Studies on the mechanism of chlordecone-induced tremor in rats.

Organochlorine insecticides such as DDT and chlordecone produce tremor in exposed individuals. Using a spectral analysis technique, chlordecone-induced tremor in rats was found to be dose- and time-related and could be distinguished from pharmacological agents (i.e., harmine, oxotremorine, and apomorphine) that produce tremor or stereotypic behavior. Drugs with known pharmacological effects were used to study the possible mechanism of chlordecone-induced tremor. Although no one neurotransmitter system appears necessary for tremor, the serotonergic, gabaergic, and cholinergic systems appear to contribute to chlordecone-induced tremor. The role of the catecholaminergic system is uncertain. Subsequent experiments indicated that supraspinal processes, possibly located in the brain stem, are important contributors to chlordecone-induced tremor. Activation of the cerebellum via the olivocerebellar tract to produce tremor cannot explain chlordecone's tremorgenic effects.