Baclofen reestablishes c-fos expression during nicotine withdrawal syndrome in mice

MOUTINHO LIRANE; INDUNI ANDREA S; VARANI ANDRES; BALERIO GRACIELA

Rosario. Santa Fe.

Congreso; XLI Reunion anual de la Sociedad Argentina de Farmacologia Experimental; 2009

Sociedad argentina de Farmacologia Experimental

C-Fos, a member of Fos family of transcription factors, is implicated in behavioural responses and synaptic plasticity induced by abused drugs. Our previous studies demonstrated that baclofen (BAC), GABAB receptor agonist, was able to prevent the somatic expression and reestablish the dopaminergic and serotonergic activity during NIC withdrawal syndrome in mice. The aim of the present study was to evaluate the immediate early gene c-Fos expression in various brain areas in mice during NIC withdrawal syndrome and its prevention with BAC. Swiss mice received NIC (2.5 mg/kg, sc) 4 times daily, for 7 days. On day 8th, dependent mice received the NIC receptor 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. Animals were anesthetized and transcardially perfused with paraformaldehyde. Brains were removed and cut to perform immunohistochemical studies. Our results showed a significant decrease in c-Fos expression in the dentate gyrus of hippocampus (p