Specific phase of sleep called rapid eye movement (REM) sleep may help protect against predator attack with its brief but periodic awakenings as per a study at the Chinese Academy of Sciences Headquarters, published in Neuron.
In 1966, Dr. Frederick Snyder reported the “sentinel” function of REM could help animals prepare a fight or flight response against potential predator attacks. However, to date, there has been no experimental evidence for this hypothesis.
‘Rapid eye movement (REM) sleep may help protect against predator attack as a common circuit regulating both innate fear and REM sleep has been identified.
The team aimed to uncover the neural mechanisms underlying this REM-specific function because REM sleep is generally characterized by higher arousal thresholds than non-rapid-eye-movement (NREM) sleep.
It was found that mSTN-CRH neurons (medial subthalamic nucleus- corticotropin-releasing hormone) produced a lowered arousal threshold during REM sleep for detecting predator threats, as well as increased defensive responses after awakening.
“Our study raises the question of whether it is possible to treat mood disorders by targeting the common regulatory circuit of sleep and fear. We will continue working on this question,” says Dr. Yu-Ting Tseng, lead author of the study.