterior, lateralis and pulvinar- and in the associational areas of the cortex-frontal, cingulate and occipito-parieto-temporal- to which these nuclei project. As in the cat, this diffuse system appears organized for mass action upon associational thalamus and cortex, and the high degree of rostral specialization in the monkey suggests the potential importance in frontal lobe function in the primate brain.