Effects of chlordimeform and lindane on monoamine levels in the central nervous system of the american cockroach, Periplaneta americana L

Abstract The effects of chlordimeform and lindane on levels of 5-hydroxytryptamine, tryptophan, and N -acetyl dopamine were studied in the cerebral ganglia of the american cockroach, Periplaneta americana . The effects of chlordimeform on nerve cord levels of 5-hydroxytryptamine, tryptophan, dopamine, and octopamine, and the effect of lindane on cerebral ganglia levels of dopamine were also investigated in this species. Topical applications of chlordimeform deplete 5-hydroxytryptamine and tryptophan from the cerebral ganglia whereas levels of n -acetyl dopamine are elevated. The effect of chlordimeform on these compounds is dose-dependent. Similar chlordimeform-induced effects are observed in the nerve cord, and octopamine levels are also depleted in this tissue following treatment with chlordimeform. A biphasic response to chlordimeform is observed in the nerve cord for dopamine levels with a 40% decrease evident after 2 hr and a 30% increase apparent after 6 hr. In contrast to chlordimeform, lindane does not affect 5-hydroxytryptamine and tryptophan levels in the cebral ganglion but low doses of this insecticide effect increases in brain levels of dopamine and n -acetyl dopamine.