Ingestion-related activity of caudate and entopeduncular neurons in the cat

Single-unit activity was recorded in the caudate nucleus and entopeduncular nucleus in cats during ingestion. In both nuclei, ingestion-related neurons were of two types: those with no facial somatosensory receptive field and an ingestion-related response, and those with a facial somatosensory field and an ingestion response. Neurons in both regions contained cells with conditioned responses to the noise produced by the solenoid that delivered milk. No caudate neurons and only 3% of entopeduncular neurons were phasically related to jaw muscle activity. These results indicate that neurons in both input and output regions of the basal ganglia in the cat have complex ingestion-related response characteristics with little relationship to specific orolingual movements.