Caloric Restriction Increases the Sensitivity to the Hyperphagic Effect of Nociceptin/orphanin FQ Limiting Its Ability to Reduce Binge Eating in Female Rats.
Caloric restriction increases the sensitivity to the hyperphagic effect of nociceptin/orphanin FQ limiting its ability to reduce binge eating in female rats.
Psychopharmacology (Berl). 2013 Mar 2;
Micioni Di Bonaventura MV, Ubaldi M, Liberati S, Ciccocioppo R, Massi M, Cifani C
RATIONALE: Nociceptin/orphanin FQ (N/OFQ) is a functional antagonist of corticotrophin-releasing factor, the main mediator of the stress response. Stress represents a key determinant of binge eating (BE) for highly palatable food (HPF). OBJECTIVES: In relation to the antistress properties of N/OFQ, we evaluated its effect on BE. After the observation that episodes of food restriction increase the sensitivity to its hyperphagic effects, the function of NOP receptor and N/OFQ was investigated after cycles of food restrictions. MATERIALS AND METHODS: In BE experiments, four groups were used: rats fed normally and not stressed or stressed, rats exposed to cycles of restriction/refeeding and then stressed, or not stressed. In the other experiments, two groups were used: rats exposed or not to food restriction. RESULTS: Only restricted and stressed rats exhibited BE for HPF (containing chocolate cream). Intracerebroventricular injections of N/OFQ of 0.5 nmol/rat significantly reduced BE. N/OFQ 1 nmol/rat did not reduce BE but significantly increased HPF intake following food restrictions. Cycles of food restriction increased animals’ sensitivity to the hyperphagic effect of N/OFQ for HPF. In situ hybridization studies following food restrictions showed decreased ppN/OFQ mRNA expression in the bed nucleus of the stria terminalis and increased expression of ppN/OFQ and NOP receptor mRNA in the ventral tegmental area and in the ventromedial hypothalamus, respectively. CONCLUSIONS: These findings indicate that N/OFQ slightly reduces BE at low doses, while higher doses increase HPF intake, due to increased sensitivity to its hyperphagic effect following a history of caloric restrictions. HubMed – eating
The uniqueness of negative urgency as a common risk factor for self-harm behaviors, alcohol consumption, and eating problems.
Addict Behav. 2013 Feb 5; 38(5): 2158-2162
Dir AL, Karyadi K, Cyders MA
Research suggests that self-control, affective lability, and negative urgency are associated with deliberate self-harm, problematic alcohol consumption, and eating problems. Few studies have fully examined how negative urgency might uniquely explain the effects of self-control and affective lability on these outcomes, as compared to other impulsivity-related traits. This was the goal of the current study. Of an initial group of 734 undergraduate students, 29% indicated a history of deliberate self-harm. These 215 individuals were randomly matched with a group of non-self-harmers (total N=430; mean age=22.36, SD=6.59; 76.2% female). Self-harmers showed higher rates of alcohol use (F(2, 186)=5.48, p<.001) and eating problems (F(2, 186)=7.74, p<.001). In a structural equation model, negative urgency was significantly associated with self-harming frequency (?=3.81, p<.001), variety of self-harm methods (?=5.79, p<.001), the number of years of self-harming (?=2.75, p<.001), problematic alcohol use (?=1.80, p<.05), and eating problems (?=3.99, p<.001). Negative urgency was positively associated with affective lability (?=7.71, p<.001) and negatively associated with self-control (?=-13.59, p<.001). Negative urgency is the only impulsivity-related trait that is a common risk factor associated with increased self-harm, problematic alcohol use, and eating problems. HubMed – eating
The effects of body temperature and mass on the postprandial metabolic responses of the African egg-eating snakes Dasypeltis scabra and Dasypeltis inornata.
Comp Biochem Physiol A Mol Integr Physiol. 2013 Feb 27;
Greene S, McConnachie S, Secor S, Perrin M
African egg-eating snakes (Dasypeltis) feed only on freshly laid bird eggs which they perforate within their esophagus before swallowing the liquid contents and regurgitating the empty shell. Compared to a snake’s typical intact meal, the liquid diet of Dasypeltis would expectedly generate a more moderate postprandial metabolic response and specific dynamic action (SDA). Free-ranging Dasypeltis feed over a range of ambient temperatures and thereby experience predicted temperature-dependent shifts in the duration and magnitude of their postprandial metabolic response. Such shifts would undoubtedly be shared among different species and age classes of Dasypeltis. To examine these expectations, we measured pre- and postprandial metabolic rates of adult Dasypeltis inornata and adult and neonate Dasypeltis scabra in response to liquid egg meals weighing 20% of snake body mass at 20, 25, 27, 30, and 32°C. With an increase in body temperature, postprandial metabolic profiles of neonate and adult snakes became narrower and shorter in duration. Specific dynamic action varied among temperature treatments, increasing from 20 to 32°C. Standard metabolic rate, postprandial peak metabolic rate, and SDA scaled with mass exponents that typically did not differ from 1.0. As expected, Dasypeltis digesting a liquid egg diet experienced a more modest postprandial response and SDA, expending on average only 10.6% of the meal’s energy on the breakdown, absorption, and assimilation of the egg meal, whereas other colubrids consuming intact rodent or fish meals expend on average 16.3% of the meal’s energy on digestion and assimilation. Actively foraging and feeding throughout the avian egg laying season enable Dasypeltis to survive when eggs are not available. The adaptive suite of traits that enable Dasypeltis to consume eggs of large relative size and ingest only the liquid contents may also be joined by physiological adaptations specific to their liquid diet and extended bouts of fasting. HubMed – eating
The relationship between decision-making and perfectionism in obsessive-compulsive disorder and eating disorders.
J Behav Ther Exp Psychiatry. 2013 Feb 8; 44(3): 316-321
Boisseau CL, Thompson-Brenner H, Pratt EM, Farchione TJ, Barlow DH
BACKGROUND AND OBJECTIVES: Obsessive-compulsive disorder (OCD) and eating disorders (EDs) show phenotypic similarities and have been independently associated with deficits in decision-making and maladaptive perfectionism. However, research directly comparing the two disorders is sparse and the significance of observed similarities remains in question. Therefore, the present study compared decision-making in OCD and EDs in relationship to perfectionistic personality traits. METHODS: Sixty-one women were enrolled in the study comprising 3 mutually exclusive groups: 19 with OCD, 17 with EDs, and 21 healthy controls. Decision-making performance on the Iowa Gambling Task under two conditions, ambiguity and risk, was examined in relationship to perfectionistic traits. RESULTS: Behavioral results indicated that EDs participants, relative to both OCD and control participants, were impaired in decision-making under conditions of risk. Heightened perfectionism was associated with less risky decision-making in OCD, but more risky decision-making in EDs. LIMITATIONS: Sample size was small and all participants were women, which may limit generalizability. CONCLUSION: Results support decision-making deficits in EDs, which may be related to a dysfunctional determination of risk versus reward. This study is the first to suggest that the relationship between perfectionism and risk taking may manifest differently in these phenotypically similar disorders. HubMed – eating