title: Intravascular food reward.
abstract: Consumption of calorie-containing sugars elicits appetitive behavioral responses and dopamine release in the ventral striatum, even in the absence of sweet-taste transduction machinery. However, it is unclear if such reward-related postingestive effects reflect preabsorptive or postabsorptive events. In support of the importance of postabsorptive glucose detection, we found that, in rat behavioral tests, high concentration glucose solutions administered in the jugular vein were sufficient to condition a side-bias. Additionally, a lower concentration glucose solution conditioned robust behavioral responses when administered in the hepatic-portal, but not the jugular vein. Furthermore, enteric administration of glucose at a concentration that is sufficient to elicit behavioral conditioning resulted in a glycemic profile similar to that observed after administration of the low concentration glucose solution in the hepatic-portal, but not jugular vein. Finally using fast-scan cyclic voltammetry we found that, in accordance with behavioral findings, a low concentration glucose solution caused an increase in spontaneous dopamine release events in the nucleus accumbens shell when administered in the hepatic-portal, but not the jugular vein. These findings demonstrate that the postabsorptive effects of glucose are sufficient for the postingestive behavioral and dopaminergic reward-related responses that result from sugar consumption. Furthermore, glycemia levels in the hepatic-portal venous system contribute more significantly for this effect than systemic glycemia, arguing for the participation of an intra-abdominal visceral sensor for glucose.
authors: Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, United States of America. albinojorgemai@gmail.com
authors: Albino J
authors: AJ
authors: Oliveira-Maia
authors: Craig D
authors: CD
authors: Roberts
authors: Q David
authors: QD
authors: Walker
authors: Brooke
authors: B
authors: Luo
authors: Cynthia
authors: C
authors: Kuhn
authors: Sidney A
authors: SA
authors: Simon
authors: Miguel A L
authors: MA
authors: Nicolelis
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001786:Blood Glucose / Q000378:metabolism; D003042:Cocaine / Q000008:administration & dosage; D004298:Dopamine / Q000378:metabolism; D004563:Electrochemistry / Q000379:methods; D005247:Feeding Behavior; D005502:Food; D005947:Glucose / Q000378:metabolism; D007601:Jugular Veins / Q000473:pathology; D008297:Male; D008955:Models, Cardiovascular; D009092:Mucous Membrane / Q000378:metabolism; D011169:Portal Vein / Q000473:pathology; D051381:Rats; D020318:Rats, Long-Evans; D017207:Rats, Sprague-Dawley; D012201:Reward; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D003042:Cocaine; D005947:Glucose; D004298:Dopamine