title: A neurotoxic regimen of methamphetamine impairs novelty recognition as measured by a social odor-based task.
abstract: Repeated administration of methamphetamine (mAMPH) to rodents in a single-day "binge" regimen damages forebrain monoaminergic nerve terminals and produces subsequent cognitive deficits. Here we investigate performance on a social odor-based task, demonstrating enduring mAMPH-induced deficits in recognition memory. Three weeks after a neurotoxic mAMPH regimen, singly-housed male Long-Evans rats had four wooden beads placed in their home cage: three beads containing odors from their home cage (HC beads) and one bead from a cage of a rat not present in the colony room (N1 bead). Exploration times for each bead were recorded during three 1-min habituation trials separated by 1-min intertrial intervals. Twenty-four hours later, a 1-min memory test was conducted, in which animals were presented with two HC beads, one N1 bead, and one bead from another novel animal (N2). Saline- and mAMPH-treated rats showed similar, progressive decreases in exploration time for the N1 bead during the habituation trials, indicating equivalent short-term olfactory habituation to the novel odor. By contrast, during the subsequent memory test, saline-treated rats showed a strong preference for the N2 bead over the N1 bead while mAMPH-treated rats showed no preference. The use of the rats' primary sensory modality (olfaction) coupled with the social significance (from conspecifics) of the odors produces strong, long-lasting memories. Our results show that prior treatment with a neurotoxic regimen of mAMPH impairs long-term memory for the previously experienced odors. As compared with previously employed object recognition tasks, this test may be advantageous for investigating mAMPH-induced memory impairments in rodents.
authors.affiliation: Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, United States. sjodell@uci.edu
authors.forename: Steven J
authors.initials: SJ
authors.lastname: O'Dell
authors.forename: Leila M
authors.initials: LM
authors.lastname: Feinberg
authors.forename: John F
authors.initials: JF
authors.lastname: Marshall
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001345:Autoradiography; D001522:Behavior, Animal / Q000187:drug effects*; D001921:Brain / Q000378:metabolism; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D003071:Cognition / Q000187:drug effects*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D005106:Exploratory Behavior / Q000187:drug effects*; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology*; D009812:Odorants; D016601:RNA-Binding Proteins / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D021641:Recognition, Psychology / Q000187:drug effects* / Q000502:physiology; D012903:Smell / Q000187:drug effects
chemical_list: D000697:Central Nervous System Stimulants; D050483:Dopamine Plasma Membrane Transport Proteins; D016601:RNA-Binding Proteins; C482440:Sert1 protein, rat; D008694:Methamphetamine