Studies on the possible sites of chlordecone-induced tremor in rats.

A series of psychopharmacological agents were administered to adult male Fischer-344 rats pretreated with a tremorigenic dose of chlordecone in an attempt to elucidate the involvement of spinal and supraspinal processes in the mediation and/or expression of chlordecone-induced tremor. Agents effective in attenuating the frequency of tremor were chlordiazepoxide, muscimol, and mecamylamine; quipazine exacerbated the tremor. Catecholaminergic agents including yohimbine, clonidine, propranolol, and haloperidol did not affect the frequency of chlordecone-induced tremor. Disinhibition of postsynaptic inhibitory sites in the spinal cord with strychnine and antagonism of spinal and supraspinal polysynaptic pathways with mephenesin exacerbated and attenuated the effects of chlordecone, respectively. Destruction of the climbing fibers with 3-acetylpyridine effectively blocked harmine, but not chlordecone-induced tremor, suggesting that chlordecone does not act through this pathway.