Introduction: Gonadotropin inhibitory hormone (GnIH) and Agouti-related peptide (AgRP) are orexigenic peptides expressed in the arcuate nucleus (Arc) of the hypothalamus in the ewe. In addition, effects of GnIH and AgRP on the regulation of gonadotropin releasing hormone secretion have been shown in some mammals. The objective of the present study was to investigate the coexpression of GnIH ...

Figure 1: Regulation of food intake by negative valence and positive valence appetitive systems, visceral aversive pathways, and the relationship with homeostatic deficit. Negative valence appetitive systems (e.g., AGRP neurons) are under homeostatic control, but AGRP neurons are rapidly inhibited by cues that predict food, thus consumption is associated with the positive valence system. Positi...

The arcuate nucleus of the hypothalamus contains at least two populations of neurons that continuously monitor signals reflecting energy status and promote the appropriate behavioral and metabolic responses to changes in energy demand. Activation of neurons making pro-opiomelanocortin (POMC) decreases food intake and increases energy expenditure through activation of G protein-coupled melanocor...

Metabolic fuels act on hypothalamic neurons to regulate feeding behavior and energy homeostasis, but the signaling mechanisms mediating these effects are not fully clear. Rats placed on a low-protein diet (10% of calories) exhibited increased food intake (P < 0.05) and hypothalamic Agouti-related protein (Agrp) gene expression (P = 0.002). Direct intracerebroventricular injection of either an a...

The melanocortin 4 receptor (MC4R) is a G protein-coupled receptor mainly expressed in the central nervous system of vertebrates. Activation of the MC4R leads to a decrease in food intake, whereas inactivating mutations are a genetic cause of obesity. The binding of agouti-related protein (AGRP) reduces not only agonist-stimulated cAMP production (competitive antagonist) but also the basal acti...

Neuropeptide Y (NPY)/Agouti-related peptide (AgRP)-expressing neurons in the hypothalamus induce feeding and decrease energy expenditure. With consumption of a diet high in fat, there is an increase in circulating saturated free fatty acids, including palmitate, leading to the development of neuroinflammation and secretion of cytokines, such as TNFα, and in turn activation of the canonical IKKβ...