DDT myoclonus: sites and mechanism of action

Intragastric injection of the insecticide DDT produces a stimulus-sensitive myoclonus in mice and rats. Unilateral stereotaxic infusions of DDT into rat medullary reticular formation also induced generalized myoclonus, identical to that produced by systemic administration. Similar myoclonus, but of lesser intensity, occurred when DDT was injected into cerebellar nuclei, red nucleus, and the inferior olive. Multiple other regions of the brain were resistant to the myoclonic action of locally infused DDT. Direct infusions into the medullary reticular formation of allethrin, which has a similar action on neuronal membranes as DDT, or the glycine receptor antagonist, strychnine, also elicited myoclonus.