Role of glutamatergic signaling in the acquisition and expression of learned sugar preferences in C57BL/6 mice.

C57BL/6 (B6) mice learn to prefer glucose or sucrose to initially isopreferred or even more preferred nonnutritive sweeteners due to the postoral appetite stimulating (appetition) actions of glucose. Recent evidence indicates that specific duodenal neuropod cells transmit the glucose appetition signal to the brain via glutamatergic synaptic connections with vagal afferents. The present study found that intraperitoneal pretreatment with a glutamatergic receptor antagonist cocktail (kynurenic acid (KA)/D-2-amino-3-phosphonopentanoic acid (AP3)) in B6 mice did not block the expression of their learned preference for 8% glucose solution over an initially-preferred 0.

Conditioned preference and avoidance induced in mice by the rare sugars isomaltulose and allulose.

Isomaltulose, a slowly digested isocaloric analog of sucrose, and allulose, a noncaloric fructose analog, are promoted as "healthful" sugar alternatives in human food products. Here we investigated the appetite and preference conditioning actions of these sugar analogs in inbred mouse strains. In brief-access lick tests (Experiment 1), C57BL/6 (B6) mice showed similar concentration dependent increases in licking for allulose and fructose, but less pronounced concentration-dependent increases in licking for isomaltulose than sucrose.

Differential patterns of opioid and dopamine D1 receptor antagonism on nutritive and non-nutritive sweetener intakes in C57BL/6:129 hybrid mice relative to inbred C57BL/6 and 129 mice.

Opioid and dopamine (DA) D1 receptor antagonists differentially reduce nutritive and non-nutritive sweetener intakes in inbred mouse strains. Sucrose intake was more effectively reduced by naltrexone in C57BL/6 (B6) mice relative to 129P3 (129) mice, but more effectively reduced by SCH23390 in 129 mice relative to B6 mice. Opioid and DA D1 antagonists differentially reduced saccharin intakes in B6 mice relative to other strains.

Differential fructose and glucose appetition in DBA/2, 129P3 and C57BL/6 × 129P3 hybrid mice revealed by sugar versus non-nutritive sweetener tests.

Inbred mouse strains differ in their postoral appetite stimulating response (appetition) to fructose as demonstrated in intragastric (IG) sugar conditioning and oral sugar vs. nonnutritive conditioning experiments. For example, FVB and SWR strains show experience-induced preferences for 8% fructose over a 0.