ANTIDEPRESSANT-LIKE ACTION OF NICARDIPINE, VERAPAMIL AND HEMICHOLINIUM-3 INJECTED INTO THE ANTERIOR HYPOTHALAMUS IN THE RAT FORCED SWIM TEST

Male Wistar rats, chronically implanted with cannulas into the anterior hypothalamus, were acutely injected with the calcium channel inhibitors, diltiazem, nicardipine and verapamil, or the choline uptake blocker hemicholinium-3 and tested in the forced swim test. Hemicholinium-3, nicardipine and verapamil markedly increased the duration of active swimming. This antidepressant-like effect did not appear to reflect merely a hyperactive state as the drug-treated rats did not differ from vehicle-injected controls in their open field motility scores. Diltiazem failed to influence rats' performance in either test. Since nicardipine and verapamil, but not diltiazem, share choline uptake property with hemicholinium-3, it seems that this actiion plays a role in the antidepressant-like effect of all three drugs in the forced swim test. © 1990.