Increased c-Fos expression in the medial part of the lateral habenula during cue-evoked heroin-seeking in rats.
Conditioned environmental stimuli are known to be important determinants of drug seeking behavior. c-Fos, the protein product of the protooncogene c-Fos, is expressed in neurons when there are drug-associated cue-induced drug-seeking behaviour. Therefore, its expression could serve as a marker of regional neuronal activation. Using an extinction/reinstatement paradigm of relapse animal model, we trained Sprague-Dawley rats to nose-poke for i.v. heroin (0.05 mg/kg/infusion) either daily for 4h or 25 infusions for 14 consecutive days. We then tested these animals for cue-evoked heroin-seeking behavior after abstinence from self-administration of heroin for 14 days. Expression of c-Fos was examined in the lateral habenula (LHb), a region important for conveying information between the limbic forebrain and midbrain. Findings showed that heroin-associated conditioned stimuli could induce robust heroin-seeking behavior that was associated with increased c-Fos immunoreactivity in the medial part of the LHb. This observation suggests the involvement of the LHb in mediating drug cue-induced heroin-seeking behavior after abstinence from self-administration of heroin.
Laboratory of Behavioral Neuroscience, Ningbo Addiction Research and Treatment Center, 42 Xibeijie St., Ningbo 315010, PR China. fqzhang@nbip.net
Fuqiang
F
Zhang
Wenhua
W
Zhou
Huifen
H
Liu
Huaqiang
H
Zhu
Shuaien
S
Tang
Miaojun
M
Lai
Guodong
G
Yang
D000818:Animals; D016739:Behavior, Addictive / Q000503:physiopathology; D003213:Conditioning, Psychological / Q000502:physiology; D005108:Extinction, Psychological; D019262:Habenula / Q000378:metabolism*; D003932:Heroin / Q000494:pharmacology*; D006556:Heroin Dependence / Q000503:physiopathology*; D008297:Male; D009294:Narcotics / Q000494:pharmacology*; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis* / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley
D009294:Narcotics; D016760:Proto-Oncogene Proteins c-fos; D003932:Heroin