title: Involvement of rat dopaminergic system of nucleus accumbens in nicotine-induced anxiogenic-like behaviors.
abstract: The objective of the present study was to investigate the involvement of dopamine D₁ and D₂ receptors of the nucleus accumbens (NAc) shell in the anxiogenic-like effect of intra-central amygdala (CeA) nicotine administration. Male Wistar rats with cannula implants in the left CeA and the left shell of NAc were submitted to the elevated plus-maze (EPM). Intra-CeA injections of nicotine (1 μg/rat) decreased % open arm time spent (%OAT) but not % open arm entries (%OAE) and locomotor activity, indicating the possibility of an anxiogenic-like response. Intra-NAc injection of D₁ dopamine receptor antagonist, SCH23390 (0.5 μg/rat) but not other doses of the antagonist (0.06, 0.125 and 0.25 μg/rat) increased both %OAT and %OAE, showing an anxiolytic-like effect for the higher dose of the drug. Similar administration route of sulpiride (0.25, 0.5, 0.75 and 1 μg/rat), a selective antagonist at dopamine D₂ receptor, had no significant effect on OAT%, OAE% and locomotor activity. Moreover, intra-CeA injection of nicotine (1 μg) with intra-NAc injection of sub-threshold doses of antagonists increased %OAT and %OAE without significant effect on locomotor activity. These findings may suggest the involvement of dopamine transmission, through D₁ and D₂ receptors of NAc shell, in the anxiogenic-like effect of nicotine in the EPM task.
authors.affiliation: Department of Neuroscience, School of Advanced Medical Technologies, Tehran University of Medical Sciences, Tehran, Iran. zarinmr@ams.ac.ir
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Zarrindast
authors.forename: Solmaz
authors.initials: S
authors.lastname: Khalifeh
authors.forename: Ameneh
authors.initials: A
authors.lastname: Rezayof
authors.forename: Parvin
authors.initials: P
authors.lastname: Rostami
authors.forename: Arash
authors.initials: A
authors.lastname: Aghamohammadi Sereshki
authors.forename: Maryam
authors.initials: M
authors.lastname: Zahmatkesh
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001007:Anxiety / Q000188:drug therapy*; D004298:Dopamine / Q000502:physiology*; D059290:Dopaminergic Neurons / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D017447:Receptors, Dopamine D1 / Q000502:physiology; D017448:Receptors, Dopamine D2 / Q000502:physiology
chemical_list: D014151:Anti-Anxiety Agents; D018722:Nicotinic Agonists; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D009538:Nicotine; D004298:Dopamine