Electrolytic lesions of the nucleus accumbens enhance locomotor sensitization to nicotine in rats.
Electrolytic lesions of the medial core of the nucleus accumbens (NAc) in male Long-Evans rats increased spontaneous locomotion, enhanced the locomotor stimulating effect of acute 5.0 mg/kg cocaine, enhanced the development and subsequent expression of locomotor sensitization produced by repeated injections of 0.4 mg/kg nicotine but not 7.5 mg/kg cocaine, and enhanced the expression of conditioned locomotion. Given that 6-hydroxydopamine lesions of the NAc typically have effects on locomotor-related processes that are opposite of those produced by electrolytic and excitotoxic lesions, these data are consistent with a hypothesis that the NAc output, especially from the core, inhibits a variety of such processes and that the DA input to the NAc enhances these processes by inhibiting this inhibitory output.
Kelsey
John E
JE
Department of Psychology and Program in Neuroscience, Bates College, Lewiston, ME 04240, USA. jkelsey@bates.edu
Willmore
Ellen J
EJ
D000661:Amphetamine / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D003042:Cocaine / Q000494:pharmacology; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004572:Electrolysis / Q000379:methods*; D008124:Locomotion / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000293:injuries* / Q000503:physiopathology*; D051381:Rats; D020318:Rats, Long-Evans
D000697:Central Nervous System Stimulants; D018765:Dopamine Uptake Inhibitors; D018722:Nicotinic Agonists; D009538:Nicotine; D000661:Amphetamine; D003042:Cocaine