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The role of orexin/hypocretin in the central nervous system and peripheral tissues

Tomomi Tsunematsu1, Akihiro Yamanaka

  • 1Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan.

Vitamins and Hormones
|May 30, 2012
PubMed

Insights

The orexin system regulates sleep-wake cycles and influences energy balance, emotions, and stress. This review explores orexin

Area of Science:

  • Neuroscience
  • Endocrinology
  • Physiology

Background:

  • Orexin (hypocretin) is a neuropeptide synthesized in the lateral hypothalamus.
  • It acts via orexin 1 and orexin 2 receptors, which are G-protein-coupled receptors.
  • Orexin signaling is crucial for maintaining sleep-wakefulness, with impairments leading to narcolepsy.

Purpose of the Study:

  • To review the diverse physiological roles of the orexin system.
  • To discuss orexin's functions within the central nervous system and peripheral tissues.

Main Methods:

  • Literature review of existing studies on orexin.
  • Analysis of research on orexin's impact on neurological and peripheral functions.

Main Results:

  • Orexin is vital for regulating sleep and wakefulness.
  • The orexin system also influences energy homeostasis, emotional regulation, stress responses, and reward pathways.
  • Emerging evidence indicates orexin affects peripheral tissues directly or via autonomic and endocrine pathways.

Conclusions:

  • The orexin system has widespread physiological importance beyond sleep regulation.
  • Orexin's influence extends to peripheral tissues, mediated by direct receptor activation or indirect neural and endocrine mechanisms.

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