SEU made new progress in the study of sleep regulation mechanism

How is your sleep recently? Is it sound and sweet? Or have you gone through insufferable insomnia? Sleep is essential to our health. Only two to three nights without sufficient sleep may cause low mood, irritability, and inattentiveness.

There are also a group of people who can sleep anytime, anywhere, and are known as "Sleeping Gods". To sleep well, we need a comfortable environment. We need darkness to provide us with calmness; meanwhile, temperature is also of great importance. You may get inspired to learn more about what SEU Research Team has found.

In the early morning of March 19, Beijing time, Prof. Han Junhai’s research team from School of Life Sciences and Technology of SEU reported the latest progress in the study of sleep regulation mechanism. The related results titled “A subset of DN1p integrate neurons thermo-sensory inputs to promote wakefulness via CNMa signaling” were published online in Current Biology, an internationally renowned academic journal.

Sleep, as a common behavior for the animalia, profoundly affects the physiological processes of animals such as learning, memory, immunity, and metabolism etc. It may be affected by such environmental factors as light and temperature, but the neural mechanism of regulation of sleep by temperature is still unclear. In response to this issue, Prof. Han Junhai’s team conducted research by using fruit flies as the model.

Studies have shown that an increase in ambient temperature can reduce the sleep time at night, and vice versa, the sleep time can also gradually increase with the recovery of ambient temperature, indicating the reversibility of the regulation of sleep by the ambient temperature at night (Fig. 1). Studies have identified that Anterior cells (ACs) neurons, as the thermoreceptor, can sense the increase in environmental temperature and release the neurotransmitter acetylcholine to promote the awakening of fruit flies.

Fig. 1 Continuous sleep trace of fruit flies during temperature shifting

Further research revealed that a small cluster of DN1p neurons had received the acetylcholine signal as released by the AC neurons, and promoted wakefulness by releasing the neuropeptide CNMa, thus resulting in a decrease in sleep time at night. The study finally revealed that CNMa receptors, expressed in Dh44-positive PI neurons, inhibited the activity of such neurons after receiving CNMa signals as released by DN1p neurons, thereby promoting wakefulness (Fig. 2).

Fig. 2 CNMaR in Dh44+ PI neurons is a target of CNMa signaling to promote wakefulness

This study has revealed the mechanism by which the AC-DN1p-PI neural circuit can perceive changes in external environmental temperature so as to regulate sleep behavior, and identified the role of new CNMa/CNMaR inhibitory signals in sleep regulation. This research has provided new ideas and insights for explaining the neural mechanism of environmental factors affecting the biological instinctive behavior.

SEU Ph.D. candidate Jin Xi and Associate Researcher Tian Yao are the co-first authors of this paper, with Prof. Han Junhai as the corresponding author. This work was funded by the National Natural Science Foundation of China, Shenzhen-Hong Kong Brain Science Innovation Research Fund and Jiangsu Outstanding Youth Science Fund.

Regular sleep, healthy future. You should help protect your sleep—and all the benefits that come with it—by maintaining a sound sleep routine, no matter what else is going on in the world.

/Editor's note