Feeding behavior is an essential part of the energy balance control. It allows the maintenance of health and an adequate body weight. In the last years, the description of leptin action as a lipostatic or satiety factor in the hypotha1amus originated a burst of information about its action in food intake control and related disorders (obesity and anorexia). In parallel, an increasing number of peptides and receptors implicated in energy homeostasis have invaded the field. In this regard, melanin-concentrating hormone (MCH) has been related to the tonic control of feeding. MCH neurons are located in the hypothalamus, what made it a natural candidate for neuroendocrine, autonomic and behavioral control of the homeostasis and species subsistence. Accordingly, various findings support MCH action in feeding behavior: 1) MCH mRNA is abundant in fasted animals or obese (ob/ob) mice; 2) MCH administration in the cerebral ventricles or in specific hypothalamic nuclei that express MCH receptor (MCH -IR) induces hyperphagia and increases body weight; 3) MCH knock-out mice shows decreased body weight due to hypophagia and rise in energy expenditure; 4) MCH-IR knock-out mice are lean albeit hyperphagic; 5) administration of MCH-IR specific antagonists decreases body weight gain. Intriguingly however, the brain sites where MCH mar act inducing feeding, and the cell biology of these putative systems are not completely understood. It is important to point out that feeding is a complex behavior that includes homeostatic and hedonistic mechanisms, embracing since hunger sensation until motor activity, exploratory behavior, emotional responses, anxiety, memory and learning processes. Therefore, this study attempts to investigate MCH action in various feeding aspects and the related circuitry. Initially, we plain to analyze MCH participation in spatial orientation in the search for food, using a maze paradigm and different types of food: only nutritional or with hedonic value. In addition, using the same paradigm we propose to investigate the animal performance following lesion, or injection of MCH or anti-MCH in specific brain nuclei previously identified. In these regions, we intend to investigate the neurochemistry, the occurrence of synaptic terminals using electron microscopy, and describe the synaptic characterization. Finally, we aim to look into MCH role in complex systems of search for food that include predatory behavior. (AU)
Articles published in Agência FAPESP Newsletter about the research grant:
PACHECO FERREIRA, JOZELIA GOMES;
BITTENCOURT, JACKSON CIONI;
Melanin-concentrating hormone and sleep.
CURRENT OPINION IN NEUROBIOLOGY,
Web of Science Citations: 9.
DOS SANTOS JUNIOR, EDMILSON D.;
DA SILVA, ANDRE V.;
DA SILVA, KELLY R. T.;
HAEMMERLE, CARLOS A. S.;
BATAGELLO, DANIELLA S.;
DA SILVA, JOELCIMAR M.;
LIMA, LEANDRO B.;
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BITTENCOURT, JACKSON C.
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