It has been established that many neurodevelopmental disorders are associated with altered sensory processing and disrupted sleep. Additionally, to fall asleep and stay asleep, individuals must filter out sensations from the environment, indicating that sensory processing is ongoing throughout quiescence. Thus, we explore if this altered sensory processing is related to disrupted sleep in neurodevelopmental disorders, using Drosophila.

The experiments were conducted using adult female flies under 25°C in Multi-Beam Drosophila Activity Monitors, which were placed 40 centimeters above the vortexer. Vibration was generated by the vortexer on the bottom rack, and data was collected for 24 hours baseline sleep followed by 24 hours vibration sleep.

Continuous vibration significantly increases daytime sleep in multiple control fly lines. In contrast, NF1, NRX, and FMR mutant flies show very little or no increase in sleep in response to vibration.

Additionally, Shank mutation has minimal effect on daytime sleep at baseline, and the vibration-induced change in sleep is not significantly different between Shank mutants and controls. Both Shank mutants and genetic controls show a significant increase in daytime sleep when exposed to vibration. 

Previous work has shown that vibration-induced sleep (VIS) is mediated in part by mechanosensory neurons in the antenna. Here, we surgically removed all three antennal segments from adult female flies. After 3 days of recovery, we performed sleep assays on flies that received the antennectomy and intact controls. Intact wild-type flies show increased sleep with vibration. This change is significantly reduced in wild-type flies that received antennectomies. Mutant flies, in contrast, show no change in VIS following antennectomy. This was independent of whether they show VIS as intacts or not.

Our work suggests that sensory input may influence sleep differently in these neurodevelopmental disorders and that different neurodevelopmental disorders have varying effects on sensory processing during sleep. Our Antennectomy results demonstrate that the VIS observed in wild-type controls relies substantially on mechanosensory neurons in the antenna. Reducing mechanosensory input in mutant flies had little effect on their response to vibration. Results suggest that NF1, FMR and NRX mutant flies may be hyposensitive to mechanosensory stimuli, whereas Shank mutants may be hypersensitive.