DATE2025.06.24 #Press Releases

Identification of Neurons that Act as a Switch for REM Sleep, a Major Source of Dreams

— Neurons active exclusively during REM sleep revealed after decades of mystery —

Summary

A research team led by Mr. Yoshifumi Arai (a graduate student at the time of research) and Professor Yu Hayashi of the Department of Biological Sciences, School of Science, The University of Tokyo (also a visiting professor at the International Institute for Integrative Sleep Medicine [WPI-IIIS], Tsukuba Institute for Advanced Research [TIAR], University of Tsukuba), has identified for the first time the identity and function of neurons in the brainstem that are exclusively active during REM sleep—a long-standing enigma in sleep research (Figure).

These neurons, commonly referred to as “REM-on neurons,” are inactive during wakefulness but begin to fire just before the onset of REM sleep. Although it was known for decades that such neurons exist in the brainstem, the exact identity of the cells and whether they were truly involved in controlling REM sleep had remained unclear.

In our previous research, we identified “CRHBP-positive neurons” as critical for the regulation of REM sleep, and we also found that these neurons are lost in patients with Parkinson’s disease who suffer from sleep disturbances. In the present study, we discovered through recordings in the brains of living mice that a subset of CRHBP-positive neurons exhibits the same firing patterns as REM-on neurons.

This discovery sheds light on the neural basis of REM sleep—the sleep phase associated with dreaming—and holds promise for advancing our understanding and treatment of sleep disorders and neurological diseases.

Figure: Neurons that become active just before the onset of REM sleep and are responsible for its induction and maintenance
Neurons in the brainstem known as CRHBP-positive neurons begin to fire just before REM sleep starts and play a crucial role in the induction and maintenance of REM sleep.

Journals

Journal name	Journal of Neuroscience
Title of paper	Diverse firing profiles of Crhbp-positive neurons in the dorsal pons suggestive of their pleiotropic roles in REM sleep regulation in mice