AIF1 and obesity due to melanocortin 4 receptor deficiency: Consistent with previous findings that have demonstrated the occurrence of microgliosis in the hypothalamus of HFD-fed mice with obesity, we found an increased number of microglial cells and an elevated concentration of the Iba-1 protein in microglia of the hypothalamic nuclei, including arcuate nucleus (ARC), ventromedial nucleus of the hypothalamus (VMH), and dorsomedial nucleus of the hypothalamus (DMH).