Attenuation of restraint induced behavioral deficits by buspirone and propranolol in rats

To determine the effect of buspirone and propranolol on restraint stress-induced behavioral deficits in a learned helplessness model.

Experimental study.

The experiment was performed in the Department of Biochemistry, University of Karachi and completed during a period of three months (3 June 2004 to 17 August 2004).

The study was conducted on 36 male albino Wistar rats. Animals injected with saline, buspirone (0.2 mg/kg) and propranolol (1 mg/kg) for 2 weeks were exposed to an episode of 2 hours restraint stress. Cumulative food intake and body weight changes were monitored over a period of 24 hours. Exploratory activity in the lit area of light dark box was monitored 24 hours after the termination of restraint period.

Single (2 hours) restraint stress decreased 24 hours cumulative food intake and growth rate. Exploratory activity in the lit compartment of a light-dark box also decreased. Prior administration of buspirone as well as propranolol attenuated restraint-induced deficits of food intake and growth rate. Administration of buspirone and propranolol increased lit area exploration in unrestrained animals and attenuated restraint-induced deficits of exploration.

The results show that anorexiogenic and anxiogenic effects of restraint stress were smaller in animals injected with buspirone or propranolol. Buspirone and propranolol could attenuate stress-induced behavioral deficits.