Takeshi Sakurai^a,b  Yuki C. Saito^a  Masashi Yanagisawa^a

^aInternational Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan;
^bFaculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan

© 2021 The Author(s)
Published by S. Karger AG, Basel

• Chapter 2 graphical abstract

Orexins have received a lot of attention as potent endogenous arousal-promoting peptides, and orexin receptor antagonists have shown clinical efficacy for the treatment of insomnia. Orexin neurons are thought to act primarily on monoaminergic neurons to maintain arousal and vigilance. In this chapter, we discuss the functional interaction between monoaminergic systems, including noradrenaline, serotonin and histamine, and orexin neurons, as well as interactions between the acetylcholine system and the orexin neurons, focusing, in particular, on their function in the regulation of sleep-wakefulness states. Orexin also has close interactions with the dopaminergic system, and many studies have suggested roles of orexin signaling in the reward system and roles for orexins in drug addiction.

• Orexin neurons strongly excite monoaminergic neurons in the brain stem regions.
• These connections play important roles in the regulation of sleep and wakefulness.

• Request