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Cytotopographical specialization of enzymatically isolated rabbit retinal Müller (glial) cells: K + conductivity of the cell membrane
Author(s) -
Reichenbach Andreas,
Eberhardt Wolfgang
Publication year - 1988
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.440010304
Subject(s) - biology , depolarization , membrane , biophysics , intracellular , membrane potential , neuroglia , cell membrane , retina , anatomy , cell , conductance , microbiology and biotechnology , neuroscience , biochemistry , central nervous system , physics , condensed matter physics
Müller (radial glial) cells were isolated from rabbit retinae by means of papaine and mechanical dissociation. Regional membrane properties of these cells were studied by intracellular microelectrode recordings of potential responses to local application of high K + solutions. When different parts of the cell membrane were exposed to high K + , the amplitude of the depolarizing responses varied greatly, indicating a strong regional specialization of the membrane properties. Using morphometrical data of isolated rabbit Müller cells, and a simple circuit model, we calculated the endfoot membrane to constitute more than 80% of the total K + conductance of the cell; the specific resistivity of the endfoot membrane was about 400 Ωcm 2 , i.e., more than 40 times less than that of the membrane of the vitread process, which is immediately adjacent. This kind of regional membrane specialization seems to be optimized in respect to the Müller cells+ ability to carry spatial buffering K + currents.