The effects of antidepressants and electroconvulsive shocks on the functioning of the mesolimbic dopaminergic system: a behavioral study.

The mesolimbic dopaminergic innervation is supposed to be involved in the mechanisms of central effects exerted by various classes of psychotropic drugs. Antidepressants have been found to interact with the brain dopaminergic system as well, although the precise central location of this interaction is unknown. Some data point to the mesolimbic dopaminergic system as a possible target for antidepressant action. The aim of the present experiment was to verify this hypothesis. It was found that a long-term treatment of rats with desipramine, citalopram or electroconvulsive shocks potentiated the dopaminergic mechanisms within the nucleus accumbens, as evidenced by an increase in or the appearance of behavioral effects (exploratory locomotion, an active behavior in the Porsolt test) following microinjections of dopaminergic agonists into this brain area. Similar results obtained with different methods of treatment for depression indicate that the effect of antidepressants and electroshocks on dopaminergic mechanisms within the nucleus accumbens may be linked directly to the mechanism of their antidepressant action.