EFFECTS OF SALBUTAMOL UPON PERFORMANCE ON AN OPERANT SCREEN FOR ANTIDEPRESSANTS

The beta adrenergic (beta) agonist salbutamol increased reinforcement rates and decreased response rates on a differential-reinforcement-of- low-rate (DRL) 72-S schedule. These changes in DRL 72-S schedule perfo rmance are also produced by most clinically used antidepressants. The effects of salbutamol on a DRL 72-S schedule were dose-dependently ant agonized by the beta antagonist metoprolol, but not changed by the 5HT antagonist methysergide. Additionally, neither salbutamol nor the ant agonism of salbutamol by metoprolol caused disruption of DRL 72-S sche dule performance. These results indicate that stimulation of beta rece ptors, and not of 5HT receptors, mediates salbutamol antidepressant-li ke effects on a DRL 72-S schedule.