Striatal signaling tracks naturalistic short-term fluctuations in hunger-satiety

Abstract

The neuromodulator dopamine is integral to feeding behavior, believed to modulate food pursuit and satiety. Here, we examine how dopamine signaling in the nucleus accumbens changes during consumption as animals transition from hunger to satiety in naturalistic feeding. Dopamine transiently increases during food approach; however, the magnitude of this approach-related increase diminishes across progressive pellet ingestion, reflecting short-term satiation. These approach-related dopamine transients recover during intermeal intervals. Fasting dissociates the regulation of meal size and frequency, reflecting termination and initiation, respectively, with observable differences in dopamine corresponding to changes in meal size but not frequency. Despite substantially decreasing feeding, pharmacological satiation via a glucagon-like peptide-1 (GLP-1) agonist had no impact on average dopamine transients on food approach but abolished the short-term fluctuations related to on-going eating, suggesting that the GLP-1 agonist disengaged or decoupled dopamine from its modulatory role in meal patterning.