The neuropeptide orexin/hypocretin (OX), while largely transcribed within the hypothalamus,
is released throughout the brain to affect complex behaviors. Primarily through the
hypothalamus itself, OX homeostatically regulates adaptive behaviors needed for survival,
including food intake, sleep–wake regulation, mating, and maternal behavior. However,
through extrahypothalamic limbic brain regions, OX promotes seeking and intake of
rewarding substances of abuse, like palatable food, alcohol, nicotine, and cocaine. This …