Indeed, an excitatory-to-inhibitory switch of synapses on orexin somata has been reported in obese mice, both in the genetic model of obesity represented by leptin-deficient ob/ob mice and in mice subjected to high-fat diet (HFD), a model of diet-induced obesity (Cristino et al., 2013). The gene discussed is HCRT; the disease is obesity due to melanocortin 4 receptor deficiency.