Objective: To determine the effect of buspirone and propranolol on restraint stress-induced behavioral deficits in a learned helplessness model.
Design: Experimental study.
Place and duration of 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).
Subjects and methods: 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.
Results: 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.
Conclusion: 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.