Food reward in the absence of taste receptor signaling.
Food palatability and hedonic value play central roles in nutrient intake. However, postingestive effects can influence food preferences independently of palatability, although the neurobiological bases of such mechanisms remain poorly understood. Of central interest is whether the same brain reward circuitry that is responsive to palatable rewards also encodes metabolic value independently of taste signaling. Here we show that trpm5-/- mice, which lack the cellular machinery required for sweet taste transduction, can develop a robust preference for sucrose solutions based solely on caloric content. Sucrose intake induced dopamine release in the ventral striatum of these sweet-blind mice, a pattern usually associated with receipt of palatable rewards. Furthermore, single neurons in this same ventral striatal region showed increased sensitivity to caloric intake even in the absence of gustatory inputs. Our findings suggest that calorie-rich nutrients can directly influence brain reward circuits that control food intake independently of palatability or functional taste transduction.
de Araujo
Ivan E
IE
Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA. iaraujo@jbpierce.org
Oliveira-Maia
Albino J
AJ
Sotnikova
Tatyana D
TD
Gainetdinov
Raul R
RR
Caron
Marc G
MG
Nicolelis
Miguel A L
MA
Simon
Sidney A
SA
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D001786:Blood Glucose / Q000502:physiology; D002755:Choice Behavior / Q000502:physiology; D003216:Conditioning, Operant / Q000502:physiology; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005518:Food Preferences / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D009714:Nucleus Accumbens / Q000166:cytology; D012201:Reward; D015398:Signal Transduction / Q000502:physiology*; D018709:Statistics, Nonparametric; D013268:Stimulation, Chemical; D013395:Sucrose / Q000008:administration & dosage; D013549:Sweetening Agents / Q000008:administration & dosage; D050053:TRPM Cation Channels / Q000172:deficiency / Q000502:physiology*
D001786:Blood Glucose; D013549:Sweetening Agents; D050053:TRPM Cation Channels; C498617:Trpm5 protein, mouse; D013395:Sucrose; D004298:Dopamine