The aim of the present study was to evaluate the possible involvement of GABAB receptors in nicotine-induced hypolocomotion and antinociceptive effects in mice. Animals were exposed to nicotine only once. Acute nicotine hydrogen tartrate salt (3mg/kg; subcutaneous, s.c.) administration induced hypolocomotion and antinociceptive responses in the tail-immersion and the hot-plate tests. The effects of pretreatment with either the GABAB receptor agonist baclofen (1, 2 and 3mg/kg; intraperitoneal, i.p.) or GABAB receptor antagonist 2-hydroxysaclofen (0.25, 0.5 and 1mg/kg; i.p.) were evaluated on these behavioral nicotine responses. The GABAB receptor agonist, baclofen (3mg/kg, i.p.) abolished nicotine-induced antinociceptive effects in the tail-immersion and the hot-plate tests, but did not modify nicotine-induced hypolocomotion. In addition, the GABAB receptor antagonist, 2-hydroxysaclofen (1mg/kg, i.p.) increased nicotine-induced antinociceptive effects in the tail-immersion and the hot-plate tests, and abolished nicotine-induced hypolocomotion. The present results shed light that the GABAB receptor has an important role in mediating specific acute nicotine responses such as hypolocomotion and antinociception in mice.

This work has been supported by grants from University of Buenos Aires (UBACyT B016 and UBACyT 2013–2016 No. 20020120100244), CONICET (PIP 11420090100303), Spanish “Ministerio de Ciencia e Innovación” (#SAF2011-29864), “Instituto de Salud Carlos III” (RETICS: #RD06/0001/0001, #RD06/0001/1004), Plan Nacional sobre Drogas (PNSD #2009/026), the Catalan Government (SGR2009-00131) and the ICREA Foundation (ICREA Academia-2008)