Effects of haloperidol on the acquisition of a spatial learning task.
The effects of systemic injections of the dopaminergic antagonist haloperidol on the acquisition of the Morris water maze with either a visible or an invisible platform (nonspatial vs. spatial learning) were investigated. An open field test was used for selecting a dosage (< or = 0.1 mg/kg), that (hardly) affected locomotor behaviour. Differential effects were found. At 0.1 mg/kg, haloperidol reduced locomotion in the open field, impaired acquisition in the Morris maze with a visible platform, and blocked escape onto an invisible one. Even though 0.07 mg/kg haloperidol reduced locomotion, both 0.04 and 0.07 mg/kg only impaired Morris maze performance in the spatial version. A large effect was found in the first trial of every day's training block. These results indicate that haloperidol at low doses can lead to a moderate but significant impairment of spatial learning. It is suggested that the effects found are related to the function of the striatal areas in cue- and noncue-directed behaviour.
Ploeger
G E
GE
Institute of Molecular Biology, and Medical Biotechnology, University of Utrecht, The Netherlands.
Spruijt
B M
BM
Cools
A R
AR
D000818:Animals; D003463:Cues; D004298:Dopamine / Q000502:physiology; D006220:Haloperidol / Q000494:pharmacology*; D007858:Learning / Q000187:drug effects*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013028:Space Perception / Q000187:drug effects*
D006220:Haloperidol; D004298:Dopamine