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Insulin, Central Dopamine D2 Receptors, and Monetary Reward Discounting in Obesity.

Eisenstein SA, Gredysa DM, Antenor-Dorsey JA, Green L, Arbeláez AM, Koller JM, Black KJ, Perlmutter JS, Moerlein SM, Hershey T - PLoS ONE (2015)

Bottom Line: Choice of larger, but delayed or less certain, monetary rewards relative to immediate, certain smaller monetary rewards was measured using delayed and probabilistic reward discounting tasks.Higher percent body fat in non-obese women related to preference for a smaller, certain reward over a larger, less likely one (greater probabilistic discounting).These results raise interesting questions about whether and how striatal D2 receptor binding and metabolic factors, including β-cell function, interact to affect reward discounting in humans.

View Article: PubMed Central - PubMed

Affiliation: Psychiatry Department, Washington University in St. Louis, St. Louis, MO, United States of America; Radiology Department, Washington University in St. Louis, St. Louis, MO, United States of America.

ABSTRACT
Animal research finds that insulin regulates dopamine signaling and reward behavior, but similar research in humans is lacking. We investigated whether individual differences in body mass index, percent body fat, pancreatic β-cell function, and dopamine D2 receptor binding were related to reward discounting in obese and non-obese adult men and women. Obese (n = 27; body mass index>30) and non-obese (n = 20; body mass index<30) adults were assessed for percent body fat with dual-energy X-ray absorptiometry and for β-cell function using disposition index. Choice of larger, but delayed or less certain, monetary rewards relative to immediate, certain smaller monetary rewards was measured using delayed and probabilistic reward discounting tasks. Positron emission tomography using a non-displaceable D2-specific radioligand, [11C](N-methyl)benperidol quantified striatal D2 receptor binding. Groups differed in body mass index, percent body fat, and disposition index, but not in striatal D2 receptor specific binding or reward discounting. Higher percent body fat in non-obese women related to preference for a smaller, certain reward over a larger, less likely one (greater probabilistic discounting). Lower β-cell function in the total sample and lower insulin sensitivity in obese related to stronger preference for an immediate and smaller monetary reward over delayed receipt of a larger one (greater delay discounting). In obese adults, higher striatal D2 receptor binding related to greater delay discounting. Interestingly, striatal D2 receptor binding was not significantly related to body mass index, percent body fat, or β-cell function in either group. Our findings indicate that individual differences in percent body fat, β-cell function, and striatal D2 receptor binding may each contribute to altered reward discounting behavior in non-obese and obese individuals. These results raise interesting questions about whether and how striatal D2 receptor binding and metabolic factors, including β-cell function, interact to affect reward discounting in humans.

No MeSH data available.


Related in: MedlinePlus

Striatal D2 Receptor Binding Relates to Delayed Reward Discounting in Obese but not Non-obese Individuals.(A) In obese individuals, higher striatal D2 receptor binding related to preference for a smaller, immediate monetary reward over a larger but delayed reward. (B) This relationship was not observed in non-obese individuals. Data points are standardized residuals of variables after controlling for age, gender, education, and ethnicity. DRDAuC, area under the curve for delayed reward discounting; D2R BPND, dopamine D2 receptor specific binding.
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pone.0133621.g003: Striatal D2 Receptor Binding Relates to Delayed Reward Discounting in Obese but not Non-obese Individuals.(A) In obese individuals, higher striatal D2 receptor binding related to preference for a smaller, immediate monetary reward over a larger but delayed reward. (B) This relationship was not observed in non-obese individuals. Data points are standardized residuals of variables after controlling for age, gender, education, and ethnicity. DRDAuC, area under the curve for delayed reward discounting; D2R BPND, dopamine D2 receptor specific binding.

Mentions: Striatal D2R BPND significantly related to DRDAuC in obese individuals (Fig 3A, Table 2, S3 Table), such that obese participants with higher striatal D2R BPND discounted delayed rewards to a higher degree than those with lower striatal D2R. This relationship was not significant in non-obese individuals (Fig 3B, Table 2and S3 Table). Within the total sample, the significance level of the relationship between striatal D2R BPND and DRDAuC was trend-level (Table 2and S3 Table).


