Cation permeability change caused by l-glutamate in cultured rat hippocampal neurons

Seiji Ozawa, Tomoko Nakamura, Michisuke Yuzaki

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

The ionic mechanism of the membrane permeability changes caused by l-glutamate in hippocampal neurons prepared from 17- to 19-day-old fetal rat in dispersed cell cultures was studied with the whole-cell variation of the patch electrode voltage-clamp technique. The cultured hippocampal neurons became sensitive to glutamate 7 days after plating, and thereafter the sensitivity gradually increased. The conductance increase caused by glutamate was voltage-sensitive, decreasing with membrane hyperpolarization at potentials more negative than -40 mV. The relative permeability of glutamate-activated channels to alkali metal and alkaline earth cations was estimated by reversal potential measurements. The alkali metal cations, Li+, Na+, K+, Rb+ and Cs+ were permeant to the glutamate channels, and the selectively among them was weak. The alkaline earth cations, Ca2+, Sr2+ and Ba2+ were more permeant than the alkali metals. The permeability ratios of these divalent cations relative to Na+ were 2.4 (Ca2+), 2.4 (Sr2+) and 2.8 (Ba2+), respectively. Mg2+ was much less permeant and the permeability ratio (PMg/PNa) was only 0.1. Anion conductance made no contribution to the glutamate-induced current. Functional implications of the glutamate-induced increase in Ca2+-influx were discussed.

Original languageEnglish
Pages (from-to)85-94
Number of pages10
JournalBrain Research
Volume443
Issue number1-2
DOIs
Publication statusPublished - 1988 Mar 8
Externally publishedYes

Fingerprint

Cations
Glutamic Acid
Permeability
Neurons
Alkali Metals
Membranes
Divalent Cations
Patch-Clamp Techniques
Anions
Electrodes
Cell Culture Techniques

Keywords

  • Alkali metal cation
  • Calcium
  • Cultured hippocampal neuron
  • l-Glutamate
  • Magnesium
  • Membrane permeability
  • Whole-cell voltage-clamp

ASJC Scopus subject areas

  • Developmental Biology
  • Molecular Biology
  • Clinical Neurology
  • Neuroscience(all)

Cite this

Cation permeability change caused by l-glutamate in cultured rat hippocampal neurons. / Ozawa, Seiji; Nakamura, Tomoko; Yuzaki, Michisuke.

In: Brain Research, Vol. 443, No. 1-2, 08.03.1988, p. 85-94.

Research output: Contribution to journalArticle

Ozawa, Seiji ; Nakamura, Tomoko ; Yuzaki, Michisuke. / Cation permeability change caused by l-glutamate in cultured rat hippocampal neurons. In: Brain Research. 1988 ; Vol. 443, No. 1-2. pp. 85-94.
@article{4883cc14f9b9425da7be8c8fec57775e,
title = "Cation permeability change caused by l-glutamate in cultured rat hippocampal neurons",
abstract = "The ionic mechanism of the membrane permeability changes caused by l-glutamate in hippocampal neurons prepared from 17- to 19-day-old fetal rat in dispersed cell cultures was studied with the whole-cell variation of the patch electrode voltage-clamp technique. The cultured hippocampal neurons became sensitive to glutamate 7 days after plating, and thereafter the sensitivity gradually increased. The conductance increase caused by glutamate was voltage-sensitive, decreasing with membrane hyperpolarization at potentials more negative than -40 mV. The relative permeability of glutamate-activated channels to alkali metal and alkaline earth cations was estimated by reversal potential measurements. The alkali metal cations, Li+, Na+, K+, Rb+ and Cs+ were permeant to the glutamate channels, and the selectively among them was weak. The alkaline earth cations, Ca2+, Sr2+ and Ba2+ were more permeant than the alkali metals. The permeability ratios of these divalent cations relative to Na+ were 2.4 (Ca2+), 2.4 (Sr2+) and 2.8 (Ba2+), respectively. Mg2+ was much less permeant and the permeability ratio (PMg/PNa) was only 0.1. Anion conductance made no contribution to the glutamate-induced current. Functional implications of the glutamate-induced increase in Ca2+-influx were discussed.",
keywords = "Alkali metal cation, Calcium, Cultured hippocampal neuron, l-Glutamate, Magnesium, Membrane permeability, Whole-cell voltage-clamp",
author = "Seiji Ozawa and Tomoko Nakamura and Michisuke Yuzaki",
year = "1988",
month = "3",
day = "8",
doi = "10.1016/0006-8993(88)91601-0",
language = "English",
volume = "443",
pages = "85--94",
journal = "Brain Research",
issn = "0006-8993",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Cation permeability change caused by l-glutamate in cultured rat hippocampal neurons

