Chronic rapid eye movement (paradoxical) sleep deprivation (REM-SD) of rats leads to two conspicuous pathologies: hyperphagia coincident with body weight loss, prompted by elevated metabolism. Our goals were to test the hypotheses that 1) as a stressor, REM-SD would increase CRH gene expression in the hypothalamus and that 2) to account for hyperphagia, hypothalamic gene expression of the orexi...

Medial nucleus tractus solitarius (mNTS) neurons express leptin receptors (LepRs), and intra-mNTS delivery of leptin reduces food intake and body weight. Here, the contribution of endogenous LepR signaling in mNTS neurons to energy balance control was examined. Knockdown of LepR in mNTS and area postrema (AP) neurons of rats (LepRKD) via adeno-associated virus short hairpin RNA-interference (AA...

Whether or not factors besides hyperphagia influence cellularity of adipose tissue in gold thioglucose (GTG)-treated mice was examined. The animals were treated with GTG (800 mg/kg body weight) or saline as control. Control and one of the GTG-treated groups were given a diet ad libitum and another of the GTG-treated groups was pair-fed to control. In GTG-treated group fed ad libitum, hyperphagi...

Atypical antipsychotics such as olanzapine often induce excessive weight gain and type 2 diabetes. However, the mechanisms underlying these drug-induced metabolic perturbations remain poorly understood. Here, we used an experimental model that reproduces olanzapine-induced hyperphagia and obesity in female C57BL/6 mice. We found that olanzapine treatment acutely increased food intake, impaired ...

Prader-Willi syndrome (PWS) is a genetic disease caused by the loss of expression of genes of paternal origin in the region 15q11--q13 of chromosome 15. The main characteristics of the syndrome include neonatal hypotonia, feeding problems in infancy, characteristic facies, intellectual disability, behavioral changes, GH deficiency, hypogonadism, and hyperphagia. Hyperphagia leads to the develop...

Introduction 1Food intake in humans and other mammals is a complex process, resulting from the integration of homeostatic systems that monitor energy stores with hedonic drive resulting from the behaviorally reinforcing properties of food (Fig. 1) (Lutter and Nestler, 2009). Under conditions of food scarcity, the hedonic and homeostatic drives cooperate to enhance the intake of highly palatable...

Given the unabated obesity problem, there is increasing appreciation of expressions like "my eyes are bigger than my stomach," and recent studies in rodents and humans suggest that dysregulated brain reward pathways may be contributing not only to drug addiction but also to increased intake of palatable foods and ultimately obesity. After describing recent progress in revealing the neural pathw...

The success of antipsychotic drug treatment in patients with schizophrenia is limited by the propensity of these drugs to induce hyperphagia, weight gain and other metabolic disturbances, particularly evident for olanzapine and clozapine. However, the molecular mechanisms involved in antipsychotic-induced hyperphagia remain unclear. Here, we investigate the effect of olanzapine administration o...

Rapid growth of a transplantable insulinoma in rats over a 14 day period results in hyperphagia together with a selective increase in the weight and enteroglucagon (GLI) concentration of the small intestine. Measurement of serotonin concentrations by an HPLC/fluorometric method demonstrated an increase in blood (91%; p less than 0.05) and in extracts of colon (22%; p less than 0.05) but no chan...