Ultrastructural localization of the receptor for leptin in the rat hypothalamus

Ultrastructural localization of the leptin receptor in the rat hypothalamus was studied by immunocytochemistry. The antiserum against the leptin receptor which was used specifically recognized the carboxy terminal of the cytoplasmic domain. Intense leptin receptor immunoreactivity was detected in the arcuate, paraventricular, and ventromedial nuclei of the hypothalamus and in the lateral hypothalamic area. At the ultrastructural level, leptin receptor-like immunoreactivity appeared to be concentrated predominantly in perikarya and dendrites of these areas and strong immunolabeling for the leptin receptor was detected in the plasma membrane, rough endoplasmic reticulum, Golgi apparatus, and cytoplasmic matrix. This study provides the first detailed fine structure of leptin receptor-immunoreactive neurons in the rat hypothalamus. It may help to provide better understanding of the functions of leptin in the rat hypothalamus.