title: Combined compared to dissociated oral and intestinal sucrose stimuli induce different brain hedonic processes.
abstract: The characterization of brain networks contributing to the processing of oral and/or intestinal sugar signals in a relevant animal model might help to understand the neural mechanisms related to the control of food intake in humans and suggest potential causes for impaired eating behaviors. This study aimed at comparing the brain responses triggered by oral and/or intestinal sucrose sensing in pigs. Seven animals underwent brain single photon emission computed tomography ((99m)Tc-HMPAO) further to oral stimulation with neutral or sucrose artificial saliva paired with saline or sucrose infusion in the duodenum, the proximal part of the intestine. Oral and/or duodenal sucrose sensing induced differential cerebral blood flow changes in brain regions known to be involved in memory, reward processes and hedonic (i.e., pleasure) evaluation of sensory stimuli, including the dorsal striatum, prefrontal cortex, cingulate cortex, insular cortex, hippocampus, and parahippocampal cortex. Sucrose duodenal infusion only and combined sucrose stimulation induced similar activity patterns in the putamen, ventral anterior cingulate cortex and hippocampus. Some brain deactivations in the prefrontal and insular cortices were only detected in the presence of oral sucrose stimulation. Finally, activation of the right insular cortex was only induced by combined oral and duodenal sucrose stimulation, while specific activity patterns were detected in the hippocampus and parahippocampal cortex with oral sucrose dissociated from caloric load. This study sheds new light on the brain hedonic responses to sugar and has potential implications to unravel the neuropsychological mechanisms underlying food pleasure and motivation.
authors.affiliation: INRA, UR1341 Alimentation et Adaptations Digestives, Nerveuses et Comportementales Saint Gilles, France ; INRA, UMR1348 Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Élevage Saint Gilles, France ; Agrocampus Ouest, UMR1348 Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Élevage Rennes, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Clouard
authors.affiliation: INRA, UMR1348 Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Élevage Saint Gilles, France ; Agrocampus Ouest, UMR1348 Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Élevage Rennes, France.
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Meunier-Salaün
authors.affiliation: INRA, UR1341 Alimentation et Adaptations Digestives, Nerveuses et Comportementales Saint Gilles, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Meurice
authors.affiliation: INRA, US1395 Ani-Scans, Rennes France.
authors.forename: Charles-Henri
authors.initials: CH
authors.lastname: Malbert
authors.affiliation: INRA, UR1341 Alimentation et Adaptations Digestives, Nerveuses et Comportementales Saint Gilles, France.
authors.forename: David
authors.initials: D
authors.lastname: Val-Laillet
keywords: brain metabolism; cognition; food motivation; reward; sugar sensing