EFFECTS OF HALOPERIDOL AND D-AMPHETAMINE ON WORKING AND REFERENCE MEMORY PERFORMANCE IN A SPATIAL CONE FIELD TASK

The present study was designed to examine the effects of haloperidol ( 0.03, 0.1 mg/kg, intraperitoneal (i.p.)) and d-amphetamine (0.3, 1.0 m g/kg, i.p.) in a cone field task in which spatial working and referenc e memory (WM and RM, respectively) were assessed simultaneously. The a pparatus is a large open field in which 16 cones are placed with four cones baited by placing a food reward in the top. After food deprived rats had acquired this task they showed a high level of performance, t hat is avoided visits to non-baited cones (RM) and made few revisits t o baited cones (WM). Haloperidol had a greater negative effect on RM t han on WM performance, but also decreased the number of food rewards c ollected. On the other hand, the high dose of d-amphetamine induced a clear WM performance deficit, whereas RM performance was only marginal ly affected. The present study suggests that spatial discrimination pe rformance can be dissociated using the measures RM and WM in the prese nt task. Further, the deficits induced by haloperidol and d-amphetamin e may not be specifically related with impaired mnemonic functions. Be hav Pharmacol 1998; 9:429-436 (C) 1998 Lippincott Williams & Wilkins.