AU - Ozawa, Seiji

AU - Nakamura, Tomoko

AU - Yuzaki, Michisuke

PY - 1988/3/8

Y1 - 1988/3/8

N2 - The ionic mechanism of the membrane permeability changes caused by l-glutamate in hippocampal neurons prepared from 17- to 19-day-old fetal rat in dispersed cell cultures was studied with the whole-cell variation of the patch electrode voltage-clamp technique. The cultured hippocampal neurons became sensitive to glutamate 7 days after plating, and thereafter the sensitivity gradually increased. The conductance increase caused by glutamate was voltage-sensitive, decreasing with membrane hyperpolarization at potentials more negative than -40 mV. The relative permeability of glutamate-activated channels to alkali metal and alkaline earth cations was estimated by reversal potential measurements. The alkali metal cations, Li+, Na+, K+, Rb+ and Cs+ were permeant to the glutamate channels, and the selectively among them was weak. The alkaline earth cations, Ca2+, Sr2+ and Ba2+ were more permeant than the alkali metals. The permeability ratios of these divalent cations relative to Na+ were 2.4 (Ca2+), 2.4 (Sr2+) and 2.8 (Ba2+), respectively. Mg2+ was much less permeant and the permeability ratio (PMg/PNa) was only 0.1. Anion conductance made no contribution to the glutamate-induced current. Functional implications of the glutamate-induced increase in Ca2+-influx were discussed.

AB - The ionic mechanism of the membrane permeability changes caused by l-glutamate in hippocampal neurons prepared from 17- to 19-day-old fetal rat in dispersed cell cultures was studied with the whole-cell variation of the patch electrode voltage-clamp technique. The cultured hippocampal neurons became sensitive to glutamate 7 days after plating, and thereafter the sensitivity gradually increased. The conductance increase caused by glutamate was voltage-sensitive, decreasing with membrane hyperpolarization at potentials more negative than -40 mV. The relative permeability of glutamate-activated channels to alkali metal and alkaline earth cations was estimated by reversal potential measurements. The alkali metal cations, Li+, Na+, K+, Rb+ and Cs+ were permeant to the glutamate channels, and the selectively among them was weak. The alkaline earth cations, Ca2+, Sr2+ and Ba2+ were more permeant than the alkali metals. The permeability ratios of these divalent cations relative to Na+ were 2.4 (Ca2+), 2.4 (Sr2+) and 2.8 (Ba2+), respectively. Mg2+ was much less permeant and the permeability ratio (PMg/PNa) was only 0.1. Anion conductance made no contribution to the glutamate-induced current. Functional implications of the glutamate-induced increase in Ca2+-influx were discussed.

KW - Alkali metal cation

KW - Calcium

KW - Cultured hippocampal neuron

KW - l-Glutamate

KW - Magnesium

KW - Membrane permeability

KW - Whole-cell voltage-clamp

UR - http://www.scopus.com/inward/record.url?scp=0023845133&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023845133&partnerID=8YFLogxK

U2 - 10.1016/0006-8993(88)91601-0

DO - 10.1016/0006-8993(88)91601-0

M3 - Article

C2 - 2896060

AN - SCOPUS:0023845133

VL - 443

SP - 85

EP - 94

JO - Brain Research

JF - Brain Research

SN - 0006-8993

IS - 1-2

ER -