title: Differences in BOLD responses to intragastrically infused glucose and saccharin in rats.
abstract: The postingestive effect is different between caloric and noncaloric sweeteners. The gut administration of glucose induces a preference for flavored water which is paired with the intragastric infusion of glucose. However, a comparison of the brain response to the gut glucose and saccharin stimuli still remains to be demonstrated. Here, using functional magnetic resonance imaging, we investigated the blood oxygenation level-dependent signal response to gut glucose and saccharin in the brain of conscious rats. Glucose induced a positive signal increase in the amygdala and nucleus accumben, both of which receive dopaminergic input from the ventral tegmental area. In contrast, saccharin administration did not activate these areas. Both glucose and saccharin increased the blood oxygenation level-dependent signal intensity in the insular cortex and the nucleus of the solitary tract. These results show that there were significant differences between postingestive glucose and saccharin-induced increases in the blood oxygenation level-dependent signal in rats. Together with previous findings, these results suggest distinct activation patterns in the brain for both glucose and saccharin, which is partially due to different changes of internal signals, including the blood glucose and insulin levels.
authors.affiliation: Institute for Innovation, Ajinomoto Co., Inc., Suzuki-cho 1-1, Kawasaki-ku, Kawasaki 210-8601, Japan Present address: CEA/DSV/I2BM/NeuroSpin, Bât 145, Point Courrier 156, 91191 Gif-sur-Yvette, France tsurugizawa@gmail.com.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Tsurugizawa
authors.affiliation: Institute for Innovation, Ajinomoto Co., Inc., Suzuki-cho 1-1, Kawasaki-ku, Kawasaki 210-8601, Japan.
authors.forename: Hisayuki
authors.initials: H
authors.lastname: Uneyama
mesh_terms: D000679:Amygdala / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000502:physiology*; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology; D010100:Oxygen / Q000097:blood; D017207:Rats, Sprague-Dawley; D012439:Saccharin / Q000008:administration & dosage / Q000494:pharmacology*; D013270:Stomach / Q000187:drug effects / Q000502:physiology; D013549:Sweetening Agents / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D013549:Sweetening Agents; D012439:Saccharin; D005947:Glucose; D010100:Oxygen
keywords: functional MRI; glucose; nucleus accumbens; rat; saccharin