title: Striatal ups and downs: their roles in vulnerability to addictions in humans.
abstract: Susceptibility to addictive behaviors has been related to both increases and decreases in striatal function. Both profiles have been reported in humans as well as in animal models. Yet, the mechanisms underlying these opposing effects and the manner in which they relate to the behavioral development and expression of addiction remain unclear. In the present review of human studies, we describe a number of factors that could influence whether striatal hyper- or hypo-function is observed and propose a model that integrates the influence of these opposite responses on the expression of addiction related behaviors. Central to this model is the role played by the presence versus absence of addiction related cues and their ability to regulate responding to abused drugs and other rewards. Striatal function and incentive motivational states are increased in the presence of these cues and decreased in their absence. Alternations between these states might account for the progressive narrowing of interests as addictions develop and point to relevant processes to target in treatment.
authors: Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montreal, Quebec, H3A 1A1 Canada. Electronic address: marco.leyton@mcgill.ca.
authors: Marco
authors: M
authors: Leyton
authors: Paul
authors: P
authors: Vezina
mesh_terms: D000818:Animals; D016739:Behavior, Addictive / Q000378:metabolism / Q000503:physiopathology*; D001921:Brain / Q000378:metabolism / Q000503:physiopathology*; D003463:Cues; D006801:Humans; D013287:Illicit Drugs / Q000378:metabolism / Q000494:pharmacology; D009042:Motivation / Q000502:physiology*; D012201:Reward
chemical_list: D013287:Illicit Drugs
keywords: Basal ganglia; Conditioning; Dopamine; Drug addiction; Drug self-administration; Functional magnetic resonance imaging; Positron emission tomography; Sensitization; Striatum