Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study. - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Psychopharmacology Année : 2009

Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study.

Résumé

RATIONALE: The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity beta2-containing nicotinic receptors (beta2*nAChRs) are located. OBJECTIVES: We intend to see which brain circuits are activated when nicotine is given in animals naïve for nicotine and whether the beta2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas. MATERIALS AND METHODS: We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and beta2 knockout (KO) mice. RESULTS: Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, beta2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via alpha7 nicotinic receptors. CONCLUSIONS: Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on beta2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice.

Dates et versions

hal-00349644 , version 1 (03-01-2009)

Identifiants

Citer

Sandra V. Suarez, A. Amadon, Elisa Giacomini, Andreas Wiklund, Jean-Pierre Changeux, et al.. Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study.. Psychopharmacology, 2009, 202 (4), pp.599-610. ⟨10.1007/s00213-008-1338-x⟩. ⟨hal-00349644⟩
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