Neuronal localization of dopamine-sensitive adenylate cyclase within the rat olfactory tubercle

We have used selective chemical lesions to localize dopamine-sensitive adenylate cyclase within the rat olfactory tubercle. Stereotaxic injections were made directly into the tubercle with kainic acid, or with 6-OH dopamine. Animals were sacrificed 3 days later by decapitation and homogenates of the olfactory tubercle were assayed for dopamine-sensitive adenylate cyclase. The kainic acid lesion reduced the dopamine-sensitive adenylate cyclase activity by 80% as compared to values from sham lesioned or unlesioned controls. Homogenates of 6-OH dopamine-treated tubercles were slightly greater in dopamine-sensitive adenylate cyclase activity than untreated controls. Sections from kainic acid-treated tubercles showed extensive neuronal losses with increased numbers of glial cells. Examination of 6-OH dopamine-treated tissue by glyoxylic acid-induced histofluorescence established the loss of dopaminergic terminals.The marked decrease of dopamine-sensitive adenylate cyclase accompanying the selective loss of neurons (kainic acid treatment) but not accompanying the loss of dopaminergic terminals (6-OH dopamine treatment) suggests that this enzyme occurs in the neurons and not in the glia or in the dopaminergic terminals of this region.