New research from the lab (Chronobiology and Behavioral Neurogenetics lab) published in the Journal of Neuroscience

Why Motion Makes You Sleepy: Insights from Fruit Flies

By Society for Neuroscience

Experimental setup and design. Credit: Lone et al., JNeurosci 2021

Long car rides make people drowsy, rocking soothes fussy babies to sleep, and even fruit flies doze off while spinning in slow circles. While the mechanism behind motion-induced sleep in humans remains unclear, new research published in The Journal of Neuroscience suggests it depends on motion-sensitive neurons in sensory organs—at least in fruit flies.

In their study, Lone et al. monitored the sleep patterns of fruit flies while they were rotated in circles on a shaker. They conducted experiments during both day and night on multiple genetic strains of flies. Slow rotational movements increased daytime sleep in both male and female flies, and this effect persisted even in flies lacking key circadian clock genes—suggesting the process is independent of the time of day.

The researchers also examined the role of nanchung receptors, ion channels found in sensory organs that respond to vibrations, motion, and mechanical sensations. They found that motion-induced sleep was significantly reduced in flies lacking nanchung-expressing neurons, and even more so when these neurons were physically removed. This suggests that a similar mechanism may exist in humans, possibly involving vibration-sensitive cells in the inner ear.