J Physiol Society Membership
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Physiol Vol 486, Issue Pt 1 pp 207-221
Copyright © 1995 by The Physiological Society
This Article
Right arrow Full Text (PDF)
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Taylor, W R
Right arrow Articles by Copenhagen, D R
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Taylor, W R
Right arrow Articles by Copenhagen, D R

Characterization of spontaneous excitatory synaptic currents in salamander retinal ganglion cells.

 W R Taylor, E Chen and D R Copenhagen

Department of Ophthalmology, University of California San Francisco School of Medicine 94143, USA.

1. Spontaneous excitatory postsynaptic currents (sEPSCs) were recorded under voltage-clamp conditions. Consistent with activation of non-NMDA-type glutamate receptors, the sEPSCs reversed at potentials above 0 mV, were blocked by 1 microM CNQX and prolonged by 2 mM aniracetam. 2. The peak conductance of the averaged sEPSCs (n = 70-400) was 130 +/- 60 pS (mean +/- S.D.; 17 cells, ranging from 70 to 290 pS). Amplitude distributions were skewed towards larger amplitudes. 3. The decay of individual and mean sEPSCs was exponential with a mean time constant (tau d) of 3.75 +/- 0.84 ms (n = 13), which was voltage independent. The 10-90% rise time of the sEPSCs was 1.30 +/- 0.44 ms (n = 13). There was no correlation between sEPSC rise time and tau d suggesting that dendritic filtering alone did not shape the time course of sEPSCs. 4. Light-evoked EPSCs in these retinal ganglion cells are mediated by concomitant activation of NMDA and non-NMDA receptors; however, no NMDA component was discerned in the sEPSCs, even when recording at -96 mV in Mg(2+)-free solutions. The decay time course was not altered by 20 microM AP7, an NMDA antagonist, nor was an NMDA component unmasked by adding glycine or D-serine. These results suggest that NMDA and non-NMDA receptors are not coactivated by a single vesicle of transmitter during spontaneous release, and thus are probably not colocalized in the postsynaptic membrane at the sites of spontaneous release. 5. The sEPSCs were an order of magnitude faster than the non-NMDA receptor-mediated EPSCs evoked by light stimuli, and it is proposed that the EPSC time course is determined largely by the extended time course of release of synaptic vesicles from bipolar cells. The quantal content of a light-evoked non-NMDA receptor-mediated EPSC in an on-off cell is about 200 quanta.




This article has been cited by other articles:


Home page
 J. Physiol.Home page
M. Hou, L. Duan, and M. M. Slaughter
Synaptic inhibition by glycine acting at a metabotropic receptor in tiger salamander retina
J. Physiol., June 15, 2008; 586(12): 2913 - 2926.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
Y. Xia, S. Nawy, and R. C. Carroll
Activity-Dependent Synaptic Plasticity in Retinal Ganglion Cells
J. Neurosci., November 7, 2007; 27(45): 12221 - 12229.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
Y. Xia, R. C. Carroll, and S. Nawy
State-dependent AMPA receptor trafficking in the Mammalian retina.
J. Neurosci., May 10, 2006; 26(19): 5028 - 5036.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
L. Cadetti, D. Tranchina, and W. B. Thoreson
A comparison of release kinetics and glutamate receptor properties in shaping rod-cone differences in EPSC kinetics in the salamander retina
J. Physiol., December 15, 2005; 569(3): 773 - 788.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
J. Vigh and H. von Gersdorff
Prolonged Reciprocal Signaling via NMDA and GABA Receptors at a Retinal Ribbon Synapse
J. Neurosci., December 7, 2005; 25(49): 11412 - 11423.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
J. B. Demb, P. Sterling, and M. A. Freed
How Retinal Ganglion Cells Prevent Synaptic Noise From Reaching the Spike Output
J Neurophysiol, October 1, 2004; 92(4): 2510 - 2519.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
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]

Home page
 J. Neurophysiol.Home page
K. Matsui, J. Hasegawa, and M. Tachibana
Modulation of Excitatory Synaptic Transmission by GABAC Receptor-Mediated Feedback in the Mouse Inner Retina
J Neurophysiol, November 1, 2001; 86(5): 2285 - 2298.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
G. B. Awatramani and M. M. Slaughter
Intensity-Dependent, Rapid Activation of Presynaptic Metabotropic Glutamate Receptors at a Central Synapse
J. Neurosci., January 15, 2001; 21(2): 741 - 749.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
S.-I. Watanabe, A. Koizumi, S. Matsunaga, J. W. Stocker, and A. Kaneko
GABA-Mediated Inhibition Between Amacrine Cells in the Goldfish Retina
J Neurophysiol, October 1, 2000; 84(4): 1826 - 1834.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
M. A. Freed
Parallel Cone Bipolar Pathways to a Ganglion Cell Use Different Rates and Amplitudes of Quantal Excitation
J. Neurosci., June 1, 2000; 20(11): 3956 - 3963.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
M. A. Freed
Rate of Quantal Excitation to a Retinal Ganglion Cell Evoked by Sensory Input
J Neurophysiol, May 1, 2000; 83(5): 2956 - 2966.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
K. Matsui, N. Hosoi, and M. Tachibana
Active Role of Glutamate Uptake in the Synaptic Transmission from Retinal Nonspiking Neurons
J. Neurosci., August 15, 1999; 19(16): 6755 - 6766.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
M. H. Higgs and P. D. Lukasiewicz
Glutamate Uptake Limits Synaptic Excitation of Retinal Ganglion Cells
J. Neurosci., May 15, 1999; 19(10): 3691 - 3700.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
F. Kawai and P. Sterling
AMPA Receptor Activates a G-Protein that Suppresses a cGMP-Gated Current
J. Neurosci., April 15, 1999; 19(8): 2954 - 2959.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
F. Gao and S. M. Wu
Characterization of Spontaneous Inhibitory Synaptic Currents in Salamander Retinal Ganglion Cells
J Neurophysiol, October 1, 1998; 80(4): 1752 - 1764.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
N. Tian, T. N. Hwang, and D. R. Copenhagen
Analysis of Excitatory and Inhibitory Spontaneous Synaptic Activity in Mouse Retinal Ganglion Cells
J Neurophysiol, September 1, 1998; 80(3): 1327 - 1340.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
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]

Home page
 J. Neurosci.Home page
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 page
 J. Neurophysiol.Home page
C. A. Kittila and S. C. Massey
Pharmacology of Directionally Selective Ganglion Cells in the Rabbit Retina
J Neurophysiol, February 1, 1997; 77(2): 675 - 689.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1995 The Physiological Society.