title: Modulation of the mouse prefrontal cortex activation by neuronal nicotinic receptors during novelty exploration but not by exploration of a familiar environment.
abstract: Organization of locomotor behavior is altered in mice knockout for the β2 subunit of the nicotinic receptor-β2-/- mice-during novelty exploration. We investigated the neuronal basis of this alteration by measuring activation of the immediate early gene c-fos in the brains of wild-type (WT) and β2-/- mice after exploration of a novel or a familiar environment. Results show 1) no constitutive difference between WT and β2-/- mice in c-fos gene expression in any brain region, 2) novelty exploration triggered activation of the hippocampus and the reward circuit while exploration of a familiar environment produced increased activation in the amygdala, and 3) in β2-/- mice, exploration of novelty, but not familiarity, induced an increase in activation in the prelimbic prefrontal cortex (PFC) compared with WT mice. c-Fos immunoreactivity after different stages of learning in a maze increased similarly in the prelimbic area of both WT and β2-/- mice, while their performance differed. In WT mice, exploration of a novel environment triggered an increase in c-Fos expression in the reward circuit and the hippocampus, while in β2-/- mice, the amygdala and the motor cortex were additionally activated. We also highlight the role of nicotinic receptors during activation of the PFC, specifically during free exploration of a novel environment.
authors.affiliation: Unité de Génétique Humaine et Fonctions Cognitives, Département des Neurosciences, Institut Pasteur, 75015 Paris, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bourgeois
authors.forename: Vannary
authors.initials: V
authors.lastname: Meas-Yeadid
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Lesourd
authors.forename: Philippe
authors.initials: P
authors.lastname: Faure
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Pons
authors.forename: Uwe
authors.initials: U
authors.lastname: Maskos
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Changeux
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Olivo-Marin
authors.forename: Sylvie
authors.initials: S
authors.lastname: Granon
mesh_terms: D000818:Animals; D005106:Exploratory Behavior / Q000502:physiology*; D020869:Gene Expression Profiling; D007150:Immunohistochemistry; D018782:Maze Learning / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000096:biosynthesis; D011978:Receptors, Nicotinic / Q000172:deficiency / Q000378:metabolism*; D012201:Reward
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D011978:Receptors, Nicotinic