Energyhomeostatic neurons of the mouse hypothalamus

The ability to take up and metabolize nutrients isvitally important for the survival of every livingorganism. Higher organisms need to control theirenergy uptake and expenditure, as a positive energybalance over time can lead to obesity and even earlydeath. The regulation of energy homeostasis,according to the neurocentric model, is performed bya small neuronal subnetwork in the hypothalamus. Thisnetwork comprises, among others, satiety mediating,pro-opiomelanocortin (POMC) expressing neurons andhunger mediating, agouti-related protein (AgRP)expressing neurons. They integrate signals from theperiphery about the nutritional status of theorganism and relay this information onto second orderneurons (e.g. SIM1 neurons in the paraventricularnucleus of the hypothalamus). Diet-induced obese micethat have received a high-fat diet can be used toinvestigate the effects of a prolonged positiveenergy balance on this network. In this thesis, theeffects of a high-fat diet on the calcium homeostasisof POMC neurons were investigated. In addition,candidates for putative second order neurons to POMCneurons (SIM1 neurons) and their cellular propertieswere characterized.