title: Effects of haloperidol, sulpiride and SCH 23390 on passive avoidance learning in mice.
abstract: The main purpose of the present study was to examine the effect of dopamine blockers on memory processes by means of a one-trial passive avoidance (PA) task with ddY mice. Haloperidol (0.025-0.4 mg/kg i.p.) did not affect the PA response when it was given before the training or retention test. Sulpiride (10-80 mg/kg i.p.) had different effects, depending on the doses employed: A lower dose (20 mg/kg) of sulpiride, which is thought to block presynaptic receptors, impaired the PA response but higher doses (40 and 80 mg/kg i.p.) did not affect it when sulpiride was given before the training or retention test. SCH 23390 (0.025-0.1 mg/kg i.p.) impaired the PA response only when it was given before the training. These results suggest that blocking of postsynaptic D-2 receptors does not impair memory processes but blocking of presynaptic D-2 receptors impairs both acquisition and retrieval stages of memory processes following an increase in dopamine release. The involvement of D-1 receptors in memory processes involved in the PA response may be essentially different from that of D-2 receptors, since the blocking of D1 receptors impaired only memory acquisition.
authors.affiliation: Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Meijo University, Nagoya, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ichihara
authors.forename: T
authors.initials: T
authors.lastname: Nabeshima
authors.forename: T
authors.initials: T
authors.lastname: Kameyama
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001552:Benzazepines / Q000494:pharmacology*; D004597:Electroshock; D006220:Haloperidol / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D013469:Sulpiride / Q000494:pharmacology*
chemical_list: D001552:Benzazepines; D013469:Sulpiride; D006220:Haloperidol