Get access

Single Channel Recording from Glial Cells on the Untreated Surface of the Frog Optic Nerve

Authors

  • Hector Marrero,

    1. Institute of Neurobiology and Departments of Physiology, University of Puerto Rico Medical Sciences Campus, 201 Blvd del Valle, San Juan, Puerto Rico 00901
    Search for more papers by this author
  • Paula M. Orkand,

    1. Institute of Neurobiology and Departments of Physiology, University of Puerto Rico Medical Sciences Campus, 201 Blvd del Valle, San Juan, Puerto Rico 00901
    2. Institute of Neurobiology and Departments of Anatomy, University of Puerto Rico Medical Sciences Campus, 201 Blvd del Valle, San Juan, Puerto Rico 00901
    Search for more papers by this author
  • Helmut Kettenmann,

    1. Institute of Neurobiology and Departments of Physiology, University of Puerto Rico Medical Sciences Campus, 201 Blvd del Valle, San Juan, Puerto Rico 00901
    2. Department of Neurobiology, University of Heidelberg, Heidelberg, FRG
    Search for more papers by this author
  • Richard K. Orkand

    Corresponding author
    1. Institute of Neurobiology and Departments of Physiology, University of Puerto Rico Medical Sciences Campus, 201 Blvd del Valle, San Juan, Puerto Rico 00901
      Dr R. K. Orkand, as above
    Search for more papers by this author

Dr R. K. Orkand, as above

Abstract

The patch clamp technique has been used to record single channel currents from the untreated surface of the intact frog optic nerve after the meninges and basal lamina have been mechanically removed. Cells filled via dialysis with Lucifer yellow (LY) from the patch pipette had a typical astrocyte morphology and were dye-coupled to adjacent astrocytes. This is consistent with the electron-microscopic observation that all the cells on the surface of this nerve are astrocytes. Two types of ion channels were studied in detached patches. One, identified as a K+ channel, had a conductance of 88±4 (S.E.) n= 9 pS and an equilibrium potential of −59±8 mV in physiological K+ solutions. The steady-state open probability was not significantly altered by changing the membrane potential. A second channel had a large conductance of 300–1200 pS, a reversal potential of ∼ 0 mV in symmetrical and non-symmetrical solutions, and was open only in the voltage range of ±20 mV. These are the characteristics of a large anionic channel described in other preparations including cultured astrocytes.

Get access to the full text of this article

Ancillary