title: Effect of entorhinal cortex lesion on hippocampal cholinergic system in rat in operant learning task as studied by in vivo brain microdialysis.
abstract: An in vivo microdialysis method was used to study the cholinergic alteration of the hippocampus in entorhinal cortex-lesioned rats performing a positive reinforcement operant learning task. Rats with bilateral entorhinal cortex lesions were implanted with a dialysis probe into the hippocampal CA3 after ten learning sessions. After 7 days, the bilateral entorhinal cortex-lesioned rats showed impaired acquisition of positive reinforcement operant learning. The basal level of the acetylcholine efflux decreased within 30 min before the beginning of a learning session. The hippocampal acetylcholine efflux showed a significantly diminished increase and rapidly returned to the basal level during the 60 min after the beginning of a learning session. These results suggested that enorhinal cortex lesion may cause damage to the hippocampal cholinergic system with disruption of the entorhinal cortex-hippocampus relay passage.
authors.affiliation: Department of Neuropsychiatry, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Shinjo
authors.forename: A
authors.initials: A
authors.lastname: Ueki
authors.forename: C
authors.initials: C
authors.lastname: Miwa
authors.forename: Y
authors.initials: Y
authors.lastname: Morita
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001923:Brain Chemistry / Q000502:physiology*; D003216:Conditioning, Operant; D018728:Entorhinal Cortex / Q000503:physiopathology*; D006624:Hippocampus / Q000503:physiopathology*; D008297:Male; D017551:Microdialysis; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000109:Acetylcholine