title: Flavor preferences conditioned by intragastric monosodium glutamate in mice.
abstract: The consumption of monosodium glutamate (MSG) solutions has been shown to reinforce preferences for MSG and for MSG-paired flavors in mice. These effects appear to have a strong postoral component, such that MSG detected in the gut is associated with concurrently consumed flavors. Two experiments investigated postoral MSG reward by infusing 400mM MSG intragastrically (IG) to C57BL/6 mice as they consumed a conditioned stimulus (CS+) flavor. An alternate CS- flavor was paired with IG water. In Experiment 1, the grape and cherry CS flavors were unsweetened, and intakes and preferences for the CS+ flavor were modest. Experiment 2 attempted to generate stronger preferences by adding 0.05% saccharin to the CS flavors. Sweet taste did enhance intakes during training and testing but did not significantly increase percent CS+ intake or persistence of the preference. However, only conditioning with the sweet CS+ resulted in the mice expressing a preference for oral MSG in an initial choice test with water. These findings extend recent studies demonstrating postoral MSG conditioning in rats.
authors.affiliation: Department of Psychology, Brooklyn College of CUNY, 2900 Bedford Avenue, Brooklyn, NY 11210, USA. kackroff@gc.cuny.edu.
authors.forename: Karen
authors.initials: K
authors.lastname: Ackroff
authors.forename: Anthony
authors.initials: A
authors.lastname: Sclafani
mesh_terms: D000818:Animals; D002755:Choice Behavior / Q000502:physiology; D005518:Food Preferences / Q000187:drug effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012970:Sodium Glutamate / Q000494:pharmacology*; D013549:Sweetening Agents / Q000494:pharmacology; D013649:Taste / Q000502:physiology
chemical_list: D013549:Sweetening Agents; D012970:Sodium Glutamate
keywords: C57BL/6; MSG; gastric infusion; intestinal chemosensing; sweet taste; umami