Muscles, not brain, may be behind sleep disorders

Surprising revelation challenges the notion that brain controls all aspects of sleep

The answer to combat sleep disorders may not be in the brain, say scientists who have found that a protein present in the muscles can lessen the effects of sleep loss.

Researchers from University of Texas Southwestern in the US demonstrated how a circadian clock protein in the muscle — BMAL1 — regulates the length and manner of sleep in mice.

The surprising revelation challenges the widely accepted notion that the brain controls all aspects of sleep, they said.

The team found that while the protein’s presence or absence in the brain had little effect on sleep recovery, mice with higher levels of BMAL1 in their muscles recovered from sleep deprivation more quickly.

Removing BMAL1 from the muscle severely disrupted normal sleep, leading to an increased need for sleep, deeper sleep, and a reduced ability to recover, researchers said.

"These studies show that factors in muscles can signal to the brain to influence sleep. If similar pathways exist in people, this would provide new drug targets for the treatment of sleep disorders,” said Joseph S Takahashi, Chairman of Neuroscience at UT Southwestern Medical Center.

"This finding is completely unexpected and changes the ways we think sleep is controlled," Takahashi added. The study was published in the journal eLife.