Mechanosensation and nociception Nematodes sense touch stimuli using molecules that are conserved with humans and other mammals. We are interested in the molecular basis of mechanotransduction in neurons, and have characterized the how members of the TRP and DEG/ENaC channel families affect the functions of specific nematode touch neurons. These molecules also function in polymodal nociceptors, which sense painful touch as well as as noxious chemicals. We are also interested in how touch sensory information is integrated in the worm brain, and how worms remember touch sensory information.
	Here is a movie of a worm responding to body touch. The worm switches from crawling forward to crawling backward, a simple escape reflex. This worm is immobilized with glue, and is being stimulated by a mechanical probe on its nose. The stimulus shown activates nose touch neurons called OLQ. Here is a psuedocolour movie of a body touch neuron responding to touch. Red indicates calcium influx accompanying neuronal excitation.
Recent papers: Sensory transduction in nociceptors and touch neurons: Kindt KS, Viswanath V, Macpherson L, Quast K, Hu H, Patapoutian A, Schafer WR (2007) “Caenorhabditis elegans TRPA-1 functions in mechanosensation.” Nature Neurosci 10: 568-577. Epub 2007 Apr 22. Supplemental material. Frøkjær-Jensen C, Kindt KS, Kerr RA, Suzuki H, Melnik-Martinez K, Gerstbrein B, Driscoll M, Schafer WR (2006) "Effects of voltage-gated calcium channel subunit genes on calcium influx in cultured C. elegans mechanosensory neurons" J. Neurobiol. 66: 1125-1139 Epub 2006 Jul 11 Hilliard MA, Apicella AJ, Kerr R, Suzuki H, Bazzicalupo P, Schafer WR. (2005) "In vivo imaging of C. elegans ASH neurons: cellular response and adaptation to chemical repellents" EMBO Journal 24: 63-72. Epub 2004 Dec 02. Kahn-Kirby AH, Dantzker JLM, Apicella AJ, Schafer WR, Browse J, Bargmann CI, Watts JL (2004) "Specific polyunsaturated fatty acids drive TRPV-dependent sensory signaling in vivo" Cell 19: 889-900. Fukuto HS, Ferkey DM, Apicella AJ, Lans H, Sharmeen T, Chen W, Lefkowitz RJ, Jansen G, Schafer WR, Hart AC. (2004) "G Protein-coupled receptor kinase function is essential for chemosensation in C. elegans" Neuron 42: 581-593. Suzuki H, Kerr R, Bianchi L, Frøkjær-Jensen C, Slone D, Xue J, Gerstbrein B, Driscoll M, Schafer WR. (2003) "In vivo functional analysis of C. elegans mechanosensory neurons reveals a specific role for MEC-4 channels in the process of gentle touch transduction" Neuron 39: 1005-1017.
Sensory circuits: Kindt KS, Quast KB, Giles AG, De S, Hendrey D, Nicastro I, Rankin CH, Schafer WR (2007) "Dopamine mediates context-dependent modulation of sensory plasticity in C. elegans" Neuron 55: 662-676. Supplemental material. Tomioka M, Adachi T, Suzuki H, Kunitomo H, Schafer WR, Iino Y (2006) "The insulin/PI3 –kinase pathway regulates salt chemotaxis learning in Caenorhabditis elegans" Neuron 51: 613-626 Sanyal S, Wintle RF, Kindt K, Nuttley WM, Arvan R, Fitzmaurice P, Bigras E, Merz D, Hebert TE, van der Kooy D, Schafer WR, Culotti JG and Van Tol HHM. (2004) "Dopamine modulates the plasticity of mechanosensory responses in C. elegans" EMBO Journal 23: 473-482.