title: Stimulation of cortical acetylcholine release following blockade of ionotropic glutamate receptors in nucleus accumbens.
abstract: In vivo microdialysis techniques were used to determine the ability of glutamate receptors within the nucleus accumbens to trans-synaptically modulate the basal forebrain cortical cholinergic system. Rats were implanted with a dialysis probe in the medial prefrontal cortex to measure changes in cortical acetylcholine efflux and in the ipsilateral nucleus accumbens to locally manipulate glutamate receptor activity. Intra-accumbens perfusion of the broad spectrum ionotropic glutamate receptor antagonist kynurentate (1.0, 5.0 mm) led to a dose-dependent increase (maximum of 200%) in cortical acetylcholine efflux. This stimulated efflux was reproduced with the intra-accumbens perfusion of the AMPA/kainate antagonist DNQX (0.1, 0.25, 2.5 mm; maximum increase of 200%) or the NMDA antagonist D-CPP (10.0, 100.0, 200 micro M; maximum increase of 400%). These results reveal a significant glutamatergic tone within the accumbens of awake rats and support the hypothesis that accumbens efferents to basal forebrain modulate the excitability of the basal forebrain cortical cholinergic system.
authors.affiliation: Department of Psychology, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Gretchen
authors.initials: G
authors.lastname: Neigh-McCandless
authors.forename: B Adar
authors.initials: BA
authors.lastname: Kravitz
authors.forename: Martin
authors.initials: M
authors.lastname: Sarter
authors.forename: John P
authors.initials: JP
authors.lastname: Bruno
mesh_terms: D000109:Acetylcholine / Q000032:analysis*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D007736:Kynurenic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D017551:Microdialysis; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors; D009714:Nucleus Accumbens / Q000378:metabolism; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats
chemical_list: D018691:Excitatory Amino Acid Antagonists; D011810:Quinoxalines; C056723:FG 9041; D016202:N-Methylaspartate; D007736:Kynurenic Acid; D000109:Acetylcholine