Dopaminergic unit activity in freely moving cats: lack of relationship to feeding, satiety, and glucose injections.

The activity of dopaminergic neurons in the substantia nigra was recorded from freely moving cats during feeding and satiety, and following injections of glucose. At no time during feeding or in the postprandial satiety period was there a significant increase or decrease in firing rate of these neurons relative to baseline. Additionally, no change in firing rate was observed following injections of glucose (300, 500 and 1000 mg/kg) or glucose in combination with insulin (300 mg/kg glucose and 0.8 units/kg insulin).