| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Journal of Neurophysiology, Vol 69, Issue 5 1541-1555, Copyright © 1993 by APS
ARTICLES |
L. M. Grover, N. A. Lambert, P. A. Schwartzkroin and T. J. Teyler
Neurobiology Department, Northeastern Ohio Universities College of Medicine, Rootstown 44272.
1. Activation of GABAA receptors can produce both hyperpolarizing and depolarizing responses in CA1 pyramidal cells. The hyperpolarizing response is mediated by a Cl- conductance, but the ionic basis of the depolarizing response is not clear. We compared the GABAA receptor-mediated depolarizations induced by synaptically released gamma-aminobutyric acid [GABA; depolarizing inhibitory postsynaptic potentials (dIPSPs)] with those produced by exogenous GABA (depolarizing GABA responses). Short trains of high-frequency (200 Hz) stimuli were used to generate dIPSPs. We found that dIPSPs generated by trains of stimuli and depolarizing responses to exogenous GABA were accompanied by a conductance increase and had a similar reversal potential, indicating a similar ionic basis for both responses. 2. We wished to determine whether an HCO3- current contributed to the GABAA-mediated depolarizations. We found that dIPSPs and depolarizing GABA responses were sensitive to perfusion with HCO3(-)-free medium. Interpretation of these data was complicated by the mixed nature of the responses: dIPSPs were invariably accompanied by conventional, Cl(-)-mediated fast hyperpolarizing IPSPs (fIPSPs), and response to exogenous GABA usually consisted of biphasic hyperpolarizing and depolarizing responses. However, it was sometimes possible to elicit responses to GABA that appeared purely depolarizing (monophasic depolarizing GABA responses). 3. We analyzed monophasic depolarizing GABA responses and found no change in reversal potential when slices were perfused with HCO(3-)-free medium. We also made whole-cell recordings from CA1 pyramidal cells, attempting to reduce [HCO3-]i, and compared the reversal potential for monophasic depolarizing GABA responses with similar responses recorded with fine intracellular microelectrodes. We found no difference in reversal potential. We also examined effects of the carbonic anhydrase inhibitor acetazolamide (ACTZ) on depolarizing GABA responses. ACTZ reduced these responses but did not change their reversal potential. 4. Effects of HCO(3-)-free medium were not specific to GABAA receptor-mediated responses. GABAB receptor-mediated slow IPSPs (sIPSPs) were also reduced, as were excitatory postsynaptic potentials (EPSPs). Analyses of field potentials and spontaneous fIPSPs suggested a decrease in presynaptic excitability during perfusion with HCO(3-)-free medium. In addition, pyramidal cells showed decreased input resistance when perfused with HCO(3-)-free medium. 5. The sensitivity of GABAA receptor-mediated depolarizations to HCO(3-)-free medium can be explained by a decrease in presynaptic excitability and an increased resting conductance in postsynaptic neurons.(ABSTRACT TRUNCATED AT 400 WORDS)
This article has been cited by other articles:
|
|
 |
|
  N. Lozovaya, N. Yatsenko, A. Beketov, T. Tsintsadze, and N. Burnashev Glycine Receptors in CNS Neurons as a Target for Nonretrograde Action of Cannabinoids J. Neurosci., August 17, 2005; 25(33): 7499 - 7506. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. T. Kantrowitz, N. N. Francis, A. Salah, and K. L. Perkins Synaptic Depolarizing GABA Response in Adults Is Excitatory and Proconvulsive When GABAB Receptors Are Blocked J Neurophysiol, May 1, 2005; 93(5): 2656 - 2667. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Fan, B. Zou, Y. Ruan, Z. Pang, and Z. C. Xu In Vivo Demonstration of a Late Depolarizing Postsynaptic Potential in CA1 Pyramidal Neurons J Neurophysiol, March 1, 2005; 93(3): 1326 - 1335. