Spatial working memory in rats: effects of monoaminergic antagonists.
To assess the possible involvement of the monoaminergic neurotransmitters norepinephrine, dopamine and serotonin in the maintenance of spatial working memory rats were treated with antagonists 0 or 2 hr after completing the first 4 choices in an 8 arm maze. Haloperidol (0.25-1 mg/kg), when administered 2 hr after Choice 4, produced a small but consistent impairment in performance on retention tests given 5 hr after the first 4 choices. This deficit closely resembled natural forgetting in terms of the type of errors committed. By contrast, haloperidol in the same doses given 0 hr after Choice 4 or 3 hr before the first 4 choices did not affect retention. Likewise treatment with propranolol (10-20 mg/kg), phentolamine (5-20 mg/kg) or methysergide (5-15 mg/kg) did not impair spatial memory, regardless of when these drugs were injected within the session. Evidently dopaminergic neuronal systems are important in the maintenance of normal spatial working memory.
D000818:Animals; D001679:Biogenic Amines / Q000037:antagonists & inhibitors*; D004305:Dose-Response Relationship, Drug; D006220:Haloperidol / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D008568:Memory / Q000187:drug effects*; D008784:Methysergide / Q000494:pharmacology*; D010643:Phenoxybenzamine / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D013028:Space Perception / Q000187:drug effects*
D001679:Biogenic Amines; D010643:Phenoxybenzamine; D011433:Propranolol; D006220:Haloperidol; D008784:Methysergide; D010646:Phentolamine