Localisation of tricyclic antidepressant binding sites on serotonin nerve terminals.

High-affinity specific [3H]imipramine binding has been demonstrated in the brain and platelets of various species including man. Electrolytic lesions of the rat dorsal raphe, which resulted in a significant decrease in the endogenous levels of serotonin produced a reduction in the density of [3H]imipramine binding sites in the hypothalamus and cortex. The affinity constants were unchanged. These results suggest that [3H]imipramine binding sites are located on serotonin nerve terminals.