title: Glucose increases hippocampal extracellular acetylcholine levels upon activation of septal GABA receptors.
abstract: Activation of septal GABA receptors impairs learning and memory and this effect likely involves an influence on the hippocampus. We found previously that the memory-impairing effects of septal infusions of the GABA agonist muscimol are reversed by hippocampal infusions of glucose and suggested that glucose reverses these deficits by increasing hippocampal acetylcholine (ACh). In this study, we report that septal infusions of muscimol produce dose-dependent decreases in ACh levels in hippocampal dialysates. Importantly, increasing glucose levels in the hippocampus elevates hippocampal extracellular ACh levels in rats given septal infusions of muscimol, but not in rats given vehicle. Thus, glucose increases hippocampal extracellular ACh levels when the ACh system is inhibited, an effect that likely contributes to the effects of glucose on memory.
authors.affiliation: Department of Psychology, University of Alberta, AB, Edmonton, Canada.
authors.forename: Aldemar
authors.initials: A
authors.lastname: Degroot
authors.forename: Tom
authors.initials: T
authors.lastname: Kornecook
authors.forename: Remi
authors.initials: R
authors.lastname: Quirion
authors.forename: Suzanne
authors.initials: S
authors.lastname: DeBow
authors.forename: Marise B
authors.initials: MB
authors.lastname: Parent
mesh_terms: D000109:Acetylcholine / Q000032:analysis*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005110:Extracellular Space / Q000737:chemistry; D018755:GABA Agonists / Q000008:administration & dosage / Q000494:pharmacology; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology*; D006624:Hippocampus / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D007276:Injections, Intraventricular; D008297:Male; D009118:Muscimol / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D018079:Receptors, GABA / Q000378:metabolism*; D020665:Septum of Brain / Q000378:metabolism
chemical_list: D018755:GABA Agonists; D018079:Receptors, GABA; D009118:Muscimol; D005947:Glucose; D000109:Acetylcholine