Electrophysiological Studies of Two Types of Thalamo-cortical Neurones and Their Responses to Stimulation of Mesencephalic Reticular Formation

Publisher Website
Google Scholar
Abstract
Thalamo-cortical (T-C) neurons projecting their axons to the motor cortex were recorded intra- or extra-cellularly in the anterior ventral and lateral ventral nuclear complex of the thalamus in lightly nembutalized cats. The T-C neurons responded antidromically to stimulation of the motor cortex, and were examined in connection with effects of stimulation of the centrum medianum-parafascicular complex (CM), pallidum (Pal), cerebellar nuclei (CN) and mesencephalic reticular formation (RF). The T-C neurons were classified into 2 groups, A and B. The A-group neurons responded neither to stimulation of CM nor to that of Pal. By contrast, the B-group neurons were activated from either CM, Pal or both. The effect of RF stimulation was facilitatory in many of the A-group neurons whereas it was mostly inhibitory in the B-group neurons. CN stimulation activated most of the T-C neurons in both A and B groups. The A-group neurons were categorized as the deep T-C neurons mediating the deep T-C response of the cortex (the early surface-positive-deep-negative component of the augmenting response) and the B-group neurons as the superficial T-C neurons mediating the superficial T-C response of the cortex (the recruiting response and the late surface-negative-deep-positive component of the augmenting response). Desynchronization of electrocorticograms in response to RF stimulation was suggested to result from inhibition of the superficial T-C neurons and facilitation of the deep T-C neurons.

This publication has 3 references indexed in Scilit: