CONICET | Buscador de Institutos y Recursos Humanos

.O {color:black; font-size:149%;} a:link {color:#AD1F1F !important;} a:active {color:#A5644E !important;} a:visited {color:#FFC42F !important;}   The most important mediator of drug reward is the mesolimbic dopamine (DA) system, comprised of DA neurons in the ventral tegmental area (VTA) and the projection in the nucleus accumbens (Chao & Nestler, 2004). The transcription factor Nurr1, a member of the NGFI-B family of nuclear orphan receptors, is highly expressed in rodent VTA dopamine neurons and is essential for their phenotypic development and maintenance (Bannon et al., 2002). There are several lines of evidence indicating that the mesolimbic DA system, and particularly the VTA, plays a critical role in the ability of nicotine to impact behavior (Vezina et al., 2007) However, it is still unknown whether Nurr1 participates in nicotine-induced behavioral changes. Utilizing animal models that are based on differential individual responsiveness to drugs may be an effective strategy for identifying genes and cellular mechanisms that can contribute to vulnerability to drug addiction (Allen et al., 2007). In this regard, we investigated the expression of Nurr1 protein in the VTA of rats that displayed high or low locomotor activity in response to a single injection of nicotine. In addition, we trained the animals in a conditioned place preference (CPP) paradigm, in order to evaluate nicotine rewarding properties in these two behavioral groups.