title: Electrolytic lesions of the nucleus accumbens core (but not the medial shell) and the basolateral amygdala enhance context-specific locomotor sensitization to nicotine in rats.
abstract: We previously demonstrated that lesions of the nucleus accumbens (NAc) core enhanced locomotion and locomotor sensitization to repeated injections of nicotine in rats (Kelsey & Willmore, 2006). In this study, we compared the effects of separate lesions of the NAc core, NAc medial shell, and basolateral amygdala on context-specific locomotor sensitization to repeated injections of 0.4 mg/kg nicotine. Electrolytic lesions of the NAc core increased locomotion, and lesions of the core (but not the shell) and the basolateral amygdala enhanced context-specific locomotor sensitization by enhancing the development of sensitization in paired rats and decreasing expression in unpaired rats relative to sham-operated rats when challenged with an injection of 0.4 mg/kg nicotine in the locomotor chambers. These data are consistent with findings that the NAc core and the basolateral amygdala share a variety of behavioral functions and anatomical connections. The findings that lesions of these structures enhance context-specific locomotor sensitization while typically impairing other reward-related behaviors also indicate that the processes underlying locomotor sensitization and reward are not identical.
authors.affiliation: Program in Neuroscience, Department of Psychology, Bates College, Lewiston, ME 04240, USA. jkelsey@bates.edu
authors.forename: John E
authors.initials: JE
authors.lastname: Kelsey
authors.forename: Lyle P
authors.initials: LP
authors.lastname: Gerety
authors.forename: Rejean M
authors.initials: RM
authors.lastname: Guerriero
mesh_terms: D000679:Amygdala / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D004572:Electrolysis; D008297:Male; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology*; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D020318:Rats, Long-Evans
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine