Retinal glial cell glutamate transporter is coupled to an ionic conductance

Scott Eliasof, Craig Jahr

Research output: Contribution to journalArticle

99 Citations (Scopus)

Abstract

Application of L-glutamate to retinal glial (Müller) cells results in an inwardly rectifying current due to the net influx of one positive charge per molecule of glutamate transported into the cell. However, at positive potentials an outward current can be elicited by glutamate. This outward current is eliminated by removal of external chloride ions. Substitution of external chloride with the anions thiocyanate, perchlorate, nitrate, and iodide, which are known to be more permeant at other chloride channels, results in a considerably larger glutamate-elicited outward current at positive potentials. The large outward current in external nitrate has the same ionic dependence, apparent affinity for L-glutamate, and pharmacology as the glutamate transporter previously reported to exist in these cells. Varying the concentration of external nitrate shifts the reversal potential in a manner consistent with a conductance permeable to nitrate. Together, these results suggest that the glutamate transporter in retinal glial cells is associated with an anionic conductance. This anionic conductance may be important for preventing a reduction in the rate of transport due the depolarization that would otherwise occur as a result of electrogenic glutamate uptake.

Original languageEnglish (US)
Pages (from-to)4153-4158
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume93
Issue number9
StatePublished - Apr 30 1996

Fingerprint

Amino Acid Transport System X-AG
Neuroglia
Glutamic Acid
Nitrates
Chlorides
Chloride Channels
Iodides
Anions
Pharmacology
Ions

ASJC Scopus subject areas

  • General
  • Genetics

Cite this

Retinal glial cell glutamate transporter is coupled to an ionic conductance. / Eliasof, Scott; Jahr, Craig.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 93, No. 9, 30.04.1996, p. 4153-4158.

Research output: Contribution to journalArticle

@article{fb7e31c8bca64a7789c0a42cf29bdfe2,
title = "Retinal glial cell glutamate transporter is coupled to an ionic conductance",
abstract = "Application of L-glutamate to retinal glial (M{\"u}ller) cells results in an inwardly rectifying current due to the net influx of one positive charge per molecule of glutamate transported into the cell. However, at positive potentials an outward current can be elicited by glutamate. This outward current is eliminated by removal of external chloride ions. Substitution of external chloride with the anions thiocyanate, perchlorate, nitrate, and iodide, which are known to be more permeant at other chloride channels, results in a considerably larger glutamate-elicited outward current at positive potentials. The large outward current in external nitrate has the same ionic dependence, apparent affinity for L-glutamate, and pharmacology as the glutamate transporter previously reported to exist in these cells. Varying the concentration of external nitrate shifts the reversal potential in a manner consistent with a conductance permeable to nitrate. Together, these results suggest that the glutamate transporter in retinal glial cells is associated with an anionic conductance. This anionic conductance may be important for preventing a reduction in the rate of transport due the depolarization that would otherwise occur as a result of electrogenic glutamate uptake.",
author = "Scott Eliasof and Craig Jahr",
year = "1996",
month = "4",
day = "30",
language = "English (US)",
volume = "93",
pages = "4153--4158",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "9",

}

TY - JOUR

T1 - Retinal glial cell glutamate transporter is coupled to an ionic conductance

AU - Eliasof, Scott

AU - Jahr, Craig

PY - 1996/4/30

Y1 - 1996/4/30

N2 - Application of L-glutamate to retinal glial (Müller) cells results in an inwardly rectifying current due to the net influx of one positive charge per molecule of glutamate transported into the cell. However, at positive potentials an outward current can be elicited by glutamate. This outward current is eliminated by removal of external chloride ions. Substitution of external chloride with the anions thiocyanate, perchlorate, nitrate, and iodide, which are known to be more permeant at other chloride channels, results in a considerably larger glutamate-elicited outward current at positive potentials. The large outward current in external nitrate has the same ionic dependence, apparent affinity for L-glutamate, and pharmacology as the glutamate transporter previously reported to exist in these cells. Varying the concentration of external nitrate shifts the reversal potential in a manner consistent with a conductance permeable to nitrate. Together, these results suggest that the glutamate transporter in retinal glial cells is associated with an anionic conductance. This anionic conductance may be important for preventing a reduction in the rate of transport due the depolarization that would otherwise occur as a result of electrogenic glutamate uptake.

AB - Application of L-glutamate to retinal glial (Müller) cells results in an inwardly rectifying current due to the net influx of one positive charge per molecule of glutamate transported into the cell. However, at positive potentials an outward current can be elicited by glutamate. This outward current is eliminated by removal of external chloride ions. Substitution of external chloride with the anions thiocyanate, perchlorate, nitrate, and iodide, which are known to be more permeant at other chloride channels, results in a considerably larger glutamate-elicited outward current at positive potentials. The large outward current in external nitrate has the same ionic dependence, apparent affinity for L-glutamate, and pharmacology as the glutamate transporter previously reported to exist in these cells. Varying the concentration of external nitrate shifts the reversal potential in a manner consistent with a conductance permeable to nitrate. Together, these results suggest that the glutamate transporter in retinal glial cells is associated with an anionic conductance. This anionic conductance may be important for preventing a reduction in the rate of transport due the depolarization that would otherwise occur as a result of electrogenic glutamate uptake.

UR - http://www.scopus.com/inward/record.url?scp=0029864153&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029864153&partnerID=8YFLogxK

M3 - Article

C2 - 8633032

AN - SCOPUS:0029864153

VL - 93

SP - 4153

EP - 4158

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 9

ER -