EFFECTS OF DIAZEPAM ON CONFLICT BEHAVIOR AND ON PLASMA-CORTICOSTERONELEVELS IN MALE AND FEMALE RATS

The anxiolytic properties of diazepam and its effects on plasma cortic osterone levels were compared in male and female, water deprived rats exposed to the punished (0.8 mA) drinking procedure. The effects of di azepam on unpunished licking, tested under familiar or unfamiliar cond itions, and on the lick latency were also studied and a comparison bet ween the two sexes was made. Both punished and unpunished drinking wer e less in females than in males. In both sexes, a clear anticonflict e ffect, i.e. a much greater effect on punished than on unpunished drink ing, was obtained with 2 and 4 mg/kg, but not with 1 mg/kg, of diazepa m i.p. Plasma corticosterone levels were higher in water deprived fema les than in males. Following the punished and unpunished drinking proc edure, plasma corticosterone levels were found to have decreased more in female than in male rats, especially after administration of 1 mg/k g of diazepam. Diazepam had similar anticonflict effects in rats of bo th sexes but had a greater suppressive effect on the plasma corticoste rone levels in female rats. There was no correlation between the anxio lytic effects of diazepam and its effect on the plasma corticosterone levels. When testing was done under unfamiliar conditions, the latency to licking was greater in female than in male rats and diazepam (1, 2 and 4 mg/kg) increased this latency in both sexes. The results sugges t sex differences in the neuroendocrine, but not in the anxiolytic, ef fects of diazepam.