Acute behavioural responses to nicotine and nicotine withdrawal syndrome are modified in GABAB1 knockout mice

NEUROPHARMACOLOGY

卷:63

Article

Varani, Andres P.¹  Moutinho, Lirane Machado¹  Bettler, Bernhard²  Balerio, Graciela N.^1,3 

[1] Inst Invest Farmacol CONICET, Buenos Aires, DF, Argentina

[2] Univ Basel, Dept Biomed, Inst Physiol, Pharmazentrum, CH-4056 Basel, Switzerland

[3] Univ Buenos Aires, Fac Farm & Bioquim, Catedra Farmacol, RA-1113 Buenos Aires, DF, Argentina

关键词: Nicotine;    GABA(B) receptor;    Nociception;    Anxiety-like behaviour;    Withdrawal;    c-Fos;   

DOI  :  10.1016/j.neuropharm.2012.06.006

来源: Elsevier

【 摘 要 】

Nicotine is the main active component of tobacco, and has both acute and chronic pharmacological effects that can contribute to its abuse potential in humans. The aim of the present study was to evaluate a possible role of GABA(B) receptors in acute and chronic responses to nicotine administration, by comparing GABA(B1) knockout mice and their wild-type littermates. In wild-type mice, acute nicotine administration (0.5, 1, 3 and 6 mg/kg, sc) dose-dependently decreased locomotor activity, and induced antinociceptive responses in the tail-immersion and hot-plate tests. In GABA(B1) knockout mice, the hypolocomotive effect was observed only with the highest dose of nicotine, and the antinociceptive responses in both tests were significantly reduced in GABA(B1) knockout mice compared to their wild-type littermate. Additionally, nicotine elicited anxiolytic- (0.05 mg/kg) and anxiogenic-like (0.8 mg/kg) responses in the elevated plus-maze test in wild-type mice, while selectively the anxiolytic-like effect was abolished in GABA(B1) knockout mice. We further investigated nicotine withdrawal in mice chronically treated with nicotine (25 mg/kg/day, sc). Mecamylamine (1 mg/kg, sc) precipitated several somatic signs of nicotine withdrawal in wild-type mice. However, signs of nicotine withdrawal were missing in GABA(B1) knockout mice. Finally, there was a decreased immunoreactivity of Fos-positive nuclei in the bed nucleus of the stria terminalis, basolateral amygdaloid nucleus and hippocampal dentate gyrus in abstinent wildtype but not in GABA(B1) knockout mice. These results reveal an interaction between the GABA(B) system and the neurochemical systems through which nicotine exerts its acute and long-term effects. (C) 2012 Elsevier Ltd. All rights reserved.

【 授权许可】

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