Central neuropeptides, including corticotropin releasing factor and perhaps substance P as well, initiate a systemic stress mobilization response by activating the sympathetic nervous system, hypothalamic pituitary axis, and the renin angiotensin system,
The novel neuropeptides hypocretin and orexin, located recently on the lateral hypothalamic cells, has been linked to both feeding and sleeping/waking cycles. Recent studies have found an association between defects in hypocretin/orexin and narcolepsy.