title: Differential effects of 5-HT(2A) and 5-HT(2C) receptor blockade on strategy-switching.
abstract: Recent experiments indicate that blockade of serotonin (5-HT) 2A and 2C receptors have differential effects on reversal learning. The present experiments investigated the effects of the 5-HT(2A) receptor antagonist, ketanserin and 5-HT(2C) receptor antagonist, SB242084 on acquisition and strategy-switching in a visual cue-response paradigm. Long-Evans rats were trained in a cross-maze to enter an arm based on color (visual cue version) or a specific turn response (response version). Systemic treatment with ketanserin did not affect initial learning of a visual cue or response discrimination, but ketanserin at 0.5 mg/kg significantly enhanced a switch between visual cue and response strategies. Ketanserin facilitated strategy-switching by inhibiting responses to a previously relevant strategy without affecting choices to never-reinforced strategies. Treatment with SB242084 (0.5, 1.0 or 2.0 mg/kg) did not affect acquisition of a visual cue or response discrimination. SB242084 treatment also did not affect strategy-switching. The present findings suggest that blockade of 5-HT(2A), but not 5-HT(2C), receptors enhance strategy switching.
authors.affiliation: Program in Neuroscience, University of Illinois at Chicago, Chicago, IL 60607, United States.
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Baker
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Thompson
authors.forename: John A
authors.initials: JA
authors.lastname: Sweeney
authors.forename: Michael E
authors.initials: ME
authors.lastname: Ragozzino
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000631:Aminopyridines / Q000494:pharmacology; D000818:Animals; D002755:Choice Behavior / Q000187:drug effects*; D003463:Cues; D003657:Decision Making / Q000187:drug effects; D004192:Discrimination, Psychological / Q000187:drug effects; D007211:Indoles / Q000494:pharmacology; D007650:Ketanserin / Q000494:pharmacology; D007858:Learning / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D010775:Photic Stimulation; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D020318:Rats, Long-Evans; D044402:Receptor, Serotonin, 5-HT2A / Q000187:drug effects*; D044405:Receptor, Serotonin, 5-HT2C / Q000187:drug effects*; D012702:Serotonin Antagonists / Q000494:pharmacology*
chemical_list: C107820:6-chloro-5-methyl-1-((2-(2-methylpyrid-3-yloxy)pyrid-5-yl)carbamoyl)indoline; D000317:Adrenergic alpha-Antagonists; D000631:Aminopyridines; D007211:Indoles; D044402:Receptor, Serotonin, 5-HT2A; D044405:Receptor, Serotonin, 5-HT2C; D012702:Serotonin Antagonists; D007650:Ketanserin; D011224:Prazosin