The cell bodies of orexinergic neurons are present in
Locus ceruleus
Dorsal raphe
Lateral hypothalamic area
Hippocampus
Brains from humans with narcolepsy often contain fewer hypocretin (orexin) producing neurons in the hypothalamus. hypothalamic neurons release orexin to play a role inswitching between sleep and wakefulness Ganongs review of medical physiology;26rd edition;pg:268,273
Nervous system