Influences of the basal ganglia on the medullary reticular formation.

Units were recorded extracellularly in the medullary reticular formation of chloralose-anesthetized cats during electrical stimulation of the basal ganglia (BG). Stimulating portions of the BG (caudate nucleus, entopeduncular nucleus, substantia nigra) evoked unit responses in a considerable proportion of these neurons. The majority of reticular cells that were affected by the BG were also receptive to somatic sensory inputs from the face. These units' sensory properties were influenced by BG stimulation. Cells exclusively responsive to either BG or facial inputs were uncommon. The areas of the reticular formation affected by the BG give rise to portions of the reticulospinal tracts and thereby afford the BG access to the final common path.