Presentation Details
| Dopamine Signaling in Humans: Influence of Dietary Stimulus, Metabolic State and Adiposity Valerie Darcey. Section on Nutritional and Metabolic Neuroimaging Diabetes, Endocrinology and Obesity Branch, NIDDK, NIH, Bethesda, MD, USA |
Abstract
Central dopamine signaling is increasingly understood as a downstream integrator of sensory and metabolic information rather than a unitary “reward” signal, providing a useful framework for examining how ultra-processed foods engage the brain. Human PET neuroimaging demonstrates that dopaminergic signaling is state- and nutrient-dependent. Under fasting conditions, obesity is associated with altered dopamine signaling, whereas in the early post-ingestive state, variability in chemical sensing across oral and gut domains—rather than adiposity per se—shapes dopaminergic responses, appetite, and food choice. These findings suggest that the sensory and post-ingestive features characteristic of ultra-processed foods may influence dopamine signaling in ways not captured by simple reward-deficiency models. Instead, dopamine responses during the extended post-ingestive period may be particularly informative for understanding how circulating nutrients, including lipids, drive dopamine-dependent eating behavior following consumption of highly processed foods. This work parallels robust rodent evidence that intestinal nutrient sensing drives dopamine release, while highlighting key translational challenges in humans, including the optimal timing for capturing maximal post-ingestive dopamine responses. By situating dopamine within a sensory–metabolic integration framework, this work links chemoreception, internal state, and learned food preferences to mechanisms through which some ultra-processed foods may shape motivated eating behavior.
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No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.