Limits...
Mesolimbic Dopamine Encodes Prediction Errors in a State-Dependent Manner.

Papageorgiou GK, Baudonnat M, Cucca F, Walton ME - Cell Rep (2016)

Bottom Line: Mesolimbic dopamine encodes the benefits of a course of action.These changes were rapid and selective, with dopamine release returning to pre-satiation patterns when the animals were re-tested in a standard food-restricted state.Such rapid and selective adaptation of dopamine-associated value signals could provide an important signal to promote efficient foraging for a varied diet.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Psychology, University of Oxford, 9 South Parks Road, Oxford OX1 3UD, UK. Electronic address: georgios.papageorgiou@psy.ox.ac.uk.

No MeSH data available.


Related in: MedlinePlus

Dopamine at Reward Delivery after Selective Satiation(A and B) Average effect sizes from a general linear model of post-reward dopamine signals after sucrose solution (A) or food (B) devaluation.(C) Average dopamine release on MORE food or sucrose trials divided up by the reward type that was devalued prior to the session.(D and E) Dopamine signals on expected (Exp) and SWITCH (Sw) trials after sucrose (Suc) (D) or food (E) was selectively devalued.(F and G) Dopamine discrimination index for each animal in a 5 s post reward window for SWITCH food versus expected sucrose (F) or SWITCH sucrose versus expected food (G) plotted against each animal’s food choices. Data are separated into food (filled symbols) or sucrose solution (open symbols) devaluation sessions.(H) Comparison of dopamine signals when receiving expected reward in baseline and devaluation sessions as a function of which reward type was devalued.(I) Difference between average dopamine release after reward delivery when receiving the valued option in devaluation sessions and this same reward type in the previous baseline session (collapsed over reinforcers), divided into five bins each of two blocks of trials.Lines: ∗p < 0.05 permutation tests, corrected for multiple comparisons; ∗∗p < 0.05; − p = 0.058, two-tailed t test against 0. All averages indicate mean ± SEM. DA, dopamine.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4835543&req=5

fig2: Dopamine at Reward Delivery after Selective Satiation(A and B) Average effect sizes from a general linear model of post-reward dopamine signals after sucrose solution (A) or food (B) devaluation.(C) Average dopamine release on MORE food or sucrose trials divided up by the reward type that was devalued prior to the session.(D and E) Dopamine signals on expected (Exp) and SWITCH (Sw) trials after sucrose (Suc) (D) or food (E) was selectively devalued.(F and G) Dopamine discrimination index for each animal in a 5 s post reward window for SWITCH food versus expected sucrose (F) or SWITCH sucrose versus expected food (G) plotted against each animal’s food choices. Data are separated into food (filled symbols) or sucrose solution (open symbols) devaluation sessions.(H) Comparison of dopamine signals when receiving expected reward in baseline and devaluation sessions as a function of which reward type was devalued.(I) Difference between average dopamine release after reward delivery when receiving the valued option in devaluation sessions and this same reward type in the previous baseline session (collapsed over reinforcers), divided into five bins each of two blocks of trials.Lines: ∗p < 0.05 permutation tests, corrected for multiple comparisons; ∗∗p < 0.05; − p = 0.058, two-tailed t test against 0. All averages indicate mean ± SEM. DA, dopamine.

Mentions: To examine the effect of selective satiety and, consequently, a selective change in the subjective value of one of the options, on value-related dopamine signals at the time of reward delivery, we ran a linear regression on the two devaluation sessions (Figures 2A and 2B). There was a strong influence of MORE trials on dopamine release, as well as a significant interaction between MORE trials and reward type. Importantly, the sign of the interaction term switched depending on whether food or sucrose solution was devalued (Figure 2C). This demonstrates reinforcer-specific satiety effects on value surprise trials. The same influence of selective satiety was also observed on SWITCH trials. In sucrose solution devaluation sessions, there was a transient increase in dopamine following the surprise delivery of a valued food pellet after a response on the sucrose solution lever (Figures 2A, 2D, 2F, and 2G). These signals were significantly more discriminable than during the baseline session (paired t test on the dopamine discrimination index: t(7) = 2.88, p = 0.028). The opposite pattern was observed in the food devaluation sessions: now, it was the surprising delivery of the valued sucrose solution that caused a selective increase in dopamine release, whereas there was no observable increase following a surprise pellet delivery (Figures 2B and 2E–2G). Therefore, surprise-evoked dopamine release can also be modulated by the current state-based value of the reinforcers, demonstrating that the pattern of dopamine is distinct from the physical properties of the reward.


