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The influence of membrane potential on chloride channels activated by GABA in rat cultured hippocampal neurons

Curmi, J P; Premkumar, L S; Birnir, Bryndis LU and Gage, P W (1993) In Journal of Membrane Biology 136(3). p.273-280
Abstract
Chloride currents were activated by a low concentration of GABA (0.5 microM) in neonatal rat hippocampal neurons cultured for up to 14 days. Currents elicited by 0.5 microM GABA in neurons, voltage-clamped using the whole-cell technique with pipettes containing 149 mM Cl-, reversed close to 0 mV whether pipettes contained 144 mM Na+ or 140 mM Cs+, and were blocked by 100 microM bicuculline. Current-voltage curves showed outward rectification. Single channel currents appeared in cell-attached patches when the pipette tip was perfused with pipette solution containing 0.5 microM GABA and disappeared when a solution containing 100 microM bicuculline plus 0.5 microM GABA was injected into the pipette tip. The channels showed outward... (More)
Chloride currents were activated by a low concentration of GABA (0.5 microM) in neonatal rat hippocampal neurons cultured for up to 14 days. Currents elicited by 0.5 microM GABA in neurons, voltage-clamped using the whole-cell technique with pipettes containing 149 mM Cl-, reversed close to 0 mV whether pipettes contained 144 mM Na+ or 140 mM Cs+, and were blocked by 100 microM bicuculline. Current-voltage curves showed outward rectification. Single channel currents appeared in cell-attached patches when the pipette tip was perfused with pipette solution containing 0.5 microM GABA and disappeared when a solution containing 100 microM bicuculline plus 0.5 microM GABA was injected into the pipette tip. The channels showed outward rectification and, in some patches, had a much lower probability of opening at hyperpolarized potentials. The average chord conductance in 10 patches hyperpolarized by 80 mV was 7.8 +/- 1.6 pS (SEM) compared with a chord conductance of 34.1 +/- 3.5 pS (SEM) in the same patches depolarized by 80 mV. Similar single channel currents were also activated in cell-free, inside-out patches in symmetrical chloride solutions when 0.5 microM GABA was injected into the pipette tip. The channels showed outward rectification similar to that seen in cell-attached patches, and some channels had a lower probability of opening at hyperpolarized potentials. The average chord conductance in 13 patches hyperpolarized by 80 mV was 11.8 +/- 2.3 pS (SEM) compared with 42.1 +/- 3.1 pS (SEM) in the same patches depolarized by 80 mV. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
GABA, Chloride channels, Outward rectification, Hippocampus
in
Journal of Membrane Biology
volume
136
issue
3
pages
273 - 280
publisher
Springer
external identifiers
  • pmid:8114077
  • scopus:0027134917
ISSN
0022-2631
DOI
10.1007/BF00233666
language
English
LU publication?
no
id
5ba8dfa4-de1f-46bc-9a13-9fcbd25991d2 (old id 1107178)
date added to LUP
2008-07-30 12:43:32
date last changed
2017-08-27 05:29:30
@article{5ba8dfa4-de1f-46bc-9a13-9fcbd25991d2,
  abstract     = {Chloride currents were activated by a low concentration of GABA (0.5 microM) in neonatal rat hippocampal neurons cultured for up to 14 days. Currents elicited by 0.5 microM GABA in neurons, voltage-clamped using the whole-cell technique with pipettes containing 149 mM Cl-, reversed close to 0 mV whether pipettes contained 144 mM Na+ or 140 mM Cs+, and were blocked by 100 microM bicuculline. Current-voltage curves showed outward rectification. Single channel currents appeared in cell-attached patches when the pipette tip was perfused with pipette solution containing 0.5 microM GABA and disappeared when a solution containing 100 microM bicuculline plus 0.5 microM GABA was injected into the pipette tip. The channels showed outward rectification and, in some patches, had a much lower probability of opening at hyperpolarized potentials. The average chord conductance in 10 patches hyperpolarized by 80 mV was 7.8 +/- 1.6 pS (SEM) compared with a chord conductance of 34.1 +/- 3.5 pS (SEM) in the same patches depolarized by 80 mV. Similar single channel currents were also activated in cell-free, inside-out patches in symmetrical chloride solutions when 0.5 microM GABA was injected into the pipette tip. The channels showed outward rectification similar to that seen in cell-attached patches, and some channels had a lower probability of opening at hyperpolarized potentials. The average chord conductance in 13 patches hyperpolarized by 80 mV was 11.8 +/- 2.3 pS (SEM) compared with 42.1 +/- 3.1 pS (SEM) in the same patches depolarized by 80 mV.},
  author       = {Curmi, J P and Premkumar, L S and Birnir, Bryndis and Gage, P W},
  issn         = {0022-2631},
  keyword      = {GABA,Chloride channels,Outward rectification,Hippocampus},
  language     = {eng},
  number       = {3},
  pages        = {273--280},
  publisher    = {Springer},
  series       = {Journal of Membrane Biology},
  title        = {The influence of membrane potential on chloride channels activated by GABA in rat cultured hippocampal neurons},
  url          = {http://dx.doi.org/10.1007/BF00233666},
  volume       = {136},
  year         = {1993},
}