Anxiogenic and anorexiogenic effects of restraint stress in rats pretreated with buspirone or propranolol

The present study is designed to monitor the effects of buspirone and propranolol on responses to stress. Exposure to single (2h) restraint stress decreased food intake, growth rate and time spent in the lit compartment of a light-dark activity box. The deficits were not observed following 5 (2-h/day) restraint stress, suggesting that adaptation occurred. Prior administration of buspirone and propranolol did not alter food intake and growth rates of unrestrained animals but attenuated restraint-induced deficits of food intake and growth rate. Administration of propranolol and buspirone resulted in an increase in time spent in light compartment of unrestrained animals and attenuated restraint-induced deficits of light-dark box activity, suggesting that the drugs could diminish novelty-induced as well as restraint-stress-induced anxiety. Adaptation in restraint-induced deficits of food intake, growth rate and anxiety was also produced in buspirone and propranolol treated animals after 5 restraint-stress of 2-h/day. The results are discussed in the context of a role of serotonin in the attenuation of restraint-induced behavioral deficits.