Mechanical sensing is important for all organisms, but is the least understood of the senses. As mechanical stimuli come in diverse forms, organisms often have sensors or sensory systems that specialise in a form of mechanical stimuli, such as touch or vibration. Here we tested the hypothesis that the nematode worm Caenorhabditis elegans exhibits a behavioural response to vibration that is distinct from its responses to touch. We show that wild type strain worms respond to sustained low frequency vibration in a manner distinct from the known responses to non-localised mechanical stimuli. Furthermore, the behavioural responses of mutant strains suggest different roles for ciliated versus non-ciliated neurons in mediating the response. Although further study is required to identify the vibration sensing pathway, our data support that C. elegans can sense substrate-borne vibrations using cells distinct from those used in gentle touch.
Robert I. Holbrook and Beth Mortimer