Leptin signaling in the dorsomedial hypothalamus and its role in feeding circuits

• Published in: Appetite 2007-07, Vol.49 (1), p.289-289
• Main Authors: Faouzi, M., Leinninger, G.M., Louis, G., Leshan, R., Jones, J.C., Rhodes, C.J., Münzberg, H.
• Format: Article
• Language: English
• ISSN: 0195-6663; 1095-8304
• DOI: 10.1016/j.appet.2007.03.065

Leptin, an adipocyte-derived hormone, is well known to act in the hypothalamus to reduce food intake and deficiency of leptin signaling leads to morbid obesity, hyperphagia and disturbed thermoregulation. Many hypothalamic sites express leptin receptors (LRb), however, our knowledge about the role of these different target sites in the regulation of food intake is very limited. The dorsomedial hypothalamus (DMH) shows abundant expression of LRb and robust signaling in response to leptin. Using a cre/loxP system to express a virus driven EGFPf in distinct hypothalamic sites we were able to study the projection fields specifically of DMH/LRb neurons throughout the brain. Consistent with known roles of the DMH in the regulation of stress responses and food intake we found DMH/LRb projections in according areas like the bed nucleus of stria terminalis, the medial preoptic area, raphe pallidus, paraventricular nucleus and arcuate nucleus (ARC). Interestingly, LRb neurons in the DMH are densely innervated by orexigenic (AgRP) and anorexigenic (CART) fibers that likely originate from the ARC and are known to co-express LRb, suggesting a reciprocal regulation of the ARC/LRb and DMH/LRb system.