The ability of amphetamine to evoke arc (Arg 3.1) mRNA expression in the caudate, nucleus accumbens and neocortex is modulated by environmental context

• Published in: Brain research Vol. 930; no. 1; pp. 30 - 36
• Main Authors: Klebaur, Jennifer E., Ostrander, Michelle M., Norton, Camille S., Watson, Stanley J., Akil, Huda, Robinson, Terry E.
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 15-03-2002; Amsterdam Elsevier; New York, NY
• Subjects: Amphetamine; Amphetamine - pharmacology; Animals; Apoptosis Regulatory Proteins; arc; Arg 3.1; Biological and medical sciences; Brain Chemistry - drug effects; Caudate Nucleus - drug effects; Caudate Nucleus - metabolism; Central Nervous System Stimulants - pharmacology; Environment; Immediate early gene; In Situ Hybridization; Male; Medical sciences; Muscle Proteins - biosynthesis; Muscle Proteins - genetics; Neocortex - drug effects; Neocortex - metabolism; Neuropharmacology; Novelty; Nucleus Accumbens - drug effects; Nucleus Accumbens - metabolism; Pharmacology. Drug treatments; Prefrontal Cortex - drug effects; Prefrontal Cortex - metabolism; Psychoanaleptics: cns stimulant, antidepressant agent, nootropic agent, mood stabilizer..., (alzheimer disease); Psychology. Psychoanalysis. Psychiatry; Psychopharmacology; Rats; Rats, Sprague-Dawley; RNA, Messenger - biosynthesis; Sensitization; Amphetamine; arc; Arg 3.1; Sensitization; Neural basis of behavior; Novelty; Immediate early gene; Cerebral cortex; Rat; CNS stimulant; Psychotropic; Rodentia; Central nervous system; Basal ganglion; Gene expression; Nucleus accumbens; Vertebrata; Mammalia; Caudate nucleus; Animal; Environment novelty; Amfetamine; Brain (vertebrata)
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/S0006-8993(01)03400-X

The ability of amphetamine or cocaine to induce the expression of c-
fos mRNA in a number of brain regions is greatly enhanced when these drugs are administered in a distinct and relatively novel environment, relative to when they are given in the home cage. The purpose of this study was to determine if environmental context has a similar effect on the ability of amphetamine to induce the expression of
arc (also known as Arg 3.1), an ‘effector’ immediate early gene (IEG) thought to play a direct role in cellular plasticity. Rats were administered either saline or amphetamine (0.5 mg/kg, i.v.), in their home cage or in a distinct test environment. Fifty minutes later, they were decapitated and their brains processed for in situ hybridization histochemistry. In the prefrontal cortex, caudate-putamen and core of the nucleus accumbens, amphetamine significantly increased
arc mRNA expression under both conditions, but the level of expression was significantly enhanced when amphetamine was given in a distinct environment. In the shell of the nucleus accumbens amphetamine significantly increased the expression of
arc mRNA only when it was administered in the distinct environment. Thus, the ability of amphetamine to induce the expression of
arc varies as a function of the environmental context in which it is administered. This could contribute to the ability of environmental context to modulate forms of drug experience-dependent neuroplasticity, including behavioral sensitization.