title: An investigation of the effect of tacrine and physostigmine on spatial working memory deficits in the olfactory bulbectomised rat.
abstract: The olfactory bulbectomised (OB) rat is being increasingly used as a model of impaired learning and mnemonic functioning. In this study the model has been utilised to determine the effect of the acetylcholinesterase inhibiting compounds tacrine and physostigmine on spatial working memory deficits associated with the OB rat. One-hundred and twenty male rats were randomly allocated to OB or sham operated groups and received chronic i.p. treatment with either saline, physostigmine (0.1 mg/kg) or tacrine (0.1 and 0.3 mg/kg). Two weeks after beginning treatment animals were tested on the Morris water maze and open field test. The results indicated that the OB surgery was associated with spatial working memory disturbances that were effectively attenuated with both doses of tacrine, but not physostigmine. Increased hyperactivity and defecation was observed in OB animals in the Open-field test, however, these changes were not ameliorated by either drug treatment. The ability for tacrine but not physostigmine to attenuate OB cognitive deficits may be associated with the different half-life of these compounds. This study provides further support for the use of the OB rat as a drug discovery model for the investigation of novel therapeutic compounds that target the cholinergic system.
authors.affiliation: Department of Psychiatry, Austin and Repatriation Medical Centre, Level 10 Lance Townsend Building, Studley Road, Heidelberg, Vic. 3084, Australia. k.hallam@pgrad.unimelb.edu.au
authors.forename: K T
authors.initials: KT
authors.lastname: Hallam
authors.forename: J E
authors.initials: JE
authors.lastname: Horgan
authors.forename: C
authors.initials: C
authors.lastname: McGrath
authors.forename: T R
authors.initials: TR
authors.lastname: Norman
mesh_terms: D000544:Alzheimer Disease / Q000503:physiopathology; D000818:Animals; D001143:Arousal / Q000187:drug effects / Q000502:physiology; D020532:Basal Nucleus of Meynert / Q000187:drug effects / Q000502:physiology; D002799:Cholinergic Fibers / Q000187:drug effects / Q000502:physiology; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D003672:Defecation / Q000187:drug effects / Q000502:physiology; D004924:Escape Reaction / Q000187:drug effects* / Q000502:physiology; D007274:Injections, Intraperitoneal; D018782:Maze Learning / Q000187:drug effects* / Q000502:physiology; D008570:Memory, Short-Term / Q000187:drug effects / Q000502:physiology*; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009830:Olfactory Bulb / Q000187:drug effects* / Q000502:physiology*; D009949:Orientation / Q000187:drug effects / Q000502:physiology*; D010830:Physostigmine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012931:Social Environment; D013619:Tacrine / Q000494:pharmacology*
chemical_list: D002800:Cholinesterase Inhibitors; D013619:Tacrine; D010830:Physostigmine