The functional projections of the anterior ventralis nucleus, as revealed by autoradiography

The effect of stimulation of ventral anterior nuclei of the thalamus (VA) was studied in different areas of cat cortex (sensory, motor and association) with [3H]glycine autoradiography. One-hour VA stimulation resulted in the most intensive [3H]glycine incorporation in the second, third and fifth layers of the anterior suprasylvian gyrus and of the motor cortex. The labelling was less intensive in the sensory (auditory) and association (posterior middle suprasylvian association area) cortices, but the effect of VA stimulation reached these regions as well. The VA stimulation resulted in evoked potentials over the whole area examined, with highest amplitude and shortest latency in the anterior suprasylvian gyrus. It is suggested that the [3H]glycine autoradiography is suitable to study the functional projection of non-specific thalamocortical systems.