Just as in other more complex organisms, sleep is modulated both by the circadian clock and sleep homoestatic mechanisms even in flies. Our studies unravel communication between Drosophila circadian pacemaker circuit and the sleep homeostat as many aspects of sleep recovery are affected by the circadian clock (Sheetal Potdar PhD thesis, 2018). We uncover that mutations in the circadian clock also impact the time-of-day dependence of the sleep homeostat. We demonstrate that an important circadian neuropeptide PDF, via its receptor communicates with dopaminergic neurons downstream of the circadian pacemaker, which in turn impinge on sleep control centres (Potdar and Sheeba, 2018; eNeuro). We show that one of the adaptive values for the evolution of sleep stems from its ability to ensure higher reproductive output in female flies (Potdar et al., J 2018; Experimental Biology).
In collaboration with Shahnaz Rahman Lone (Central University of Punjab) we are investigating the role of mechanosensory stimulation in inducing daytime sleep in flies (Lone et al., Biorxiv). Our studies using video recordings and IR based locomotion detection show that mechanosensory inputs from the antennae and legs via Antennal Mechanosensory Motor Center neurons communicate to sense gentle orbital motion and drive sleep in flies.
