Glucose utilization rates regulate intake levels of artificial sweeteners.
It is well established that animals including humans attribute greater reinforcing value to glucose-containing sugars compared to their non-caloric counterparts, generally termed 'artificial sweeteners'. However, much remains to be determined regarding the physiological signals and brain systems mediating the attribution of greater reinforcing value to sweet solutions that contain glucose. Here we show that disruption of glucose utilization in mice produces an enduring inhibitory effect on artificial sweetener intake, an effect that did not depend on sweetness perception or aversion. Indeed, such an effect was not observed in mice presented with a less palatable, yet caloric, glucose solution. Consistently, hungry mice shifted their preferences away from artificial sweeteners and in favour of glucose after experiencing glucose in a hungry state. Glucose intake was found to produce significantly greater levels of dopamine efflux compared to artificial sweetener in dorsal striatum, whereas disrupting glucose oxidation suppressed dorsal striatum dopamine efflux. Conversely, inhibiting striatal dopamine receptor signalling during glucose intake in sweet-naïve animals resulted in reduced, artificial sweetener-like intake of glucose during subsequent gluco-deprivation. Our results demonstrate that glucose oxidation controls intake levels of sweet tastants by modulating extracellular dopamine levels in dorsal striatum, and suggest that glucose utilization is one critical physiological signal involved in the control of goal-directed sweetener intake.
I. E de Araujo: The John B. Pierce Laboratory & Yale University School of Medicine, 290 Congress Avenue, New Haven, CT 06519, USA. IAraujo@jbpierce.org or ivan.araujo@yale.edu.
Luis A
LA
Tellez
Xueying
X
Ren
Wenfei
W
Han
Sara
S
Medina
Jozélia G
JG
Ferreira
Catherine W
CW
Yeckel
Ivan E
IE
de Araujo
D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism / Q000502:physiology; D004298:Dopamine / Q000378:metabolism; D004435:Eating / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D006815:Hunger / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010084:Oxidation-Reduction; D011954:Receptors, Dopamine / Q000378:metabolism; D013549:Sweetening Agents / Q000378:metabolism*; D013649:Taste / Q000502:physiology
D011954:Receptors, Dopamine; D013549:Sweetening Agents; D005947:Glucose; D004298:Dopamine