LEP and obesity due to melanocortin 4 receptor deficiency: It has been postulated that, in obesity, neurons located in the ventromedial hypothalamic nucleus that express leptin receptors become desensitized to chronically elevated levels of leptin (hyperleptinemia) suppressing its anorexigenic effects while selectively preserving sympathoexcitation (known as “selective leptin resistance”) [57, 58].