Intracortical glutamate injection produces helpless-like behavior in the rat

Acute injection of glutamate into frontal neocortex of naive rats produced a subsequent deficit in escape performance behavior that was similar to that produced by exposure to uncontrollable shock. The behavioral deficit was dose-related. The behavioral deficit was similar in time-course to that produced by 15 min (but not 40 min) of exposure to learned helplessness induction. Unlike learned helplessness produced by exposure to inescapable shock, the behavioral deficit produced by intracortical glutamate injection was not prevented by chronic intraperitoneal administration of imipramine.