title: Neuronal mechanism for acute mechanosensitivity in tactile-foraging waterfowl.
abstract: Relying almost exclusively on their acute sense of touch, tactile-foraging birds can feed in murky water, but the cellular mechanism is unknown. Mechanical stimuli activate specialized cutaneous end organs in the bill, innervated by trigeminal afferents. We report that trigeminal ganglia (TG) of domestic and wild tactile-foraging ducks exhibit numerical expansion of large-diameter mechanoreceptive neurons expressing the mechano-gated ion channel Piezo2. These features are not found in visually foraging birds. Moreover, in the duck, the expansion of mechanoreceptors occurs at the expense of thermosensors. Direct mechanical stimulation of duck TG neurons evokes high-amplitude depolarizing current with a low threshold of activation, high signal amplification gain, and slow kinetics of inactivation. Together, these factors contribute to efficient conversion of light mechanical stimuli into neuronal excitation. Our results reveal an evolutionary strategy to hone tactile perception in vertebrates at the level of primary afferents.
authors.affiliation: Department of Cellular and Molecular Physiology.
authors.forename: Eve R
authors.initials: ER
authors.lastname: Schneider
authors.affiliation: Department of Cellular and Molecular Physiology, Yale Program in Cellular Neuroscience, Neurodegeneration and Repair.
authors.forename: Marco
authors.initials: M
authors.lastname: Mastrotto
authors.affiliation: Department of Cellular and Molecular Physiology, Yale Program in Cellular Neuroscience, Neurodegeneration and Repair.
authors.forename: Willem J
authors.initials: WJ
authors.lastname: Laursen
authors.affiliation: Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520.
authors.forename: Vincent P
authors.initials: VP
authors.lastname: Schulz
authors.affiliation: Department of Cellular and Molecular Physiology, Yale Program in Cellular Neuroscience, Neurodegeneration and Repair.
authors.forename: Jena B
authors.initials: JB
authors.lastname: Goodman
authors.affiliation: Department of Cellular and Molecular Physiology.
authors.forename: Owen H
authors.initials: OH
authors.lastname: Funk
authors.affiliation: Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520.
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Gallagher
authors.affiliation: Department of Cellular and Molecular Physiology, Yale Program in Cellular Neuroscience, Neurodegeneration and Repair, sviatoslav.bagriantsev@yale.edu elena.gracheva@yale.edu.
authors.forename: Elena O
authors.initials: EO
authors.lastname: Gracheva
authors.affiliation: Department of Cellular and Molecular Physiology, sviatoslav.bagriantsev@yale.edu elena.gracheva@yale.edu.
authors.forename: Sviatoslav N
authors.initials: SN
authors.lastname: Bagriantsev
mesh_terms: D000818:Animals; D015536:Down-Regulation; D004372:Ducks / Q000502:physiology*; D005247:Feeding Behavior; D015640:Ion Channel Gating; D007473:Ion Channels / Q000378:metabolism; D040542:Mechanotransduction, Cellular; D009474:Neurons / Q000502:physiology*; D012684:Sensory Thresholds; D050053:TRPM Cation Channels / Q000378:metabolism; D050916:TRPV Cation Channels / Q000378:metabolism; D013823:Thermoreceptors / Q000378:metabolism; D014110:Touch / Q000502:physiology*; D012668:Trigeminal Ganglion / Q000502:physiology; D015854:Up-Regulation
chemical_list: D007473:Ion Channels; D050053:TRPM Cation Channels; D050916:TRPV Cation Channels
keywords: Piezo2; TRPM8; TRPV1; mechanotransduction