Structural and behavioral correlates of abnormal encoding of money value in the sensorimotor striatum in cocaine addiction

Medical Research, Brookhaven National Laboratory, Upton, NY, USA Department of Psychology, Stony Brook University, Stony Brook, NY, USA National Institute on Alcohol and Alcoholism, Bethesda, MD, USA National Institute on Drug Abuse, Bethesda, MD, USA.
European Journal of Neuroscience (Impact Factor: 3.18). 07/2012; 36(7):2979-88. DOI: 10.1111/j.1460-9568.2012.08211.x
Source: PubMed


Abnormalities in frontostriatal systems are thought to be central to the pathophysiology of addiction, and may underlie the maladaptive processing of the highly generalizable reinforcer, money. Although abnormal frontostriatal structure and function have been observed in individuals addicted to cocaine, it is less clear how individual variability in brain structure is associated with brain function to influence behavior. Our objective was to examine frontostriatal structure and neural processing of money value in chronic cocaine users and closely matched healthy controls. A reward task that manipulated different levels of money was used to isolate neural activity associated with money value. Gray matter volume measures were used to assess frontostriatal structure. Our results indicated that cocaine users had an abnormal money value signal in the sensorimotor striatum (right putamen/globus pallidus) that was negatively associated with accuracy adjustments to money and was more pronounced in individuals with more severe use. In parallel, group differences were also observed in both the function and gray matter volume of the ventromedial prefrontal cortex; in the cocaine users, the former was directly associated with response to money in the striatum. These results provide strong evidence for abnormalities in the neural mechanisms of valuation in addiction and link these functional abnormalities with deficits in brain structure. In addition, as value signals represent acquired associations, their abnormal processing in the sensorimotor striatum, a region centrally implicated in habit formation, could signal disadvantageous associative learning in cocaine addiction.

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Available from: Anna Konova
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    • "A recent review suggests that the presence of drug cues may modulate reward circuitry activation, where drug cues enhance reward circuitry activation relative to controls, but natural rewards produce lower levels of activity (Leyton and Vezina, 2013; Limbrick-Oldfield et al., 2013). Corroborating this, several studies using monetary or food rewards have shown that individuals with SUDs relative to controls show decreased activation in the striatum, amygdala and insula when viewing or receiving rewards (Ihssen et al., 2011; Jia et al., 2011; Konova et al., 2012; Peters et al., 2011). The ability to stimulate reward circuitry through natural rewards may diminish the desire to stimulate it through substance use, potentially reducing the risk of relapse. "
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