title: Effects of ionizing radiation on locomotory behavior and mechanosensation in Caenorhabditis elegans.
abstract: Locomotory behavior (motility) and mechanosensation are of vital importance in animals. We examined the effects of ionizing radiation (IR) on locomotory behavior and mechanosensation using a model organism, the nematode Caenorhabditis elegans. Bacterial mechanosensation in C. elegans induces the dopamine-mediated slowing of locomotion in the presence of bacteria (food), known as the basal slowing response. We previously reported an IR-induced reduction of locomotory rate in the absence of food. In the present study, we observed a similar IR-induced reduction of locomotory rate in the cat-2 mutant, which is defective in bacterial mechanosensation. The dose response pattern of the locomotory rate in the presence of food was relatively flat in wild-type animals, but not in cat-2 mutants. This suggests that the dopamine system, which is related to bacterial mechanosensation in C. elegans, might have a dominant effect on locomotory rate in the presence of food, which masks the effects of other stimuli. Moreover, we found that the behavioral responses of hydrogen peroxide-exposed wild-type animals are similar to those of IR-exposed animals. Our findings suggest that the IR-induced reduction of locomotory rate in the absence of food is mediated by a different pathway from that for bacterial mechanosensation, at least partially through IR-produced hydrogen peroxide.
authors.affiliation: Japan Atomic Energy Agency, Watanuki, Takasaki, Gunma, Japan. michiyosuzuki@ieee.org
authors.forename: Michiyo
authors.initials: M
authors.lastname: Suzuki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sakashita
authors.forename: Sumino
authors.initials: S
authors.lastname: Yanase
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ohba
authors.forename: Atsushi
authors.initials: A
authors.lastname: Higashitani
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hamada
authors.forename: Tomoo
authors.initials: T
authors.lastname: Funayama
authors.forename: Kana
authors.initials: K
authors.lastname: Fukamoto
authors.forename: Toshio
authors.initials: T
authors.lastname: Tsuji
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000528:radiation effects; D017173:Caenorhabditis elegans / Q000528:radiation effects*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000502:physiology; D002628:Chemoreceptor Cells / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D008124:Locomotion / Q000528:radiation effects*; D008954:Models, Biological; D009043:Motor Activity / Q000528:radiation effects*; D009154:Mutation; D018384:Oxidative Stress; D011839:Radiation, Ionizing; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics* / Q000502:physiology
chemical_list: D029742:Caenorhabditis elegans Proteins; D006861:Hydrogen Peroxide; D014446:Tyrosine 3-Monooxygenase