850 Abstracts / Appetite 52 (2009) 815–868 Effect of the melanin concentrating hormone 1 (MCH 1) receptor antagonist SNAP 94847 on food self-administration and relapse to food seeking S.G. NAIR ∗ , T. ADAMS-DEUTSCH, C.L. PICKENS, Y. SHAHAM NIDA/IRP, NIH/DHHS, Baltimore, MD, USA Many studies report an important role of MCH 1 receptors in home-cage food intake. In contrast, the role of these recep- tors in operant food self-administration or relapse to food-seeking is unknown. In Experiment 1, we trained food-restricted rats (∼16g/day) to lever press for 45mg high-fat pellets for 14 days (3 h/day, every other day) under a fixed-ratio-1, 20 s timeout rein- forcement schedule. We then tested the effect of the MCH 1 receptor antagonist SNAP 94847 (3–30mg/kg, i.p.) on pellet self- administration. In Experiment 2, we trained rats to self-administer high-fat pellets as in Experiment 1, and after extinction of the food- reinforced responding over 10–17 days, tested the effect of SNAP 94847 on reinstatement of lever responding (the operational mea- sure of food seeking) induced by MCH (20 g, icv), non-contingent exposure to three pellets (pellet-priming), cues previously asso- ciated with pellet delivery (pellet-cue), or the pharmacological stressor yohimbine (2 mg/kg, i.p.). We found that SNAP 94847 atten- uated pellet self-administration and MCH-induced reinstatement of lever responding. In contrast, SNAP 94847 had no effect on pellet-priming-, pellet-cue- or yohimbine-induced reinstatement of lever responding. These data indicate an important role of MCH 1 receptors in operant pellet self-administration and MCH-induced reinstatement of food seeking, but not in reinstatement induced by acute exposure to high-fat food, food cues or the stress-like state induced by yohimbine. doi:10.1016/j.appet.2009.04.146 Estrogen and HSD 2 labeling in the nucleus tractus solitarius of rats M.T. NGO ∗ , J.L. HACKETT, K.S. CURTIS Oklahoma State University Center for Health Sciences, Tulsa, OK, USA 11--Hydroxysteroid dehydrogenase type 2 (HSD 2 ), an enzyme found in neurons of the nucleus tractus solitarius (NTS), has been shown to be influenced by sodium need and salt intake. In female rats, salt intake is stimulated during high estrogen conditions. Therefore, the goal of this study was to determine whether estro- gen influenced basal levels of HSD 2 in the NTS of female rats. Adult female Sprague–Dawley rats were bilaterally ovariectomized and allowed to recover before treatment with estradiol benzoate (EB) or the oil vehicle (OIL) on two consecutive days. Rats were perfused 48-h after the second injection; brains were removed, post-fixed overnight, and then cut into 40 m sections. HSD 2 labeling in the NTS was visualized using standard immunohistochemical methods (primary antibody: rabbit anti-HSD 2 , Santa Cruz; secondary anti- body: Cy2 goat anti-rabbit IgG, Jackson Immunoresearch). HSD 2 labeled neurons were quantified in the caudal, middle, and rostral regions of the NTS using fluorescence microscopy and NIS Elements software. Overall, there were significantly fewer HSD 2 neurons in the caudal region compared to the middle and rostral regions. How- ever, there were no differences between OIL- and EB-treated rats in the number of HSD 2 -labeled neurons in any of the three regions of the NTS. These results show that the number of HSD 2 neurons in the NTS was not affected by the presence of estrogen under basal condi- tions. Thus, estrogen effects on basal salt intake are not attributable to differences in the number of HSD 2 neurons. doi:10.1016/j.appet.2009.04.147 Ingestion of highly palatable foods modulates c-Fos expression in the nucleus accumbens responding to stress in rats S.J. NOH ∗ , S.B. YOO, J.Y. KIM, J.-H. LEE, J.W. JAHNG Dental Research Institute, Department of Oral and Maxillofacial Surgery, Seoul National University College of Dentistry, Seoul, Republic of Korea It has been reported that ingestion of highly palatable foods attenuates the HPA axis responses to stressors. Not only stres- sors but also palatable food intake produces strong signals in the nucleus accumbens (NAcb). This study was conducted to exam- ine if ingestion of palatable food modulates the stress-induced neuronal activation in NAcb and/or gene expression of tyrosine hydroxylase (TH), rate limiting enzyme of dopamine biosynthe- sis, in the ventral tegmental area (VTA). Rats on ad libitum chow diet received daily 1h access to chocolate cookie for 7 days, and then were placed in restraint cage for 2 h following the last cookie session. Control group received 2 h restraint omitting cookie ses- sions. Tail bloods were collected at 0, 20, 60 and 120min time points during the restraint session. All rats were sacrificed imme- diately after the end of restraint, and the brains were processed for c-Fos immunohistochemistry in NAcb and TH mRNA in situ hybridization in VTA. No stress control rats were processed in par- allel. Stress-induced increases of plasma corticosterone and the hypothalamic CRH were blunted in the cookie group. Interestingly, stress-induced Fos expression was not affected in NAcb-core, and even further increased in NAcb-shell, by cookie intake. Results sug- gest that palatable food intake may increase susceptibility of NAcb neurons to stress, perhaps, in relation with blunted response of the HPA axis. The VTA-TH is under analysis. doi:10.1016/j.appet.2009.04.148 Emotional and external eating are associated with poor sleep quality in college students L.J. NOLAN ∗ , S.M. JENKINS Psychology Department, Wagner College, Staten Island, NY, USA Short sleep duration (SD) has been associated with elevated BMI [Gangwisch et al., Sleep 2005;28:1289–1296], disordered eating [Hicks & Rozette, Percept. Mot. Skills 1986;62:209–210], emotional stress [Vgontzas et al., Int. J. Obes. 2008;32:801–809] and neuroen- docrine control of appetite [Cauter et al., Horm. Res. 2007;67:2–9]. The possible role of emotional and external eating in the SD–BMI association was tested by examining the relationship between sleep quality, SD, BMI, and scores on the DEBQ in a sample of college students (N = 240, 75% female, mean age = 19 years, BMI = 23 kg/m 2 , 23% overweight or obese, 84% White). Participants were admin- istered the DEBQ, Sleep Quality Index (SQI), and asked to report height and weight in small groups in a laboratory setting. Based on SQI score, participants were divided into good sleep quality (n = 31), occasional sleep difficulty (n =177), and poor sleep quality (n = 31) groups. One-way MANOVA revealed that participants with poor sleep quality had higher emotional eating, F(2, 234) = 3.99, p = .02, and external eating scores, F(2, 236) = 3.44, p = .03. There was no difference in restraint scores or BMI. A significant correlation was found between SD and BMI, r(231) = -.15, p =.01. BMI was corre- lated only with restraint on DEBQ, r(236) = .14, p = .01. In this sample, emotional and external eating may not mediate the relationship between BMI and SD. However, students who emotionally eat may be setting unhealthy patterns that will affect BMI as they age. A relationship between emotional eating and BMI has been found in samples with higher mean age (van Strien et al., Addict. Behav. 1985;10:333–343). doi:10.1016/j.appet.2009.04.149