title: Characteristics of changes in cholinergic function and impairment of learning and memory-related behavior induced by olfactory bulbectomy.
abstract: Memory function after olfactory bulbectomy (OBX) was examined in two tasks, namely, step-through passive avoidance task and elevated plus-maze task. OBX mice showed a significant impairment of learning and memory-related behavior on the 7th and 14th day, as measured by passive avoidance task but not elevated plus maze task. The impairment of learning and memory-related behavior on the 14th day was improved by administration of the cholinesterase inhibitor physostigmine (0.1 mg/kg, i.p.), the non-selective muscarinic agonist oxotremorine (0.1 mg/kg, i.p.) or the selective muscarinic M(1) agonist McN-A-343 (10 microg/mouse, i.c.v.). In contrast, administration of the nicotinic agonist lobeline (5-9.8 mg/kg, i.p.) or the selective muscarinic M(2) antagonist methoctramine (2.25-18 microg/mouse, i.c.v.) has no effect on the impairment of learning and memory-related behavior induced by OBX. In addition, we have demonstrated that the intensity of choline acetyltransferase (ChAT) fluorescence is significantly decreased in the cortex, hippocampus and amygdala on the 14th day after OBX. These results suggest that the impairment of learning and memory-related behavior induced by OBX may be caused by degeneration of cholinergic neurons and muscarinic M(1) receptors play an important role in the improvement process.
authors.affiliation: Department of Pharmacology, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan.
authors.forename: Soichi
authors.initials: S
authors.lastname: Hozumi
authors.forename: Osamu
authors.initials: O
authors.lastname: Nakagawasai
authors.forename: Koichi
authors.initials: K
authors.lastname: Tan-No
authors.forename: Fukie
authors.initials: F
authors.lastname: Niijima
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Yamadera
authors.forename: Atsunobu
authors.initials: A
authors.lastname: Murata
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Arai
authors.forename: Hajime
authors.initials: H
authors.lastname: Yasuhara
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tadano
mesh_terms: D000679:Amygdala / Q000033:anatomy & histology / Q000502:physiology; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D002799:Cholinergic Fibers / Q000502:physiology*; D006624:Hippocampus / Q000033:anatomy & histology / Q000502:physiology; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D008856:Microscopy, Fluorescence; D009415:Nerve Net / Q000033:anatomy & histology / Q000502:physiology; D009830:Olfactory Bulb / Q000033:anatomy & histology / Q000502:physiology*; D043643:Receptor, Muscarinic M1; D011976:Receptors, Muscarinic / Q000502:physiology*
chemical_list: D043643:Receptor, Muscarinic M1; D011976:Receptors, Muscarinic; D002795:Choline O-Acetyltransferase