title: Behavioral screen for antidepressants: the effects of drugs and electroconvulsive shock on performance under a differential-reinforcement-of-low-rate schedule.
abstract: Those antidepressant drugs that are in wide clinical use decrease response rate and increase reinforcement rate when administered to rats performing on a differential-reinforcement-of-low-rate 72-s (DRL 72-s) schedule. Drugs that are not antidepressants do not have this effect. In this experiment, the following were examined for their effects on a DRL 72-s schedule: trazodone, zimelidine, fluoxetine, and bupropion (atypical antidepressants); electroconvulsive shock (ECS, which is an effective treatment for depression); and haloperidol and clozapine (antipsychotic drugs). Trazodone (3.12-25.00 mg/kg), fluoxetine (10-20 mg/kg), and ECS decreased response rate and increased reinforcement rate. Zimelidine (20 mg/kg) increased reinforcement rate and nonsignificantly decreased response rate. At doses between 2.5 and 40 mg/kg, bupropion had no effect on reinforcement rate or response rate, but at 60 mg/kg response rate was increased and reinforcement rate was nonsignificantly decreased. At the higher dose, the effects of bupropion resemble those of a psychomotor stimulant. Haloperidol (0.04 mg/kg) and clozapine (2.5-10.0 mg/kg) decreased response rate and reinforcement rate. These results suggest that the DRL 72-s schedule may be useful for testing the antidepressant potential of new drugs.
authors.forename: L S
authors.initials: LS
authors.lastname: Seiden
authors.forename: J L
authors.initials: JL
authors.lastname: Dahms
authors.forename: R A
authors.initials: RA
authors.lastname: Shaughnessy
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D016642:Bupropion; D003024:Clozapine / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D004597:Electroshock; D005473:Fluoxetine / Q000494:pharmacology; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D011427:Propiophenones / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012055:Reinforcement Schedule; D014196:Trazodone / Q000494:pharmacology; D015031:Zimeldine / Q000494:pharmacology
chemical_list: D000928:Antidepressive Agents; D011427:Propiophenones; D005473:Fluoxetine; D016642:Bupropion; D015031:Zimeldine; D003024:Clozapine; D006220:Haloperidol; D014196:Trazodone