The reversal effect of antidepressants on the escape deficit induced by inescapable shock in rats.

This experiment investigated the effect of antidepressants on the escape deficit induced by inescapable shock. Following exposure to escapable shock, rats received a single injection of either tricyclic antidepressants (imipramine, desipramine), an atypical antidepressant (nomifensine), or saline. In a subsequent two-way shuttle test, treatments with these antidepressants reversed the escape deficit of the "inescapable-shock" groups without affecting performance of the "escapable-shock" groups. It is suggested that catecholamine re-uptake inhibition of the acute actions of antidepressants contributed to this reversal effect. The findings are discussed in relation to the neurochemical hypothesis of the escape deficit induced by inescapable shock and to an animal model of depression.