Mechanosensory stimulation via Nanchung expressing neurons can induce daytime sleep in Drosophila

Abstract

The neurogenetic bases of sleep, a phenomenon considered crucial for well-being of organisms has recently been under investigation using the model organism Drosophila melanogaster. Although sleep is a state where sensory threshold for arousal is enhanced, it is known that certain kinds of repetitive sensory stimuli such as rocking, can in fact promote sleep in humans. Here we report that orbital motion aided mechanosensory stimulation promotes sleep in Drosophila, independent of the circadian clock, but controlled by the homeostatic system. Mechanosensory receptor nanchung (Nan) expressing neurons in the chordotonal organs mediate this sleep induction - flies where these neurons are either silenced or ablated display significantly reduced sleep induction upon mechanosensory stimulation. Transient activation of the Nan-expressing neurons also enhances sleep levels confirming the role of these neurons in sleep induction. Thus, we show for the first time that mechanosensory stimulation promotes sleep even in flies D. melanogaster and that it is mediated by proprioceptors.