title: Microcystins alter chemotactic behavior in Caenorhabditis elegans by selectively targeting the AWA sensory neuron.
abstract: Harmful algal blooms expose humans and animals to microcystins (MCs) through contaminated drinking water. While hepatotoxicity following acute exposure to MCs is well documented, neurotoxicity after sub-lethal exposure is poorly understood. We developed a novel statistical approach using a generalized linear model and the quasibinomial family to analyze neurotoxic effects in adult Caenorhabditis elegans exposed to MC-LR or MC-LF for 24 h. Selective effects of toxin exposure on AWA versus AWC sensory neuron function were determined using a chemotaxis assay. With a non-monotonic response MCs altered AWA but not AWC function, and MC-LF was more potent than MC-LR. To probe a potential role for protein phosphatases (PPs) in MC neurotoxicity, we evaluated the chemotactic response in worms exposed to the PP1 inhibitor tautomycin or the PP2A inhibitor okadaic acid for 24 h. Okadaic acid impaired both AWA and AWC function, while tautomycin had no effect on function of either neuronal cell type at the concentrations tested. These findings suggest that MCs alter the AWA neuron at concentrations that do not cause AWC toxicity via mechanisms other than PP inhibition.
authors.affiliation: Department of Molecular Biosciences, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, 2225 VM3B, University of California, Davis, Davis, CA 95616, USA. cemoore@ucdavis.edu.
authors.forename: Caroline E
authors.initials: CE
authors.lastname: Moore
authors.affiliation: Department of Molecular Biosciences, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, 2225 VM3B, University of California, Davis, Davis, CA 95616, USA. pjlein@ucdavis.edu.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Lein
authors.affiliation: Department of Molecular Biosciences, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, 2225 VM3B, University of California, Davis, Davis, CA 95616, USA. bpuschner@ucdavis.edu.
authors.forename: Birgit
authors.initials: B
authors.lastname: Puschner
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects; D017173:Caenorhabditis elegans / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D002628:Chemoreceptor Cells / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D002633:Chemotaxis / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D008387:Marine Toxins; D052998:Microcystins / Q000494:pharmacology*; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009498:Neurotoxins / Q000494:pharmacology*; D018034:Olfactory Receptor Neurons / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D009994:Osmolar Concentration; D054645:Protein Phosphatase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D054648:Protein Phosphatase 2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D015203:Reproducibility of Results
chemical_list: D001427:Bacterial Toxins; D029742:Caenorhabditis elegans Proteins; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D008387:Marine Toxins; D052998:Microcystins; D009419:Nerve Tissue Proteins; D009498:Neurotoxins; C524165:microcystin-LF; D054645:Protein Phosphatase 1; D054648:Protein Phosphatase 2; C057862:cyanoginosin LR