Brain molecule may lead to new sleep treatments

Researchers from the Chinese Academy of Sciences and other Chinese institutions found that a molecule called tryptamine A, or TrpA, plays a role in regulating “sleep pressure”—the increasing need for sleep after prolonged wakefulness.

The study showed that TrpA levels in the cerebrospinal fluid rise the longer animals remain awake. The molecule then activates the GPR139 neural receptor, which stimulates brain cells involved in promoting sleep.

Experiments in mice and pigs found that activating this pathway after sleep deprivation increased sleep duration and improved sleep quality. The findings suggest that GPR139 could serve as a promising target for developing new treatments for insomnia and other sleep disorders.

The researchers said the discovery could eventually help lead to safer alternatives to some existing sleep medications, which may cause side effects such as daytime drowsiness, rebound insomnia and dependence. However, further studies are needed to determine whether the same mechanism operates in humans.