Perception of breath components by the tropical bont tick, Amblyomma variegatum Fabricius (Ixodidae). I. CO2-excited and CO2-inhibited receptors.

Détails

ID Serval
serval:BIB_6B10DFB7D382
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Perception of breath components by the tropical bont tick, Amblyomma variegatum Fabricius (Ixodidae). I. CO2-excited and CO2-inhibited receptors.
Périodique
Journal of comparative physiology. A, Sensory, neural, and behavioral physiology
Auteur(s)
Steullet P., Guerin P.M.
Statut éditorial
Publié
Date de publication
07/1992
Peer-reviewed
Oui
Volume
170
Numéro
6
Pages
665-676
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Résumé
Wall-pore olfactory sensilla located in the capsule of Haller's organ on the tarsus of Amblyomma variegatum ticks bear cells responding to vertebrate breath: one of these sensilla contains a CO2-excited receptor and a second sensillum has a CO2-inhibited receptor. Each of these antagonistic CO2-receptors, which display typical phasic-tonic responses, monitors a different CO2-concentration range. The CO2-inhibited receptor is very sensitive to small concentration changes between 0 and ca. 0.2%, but variations of 0.01% around ambient (ca. 0.04%) induce the strongest frequency modulation of this receptor. An increase of just 0.001-0.002% (10-20 ppm) above a zero CO2-level already inhibits this receptor. By contrast, the CO2-excited receptor is not so sensitive to small CO2 shifts around ambient, but best monitors changes in CO2 concentrations above 0.1%. This receptor is characterized by a steep dose-response curve and a fast inactivation even at high CO2-concentrations (greater than 2%). In a wind-tunnel, Amblyomma variegatum is activated from the resting state and attracted by CO2 concentrations of 0.04 to ca. 1%, which corresponds to the sensitivity range of its CO2-receptors. The task of perceiving the whole concentration range to which this tick is attracted would thus appear to be divided between two receptors, one sensitive to small changes around ambient and the other sensitive to the higher concentrations normally encountered when approaching a vertebrate host.

Mots-clé
Animals, Carbon Dioxide/pharmacology, Chemoreceptor Cells/drug effects, Chemoreceptor Cells/metabolism, Electrophysiology, Humans, Male, Microscopy, Electron, Scanning, Receptors, Cell Surface/drug effects, Receptors, Cell Surface/metabolism, Sense Organs/physiology, Sense Organs/ultrastructure, Smell/physiology, Ticks/physiology
Pubmed
Web of science
Création de la notice
09/05/2017 10:34
Dernière modification de la notice
20/08/2019 14:25
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