Insulin, Central Dopamine D2 Receptors, and Monetary Reward Discounting in Obesity.

Eisenstein SA, Gredysa DM, Antenor-Dorsey JA, Green L, Arbeláez AM, Koller JM, Black KJ, Perlmutter JS, Moerlein SM, Hershey T - PLoS ONE (2015)

Striatal D2 Receptor Binding Relates to Delayed Reward Discounting in Obese but not Non-obese Individuals.(A) In obese individuals, higher striatal D2 receptor binding related to preference for a smaller, immediate monetary reward over a larger but delayed reward. (B) This relationship was not observed in non-obese individuals. Data points are standardized residuals of variables after controlling for age, gender, education, and ethnicity. DRDAuC, area under the curve for delayed reward discounting; D2R BPND, dopamine D2 receptor specific binding.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507849&req=5

pone.0133621.g003: Striatal D2 Receptor Binding Relates to Delayed Reward Discounting in Obese but not Non-obese Individuals.(A) In obese individuals, higher striatal D2 receptor binding related to preference for a smaller, immediate monetary reward over a larger but delayed reward. (B) This relationship was not observed in non-obese individuals. Data points are standardized residuals of variables after controlling for age, gender, education, and ethnicity. DRDAuC, area under the curve for delayed reward discounting; D2R BPND, dopamine D2 receptor specific binding.
Mentions: Striatal D2R BPND significantly related to DRDAuC in obese individuals (Fig 3A, Table 2, S3 Table), such that obese participants with higher striatal D2R BPND discounted delayed rewards to a higher degree than those with lower striatal D2R. This relationship was not significant in non-obese individuals (Fig 3B, Table 2and S3 Table). Within the total sample, the significance level of the relationship between striatal D2R BPND and DRDAuC was trend-level (Table 2and S3 Table).

Bottom Line: Choice of larger, but delayed or less certain, monetary rewards relative to immediate, certain smaller monetary rewards was measured using delayed and probabilistic reward discounting tasks.Higher percent body fat in non-obese women related to preference for a smaller, certain reward over a larger, less likely one (greater probabilistic discounting).These results raise interesting questions about whether and how striatal D2 receptor binding and metabolic factors, including β-cell function, interact to affect reward discounting in humans.

View Article: PubMed Central - PubMed

Affiliation: Psychiatry Department, Washington University in St. Louis, St. Louis, MO, United States of America; Radiology Department, Washington University in St. Louis, St. Louis, MO, United States of America.

ABSTRACT
Animal research finds that insulin regulates dopamine signaling and reward behavior, but similar research in humans is lacking. We investigated whether individual differences in body mass index, percent body fat, pancreatic β-cell function, and dopamine D2 receptor binding were related to reward discounting in obese and non-obese adult men and women. Obese (n = 27; body mass index>30) and non-obese (n = 20; body mass index<30) adults were assessed for percent body fat with dual-energy X-ray absorptiometry and for β-cell function using disposition index. Choice of larger, but delayed or less certain, monetary rewards relative to immediate, certain smaller monetary rewards was measured using delayed and probabilistic reward discounting tasks. Positron emission tomography using a non-displaceable D2-specific radioligand, [11C](N-methyl)benperidol quantified striatal D2 receptor binding. Groups differed in body mass index, percent body fat, and disposition index, but not in striatal D2 receptor specific binding or reward discounting. Higher percent body fat in non-obese women related to preference for a smaller, certain reward over a larger, less likely one (greater probabilistic discounting). Lower β-cell function in the total sample and lower insulin sensitivity in obese related to stronger preference for an immediate and smaller monetary reward over delayed receipt of a larger one (greater delay discounting). In obese adults, higher striatal D2 receptor binding related to greater delay discounting. Interestingly, striatal D2 receptor binding was not significantly related to body mass index, percent body fat, or β-cell function in either group. Our findings indicate that individual differences in percent body fat, β-cell function, and striatal D2 receptor binding may each contribute to altered reward discounting behavior in non-obese and obese individuals. These results raise interesting questions about whether and how striatal D2 receptor binding and metabolic factors, including β-cell function, interact to affect reward discounting in humans.

No MeSH data available.


Related in: MedlinePlus