Distribution of hypothalamic neurons with orexin (hypocretin) or melanin concentrating hormone (MCH) immunoreactivity and multisynaptic connections with diaphragm motoneurons.

Prior work showed that neurons in the lateral, dorsal, and perifornical regions of the tuberal and mammillary levels of the hypothalamus participate in the control of breathing. The same areas also contain large numbers of neurons that produce either orexins (hypocretins) or melanin concentrating hormone (MCH). These peptides have been implicated in regulating energy balance and physiological changes that occur in transitions between sleep and wakefulness, amongst other functions.