Proceedings of The Physiological Society
Durham University (2010) Proc Physiol Soc 21, SA10
Deconstructing Pain and Touch Sensation with Caenorhabditis elegans
M. B. Goodman1
1. Molecular and Cellular Physiology, Stanford University, Stanford, CA, California, United States.
The ability to detect touch is conserved from echinoderms to humans. It relies on specialized mechanoreceptor neurons that vary in their sensitivity and association with accessory structures. Despite its importance and conservation across taxa, very little is known about how touch works. We seek to improve understanding by studying the nematode C. elegans, a simple animal that has only 30 mechanoreceptor neurons. Our work focuses on two classes of mechanoreceptor neurons: the 6 non-ciliated touch receptor neurons (TRNs) that detect touch applied to the body wall (1, 2) and the paired ciliated ASH neurons that detect noxious mechanical stimuli applied to the nose. Genetic analysis has revealed ion channel genes needed for TRN and ASH function. To learn the precise cellular function of such channel proteins and to investigate their gating mechanisms, we combine genetic dissection with in situ electrophysiology and biomechanical analysis. The picture emerging from our recent work is that touch activates similar ion channels in the nonciliated TRNs and the ciliated ASH neurons, which differ by 100-fold in their sensitivity to external force. Challenges for the future include understanding the basis for differences in sensitivity and the biophysics of mechanotransduction channel gating.
Where applicable, experiments conform with Society ethical requirements