Open AccessThermal avoidance in Caenorhabditis elegans : An approach to the study of nociception
Author(s) -
Nicole Wittenburg,
Ralf Baumeister
Publication year - 1999
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.96.18.10477
Subject(s) - nociception , caenorhabditis elegans , noxious stimulus , neuroscience , biology , escape response , sensory system , aversive stimulus , stimulus (psychology) , avoidance behaviour , reflex , gene , genetics , psychology , receptor , psychotherapist
Upon perception of a noxious stimulus, an organism executes defense mechanisms, such as escape responses. The molecular basis of these mechanisms is poorly understood. In this paper we show that upon exposure to noxious temperature,Caenorhabditis elegans reacts by a withdrawal reflex. To analyze this thermal avoidance behavior, we developed a laser-based assay to quantify the response. The escape reflex can be observed in 98% of the adult animals, but is not executed in animals in diapause. The thermal avoidance response differs significantly from the thermotaxis behavior that is based on the perception of physiological temperature. It involves different neurons and is influenced by mutations in distinct genes. As in mammals, the strength of the thermal avoidance response is increased by application of capsaicin, the pungent ingredient in chili peppers. We find that thermal avoidance is strongly reduced in mutants affecting the neural transmission modulated by glutamate and neuropeptides as well as in mutants affecting the structure and function of sensory neurons. We suggest that the study of this nociceptive behavior inC. elegans can be used to understand the genetic and molecular basis of thermal nociception.