Nicotine regulates alpha7 nicotinic receptor subunit mRNA: implications for nicotine dependence.
Recent evidence suggests that alpha7 subunit-containing nicotinic receptors (nAChRs) within the ventral tegmental area (VTA) are involved in the processes underlying nicotine tolerance and withdrawal. The current study used in situ hybridization histochemistry with multiple radiolabelled probes to amplify mRNA signal, to examine the distribution of alpha7 nAChR subunit mRNA both in control brains and following chronic nicotine treatment (1.5 and 30.0 mg/kg/day). Low levels of alpha7 transcript were detected within substantia nigra pars compacta (SNpc), substantia nigra pars reticularis (SNpr) and VTA. Higher levels of alpha7 transcript were found within the cortex and hippocampus. Following chronic nicotine treatment, levels of alpha7 subunit mRNA were significantly elevated in SNpc, SNpr and VTA, but were unchanged in cortex and hippocampus.
Department of Pharmaceutical Biology and Pharmacology, Victorian College of Pharmacy, Monash University, Parkville, Australia.
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Loiacono
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects / Q000502:physiology; D004298:Dopamine / Q000502:physiology; D015870:Gene Expression / Q000187:drug effects; D017403:In Situ Hybridization; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011978:Receptors, Nicotinic / Q000235:genetics*; D014029:Tobacco Use Disorder / Q000503:physiopathology*; D064569:alpha7 Nicotinic Acetylcholine Receptor
C579165:Chrna7 protein, rat; D018722:Nicotinic Agonists; D012333:RNA, Messenger; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor; D009538:Nicotine; D004298:Dopamine