title: FACS analysis of neuronal-glial interactions in the nucleus accumbens following morphine administration.
abstract: BACKGROUND
  Glia, including astrocytes and microglia, can profoundly modulate neuronal function and behavior; however, very little is known about the signaling molecules that govern neuronal-glial communication and in turn affect behavior. Morphine treatment activates microglia and astrocytes in the nucleus accumbens (NAcc) to induce the synthesis of cytokines and chemokines, and this has important implications for addictive behavior. Blocking morphine-induced glial activation using the nonspecific glial inhibitor, ibudilast, has no effect on the initial rewarding properties of morphine, but completely prevents the relapse of drug-seeking behavior months later.
  
  
  OBJECTIVE
  We sought to determine the cellular source of these cytokines and chemokines in the NAcc in response to morphine, and the cell-type-specific expression pattern of their receptors to determine whether neurons have the capacity to respond to these immune signals directly.
  
  
  METHODS
  We used fluorescence-activated cell sorting of neurons (Thy1+), astrocytes (GLT1+), and microglia (CD11b+) from the NAcc for the analysis of cell type specific gene expression following morphine or saline treatment.
  
  
  RESULTS
  The results indicate that microglia and neurons each produce a subset of chemokines in response to morphine and that neurons have the capacity to respond directly to a select group of these chemokines via their receptors. In addition, we provide evidence that microglia are capable of responding directly to dopamine release in the NAcc.
  
  
  CONCLUSIONS
  Future studies will examine the mechanism(s) by which neurons respond to these immune signals produced by microglia in an effort to understand their effect on addictive behaviors.
authors.affiliation: Department of Psychology and Neuroscience, Duke University, 572 Research Dr., Room 3017, Box 91050, Durham, NC, 27705, USA, jschwarz@psych.udel.edu.
authors.forename: Jaclyn M
authors.initials: JM
authors.lastname: Schwarz
authors.forename: Susan H
authors.initials: SH
authors.lastname: Smith
authors.forename: Staci D
authors.initials: SD
authors.lastname: Bilbo
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism; D018925:Chemokines / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D058999:Drug-Seeking Behavior / Q000502:physiology*; D005434:Flow Cytometry / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects; D008297:Male; D017628:Microglia / Q000187:drug effects / Q000378:metabolism; D009020:Morphine / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000701:Analgesics, Opioid; D018925:Chemokines; D016207:Cytokines; D009020:Morphine; D004298:Dopamine