Mesolimbic Dopamine Encodes Prediction Errors in a State-Dependent Manner.

Papageorgiou GK, Baudonnat M, Cucca F, Walton ME - Cell Rep (2016)

Dopamine at Reward Delivery after Selective Satiation(A and B) Average effect sizes from a general linear model of post-reward dopamine signals after sucrose solution (A) or food (B) devaluation.(C) Average dopamine release on MORE food or sucrose trials divided up by the reward type that was devalued prior to the session.(D and E) Dopamine signals on expected (Exp) and SWITCH (Sw) trials after sucrose (Suc) (D) or food (E) was selectively devalued.(F and G) Dopamine discrimination index for each animal in a 5 s post reward window for SWITCH food versus expected sucrose (F) or SWITCH sucrose versus expected food (G) plotted against each animal’s food choices. Data are separated into food (filled symbols) or sucrose solution (open symbols) devaluation sessions.(H) Comparison of dopamine signals when receiving expected reward in baseline and devaluation sessions as a function of which reward type was devalued.(I) Difference between average dopamine release after reward delivery when receiving the valued option in devaluation sessions and this same reward type in the previous baseline session (collapsed over reinforcers), divided into five bins each of two blocks of trials.Lines: ∗p < 0.05 permutation tests, corrected for multiple comparisons; ∗∗p < 0.05; − p = 0.058, two-tailed t test against 0. All averages indicate mean ± SEM. DA, dopamine.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835543&req=5

fig2: Dopamine at Reward Delivery after Selective Satiation(A and B) Average effect sizes from a general linear model of post-reward dopamine signals after sucrose solution (A) or food (B) devaluation.(C) Average dopamine release on MORE food or sucrose trials divided up by the reward type that was devalued prior to the session.(D and E) Dopamine signals on expected (Exp) and SWITCH (Sw) trials after sucrose (Suc) (D) or food (E) was selectively devalued.(F and G) Dopamine discrimination index for each animal in a 5 s post reward window for SWITCH food versus expected sucrose (F) or SWITCH sucrose versus expected food (G) plotted against each animal’s food choices. Data are separated into food (filled symbols) or sucrose solution (open symbols) devaluation sessions.(H) Comparison of dopamine signals when receiving expected reward in baseline and devaluation sessions as a function of which reward type was devalued.(I) Difference between average dopamine release after reward delivery when receiving the valued option in devaluation sessions and this same reward type in the previous baseline session (collapsed over reinforcers), divided into five bins each of two blocks of trials.Lines: ∗p < 0.05 permutation tests, corrected for multiple comparisons; ∗∗p < 0.05; − p = 0.058, two-tailed t test against 0. All averages indicate mean ± SEM. DA, dopamine.
Mentions: To examine the effect of selective satiety and, consequently, a selective change in the subjective value of one of the options, on value-related dopamine signals at the time of reward delivery, we ran a linear regression on the two devaluation sessions (Figures 2A and 2B). There was a strong influence of MORE trials on dopamine release, as well as a significant interaction between MORE trials and reward type. Importantly, the sign of the interaction term switched depending on whether food or sucrose solution was devalued (Figure 2C). This demonstrates reinforcer-specific satiety effects on value surprise trials. The same influence of selective satiety was also observed on SWITCH trials. In sucrose solution devaluation sessions, there was a transient increase in dopamine following the surprise delivery of a valued food pellet after a response on the sucrose solution lever (Figures 2A, 2D, 2F, and 2G). These signals were significantly more discriminable than during the baseline session (paired t test on the dopamine discrimination index: t(7) = 2.88, p = 0.028). The opposite pattern was observed in the food devaluation sessions: now, it was the surprising delivery of the valued sucrose solution that caused a selective increase in dopamine release, whereas there was no observable increase following a surprise pellet delivery (Figures 2B and 2E–2G). Therefore, surprise-evoked dopamine release can also be modulated by the current state-based value of the reinforcers, demonstrating that the pattern of dopamine is distinct from the physical properties of the reward.

Bottom Line: Mesolimbic dopamine encodes the benefits of a course of action.These changes were rapid and selective, with dopamine release returning to pre-satiation patterns when the animals were re-tested in a standard food-restricted state.Such rapid and selective adaptation of dopamine-associated value signals could provide an important signal to promote efficient foraging for a varied diet.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Psychology, University of Oxford, 9 South Parks Road, Oxford OX1 3UD, UK. Electronic address: georgios.papageorgiou@psy.ox.ac.uk.

No MeSH data available.


Related in: MedlinePlus