Single unit activity in monkey caudate nucleus during operant bar pressing feeding behavior.

Unit activity and changes during bar press feeding behavior after presentation of food or non-food were analyzed in 198 neurons in the head of the caudate nucleus of monkey. Eight neurons responded uniquely at the sight of food. The degree of the food-specific responses differed depending on the nature of the food and the hunger-satiation state. On the other hand, 17 neurons responded more or less to the sight of food and during bar pressing for food. These two types of neuron seem to be important to bar pressing feeding behavior, which consists of recognition of food and a bar press task to obtain food.