[Study on the neuro-behavioral development in rats treated neonatally with drugs acting on the autonomic nervous system].

The drugs used were pargyrine, methamphetamine, reserpine, norepinephrine, epinephrine, propranolol, chlorpromazine, 6-hydroxydopamine, haloperidol, pilocarpine, neostigmine and atropine. The body The weight gain of pups receiving reserpine, chlorpromazine, 6-hydroxydopamine and pilocarpine was significantly inhibited. The mortality of pups given reserpine was significantly increased. The behavioral development of righting reflex, cliff drop avoidance and negative geotaxis of rats given reserpine, propranolol, 6-hydroxydopamine and haloperidol was significantly retarded in comparison with that of control pups. Spontaneous motor activity measured by Animex was increased in pups receiving norepinephrine, epinephrine, chlorpromazine, reserpine, propranolol and atropine. Furthermore, pharmacological challenge by the injection of methamphetamine exhibited an accentuated response to an increase in spontaneous motor activity in pups exposed to chlorpromazine, reserpine, propranolol, 6-hydroxydopamine and atropine. These findings suggest that an increase in spontaneous motor activity may be induced by the developmental impairment of central catecholamine mechanisms, especially the noradrenaline nervous system. Delayed latency, decreased rearing and preening of pups receiving propranolol were observed on the open field test. The conditioned avoidance responses using the shuttle box revealed deficits in acquisition of avoidance learning of rats given haloperidol, 6-hydroxydopamine and propranolol, suggesting that the learning deficits may be due to the developmental impairment of catecholamine mechanisms, especially the dopamine nervous system.