Differential effects of clomipramine and clorgyline on the sensitivity of cortical neurons to serotonin: effect of chronic treatment.

The sensitivity of rostral and cingulate cortical neurons to microiontophoretically administered serotonin (5-HT) was compared in groups of rats treated either acutely or chronically with clomipramine (10 mg/kg i.p.) or with clorgyline (0.3 mg/kg i.p.). The sensitivity of cortical neurons to 5-HT was significantly reduced in both cortical areas of animals treated chronically with clorgyline. By contrast, no change of sensitivity was observed in the clomipramine-treated animals. These findings are consistent with biochemical studies showing a decrease in 5-HT receptors following the chronic treatment with clorgyline and an absence of effect on 5-HT receptors following the chronic treatment with clomipramine.