title: Environmental context modulates the ability of cocaine and amphetamine to induce c-fos mRNA expression in the neocortex, caudate nucleus, and nucleus accumbens.
abstract: We reported previously that environmental novelty enhances the acute psychomotor activating effects of amphetamine, its ability to induce behavioral sensitization, and its ability to induce c-fos mRNA in the striatum and other structures, relative to when amphetamine is given in the home cage. The purpose of the present experiment was 2-fold: to determine (1) whether environmental novelty has a similar effect on the ability of cocaine to induce c-fos mRNA, and (2) whether this effect is seen in neurologically-intact rats (in previous experiments we studied the intact hemisphere of rats with a unilateral 6-OHDA lesion). In the dorsal portion of the caudate putamen, core and shell of the nucleus accumbens, and in several cortical regions, both amphetamine (1.5 mg/kg) and cocaine (15 mg/kg) induced higher levels of c-fos mRNA expression when administered in a novel environment, relative to when they were administered in the home cage. The ability of environmental context to modulate psychostimulant drug-induced immediate early gene expression may be related to its ability to modulate forms of drug experience-dependent plasticity, such as behavioral sensitization.
authors.affiliation: Biopsychology Programs, Department of Psychology, University of Michigan, East Hall, 525 East University Street, Ann Arbor, MI 48019-1109, USA.
authors.forename: J
authors.initials: J
authors.lastname: Uslaner
authors.forename: A
authors.initials: A
authors.lastname: Badiani
authors.forename: H E
authors.initials: HE
authors.lastname: Day
authors.forename: S J
authors.initials: SJ
authors.lastname: Watson
authors.forename: H
authors.initials: H
authors.lastname: Akil
authors.forename: T E
authors.initials: TE
authors.lastname: Robinson
mesh_terms: D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D002421:Caudate Nucleus / Q000187:drug effects / Q000378:metabolism*; D003042:Cocaine / Q000494:pharmacology*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology*; D004777:Environment; D017403:In Situ Hybridization; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D019579:Neocortex / Q000187:drug effects / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D010296:Parietal Lobe / Q000187:drug effects / Q000378:metabolism; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018765:Dopamine Uptake Inhibitors; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D000661:Amphetamine; D003042:Cocaine