کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5924136 | 1571184 | 2014 | 7 صفحه PDF | دانلود رایگان |
- Intragastric infusions of glucose rapidly stimulated intake and preference in rats.
- These appetition effects resembled those previously seen in mice.
- Non-metabolizable alpha-methyl-d-glucose (MDG) reduced intake and preference in rats.
- In contrast, moderate MDG concentrations are post-orally rewarding in mice.
- The method can be used to study peripheral and central post-oral food reward.
Mice adapted to drink a flavored saccharin solution (CSÂ â) paired with intragastric (IG) self-infusions of water rapidly increase their intake of a new flavored solution (CSÂ +) that is paired with IG glucose self-infusions. The present study extends this method to examine post-oral glucose appetition in rats. Food-restricted rats were trained to consume a CSÂ â flavor (e.g., grape saccharin) paired with IG water in 5 daily 1-h tests. In the next 3 tests, they drank a CSÂ + (e.g., cherry saccharin) paired with IG glucose. Rats infused with 8% glucose increased intake significantly on CSÂ + Test 1, but those infused with 16% glucose showed only a small increase in intake, which may reflect a counteracting satiating effect. Both groups further increased CSÂ + intakes in Tests 2 and 3, and preferred (81%) the CSÂ + to the CSÂ â in a two-bottle test without infusions. A second experiment investigated rats' responses to IG alpha-methyl-d-glucopyranoside (MDG), a non-metabolizable sugar analog which stimulates CSÂ + intake and preference in mice. The rats reduced their intake of the MDG-paired CSÂ + flavor over sessions, and preferred the CSÂ â to the CSÂ + in the choice test. The glucose data show that rats, like mice, rapidly detect the sugar's positive post-oral effects that can stimulate intake within the first hour of exposure. The MDG avoidance may indicate a greater sensitivity to its post-oral inhibitory effects in rats than in mice, or perhaps slower clearance of MDG in rats. The test protocol described here can be used to investigate the peripheral and central processes involved in stimulation of intake by post-oral nutrients in rats.
Journal: Physiology & Behavior - Volume 133, 22 June 2014, Pages 92-98