Abstract
It is widely recognized that sleep can be regulated by the environmental temperature, but the underlying neural mechanism remains unclear. Here, we examined the neural mechanism underlying cold-induced sleep pattern changes in Drosophila by behavior tracking and optogenetics. Drosophila exhibit a longer sleep duration, shorter sleep latency, and deeper sleep status in lower temperatures. We also demonstrated that insulin-producing cells (IPCs) can be activated in a cold environment, potentially via an indirect functional connection with the cold-sensing neurons, the 11216 neurons. Elevation of the IPCs sensitivity to cold impairs the sleep-promoting effect of cold, while blocking of IPCs’ activity primarily enhances the effect on the sleep circadian rhythm, suggesting that the cold-activated IPCs have a compensatory role in sleep regulation. Our finding revealed a potential neural circuit that could aid the maintenance of the sleep circadian rhythm at different temperatures and may offer novel insights into the mechanisms of sleep regulation.
Acknowledgements
We thank Zhefeng Gong for supporting and advising this research. We also thank Weiqiao Zhao, Caixia Gong, Jie Wang, and Kun Li for advice and assistance. We acknowledge the Bloomington Drosophila Stock Center for providing the fly stocks.