Insulin-Producing Cells Monitor the Temperature and Compensate for Cold-Induced Sleep in Drosophila

Sleep is regulated by environmental factors including temperature, but the neural circuits that receive the sensory signal and mediate the regulation remain unclear. We examined how cold could influence Drosophila sleep patterns and its neural mechanism. The results showed that Drosophila has more sleep duration, less sleep latency and deeper sleep depth under cold condition. We identified the Insulin-producing Cells (IPCs) can be activated by cold, and receive the cold signal from the 11216 cold-sensing neuron without a direct synaptic connection. Elevation of IPCs sensitivity to cold impairs the sleep-promoting effect of cold while blocking of IPCs enhance the effect mostly on sleep circadian, suggesting that the cold activated IPCs have a compensative role in sleep regulation. Our finding revealed a potential neural circuit that help maintain sleep circadian in detrimental environment and may give new insight to the complicated sleep regulation mechanism.