title: Unique gene alterations are induced in FACS-purified Fos-positive neurons activated during cue-induced relapse to heroin seeking.
abstract: Cue-induced heroin seeking after prolonged withdrawal is associated with neuronal activation and altered gene expression in prefrontal cortex (PFC). However, these previous studies assessed gene expression in all neurons regardless of their activity state during heroin seeking. Using Fos as a marker of neural activity, we describe distinct molecular alterations induced in activated versus non-activated neurons during cue-induced heroin seeking after prolonged withdrawal. We trained rats to self-administer heroin for 10 days (6 h/day) and assessed cue-induced heroin seeking in extinction tests after 14 or 30 days. We used fluorescent-activated cell sorting (FACS) to purify Fos-positive and Fos-negative neurons from PFC 90 min after extinction testing. Flow cytometry showed that Fos-immunoreactivity was increased in less than 10% of sparsely distributed PFC neurons. mRNA levels of the immediate early genes fosB, arc, egr1, and egr2, as well as npy and map2k6, were increased in Fos-positive, but not Fos-negative, neurons. In support of these findings, double-label immunohistochemistry indicated substantial coexpression of neuropeptide Y (NPY)- and Arc-immunoreactivity in Fos-positive neurons. Our data indicate that cue-induced relapse to heroin seeking after prolonged withdrawal induces unique molecular alterations within activated PFC neurons that are distinct from those observed in the surrounding majority of non-activated neurons.
authors.affiliation: Behavioral Neuroscience Branch, IRP/NIDA/NIH/DHHS, Baltimore, Maryland, USA.
authors.forename: Sanya
authors.initials: S
authors.lastname: Fanous
authors.forename: Danielle H
authors.initials: DH
authors.lastname: Guez-Barber
authors.forename: Evan M
authors.initials: EM
authors.lastname: Goldart
authors.forename: Regina
authors.initials: R
authors.lastname: Schrama
authors.forename: Florence R M
authors.initials: FR
authors.lastname: Theberge
authors.forename: Yavin
authors.initials: Y
authors.lastname: Shaham
authors.forename: Bruce T
authors.initials: BT
authors.lastname: Hope
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D016739:Behavior, Addictive / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology; D003463:Cues; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000235:genetics; D003932:Heroin / Q000008:administration & dosage*; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism; D009294:Narcotics / Q000008:administration & dosage*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons; D009478:Neuropeptide Y / Q000378:metabolism; D017397:Prefrontal Cortex / Q000166:cytology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012646:Self Administration; D018709:Statistics, Nonparametric
chemical_list: D051017:Apoptosis Regulatory Proteins; D017874:Immediate-Early Proteins; D009124:Muscle Proteins; D009294:Narcotics; D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; C491788:Nol3 protein, rat; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D003932:Heroin