Dissimilar responses of cortical neurons to chronic trazodone or desipramine treatment

Abstract

1. 1. The effects of acute and chronic trazodone or desipramine treatment on the spontaneous firing rate of cortical neurons In chloral hydrate anesthetized rats were determined. 2. 2. Either trazodone (30 or 60 mg/kg, po) or desipramine (5 or 10 mg/kg, po) was administered daily for periods of up to 11 or 16 days respectively. 3. 3. A significant reduction in the firing rate of cortical neurons was observed after acute and chronic 10 mg/kg desipramine treatment. 4. 4. Chronic treatment with 5 mg/kg desipramine had no effect on activity. 5. 5. Neither acute nor chronic treatment with trazodone produced any significant alteration in cortical unit activity. 6. 6. The results suggest that the spontaneous activity of randomly encountered cortical neurons is not involved in the mechanism of the therapeutic action produced by chronic treatment with the two clinically effective antidepressants. 7. 7. The response of the cortical neurons to antidepressant treatment might help differentiate the relative effects of the drugs on monoaminergic receptors. 8. 8. Also, the depressant effect of desipramine on the spontaneous rate of cortical neurons does not appear to be a specific effect of chronic treatment since it occurred after a single dose.