Definition of orexin in English:

Share this entry


Pronunciation: /ôˈreksin/


Either of two hormones ( orexin-A or orexin-B) produced by the mammalian hypothalamus and functional in the regulation of appetite and sleep. Also called hypocretin.
Example sentences
  • For example, physical activity increased in rats when injected with orexin, a brain chemical associated with sexual arousal.
  • The lateral hypothalamus contains cells that secrete a protein neurotransmitter called ‘orexin’ or ‘hypocretin.’
  • Human narcolepsy generally stems from a shortage of the neurons, which produce the excitatory neurotransmitter known both as hypocretin and orexin.
Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.