Accession Number:

ADA633983

Title:

Effects of Beta-blockers on Punished Responding and on Heart Rate in Pigeons

Descriptive Note:

Doctoral thesis

Corporate Author:

UNIFORMED SERVICES UNIV OF THE HEALTH SCIENCES BETHESDA MD

Personal Author(s):

Report Date:

1986-06-17

Pagination or Media Count:

90.0

Abstract:

Beta-adrenergic blocking drugs, widely used in the treatment of cardiovascular disorders, have been reported to produce antianxiety effects in people with bodily anxiety symptoms and in those in acute stress situations. Although earlier animal studies of propranolol failed to detect any substantial behavioral effect in a punishment test usually predictive of clinical antianxiety effects, propranolol and atenolol were recently reported to be active in that test in pigeons. The present study attempted to confirm that finding, to compare the effects of propranolol, metoprolol, and atenolol with that of chlordiazepoxide, a standard antianxiety agent, and to examine whether heart rate is related to the behavioral effect of the drugs. Key pecking of five pigeons was maintained under a multiple schedule of food presentation. In the presence of one key light stimulus, every fiftieth response produced food. When a different key light stimulus was present, every fiftieth response produced food and electric shock punishment. Punished responding occurred at approximately 15 of the high unpunished response rates. Propranolol, atenolol, and metoprolol doses from 1.0 to 10.0 mgkg, i.m. and chlordiazepoxide 3.0 to 10.0 mgkg, i.m. substantially increased punished responding with little effect on unpunished responding. Propranolol increased punished responding approximately twice as much as did the other drugs. The increases were generally dose-related and appeared to be related to previous behavioral andor pharmacological history. Heart rate increases during punished responding were decreased by the beta-blockers. Propranolol and, to a somewhat lesser extent, metoprolol produced large dose-related decreases. Atenolols effect was small. Chlordiazepoxide increased heart rate at higher doses. With the beta-blockers, larger increases in punished responding were generally associated with greater heart rate decreases.

Subject Categories:

  • Medicine and Medical Research
  • Stress Physiology
  • Pharmacology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE