title: Effects of cholinergic drug infusions into the dorsal part of the medial prefrontal cortex on delayed conditional discrimination performance in the rat.
abstract: Effects of bilateral infusions of cholinergic drugs into the dorsal part of the medial prefrontal cortex (dmPFC) on performance in a delayed conditional discrimination (DCD) task were examined in rats. Scopolamine dose-dependently impaired performance. No delay-dependent effect was found indicating that scopolamine did not specifically affect working memory (WM). Physostigmine alone induced a slight improvement of DCD performance independent of delay and co-administration of physostigmine with scopolamine attenuated the scopolamine-induced impairment of DCD performance. Infusion of the muscarinic M2 antagonist AQRA-471, the M3 antagonist 4-DAMP and the mixed M1-M3 antagonist UH-AH 37 did not affect performance in the DCD task, suggesting that the effect of scopolamine is not mediated by a single muscarinic receptor subtype. The results furthermore indicate that the cholinergic system in the dmPFC does not play a specific role in WM processes in the DCD task. Furthermore, the results suggest that the dmPFC cholinergic system plays a role in the attentional processes involved in the DCD task.
authors.affiliation: Solvay Duphar, CNS Pharmacology, DA Weesp, Netherlands.
authors.forename: A H
authors.initials: AH
authors.lastname: Herremans
authors.forename: T H
authors.initials: TH
authors.lastname: Hijzen
authors.forename: B
authors.initials: B
authors.lastname: Olivier
mesh_terms: D000818:Animals; D018678:Cholinergic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002800:Cholinesterase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D003216:Conditioning, Operant / Q000187:drug effects; D004192:Discrimination, Psychological / Q000187:drug effects*; D007276:Injections, Intraventricular; D008297:Male; D008845:Microinjections; D018727:Muscarinic Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018678:Cholinergic Agents; D002800:Cholinesterase Inhibitors; D018727:Muscarinic Antagonists