|
|
||||||||
Journal of Neurophysiology, Vol 54, Issue 1 134-142, Copyright © 1985 by APS
ARTICLES |
R. Gray and D. Johnston
The properties of single chloride channels activated by gamma-aminobutyric acid (GABA) were investigated with hippocampal slices from adult guinea pigs. After the slices were treated with proteolytic enzymes, gigaseal recordings were made from excised patches of pyramidal or granule cell membranes. This newly developed preparation permits the application of patch-clamp techniques to the adult mammalian central nervous system. Guinea pig hippocampal slices were prepared in a conventional manner. Once prepared, the slices were treated with two different enzymes for brief periods and gently agitated. Slices generally split apart along the boundaries of the cell body regions, exposing neuronal somata. Standard patch-clamp techniques were used for the gigaseal recordings from excised patches. Solutions for both sides of the patches consisted of symmetrical concentrations of chloride, with all cation channels blocked. GABA at concentrations of 0.5-1.0 microM was added to the solution for the extracellular side of the patches. At transmembrane potentials negative to the chloride reversal potential (0 mV), the conductance through the GABA-gated chloride channels was approximately 20 pS. When the transmembrane potential was changed to positive values, the chloride conductance increased dramatically. For example, at +40 mV the conductance through the GABA-gated channels was almost 40 pS. Ramp-clamp commands were used to measure the current-voltage (I-V) relationship through single open channels. The open-channel I-V curves displayed outward rectification. The relationship between open-channel conductance and voltage could be fitted reasonably well by a single energy-barrier model for the channel, with the higher energy barrier placed near the cytoplasmic side of the membrane (at a fractional distance through the membrane of 0.73).(ABSTRACT TRUNCATED AT 250 WORDS)
This article has been cited by other articles:
![]() |
U. Kim and L.-y. Chung Dual GABAergic Synaptic Response of Fast Excitation and Slow Inhibition in the Medial Habenula of Rat Epithalamus J Neurophysiol, September 1, 2007; 98(3): 1323 - 1332. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Luu, P. W. Gage, and M. L. Tierney GABA Increases both the Conductance and Mean Open Time of Recombinant GABAA Channels Co-expressed with GABARAP J. Biol. Chem., November 24, 2006; 281(47): 35699 - 35708. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. B. Everitt, T. Luu, B. Cromer, M. L. Tierney, B. Birnir, R. W. Olsen, and P. W. Gage Conductance of Recombinant GABA Channels Is Increased in Cells Co-expressing GABAA A Receptor-associated Protein J. Biol. Chem., May 21, 2004; 279(21): 21701 - 21706. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Eghbali, P. W. Gage, and B. Birnir Pentobarbital Modulates gamma -Aminobutyric Acid-Activated Single-Channel Conductance in Rat Cultured Hippocampal Neurons Mol. Pharmacol., September 1, 2000; 58(3): 463 - 469. [Abstract] [Full Text] |
||||
![]() |
A. Y. Valeyev, J. C. Hackman, A. M. Holohean, P. M. Wood, J. L. Katz, and R. A. Davidoff GABA-Induced Cl- Current in Cultured Embryonic Human Dorsal Root Ganglion Neurons J Neurophysiol, July 1, 1999; 82(1): 1 - 9. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Y. Valeyev, J. C. Hackman, A. M. Holohean, P. M. Wood, J. L. Katz, and R. A. Davidoff Alphaxalone Activates a Cl- Conductance Independent of GABAA Receptors in Cultured Embryonic Human Dorsal Root Ganglion Neurons J Neurophysiol, July 1, 1999; 82(1): 10 - 15. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Kapur, K. F. Haas, and R. L. Macdonald Physiological Properties of GABAA Receptors From Acutely Dissociated Rat Dentate Granule Cells J Neurophysiol, May 1, 1999; 81(5): 2464 - 2471. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. I. Tietz, J. Kapur, and R. L. Macdonald Functional GABAA Receptor Heterogeneity of Acutely Dissociated Hippocampal CA1 Pyramidal Cells J Neurophysiol, April 1, 1999; 81(4): 1575 - 1586. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. A. H. Verheugen, D. Fricker, and R. Miles Noninvasive Measurements of the Membrane Potential and GABAergic Action in Hippocampal Interneurons J. Neurosci., April 1, 1999; 19(7): 2546 - 2555. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. A. Protti, H. M. Gerschenfeld, and I. Llano GABAergic and glycinergic IPSCs in Ganglion Cells of Rat Retinal Slices J. Neurosci., August 15, 1997; 17(16): 6075 - 6085. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |