Puberty as a critical risk period for eating disorders: A review of human and animal studies

This article is part of a Special Issue “Puberty and Adolescence”.     

Using the Activity-based Anorexia Rodent Model to Study the Neurobiological Basis of Anorexia Nervosa

Anorexia nervosa (AN) is a psychiatric illness characterized by excessively restricted caloric intake and abnormally high levels of physical activity. A challenging illness to treat, due to the lack of understanding of the underlying neurobiology, AN has the highest mortality rate among psychiatric illnesses. To address this need, neuroscientists are using an animal model to study how neural circuits may contribute toward vulnerability to AN and may be affected by AN. Activity-based anorexia (ABA) is a bio-behavioral phenomenon described in rodents that models the key symptoms of anorexia nervosa. When rodents with free access to voluntary exercise on a running wheel experience food restriction, they become hyperactive – running more than animals with free access to food. Here, we describe the procedures by which ABA is induced in adolescent female C57BL/6 mice. On postnatal day 36 (P36), the animal is housed with access to voluntary exercise on a running wheel. After 4 days of acclimation to the running wheel, on P40, all food is removed from the cage. For the next 3 days, food is returned to the cage (allowing animals free food access) for 2 hr daily. After the fourth day of food restriction, free access to food is returned and the running wheel is removed from the cage to allow the animals to recover. Continuous multi-day analysis of running wheel activity shows that mice become hyperactive within 24 hr following the onset of food restriction. The mice run even during the limited time during which they have access to food. Additionally, the circadian pattern of wheel running becomes disrupted by the experience of food restriction. We have been able to correlate neurobiological changes with various aspects of the animals’ wheel running behavior to implicate particular brain regions and neurochemical changes with resilience and vulnerability to food-restriction induced hyperactivity.     

Binge-Eating Disorder in Brazilian Women on a Weight-Loss Program

Objective: To examine binge-eating disorder (BED) and its association with obesity, weight patterns, and psychopathology in a Brazilian sample of female participants of a weight-loss program in São Paulo, Brazil. Research Methods and Procedures: Two hundred and seventeen overweight (body mass index ≥ 25 kg/m²) women, ages 15 to 59 years, enrolled in the Weight Watchers Program were recruited for the study at a program branch meeting after completing the Questionnaire on Eating and Weight Patterns–Revised, Beck Depression Inventory, and the Toronto Alexithymia Scale-20. Participants were categorized into four groups: those who met questionnaire criteria for BED, those who met questionnaire criteria for bulimia nervosa (BN), those that reported binge eating but did not meet all the criteria for any eating disorder (BE), and those with no eating disorder symptoms (No ED). Groups were compared on measures of weight, depressive symptoms, and alexithymia. Results: Binge eating was frequently reported by women in this study (BED, 16.1%; BN, 4.6%; BE, 22.6%). BED women had significantly higher body mass index, greater highest weight ever, and more frequent weight cycling than the No ED group. BED women also reported more depressive symptoms than BE and No ED women, and were more alexithymic than the No ED group. BE women presented more frequent weigh cycling and were also more depressed and alexithymic than the No ED group. Discussion: BED is not uncommon in overweight Brazilian women, and similar to North American and European samples, it is associated with overweight and higher levels of psychopathology in this population.     

Systems genetic analysis of binge-like eating in a C57BL/6J x DBA/2J-F2 cross

Binge eating is a heritable trait associated with eating disorders and refers to the rapid consumption of a large quantity of energy-dense food that is, associated with loss of control and negative affect. Binge eating disorder is the most common eating disorder in the United States; however, the genetic basis is unknown. We previously identified robust mouse inbred strain differences between C57BL/6J and DBA/2J in binge-like eating of sweetened palatable food in an intermittent access, conditioned place preference paradigm. To map the genetic basis of changes in body weight and binge-like eating (BLE) and to identify candidate genes, we conducted quantitative trait locus (QTL) analysis in 128 C57BL/6J x DBA/2J-F2 mice combined with PheQTL and trait covariance analysis in GeneNetwork2 using legacy BXD-RI trait datasets. We identified a QTL on Chromosome 18 influencing changes in body weight across days in females (log of the odds [LOD] = 6.3; 1.5-LOD: 3–12 cM) that contains the candidate gene Zeb1. We also identified a sex-combined QTL influencing initial palatable food intake on Chromosome 5 (LOD = 5.8; 1.5-LOD: 21–28 cM) that contains the candidate gene Lcorl and a second QTL influencing escalated palatable food intake on Chromosome 6 in males (LOD = 5.4; 1.5-LOD: 50–59 cM) that contains the candidate genes Adipor2 and Plxnd1. Finally, we identified a suggestive QTL in females for slope of BLE on distal Chromosome 18 (LOD = 4.1; p = 0.055; 1.5-LOD: 23–35 cM). Future studies will use BXD-RI strains to fine map loci and support candidate gene nomination for gene editing.     

Anorexia nervosa,advance directives,and the law: A British perspective

This article will explore whether the law should allow people with anorexia nervosa to refuse nutrition and hydration with special reference to the English decision in Re E (Medical Treatment: Anorexia). It argues that the judge in that case made the correct decision in holding that the patient, who suffered from severe anorexia nervosa, lacked capacity to make valid advance directives under the Mental Capacity Act 2005 of the United Kingdom, and that medical procedures that are apparently against her wishes should be carried out for the sake of preserving her life. The law should generally not permit patients with anorexia nervosa to decline nutrition and hydration, precisely because their autonomous ability to make such decisions has been substantially circumscribed by this psychiatric condition.     

Estimation of scopoletin from a polyherbal formulation composition using HPLC coupled with fluorescence detector through the concept of Design of Experiment

High-performance liquid chromatography (HPLC) coupled with a fluorescence detector was used to analyse bioactive phytoconstituent scopoletin from a polyherbal composition derived from the extract prepared from roots of Argyreia nervosa, roots of Withania somnifera, and fruits of Tribulus terrestris. This analytical method was developed as a quality control tool for standardization of the composition to be formulated to enhance spermatogenesis. Chromatographic separation was achieved using Luna® (250 mm × 4.6 mm, 100 Å, 5 μm) C₁₈ column as a stationary phase, and water (0.01 M glacial acetic acid):methanol: acetonitrile (60:20:20, %v/v/v) as the mobile phase; passed through the column at a set flow rate of 1.0 ml min⁻¹. The elute in the flow cell was excited at 345 nm and the chromatogram was recorded at 444 nm as the emission wavelength. As a part of the analytical Quality by Design approach, systemic studies were conducted to identify potential risks affecting the critical attributes (area, resolution, retention time) of the analytical method, and mitigating the potential risks after optimizing the chromatographic parameters with the help of the Design of Experiment approach. The developed analytical method was subjected to the validation studies, which showed a linear relationship (r² = 0.9982) between the concentration and the area corresponding to scopoletin peak in the concentration range 10–130 ng ml⁻¹. The method was found selective, sensitive, and precise. The recovery of the scopoletin was found in a range 99.53–102.13%; confirming the accuracy of the analytical method. The amount of scopoletin was estimated to be 0.146%w/w from the polyherbal composition.