Reward signalling in brainstem nuclei under fluctuating blood glucose.
Phasic dopamine release from mid-brain dopaminergic neurons is thought to signal errors of reward prediction (RPE). If reward maximisation is to maintain homeostasis, then the value of primary rewards should be coupled to the homeostatic errors they remediate. This leads to the prediction that RPE s...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2021-01-01
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| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0243899 |
| _version_ | 1818902541757317120 |
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| author | Tobias Morville Kristoffer H Madsen Hartwig R Siebner Oliver J Hulme |
| author_facet | Tobias Morville Kristoffer H Madsen Hartwig R Siebner Oliver J Hulme |
| author_sort | Tobias Morville |
| collection | DOAJ |
| description | Phasic dopamine release from mid-brain dopaminergic neurons is thought to signal errors of reward prediction (RPE). If reward maximisation is to maintain homeostasis, then the value of primary rewards should be coupled to the homeostatic errors they remediate. This leads to the prediction that RPE signals should be configured as a function of homeostatic state and thus diminish with the attenuation of homeostatic error. To test this hypothesis, we collected a large volume of functional MRI data from five human volunteers on four separate days. After fasting for 12 hours, subjects consumed preloads that differed in glucose concentration. Participants then underwent a Pavlovian cue-conditioning paradigm in which the colour of a fixation-cross was stochastically associated with the delivery of water or glucose via a gustometer. This design afforded computation of RPE separately for better- and worse-than expected outcomes during ascending and descending trajectories of serum glucose fluctuations. In the parabrachial nuclei, regional activity coding positive RPEs scaled positively with serum glucose for both ascending and descending glucose levels. The ventral tegmental area and substantia nigra became more sensitive to negative RPEs when glucose levels were ascending. Together, the results suggest that RPE signals in key brainstem structures are modulated by homeostatic trajectories of naturally occurring glycaemic flux, revealing a tight interplay between homeostatic state and the neural encoding of primary reward in the human brain. |
| first_indexed | 2024-12-19T20:37:18Z |
| format | Article |
| id | doaj.art-03b66a6e044644a6accbb3bc0f59ea19 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-19T20:37:18Z |
| publishDate | 2021-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-03b66a6e044644a6accbb3bc0f59ea192022-12-21T20:06:29ZengPublic Library of Science (PLoS)PLoS ONE1932-62032021-01-01164e024389910.1371/journal.pone.0243899Reward signalling in brainstem nuclei under fluctuating blood glucose.Tobias MorvilleKristoffer H MadsenHartwig R SiebnerOliver J HulmePhasic dopamine release from mid-brain dopaminergic neurons is thought to signal errors of reward prediction (RPE). If reward maximisation is to maintain homeostasis, then the value of primary rewards should be coupled to the homeostatic errors they remediate. This leads to the prediction that RPE signals should be configured as a function of homeostatic state and thus diminish with the attenuation of homeostatic error. To test this hypothesis, we collected a large volume of functional MRI data from five human volunteers on four separate days. After fasting for 12 hours, subjects consumed preloads that differed in glucose concentration. Participants then underwent a Pavlovian cue-conditioning paradigm in which the colour of a fixation-cross was stochastically associated with the delivery of water or glucose via a gustometer. This design afforded computation of RPE separately for better- and worse-than expected outcomes during ascending and descending trajectories of serum glucose fluctuations. In the parabrachial nuclei, regional activity coding positive RPEs scaled positively with serum glucose for both ascending and descending glucose levels. The ventral tegmental area and substantia nigra became more sensitive to negative RPEs when glucose levels were ascending. Together, the results suggest that RPE signals in key brainstem structures are modulated by homeostatic trajectories of naturally occurring glycaemic flux, revealing a tight interplay between homeostatic state and the neural encoding of primary reward in the human brain.https://doi.org/10.1371/journal.pone.0243899 |
| spellingShingle | Tobias Morville Kristoffer H Madsen Hartwig R Siebner Oliver J Hulme Reward signalling in brainstem nuclei under fluctuating blood glucose. PLoS ONE |
| title | Reward signalling in brainstem nuclei under fluctuating blood glucose. |
| title_full | Reward signalling in brainstem nuclei under fluctuating blood glucose. |
| title_fullStr | Reward signalling in brainstem nuclei under fluctuating blood glucose. |
| title_full_unstemmed | Reward signalling in brainstem nuclei under fluctuating blood glucose. |
| title_short | Reward signalling in brainstem nuclei under fluctuating blood glucose. |
| title_sort | reward signalling in brainstem nuclei under fluctuating blood glucose |
| url | https://doi.org/10.1371/journal.pone.0243899 |
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