Effects of amphetamine on electroshock responses in developing rats

Abstract Convulsive responses were studied after chronic and acute amphetamine treatment in developing rats. Under chronic treatment, 27 litters of male rats received d‐amphetamine either at 3‐6, 8‐11, or 22‐25 days after birth and the electroshock seizure threshold (EST) was studied during maturation; each litter consisted of controls and rats treated with 1, 3, or 6 mg/kg body‐weight amphetamine. Under acute treatment, groups of rats (16 per group) received amphetamine 45 min before electroshock testing at 8, 16, or 25 days after birth. The EST was significantly higher for the 1st week after treatment in rats given amphetamine (3 mg/kg) from 8‐11 days after birth; no changes were observed in the other groups tested chronically with amphetamine. The EST was lower in rats treated acutely at 8 or 16 days and higher in rats treated at 25 days. These data demonstrate that the effects of amphetamine on convulsive responses are dependent not only on the stage of central nervous system (CNS) maturation at the time of drug administration, but also on the duration of drug treatment.