In this animationm how providing leptin to an obese mouse rapidly rewires its hypothalamus neurons is illustrated. When obese mice were given leptin injections, researchers found that the neurons in their hypothalamus were actually being rapidly rewired. Less excitatory inputs and more inhibitory inputs were connected to those neurons responsible for encouraging feeding (called NPY), and the opposite occurred for those neurons responsible for discouraging feeding (called POMC). Source: HHMI