To evaluate whether the apoptotic activity induced by the HF diet would affect differently the neuronal sub-populations of the arcuate nucleus, we performed double-staining immunohistochemistry in hypothalamic samples from Wistar rats and, while in control rats Caspase-3 was not detectable, in HF rats both orexigenic (AgRP, which is co-expressed with NPY) and anorexigenic (POMC) neurons expressed this apoptotic marker (Fig. 5A). Here, CASP3 is linked to hydrops fetalis.