Abstracts / Appetite 52 (2009) 815–868 849 Meal induced changes in BOLD fMRI activity in the rodent brain D.K. MIN 1,∗ , U.I. TUOR 2 , H.S. KOOPMANS 1 , P.K. CHELIKANI 1 1 Gastrointestinal Research Group, Faculties of Medicine and Veteri- nary Medicine, Calgary, AB, Canada 2 Institute for Biodiagnostics (West), NRC, Faculty of Medicine, Calgary, AB, Canada Blood Oxygen Level Dependent Functional Magnetic Resonance Imaging (BOLD fMRI) techniques are an important tool for inves- tigating central regulation of hunger and satiety in humans. Our objective is to develop a reproducible rodent model for studying the effect of a mixed-nutrient liquid meal (Ensure) on BOLD fMRI activity in the brain. Adult Sprague–Dawley rats with implanted intragastric (IG) catheters were adapted to 12-h Ensure access on a reverse light schedule. Under anesthesia, the rats received IG infu- sion of either saline (n = 4) or Ensure (n = 4; 12 kcal) at 2 ml/min. Brain images were acquired with a 9.4T magnet using a sur- face RF coil, and a cluster analysis program (Evident) was used to identify voxel changes within the brain which correlated with the infusion paradigms. Ensure infusion resulted in a transient reduction in MR signal intensity in the Nucleus Tractus Solitarius (NTS), hypothalamus, thalamus, hippocampus, ventral tegmental area (VTA), caudate putamen and higher cortical structures (pari- etal cortex). Time course analysis indicated that Ensure produced a 6% reduction in MR signal intensity within the hypothalamus, NTS and VTA, and a 4% reduction in signal intensity within the hip- pocampus and caudate putamen. Saline infusion did not produce a similar response. These results suggest that IG infusion of a mixed nutrient liquid meal produces a transient generalized reduction in BOLD fMRI signal intensity in brain regions that are hypothesized to regulate food consumption. doi:10.1016/j.appet.2009.04.142 Consumer views of hunger and fullness. A qualitative approach M.B. MURRAY ∗ , Z.M. VICKERS University of Minnesota, Saint Paul, MN, USA The objective of this study was to gain a better understand- ing of the complex ideas of hunger and fullness from consumers through the use of focus groups. We report results of 4 focus group interviews with (1) eight female normal weight dieters, (2) nine female normal weight non-dieters, (3) seven female overweight dieters and non-dieters, and (4) seven male normal weight dieters and non-dieters. Hunger and fullness sensations were described as having both physical and psychological components that were divided into two groups: typical and extreme. Overall, hunger was described as the presence of stomach growls, stomach hunger pains, emptiness, focus on eating, loss of energy, and desire to eat. Full- ness was described as a feeling of food in the stomach, stomach stretch, satisfaction, contentment, energized, focused, and lack of the desire to eat. Typical fullness was described with many psycho- logical components while typical hunger was primarily physical in nature. Participants described situations in which sensations of hunger and fullness overlapped, which provided evidence that hunger and fullness are not polar opposites. doi:10.1016/j.appet.2009.04.143 Learned preference for flavors experienced early vs. late in a nutritive meal K.P. MYERS ∗ , M.C. WHITNEY Bucknell University, Lewisburg, PA, USA Food preferences are strongly influenced by learned associa- tions between flavors and postingestive consequences. Rats learn to prefer a flavor that has been paired with postingestive effects of carbohydrates. The present experiment investigates this learning when multiple flavors occur in a meal accompanied by carbohy- drate, specifically, a flavor experienced in the early half vs late half of the meal. Stronger learning about either the earlier or later fla- vor may indicate how soon after meal initiation the “reinforcing” postingestive events occur. Rats with intragastric (IG) catheters were accustomed to drinking a sweet but calorically dilute solu- tion in brief daily sessions. They then experienced two types of training sessions in which flavors were added. In (+) sessions, con- sumption of flavors was accompanied by IG glucose infusion. In (-) sessions consumption of flavors was accompanied by IG water. In both types of sessions, an “early” (E) flavor was provided in the first half (10min) of the session and a “late” (L) flavor in the sec- ond half. Thus, rats were trained with four flavors: E+ and L+ in the (+) sessions, and E- and L- in the (-) sessions. Learned prefer- ences for E+ and L+ were then assessed in two-bottle choice tests between E+ vs E-, L+ vs L-, and E+ vs L+. Rats learned to prefer E+ but not L+, possibly suggesting that the reinforcing postinges- tive events have fairly rapid onset. However, we also observed an unexpected tendency of rats to suppress consumption of L+ during training, possibly limiting their opportunity to learn about L+. doi:10.1016/j.appet.2009.04.144 Identification of melanocortin receptor subtypes involved in lipolysis in murine 3T3-L1 adipocytes C. MøLLER ∗ , K. RAUN, M.L. JACOBSEN, B.S. WULFF Novo Nordisk A/S, Denmark, Maaloev, Denmark The melanocortins have been proposed to play a central role in regulating adipocyte metabolism. The metabolic effects of melanocortin peptides and their receptors have aroused an inter- est for the system, due to the global epidemics of obesity and type 2 diabetes. Five melanocortin receptors have been identi- fied: melanocortin receptor (MC) 1, MC2, MC3, MC4 and MC5. These belong to the 7-transmembrane G-protein coupled recep- tor family and are located diversely in humans. Natural occurring melanocortin peptides such as ACTH and a-MSH are generated from proopiomelanocortin (POMC). These peptides as well as the a-MSH analogs MTII, SHU-9119, LY2112688 and beta adrenergic agonist isoproterenol have been found to induce lipolysis in murine 3T3- L1 adipocytes. When MC receptors are stimulated by an agonist, triglyceride is hydrolysed to glycerol and free fatty acids (FFA), after which FFA can be measured as an index of lipolysis. By using receptor specific analogs, MC receptors of lipolytic importance can be identified. Furthermore, MC1-5 mRNA transcript abundance by means of q-PCR in differentiated 3T3-L1 adipocytes, indicate which MC receptors might be exerted during lipolysis. Our data show that only MC1, 2 and 5 are involved in 3T3-L1 lipolysis during stimula- tion. Furthermore, MC1 and 5 mRNA transcripts are up-regulated in differentiated 3T3-L1 cells compared to non-differentiated 3T3-L1 cells. doi:10.1016/j.appet.2009.04.145