Convulsant effect of lindane and regional brain concentration of GABA and dopamine.

Lindane (gamma-hexachlorocyclohexane) is an organochlorine insecticide with known neurotoxic effects. Its mechanism of action is not well understood although it has been proposed that lindane acts as a non-competitive antagonist at the gamma-aminobutyric acid (GABA)-A receptor. We studied the effect of lindane (150 mg/kg) on the GABAergic and dopaminergic systems by measuring the concentration of GABA, dopamine and its metabolites in 7 brain areas at the onset of seizures. All animals suffered tonic convulsions at 18.3 +/- 1.4 min after lindane administration. The concentration of GABA was only slightly but significantly decreased in the colliculi without modifications in the other areas. The concentration of dopamine was increased in the mesencephalon and that of its metabolite DOPAC was also increased in the mesencephalon and the striatum.