| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Journal of Neurophysiology, Vol 68, Issue 1 16-27, Copyright © 1992 by APS
ARTICLES |
C. McBain and R. Dingledine
Department of Pharmacology, University of North Carolina, Chapel Hill 27599.
1. Spontaneous miniature synaptic events were studied with tight-seal whole-cell recordings from CA3 neurons maintained in the hippocampal slice from immature rats (3-15 days). CA3 neurons suffer a constant, high-frequency barrage of inhibitory synaptic input. When inhibitory postsynaptic currents were suppressed by bicuculline, a smaller contribution from excitatory synapses was revealed. 2. Addition of tetrodotoxin (TTX) removed a persistent inward current and substantially reduced the baseline noise facilitating the detection of "miniature" excitatory currents. Addition of hyperosmotic media increased the frequency of spontaneous excitatory postsynaptic currents (EPSCs). 3. Under both physiological and elevated potassium conditions, individual spontaneous miniature EPSCs (10-30 pA amplitude) were composed of components mediated by N-methyl-D-aspartate (NMDA) and non-NMDA receptors as determined by their voltage dependence, time course, and sensitivity to selective antagonists. 6-Cyano-7-nitro-quinoxaline-2,3-dione (CNQX) or D-2-amino-5-phosphonovaleric acid (D-APV) shifted the amplitude distribution of miniature EPSCs to a smaller mode at both +40 mV and -40 mV. Similar to EPSCs recorded in CA1 neurons, the rise and decay times of the NMDA receptor component were slower than those of the non-NMDA component. The time course of the non-NMDA component was voltage independent. 4. In 13 of 21 neurons, no correlation existed between individual EPSC rise times and their corresponding halfwidth, peak amplitude, or decay time constant. This suggests that the large range of EPSC kinetics observed in each individual neuron was not due solely to cable attenuation of EPSCs widely distributed over the dendritic tree. Plots of the mean EPSC rise time against mean halfwidth for each cell, however, revealed a striking correlation, suggesting that in neonates, active synapses may be grouped in a restricted region of the dendritic tree and as such are subject to similar amounts of dendritic filtering. 5. The electrotonic length of CA3 neurons (L = 0.52) predicted that at this maturity the electrotonic compactness of the neuron facilitated voltage control over all but the most distal synapses. The reversal potential of the fast component of spontaneous events was close to 0 mV, whereas the reversal potential of exogenously applied kainate and NMDA was more positive. This discrepancy likely reflects a compromise of the voltage clamp by the activation of conductances distributed over the entire cell.(ABSTRACT TRUNCATED AT 400 WORDS)
This article has been cited by other articles:
|
|
 |
|
  S. Sylantyev, L. P. Savtchenko, Y.-P. Niu, A. I. Ivanov, T. P. Jensen, D. M. Kullmann, M.-Y. Xiao, and D. A. Rusakov Electric Fields Due to Synaptic Currents Sharpen Excitatory Transmission Science, March 28, 2008; 319(5871): 1845 - 1849. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. L. Jones and S. C. Baraban Characterization of Inhibitory Circuits in the Malformed Hippocampus of Lis1 Mutant Mice J Neurophysiol, November 1, 2007; 98(5): 2737 - 2746. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Sarid, R. Bruno, B. Sakmann, I. Segev, and D. Feldmeyer Modeling a layer 4-to-layer 2/3 module of a single column in rat neocortex: Interweaving in vitro and in vivo experimental observations PNAS, October 9, 2007; 104(41): 16353 - 16358. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Rumbaugh, J. P. Adams, J. H. Kim, and R. L. Huganir Inaugural Article: SynGAP regulates synaptic strength and mitogen-activated protein kinases in cultured neurons PNAS, March 21, 2006; 103(12): 4344 - 4351. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. Meeks and S. Mennerick Selective Effects of Potassium Elevations on Glutamate Signaling and Action Potential Conduction in Hippocampus J. Neurosci., January 7, 2004; 24(1): 197 - 206. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. I. O. Myme, K. Sugino, G. G. Turrigiano, and S. B. Nelson The NMDA-to-AMPA Ratio at Synapses Onto Layer 2/3 Pyramidal Neurons Is Conserved Across Prefrontal and Visual Cortices J Neurophysiol, August 1, 2003; 90(2): 771 - 779. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. C. Stacey and D. M. Durand Noise and Coupling Affect Signal Detection and Bursting in a Simulated Physiological Neural Network J Neurophysiol, November 1, 2002; 88(5): 2598 - 2611. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Chen and J. S. Diamond Synaptically Released Glutamate Activates Extrasynaptic NMDA Receptors on Cells in the Ganglion Cell Layer of Rat Retina J. Neurosci., March 15, 2002; 22(6): 2165 - 2173. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. C. Stacey and D. M. Durand Synaptic Noise Improves Detection of Subthreshold Signals in Hippocampal CA1 Neurons J Neurophysiol, September 1, 2001; 86(3): 1104 - 1112. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. D. Lin, A. S. Cohen, and D. A. Coulter Zinc-Induced Augmentation of Excitatory Synaptic Currents and Glutamate Receptor Responses in Hippocampal CA3 Neurons J Neurophysiol, March 1, 2001; 85(3): 1185 - 1196. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Steigerwald, T. W. Schulz, L. T. Schenker, M. B. Kennedy, P. H. Seeburg, and G. Kohr C-Terminal Truncation of NR2A Subunits Impairs Synaptic But Not Extrasynaptic Localization of NMDA Receptors J. Neurosci., June 15, 2000; 20(12): 4573 - 4581. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. C. Stacey and D. M. Durand Stochastic Resonance Improves Signal Detection in Hippocampal CA1 Neurons J Neurophysiol, March 1, 2000; 83(3): 1394 - 1402. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Araque, R. P. Sanzgiri, V. Parpura, and P. G. Haydon Calcium Elevation in Astrocytes Causes an NMDA Receptor-Dependent Increase in the Frequency of Miniature Synaptic Currents in Cultured Hippocampal Neurons J. Neurosci., September 1, 1998; 18(17): 6822 - 6829. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Matsui, N. Hosoi, and M. Tachibana Excitatory Synaptic Transmission in the Inner Retina: Paired Recordings of Bipolar Cells and Neurons of the Ganglion Cell Layer J. Neurosci., June 15, 1998; 18(12): 4500 - 4510. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B.-X. Gao, G. Cheng, and L. Ziskind-Conhaim Development of Spontaneous Synaptic Transmission in the Rat Spinal Cord J Neurophysiol, May 1, 1998; 79(5): 2277 - 2287. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Pare, E. Lebel, and E. J. Lang Differential Impact of Miniature Synaptic Potentials on the Soma and Dendrites of Pyramidal Neurons In Vivo J Neurophysiol, September 1, 1997; 78(3): 1735 - 1739. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Dzubay and C. E. Jahr Kinetics of NMDA Channel Opening J. Neurosci., July 1, 1996; 16(13): 4129 - 4134. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
