Brain regional gamma-aminobutyric acid (GABA) and locomotor activity: effect of long-term aldrin exposure.

Aldrin-induced stimulation of locomotor activity (LA) under nontolerant conditions was restored to control value after 20 or more consecutive days of aldrin administration. In contrast to the inhibition of GABAergic activity with aldrin under short-term conditions as observed in our previous study, the measurement of steady-state level of GABA, the activities of its metabolizing enzymes, turnover and the specific binding of GABA to its receptor in different regions of the brain of rats treated with aldrin (2 or 5 mg/kg/day, po) under long-term (for 30 consecutive days) conditions showed no change in the GABAergic activity in any regions of the rat brain. Moreover, the studies of the interaction between neurotransmitters (using agonist(s) and antagonist(s) of the respective neurotransmitter receptors) showed that long-term administration of aldrin restored the LA to control value by upregulation of central GABAergic activity through the interaction with dopaminergic and cholinergic systems.

Role of brain regional GABA: aldrin-induced stimulation of locomotor activity in rat.

Aldrin, a chlorinated hydrocarbon group of pesticide, is a well known central nervous system (CNS) stimulant. The CNS stimulating effect of aldrin is manifested in the form of an increase in locomotor activity (LA) of animals. Maximum increase in LA was observed at 2 h following aldrin (2-10 mg/kg, p.