Getting enough sleep is a challenge for many, but some people, called “short sleepers,” can get by on as little as four to six hours of sleep each day without showing any negative effects on functioning or memory. According to a paper published in Science Translational Medicine today (October 16), a variant in the gene NPSR1 may be responsible for naturally short sleep durations in humans and seems to reduce the need for sleep in mice.
Researchers led by Louis Ptácek and Ying-Hui Fu at the University of California, San Francisco, identified a mutation in the NPSR1 gene in two people from a family of short sleepers. NPSR1 codes for a receptor that binds to neuropeptide S, which is found in the brain and is associated with modulating sleep. The team then bred mice with the same NPSR1 mutation and found that these animals slept less and were more active compared to wildtype mice. They also performed just as well on memory tests despite getting less sleep. The “short sleeper” mice had a reduction in both rapid and non-rapid eye movement stages.
People with the NPSR1 variant tend to sleep about 2–4 hours less than average, while the experimental mice slept for 71 minutes less. “Mouse sleep is more fragmented than human sleep and does not occur in a consolidated bout as it does in humans. These differences probably result from varied sleep regulatory mechanisms between human and mice, which may contribute to differed phenotypes caused by the same genetic mutation,” the authors write in the paper.
Emily Makowski is an intern at The Scientist. Email her at firstname.lastname@example.org.