Phasic-like stimulation of the medial forebrain bundle augments striatal gene expression despite methamphetamine-induced partial dopamine denervation

Authors

  • Christopher D. Howard,

    1. School of Biological Sciences, Illinois State University, Normal, Illinois, USA
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    • These authors contributed equally to this study.

  • Elissa D. Pastuzyn,

    1. Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, Utah, USA
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    • These authors contributed equally to this study.

  • Melissa L. Barker-Haliski,

    1. Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
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  • Paul A. Garris,

    1. School of Biological Sciences, Illinois State University, Normal, Illinois, USA
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  • Kristen A. Keefe

    Corresponding author
    1. Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, Utah, USA
    2. Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
    • School of Biological Sciences, Illinois State University, Normal, Illinois, USA
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Address correspondence and reprint requests to Kristen A. Keefe, University of Utah, 30 South 2000 East, Rm. 201, Salt Lake City, UT 84112, USA. E-mail: k.keefe@utah.edu

Abstract

Methamphetamine-induced partial dopamine depletions are associated with impaired basal ganglia function, including decreased preprotachykinin mRNA expression and impaired transcriptional activation of activity-regulated, cytoskeleton-associated (Arc) gene in striatum. Recent work implicates deficits in phasic dopamine signaling as a potential mechanism linking methamphetamine-induced dopamine loss to impaired basal ganglia function. This study thus sought to establish a causal link between phasic dopamine transmission and altered basal ganglia function by determining whether the deficits in striatal neuron gene expression could be restored by increasing phasic dopamine release. Three weeks after pretreatment with saline or a neurotoxic regimen of methamphetamine, rats underwent phasic- or tonic-like stimulation of ascending dopamine neurons. Striatal gene expression was examined using in situ hybridization histochemistry. Phasic-like, but not tonic-like, stimulation induced immediate-early genes Arc and zif268 in both groups, despite the partial striatal dopamine denervation in methamphetamine-pretreated rats, with the Arc expression occurring in presumed striatonigral efferent neurons. Phasic-like stimulation also restored preprotachykinin mRNA expression. These results suggest that disruption of phasic dopamine signaling likely underlies methamphetamine-induced impairments in basal ganglia function, and that restoring phasic dopamine signaling may be a viable approach to manage long-term consequences of methamphetamine-induced dopamine loss on basal ganglia functions.

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