PARTICIPACIÓN DE RECEPTORES AMPA DE NÚCLEO ACCUMBENS CORE EN LA SENSIBILIZACIÓN DE LARGO PLAZO A COCAÍNA INDUCIDA POR ESTRES

GARCÍA KELLER, CONSTANZA; MARTÍNEZ, SAMANTA & CANCELA, LILIANA M.

ARICA, CHILE

Congreso; IV NEUROTOXICITY SOCIETY MEETING; 2009

Several evidences indicate that cocaine is able to induce behavioral and neurochemical sensitization in both, the dopaminergic (DA) and glutamatergic (Glu) mesocorticolimbic systems. The aims of this work were to study whether or not AMPA receptors participate in the behavioural manifestation of long-term cross-sensitization between stress and cocaine (21 days after a single stress session) and to investigate the participation of nucleus accumbens core (NAc Core) in this cross-sensitization. Male Wistar rats (250-350 g) were restrained for two hours (acute stress group) while control animals were left undisturbed in their cages. Twenty-one days after this single stress episode all animals were assigned to one of the following two experiments: I) Locomotor activity in response to saline or cocaine (15 mg/kg i.p.); followed by intra NAc Core microinfusions of increasing doses of AMPA (1 nM, 10 nM and 100 nM), and II) Microdialysis: dopamine release was measured by HPLC in NAc Core and NAc Shell in response to saline and cocaine (15 mg/kg i.p.)  These results clearly show a long-lasting cross-sensitization between cocaine and stress evidenced at the AMPA receptors as well as the dopamine release in the  NAc Core.