DIFFERENTIAL-EFFECTS OF AMPHETAMINE AND HALOPERIDOL ON RECOVERY AFTER GLOBAL FOREBRAIN ISCHEMIA

Gerbils subjected to sham surgery or to bilateral occlusion of the carotid arteries were given an injection, during the recovery period, of saline, d-amphetamine, or haloperidol. The animals were subsequently tested once daily for 50 days in an eight-arm radial maze. Global forebrain ischemia had no effect on learning to avoid unbaited arms (reference memory), but greatly increased the number of times animals reentered previously visited arms (working memory errors). Gerbils made ischemic and treated with amphetamine reduced working memory errors more rapidly than did saline-treated ischemic gerbils; conversely, animals made ischemic and treated with haloperidol made more working memory errors than the ischemic controls. Although all ischemic animals were hyperactive, the differential radial maze behaviors of the ischemic groups cannot be explained on the basis of increased activity.