title: Methamphetamine-induced changes in the object recognition memory circuit.
abstract: Chronic methamphetamine (meth) can lead to persisting cognitive deficits in human addicts and animal models of meth addiction. Here, we examined the impact of either contingent or non-contingent meth on memory performance using an object-in-place (OIP) task, which measures the ability to detect an object relative to its location and surrounding objects. Further, we quantified monoamine transporter levels and markers of neurotoxicity within the OIP circuitry and striatum. Male Long-Evans rats received an acute meth binge (4 × 4 mg/kg i.p., 2 h intervals) or self-administered meth (0.02 mg/infusion, i.v.; 7 days for 1 h/day, followed by 14 days for 6 h/day). Rats were tested for OIP recognition memory following one week of withdrawal. Subsequently, transporters for serotonin (SERT) and norepinephrine (NET) were quantified using Western blot in tissue obtained from the hippocampus, perirhinal cortex, and prefrontal cortex. In addition, striatal dopamine transporters, tyrosine hydroxylase, and glial fibrillary acidic protein were measured to assess potential neurotoxicity. Control (saline-treated) rats spent more time interacting with the objects in the changed locations. In contrast, contingent or non-contingent meth resulted in disrupted OIP performance as seen by similar amounts of time spent with all objects, regardless of location. While only acute meth binge produced signs of neurotoxicity, both meth regimens decreased SERT in the perirhinal cortex and hippocampus. Only meth self-administration resulted in a selective decrease in NET. Meth-induced changes in SERT function in the OIP circuitry may underlie memory deficits independently of overt neurotoxic effects. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
authors: Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA. reichel@musc.edu
authors: Carmela M
authors: CM
authors: Reichel
authors: Lauren A
authors: LA
authors: Ramsey
authors: Marek
authors: M
authors: Schwendt
authors: Jacqueline F
authors: JF
authors: McGinty
authors: Ronald E
authors: RE
authors: See
mesh_terms: D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage*; D050484:Norepinephrine Plasma Membrane Transport Proteins / Q000378:metabolism; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D021641:Recognition, Psychology / Q000187:drug effects*; D012646:Self Administration; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D018765:Dopamine Uptake Inhibitors; D005904:Glial Fibrillary Acidic Protein; D050484:Norepinephrine Plasma Membrane Transport Proteins; D050486:Serotonin Plasma Membrane Transport Proteins; D008694:Methamphetamine