TY - JOUR
T1 - Striatal dopamine release codes uncertainty in pathological gambling
AU - Linnet, Jakob
AU - Mouridsen, Kim
AU - Peterson, Ericka
AU - Møller, Arne
AU - Doudet, Doris Jeanne
AU - Gjedde, Albert
N1 - Funding Information:
This study was supported by funding from the Danish Agency for Science, Technology and Innovation grant numbers 2049-03-0002 and 2102-05-0009 , and the Ministry of Health grant number 1001326 ; and from the National Center for Responsible Gaming as provided by The Institute for Research on Pathological Gambling and Related Disorders in the Division on Addictions at Cambridge Health Alliance. Its contents are solely the responsibility of the author(s) and do not necessarily represent the official views of the Danish Agency for Science, Technology and Innovation, the Ministry of Health or the National Center, the Institute, or Cambridge Health Alliance. The authors declare that they have no competing financial interests.
PY - 2012/10/30
Y1 - 2012/10/30
N2 - Two mechanisms of midbrain and striatal dopaminergic projections may be involved in pathological gambling: hypersensitivity to reward and sustained activation toward uncertainty. The midbrain-striatal dopamine system distinctly codes reward and uncertainty, where dopaminergic activation is a linear function of expected reward and an inverse U-shaped function of uncertainty. In this study, we investigated the dopaminergic coding of reward and uncertainty in 18 pathological gambling sufferers and 16 healthy controls. We used positron emission tomography (PET) with the tracer [11C]raclopride to measure dopamine release, and we used performance on the Iowa Gambling Task (IGT) to determine overall reward and uncertainty. We hypothesized that we would find a linear function between dopamine release and IGT performance, if dopamine release coded reward in pathological gambling. If, on the other hand, dopamine release coded uncertainty, we would find an inversely U-shaped function. The data supported an inverse U-shaped relation between striatal dopamine release and IGT performance if the pathological gambling group, but not in the healthy control group. These results are consistent with the hypothesis of dopaminergic sensitivity toward uncertainty, and suggest that dopaminergic sensitivity to uncertainty is pronounced in pathological gambling, but not among non-gambling healthy controls. The findings have implications for understanding dopamine dysfunctions in pathological gambling and addictive behaviors.
AB - Two mechanisms of midbrain and striatal dopaminergic projections may be involved in pathological gambling: hypersensitivity to reward and sustained activation toward uncertainty. The midbrain-striatal dopamine system distinctly codes reward and uncertainty, where dopaminergic activation is a linear function of expected reward and an inverse U-shaped function of uncertainty. In this study, we investigated the dopaminergic coding of reward and uncertainty in 18 pathological gambling sufferers and 16 healthy controls. We used positron emission tomography (PET) with the tracer [11C]raclopride to measure dopamine release, and we used performance on the Iowa Gambling Task (IGT) to determine overall reward and uncertainty. We hypothesized that we would find a linear function between dopamine release and IGT performance, if dopamine release coded reward in pathological gambling. If, on the other hand, dopamine release coded uncertainty, we would find an inversely U-shaped function. The data supported an inverse U-shaped relation between striatal dopamine release and IGT performance if the pathological gambling group, but not in the healthy control group. These results are consistent with the hypothesis of dopaminergic sensitivity toward uncertainty, and suggest that dopaminergic sensitivity to uncertainty is pronounced in pathological gambling, but not among non-gambling healthy controls. The findings have implications for understanding dopamine dysfunctions in pathological gambling and addictive behaviors.
KW - Dopamine
KW - Iowa Gambling Task
KW - Pathological gambling
KW - Positron emission tomography
KW - Reward
KW - Uncertainty
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U2 - 10.1016/j.pscychresns.2012.04.012
DO - 10.1016/j.pscychresns.2012.04.012
M3 - Article
C2 - 22889563
AN - SCOPUS:84869889770
SN - 0925-4927
VL - 204
SP - 55
EP - 60
JO - Psychiatry Research - Neuroimaging
JF - Psychiatry Research - Neuroimaging
IS - 1
ER -