title: Chemically induced oxidative stress affects ASH neuronal function and behavior in C. elegans.
abstract: Oxidative stress (OS) impact on a single neuron's function in vivo remains obscure. Using C. elegans as a model organism, we report the effect of paraquat (PQ)-induced OS on wild type worms on the function of the ASH polymodal neuron. By calcium (Ca2+) imaging, we quantified ASH activation upon stimulus delivery. PQ-treated worms displayed higher maximum depolarization (peak of the Ca2+transients) compared to untreated animals. PQ had a similar effect on the ASH neuron response time (rising slope of the Ca2+transients), except in very young worms. OS effect on ASH was partially abolished in vitamin C-treated worms. We performed octanol and osmotic avoidance tests, to investigate the OS effect on ASH-dependent behaviors. PQ-treated worms have enhanced avoidance behavior compared to untreated ones, suggesting that elevated ASH Ca2+transients result in enhanced ASH-mediated behavior. The above findings suggest a possible hormetic effect of PQ, as a factor inducing mild oxidative stress. We also quantified locomotion parameters (velocity, bending amplitude), which are not mediated by ASH activation. Bending amplitude did not differ significantly between treated and untreated worms; velocity in older adults decreased. The differential effect of OS on behavioral patterns may mirror a selective impact on the organism's neurons.
authors.affiliation: Department of Mechanical Engineering, University of Michigan, 2350 Hayward Str., Ann Arbor, MI, 48109, USA.|Department of Internal Medicine, Division of Geriatric Medicine, Medical School, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI, 48109, USA.
authors.forename: Eleni
authors.initials: E
authors.lastname: Gourgou
authors.affiliation: Department of Mechanical Engineering, University of Michigan, 2350 Hayward Str., Ann Arbor, MI, 48109, USA.|Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Blvd., Ann Arbor, MI, 48109, USA.
authors.forename: Nikos
authors.initials: N
authors.lastname: Chronis
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D017173:Caenorhabditis elegans / Q000187:drug effects* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D008124:Locomotion / Q000187:drug effects; D009474:Neurons / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects*; D010269:Paraquat / Q000494:pharmacology*
chemical_list: D029742:Caenorhabditis elegans Proteins; D010269:Paraquat; D002118:Calcium