Using C. elegans to Study the Effects of Toxins in Sensory Ion Channels In Vivo

Caenorhabditis elegans is a powerful animal model in which transgenesis, behavior, and physiology can be merged to study in vivo the effect of natural and synthetic agonists in sensory ion channels. Worms have polymodal sensory neurons (like the ASH pair) that couple ion channel activation with a robust and easily scorable aversive-like behavior. We expressed the transient receptor potential vanilloid 1 (TRPV1) channel from rat (r) in worms' ASH neurons and determined its sensitivity to the tarantula double-knot toxin (DkTx) and the active component of chili peppers (capsaicin). This chapter describes protocols for generating and maintaining transgenic rTRPV1 worms to determine dose-dependent behavior. The goal is to provide an efficient tool to characterize the function of sensory channels (wild type and mutants) in vivo.