Neurochemical consequences following administration of CNS stimulants to the neonatal rat.

The possible induction of long-lasting catecholamine depletions in discrete brain regions by psychomotor stimulant drugs was examined in neonatal rats. Three agents, methylamphetamine, d-amphetamine, and methylphenidate were administered to groups of rat pups from days 10 to 40 of life. Pups were killed 2 weeks beyond the last drug administration. Catecholamine levels of various brain regions from groups of rats receiving 12.5, 25 or 50 mg/kg/day of each drug were compared with levels of vehicle treated pups. Both methylamphetamine and d-amphetamine at the higher doses induced long-lasting dopamine depletions in the caudate of rat pups. Methylphenidate had no long-term effect on dopamine while norepinephrine levels were not altered by any treatment.