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Kang, L. Jiang, W. He, J. Xu, M. Nedergaard, and J. Kang Presynaptic Inactivation of Action Potentials and Postsynaptic Inhibition of GABAA Currents Contribute to KA-Induced Disinhibition in CA1 Pyramidal Neurons J Neurophysiol, August 1, 2004; 92(2): 873 - 882. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Fujiwara-Tsukamoto, Y. Isomura, K. Kaneda, and M. Takada Synaptic interactions between pyramidal cells and interneurone subtypes during seizure-like activity in the rat hippocampus J. Physiol., June 15, 2004; 557(3): 961 - 979. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Ruusuvuori, H. Li, K. Huttu, J. M. Palva, S. Smirnov, C. Rivera, K. Kaila, and J. Voipio Carbonic Anhydrase Isoform VII Acts as a Molecular Switch in the Development of Synchronous Gamma-Frequency Firing of Hippocampal CA1 Pyramidal Cells J. Neurosci., March 17, 2004; 24(11): 2699 - 2707. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Isomura, M. Sugimoto, Y. Fujiwara-Tsukamoto, S. Yamamoto-Muraki, J. Yamada, and A. Fukuda Synaptically Activated Cl- Accumulation Responsible for Depolarizing GABAergic Responses in Mature Hippocampal Neurons J Neurophysiol, October 1, 2003; 90(4): 2752 - 2756. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. R. McQuiston and P. Saggau Mu-opioid Receptors Facilitate the Propagation of Excitatory Activity in Rat Hippocampal Area CA1 by Disinhibition of all Anatomical Layers J Neurophysiol, September 1, 2003; 90(3): 1936 - 1948. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Lamsa and T. Taira Use-Dependent Shift From Inhibitory to Excitatory GABAA Receptor Action in SP-O Interneurons in the Rat Hippocampal CA3 Area J Neurophysiol, September 1, 2003; 90(3): 1983 - 1995. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Tominaga, Y. Tominaga, and M. Ichikawa Optical Imaging of Long-Lasting Depolarization on Burst Stimulation in Area CA1 of Rat Hippocampal Slices J Neurophysiol, September 1, 2002; 88(3): 1523 - 1532. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Bracci, M. Vreugdenhil, S. P. Hack, and J. G. R. Jefferys Dynamic Modulation of Excitation and Inhibition During Stimulation at Gamma and Beta Frequencies in the CA1 Hippocampal Region J Neurophysiol, June 1, 2001; 85(6): 2412 - 2422. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. R. Patrylo, D. D. Spencer, and A. Williamson GABA Uptake and Heterotransport Are Impaired in the Dentate Gyrus of Epileptic Rats and Humans With Temporal Lobe Sclerosis J Neurophysiol, April 1, 2001; 85(4): 1533 - 1542. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. DeFazio, S. Keros, M. W. Quick, and J. J. Hablitz Potassium-Coupled Chloride Cotransport Controls Intracellular Chloride in Rat Neocortical Pyramidal Neurons J. Neurosci., November 1, 2000; 20(21): 8069 - 8076. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Kohling, M. Vreugdenhil, E. Bracci, and J. G. R. Jefferys Ictal Epileptiform Activity Is Facilitated by Hippocampal GABAA Receptor-Mediated Oscillations J. Neurosci., September 15, 2000; 20(18): 6820 - 6829. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. S. Schweitzer, H. Wang, Z.-Q. Xiong, and J. L. Stringer pH Sensitivity of Non-Synaptic Field Bursts in the Dentate Gyrus J Neurophysiol, August 1, 2000; 84(2): 927 - 933. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Lamsa, J. M. Palva, E. Ruusuvuori, K. Kaila, and T. Taira Synaptic GABAA Activation Inhibits AMPA-Kainate Receptor-Mediated Bursting in the Newborn (P0-P2) Rat Hippocampus J Neurophysiol, January 1, 2000; 83(1): 359 - 366. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Smirnov, P. Paalasmaa, M. Uusisaari, J. Voipio, and K. Kaila Pharmacological Isolation of the Synaptic and Nonsynaptic Components of the GABA-Mediated Biphasic Response in Rat CA1 Hippocampal Pyramidal Cells J. Neurosci., November 1, 1999; 19(21): 9252 - 9260. