Cardiovascular responses to avoidance conditioning in the dog: effects of alpha adrenergic blockade

• Published in: Pavlovian journal of biological science Vol. 11; no. 3; p. 150
• Main Authors: Anderson, D E, Yingling, J E, Brady, J V
• Format: Journal Article
• Language: English
• Published: United States 01.07.1976
• Subjects: Animals; Avoidance Learning - drug effects; Avoidance Learning - physiology; Blood Pressure - drug effects; Conditioning, Operant - drug effects; Conditioning, Operant - physiology; Dogs; Electroshock; Heart Rate - drug effects; Male; Phenoxybenzamine - pharmacology; Sympathetic Nervous System - physiology
• ISSN: 0093-2213
• DOI: 10.1007/BF03000292

Laboratory dogs were trained to press a response panel to postpone shocks during daily one-hour avoidance conditioning periods. Each dog was also confined in the experimental environment for 5 hours prior to the avoidance periods. Blood pressure and heart rate were monitored continuously during these experiments from chronically indwelling arterial catheters. Extended training resulted in the emergence of a cardiovascular response pattern during the pre-avoidance interval characterized by gradual increases in blood pressure together with decreases in heart rate. Elevations in both blood pressure and heart rate were sustained during the avoidance periods. During sessions in which alpha adrenergic activity was suppressed by phenoxybenzamine, absolute levels of blood pressure were found to be lower than during control (non-drug) sessions, but a progressive rise in blood pressure continued to be observed during pre-avoidance. These results suggest that sustained cardiovascular responses during avoidance periods are associated with activation of the sympathetic nervous system, but that the gradual rise in blood pressure during pre-avoidance is due to other factors.