Role of prefrontal cortex dopamine and noradrenaline circuitry in addiction

Abstract

Understanding the mechanisms of drug dependence has been the goal of a large number of neuroscientists, pharmacologists and clinicians who carried out research with the hope of individuating and proposing an efficacious therapy for this disorder (Sofuoglu, 2010; Kalivas and Volkow, 2011). Unfortunately, although huge efforts, drug dependence is still a relevant health, social and economical problem (Popova et al., 2012; Hiscock et al., 2011; Shorter and Kosten, 2011). Treatments for drug abuse are for the most part ineffective because the molecular and cellular mechanisms through which drugs of abuse alter neuronal circuitry are still unexplained and above all, because drugs of abuse determine a global alteration of cerebral functions that govern behaviour through decision formation, making therefore unfocused the identification of a pharmacological target (Volkow et al., 2011; Schultz 2011). One of the first strategies pursued in drug dependence therapy was directed to removal of pleasure associated with drug taking, but the compliance with the treatment has been always limited, although it could improve when it was supported by psychology based motivational therapy as in alcohol dependence (Krampe and Ehrenreich, 2010; Simkin and Grenoble, 2010). On the other hand it is not infrequent that heavy smokers or heavy drinkers stop suddenly dependence just because their will overcome year-long habits. Decision making is a process based on the interaction between prefrontal cortex (PFC) and subcortical regions involved in reward and motivation, therefore it is likely that failure in self-regulatory behavior, that is common in addicted subjects, could be dependent upon the alteration of interactions between the prefrontal cortex and subcortical regions (Heatherton and Wagner, 2011). In this chapter we will review the role of PFC in addiction with particular attention to dopamine and norepinephrine transmission