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Bracci, M. Vreugdenhil, S. P. Hack, and J. G. R. Jefferys On the Synchronizing Mechanisms of Tetanically Induced Hippocampal Oscillations J. Neurosci., September 15, 1999; 19(18): 8104 - 8113. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. L. Perkins Cl- Accumulation Does Not Account for the Depolarizing Phase of the Synaptic GABA Response in Hippocampal Pyramidal Cells J Neurophysiol, August 1, 1999; 82(2): 768 - 777. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Jarolimek, A. Lewen, and U. Misgeld A Furosemide-Sensitive K+-Cl- Cotransporter Counteracts Intracellular Cl- Accumulation and Depletion in Cultured Rat Midbrain Neurons J. Neurosci., June 15, 1999; 19(12): 4695 - 4704. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M.-K. Sun, T. J. Nelson, H. Xu, and D. L. Alkon Calexcitin transformation of GABAergic synapses: From excitation filter to amplifier PNAS, June 8, 1999; 96(12): 7023 - 7028. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. M. Grover and C. Yan Blockade of GABAA Receptors Facilitates Induction of NMDA Receptor-Independent Long-Term Potentiation J Neurophysiol, June 1, 1999; 81(6): 2814 - 2822. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. F. Jackson, B. Esplin, and R. Capek Inhibitory Nature of Tiagabine-Augmented GABAA Receptor-Mediated Depolarizing Responses in Hippocampal Pyramidal Cells J Neurophysiol, March 1, 1999; 81(3): 1192 - 1198. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A.-M. Autere, K. Lamsa, K. Kaila, and T. Taira Synaptic Activation of GABAA Receptors Induces Neuronal Uptake of Ca2+ in Adult Rat Hippocampal Slices J Neurophysiol, February 1, 1999; 81(2): 811 - 816. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Grabauskas and R. M. Bradley Tetanic Stimulation Induces Short-Term Potentiation of Inhibitory Synaptic Activity in the Rostral Nucleus of the Solitary Tract J Neurophysiol, February 1, 1998; 79(2): 595 - 604. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Lamsa and K. Kaila Ionic Mechanisms of Spontaneous GABAergic Events in Rat Hippocampal Slices Exposed to 4-Aminopyridine J Neurophysiol, November 1, 1997; 78(5): 2582 - 2591. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Kaila, K. Lamsa, S. Smirnov, T. Taira, and J. Voipio Long-Lasting GABA-Mediated Depolarization Evoked by High-Frequency Stimulation in Pyramidal Neurons of Rat Hippocampal Slice Is Attributable to a Network-Driven, Bicarbonate-Dependent K+ Transient J. Neurosci., October 15, 1997; 17(20): 7662 - 7672. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Taira, K. Lamsa, and K. Kaila Posttetanic Excitation Mediated by GABAA Receptors in Rat CA1 Pyramidal Neurons J Neurophysiol, April 1, 1997; 77(4): 2213 - 2218. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Cerne and W. J. Spain GABAA Mediated Afterdepolarization in Pyramidal Neurons From Rat Neocortex J Neurophysiol, February 1, 1997; 77(2): 1039 - 1045. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. F. Owens, L. H. Boyce, M. B. E. Davis, and A. R. Kriegstein Excitatory GABA Responses in Embryonic and Neonatal Cortical Slices Demonstrated by Gramicidin Perforated-Patch Recordings and Calcium Imaging J. Neurosci., October 15, 1996; 16(20): 6414 - 6423. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Agmon, G. Hollrigel, and D. K. O'Dowd Functional GABAergic Synaptic Connection in Neonatal Mouse Barrel Cortex J. Neurosci., August 1, 1996; 16(15): 4684 - 4695. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N Lambert and L Grover The mechanism of biphasic GABA responses Science, August 18, 1995; 269(5226): 928 - 929. [PDF]
|
|
|
|
|
|
K. Staley, B. Soldo, and W. Proctor Ionic mechanisms of neuronal excitation by inhibitory GABAA receptors Science, August 18, 1995; 269(5226): 977 - 981. [Abstract] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
