Prefrontal control of conditioned suppression and associated cardiovascular variables in the monkey (Macaca mulatta)

Rhesus monkeys were trained in a discriminated conditioned emotional responses paradigm. The discriminated conditioned response (CR) complex consisted of bar-press suppression, increased terminal aortic blood flow, and increased arterial pressure. Bar-press suppression and blood flow responses were temporarily eliminated by single-stage bilateral prefrontal lobectomy but not by extensive posterior cortical ablation, 2-stage prefrontal lobe removal, or 3-stage prefrontal cortical surface ablation. The blood pressure CR was attenuated by almost every surgical operation. The changes in heart rate paralleled changes in general activity. These data indicate that the prefrontal lobes influence the conditioned suppression of ongoing rewarded behavior and the vascular responses accompanying the suppression. The time course for recovery of the somatic CR after lobectomy differed from those of the cardiovascular CRs.