Electrophysiological properties of frog olfactory supporting cells.
Cells, identified as supporting cells by Lucifer Yellow injection, were recorded from slices of frog olfactory epithelium using patch-clamp recordings. Cell-attached single-channel recordings indicated that the intracellular potential (IP) was -68 +/- 7 mV (n = 22) with 4 mM K+ in the bath ([K+]o). IP was -67 +/- 4 mV (n = 32) in whole-cell conditions with 100 mM KCl inside the cell, suggesting a low membrane permeability for Cl-. IP depended on [K+]o in a manner described by the Goldman-Hodgkin-Katz equation with a permeability ratio pk+:PNa+ of 40. The input resistance was 32 +/- 14 M omega (n = 15), indicating a high membrane conductance at rest. Odorant stimulations evoked passive membrane depolarizations, probably reflecting an increase in [K+]o due to the neuronal activation. Whole-cell recordings with 100 mM CsCl instead of KCl in the pipette, together with the block of gap-junctions with octanol, indicated the existence of an electrical coupling between supporting cells. The electrical coupling between these glial-like cells could facilitate the clearance of K+ ions released by olfactory receptor neurons during odorant stimulation.
Trotier
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Neurobiologie Sensorielle, E.P.H.E., Massy, France. trotier@bisance.citi2.fr
D000818:Animals; D002463:Cell Membrane Permeability; D002586:Cesium; D002712:Chlorides; D004553:Electric Conductivity; D004594:Electrophysiology; D004848:Epithelium / Q000502:physiology; D005456:Fluorescent Dyes; D017629:Gap Junctions / Q000187:drug effects; D007546:Isoquinolines; D000442:Octanols / Q000494:pharmacology; D009812:Odorants; D009831:Olfactory Mucosa / Q000502:physiology*; D018408:Patch-Clamp Techniques; D011189:Potassium Chloride; D011893:Rana esculenta / Q000502:physiology*; D012996:Solutions
D002712:Chlorides; D005456:Fluorescent Dyes; D007546:Isoquinolines; D000442:Octanols; D012996:Solutions; D002586:Cesium; D011189:Potassium Chloride; C017475:lucifer yellow; C028019:cesium chloride