title: Chronic administration of the methylxanthine propentofylline impairs reinstatement to cocaine by a GLT-1-dependent mechanism.
abstract: In recent years, interactions between neurons and glia have been evaluated as mediators of neuropsychiatric diseases, including drug addiction. In particular, compounds that increase expression of the astroglial glutamate transporter GLT-1 (N-acetylcysteine and ceftriaxone) can decrease measures of drug seeking. However, it is unknown whether the compounds that influence broad measures of glial physiology can influence behavioral measures of drug relapse, nor is it clear whether the upregulated GLT-1 is functionally important for suppressing of drug seeking. To address these questions, we sought to determine whether the glial modulator and neuroprotective agent propentofylline (PPF) modifies drug seeking in rats using a reinstatement model of cocaine relapse. We found that 7 days of chronic (but not acute) administration of PPF significantly decreased both cue- and cocaine-induced reinstatement of cocaine seeking. We next determined whether the effect of systemic PPF on reinstatement depended upon its ability to restore expression of GLT-1 in the nucleus accumbens. PPF restored the cocaine-induced decrease in GLT-1 in the accumbens core; then, using an antisense strategy against glutamate transporter GLT-1, we found that restored transporter expression was necessary for PPF to inhibit cue-primed cocaine seeking. These findings indicate that modulating glial physiology with atypical xanthine derivatives like PPF is a potential avenue for developing new medications for cocaine abuse, and support the hypothesis that neuron-glial interactions contribute to mechanisms of psychostimulant addiction, particularly via expression and function of astroglial glutamate transporters.
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Reissner
authors.affiliation: 1] Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA [2] Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Australia.
authors.forename: Robyn M
authors.initials: RM
authors.lastname: Brown
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Sade
authors.initials: S
authors.lastname: Spencer
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Phuong K
authors.initials: PK
authors.lastname: Tran
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Thomas
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Kalivas
mesh_terms: D000818:Animals; D016739:Behavior, Addictive / Q000378:metabolism* / Q000503:physiopathology / Q000517:prevention & control*; D003042:Cocaine / Q000008:administration & dosage*; D027342:Excitatory Amino Acid Transporter 2 / Q000502:physiology*; D008297:Male; D009457:Neuroglia / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014970:Xanthines / Q000008:administration & dosage*
chemical_list: D027342:Excitatory Amino Acid Transporter 2; C493395:Slc1a2 protein, rat; D014970:Xanthines; C008514:methylxanthine; C032114:propentofylline; D003042:Cocaine