title: Dynamic switching between escape and avoidance regimes reduces Caenorhabditis elegans exposure to noxious heat.
abstract: To survive, animals need to minimize exposure to damaging agents. They can either stay away from noxious stimuli (defined as avoidance), requiring the detection of remote warning cues, or run away upon exposure to noxious stimuli (defined as escape). Here we combine behavioural quantitative analyses, simulations and genetics to determine how Caenorhabditis elegans minimizes exposure to noxious heat when navigating in thermogradients. We find that worms use both escape and avoidance strategies, each involving the modulation of multiple parameters like speed and the frequency of steering and withdrawal behaviours. As some behavioural parameters promote escape while impairing avoidance, and vice versa, worms need to dynamically tune those parameters according to temperature. Furthermore, selectively disrupting avoidance or escape, through mutations affecting neuropeptide or TRPV channel signalling, increases exposure to heat. We conclude that dynamically switching between avoidance and escape regimes along the innocuous-noxious temperature continuum efficiently minimizes exposure to noxious heat.
authors.affiliation: Department of Zoology/Biology, University of Fribourg, Chemin du Musée 10, Fribourg 1700, Switzerland.
authors.forename: Lisa C
authors.initials: LC
authors.lastname: Schild
authors.forename: Dominique A
authors.initials: DA
authors.lastname: Glauser
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D001833:Body Temperature Regulation / Q000502:physiology; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism; D004924:Escape Reaction / Q000502:physiology*; D005786:Gene Expression Regulation; D006358:Hot Temperature; D007473:Ion Channels / Q000235:genetics* / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D017476:Receptors, Neuropeptide Y / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D050916:TRPV Cation Channels; D050051:Transient Receptor Potential Channels / Q000235:genetics* / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; D007473:Ion Channels; C468272:NPR-1 protein, C elegans; D009419:Nerve Tissue Proteins; C464590:OCR-2 protein, C elegans; C108820:OSM-9 protein, C elegans; D017476:Receptors, Neuropeptide Y; D050916:TRPV Cation Channels; D050051:Transient Receptor Potential Channels