Involvement of GABAergic system in nicotine withdrawal: somatic and neurochemical alterations.

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

Tandil

Congreso; XL Reunión anual de la Sociedad Argentina de Farmacología Experimental; 2008

Sociedad Argentina de Farmacología Experimental

Nicotine (NIC) plays a major role in tobacco addiction. The aims of the present study were: a) to evaluate the possible involvement of GABAergic system 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 mice received NIC (2.5 mg/kg, sc) 4 times daily, for 7 days. On day 8, dependent mice received the NIC antagonist mecamylamine (MEC; 2 mg/kg, ip) 1h after the last dose of NIC. 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 DA, 5-HT and its metabolites were determined by HPLC in the striatum, cortex and hippocampus of brains collected 10 min after the last injection on day 8, since NIC withdrawal response reached a maximum between 10 and 15 min. BAC pre-treatment decreased the incidence of some NIC withdrawal signs, such as wet-dog-shakes (p