Nicotine withdrawal syndrome and prevention with Baclofen: somatic and neurochemical alterations

VARANI ANDRÉS P; MOUTINHO LIRANE; CALVO MARIELA; BALERIO GRACIELA

Buzios-Brazil

Congreso; I Congress IBRO/LARC of neurosciences for Latin America, Caribbean and Iberian Peninsula; 2008

Nicotine (NIC) is one of the active components of tobacco and plays a major role in tobacco addiction. The aims of the present study were: a) to evaluate the possible role of GABAB receptor in NIC physical dependence; b) to analyze the neurochemical variations in various brain regions of mice during NIC withdrawal syndrome and its prevention with baclofen (BAC, GABAB receptor agonist). Swiss-Webster albino mice received NIC (2.5 mg/kg, sc) four times daily, for seven consecutive days. To precipitate NIC abstinence, dependent mice were injected with the nicotine antagonist mecamylamine (MEC, 2 mg/kg, ip) 60 min after the last dose of NIC on the 8th day. A second group of dependent mice received BAC (2 mg/kg, ip) before MEC- precipitated abstinence. Somatic signs were measured for 30 min. The levels of dopamine, serotonin and its metabolites were determined by HPLC-coupled electrochemical detection in the striatum, cortex and hippocampus. BAC pre-treatment decreased the incidence of some NIC withdrawal signs, such as wet-dog-shakes (p