 |
Previous Article | Next Article 
The Journal of Neuroscience, July 1, 1999, 19(13):5265-5274
The Concentration of Synaptically Released Glutamate Outside of
the Climbing Fiber-Purkinje Cell Synaptic Cleft
Jeffrey A.
Dzubay and
Craig E.
Jahr
Vollum Institute, Neuroscience Graduate Program, Oregon Health
Sciences University, Portland, Oregon 97201
AMPA receptors and glutamate transporters expressed by cerebellar
Bergmann glial cells are activated by neurotransmitter released from
climbing fibers (Bergles et al., 1997). Based on anatomical evidence,
this is most likely the result of glutamate diffusing out of the
climbing fiber-Purkinje cell synaptic clefts (Palay and Chan-Palay,
1974). We used the change in the EC50 of the Bergmann glia
AMPA receptors produced by cyclothiazide (CTZ) to estimate the
concentration of glutamate reached at the glial membrane. The decrease
of the EC50 gives rise to a concentration-dependent potentiation of the AMPA receptor-mediated responses (Patneau et al.,
1993). By comparing the increase in amplitude of the AMPA receptor
response in the Bergmann glia (840 ± 240%; n = 8) with the shift in the glutamate dose-response curve measured in
excised patches (EC50, 1810 µM in
control vs 304 µM in CTZ), we estimate that the
extrasynaptic transmitter concentration reaches 160-190 µM. This contrasts with the concentration in the synaptic
cleft, thought to rapidly rise above 1 mM, but is still
high enough to activate glutamate receptors. These results indicate
that the sphere of influence of synaptically released glutamate can
extend beyond the synaptic cleft.
Key words:
ion channels; AMPA receptors; glutamate transporters; glutamate; extrasynaptic; glia
Copyright © 1999 Society for Neuroscience 0270-6474/99/19135265-10$05.00/0
This article has been cited by other articles:

|
 |

|
 |
 
T. Yamashita, T. Kanda, K. Eguchi, and T. Takahashi
Vesicular glutamate filling and AMPA receptor occupancy at the calyx of Held synapse of immature rats
J. Physiol.,
May 15, 2009;
587(10):
2327 - 2339.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K.-H. Sun, Y. de Pablo, F. Vincent, E. O. Johnson, A. K. Chavers, and K. Shah
Novel Genetic Tools Reveal Cdk5's Major Role in Golgi Fragmentation in Alzheimer's Disease
Mol. Biol. Cell,
July 1, 2008;
19(7):
3052 - 3069.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. E. Featherstone and S. A. Shippy
Regulation of Synaptic Transmission by Ambient Extracellular Glutamate
Neuroscientist,
April 1, 2008;
14(2):
171 - 181.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
B. J. Hall, B. Ripley, and A. Ghosh
NR2B Signaling Regulates the Development of Synaptic AMPA Receptor Current
J. Neurosci.,
December 5, 2007;
27(49):
13446 - 13456.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. J. Lee, G. Mannaioni, H. Yuan, D. H. Woo, M. B. Gingrich, and S. F. Traynelis
Astrocytic control of synaptic NMDA receptors
J. Physiol.,
June 15, 2007;
581(3):
1057 - 1081.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Piet and C. E. Jahr
Glutamatergic and Purinergic Receptor-Mediated Calcium Transients in Bergmann Glial Cells
J. Neurosci.,
April 11, 2007;
27(15):
4027 - 4035.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Takayasu, M. Iino, K. Shimamoto, K. Tanaka, and S. Ozawa
Glial glutamate transporters maintain one-to-one relationship at the climbing fiber-Purkinje cell synapse by preventing glutamate spillover.
J. Neurosci.,
June 14, 2006;
26(24):
6563 - 6572.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Takayasu, M. Iino, W. Kakegawa, H. Maeno, K. Watase, K. Wada, D. Yanagihara, T. Miyazaki, O. Komine, M. Watanabe, et al.
Differential Roles of Glial and Neuronal Glutamate Transporters in Purkinje Cell Synapses
J. Neurosci.,
September 21, 2005;
25(38):
8788 - 8793.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Matsui, C. E. Jahr, and M. E. Rubio
High-Concentration Rapid Transients of Glutamate Mediate Neural-Glial Communication via Ectopic Release
J. Neurosci.,
August 17, 2005;
25(33):
7538 - 7547.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Robert, N. Armstrong, J. E. Gouaux, and J. R. Howe
AMPA Receptor Binding Cleft Mutations That Alter Affinity, Efficacy, and Recovery from Desensitization
J. Neurosci.,
April 13, 2005;
25(15):
3752 - 3762.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J.-i. Tanaka, M. Matsuzaki, E. Tarusawa, A. Momiyama, E. Molnar, H. Kasai, and R. Shigemoto
Number and Density of AMPA Receptors in Single Synapses in Immature Cerebellum
J. Neurosci.,
January 26, 2005;
25(4):
799 - 807.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
O. H. Porras, A. Loaiza, and L. F. Barros
Glutamate Mediates Acute Glucose Transport Inhibition in Hippocampal Neurons
J. Neurosci.,
October 27, 2004;
24(43):
9669 - 9673.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Matsui and C. E. Jahr
Differential Control of Synaptic and Ectopic Vesicular Release of Glutamate
J. Neurosci.,
October 13, 2004;
24(41):
8932 - 8939.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H. Zhang and D. Sulzer
Glutamate Spillover in the Striatum Depresses Dopaminergic Transmission by Activating Group I Metabotropic Glutamate Receptors
J. Neurosci.,
November 19, 2003;
23(33):
10585 - 10592.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. Marcaggi, D. Billups, and D. Attwell
The Role of Glial Glutamate Transporters in Maintaining the Independent Operation of Juvenile Mouse Cerebellar Parallel Fibre Synapses
J. Physiol.,
October 1, 2003;
552(1):
89 - 107.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Boudaba, D. M Linn, K. C. Halmos, and J. G Tasker
Increased tonic activation of presynaptic metabotropic glutamate receptors in the rat supraoptic nucleus following chronic dehydration
J. Physiol.,
September 15, 2003;
551(3):
815 - 823.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Bordey and H. Sontheimer
Modulation of Glutamatergic Transmission by Bergmann Glial Cells in Rat Cerebellum In Situ
J Neurophysiol,
February 1, 2003;
89(2):
979 - 988.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Harrison and C. E. Jahr
Receptor Occupancy Limits Synaptic Depression at Climbing Fiber Synapses
J. Neurosci.,
January 15, 2003;
23(2):
377 - 383.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. Zhou and H. K. Kimelberg
Freshly Isolated Hippocampal CA1 Astrocytes Comprise Two Populations Differing in Glutamate Transporter and AMPA Receptor Expression
J. Neurosci.,
October 15, 2001;
21(20):
7901 - 7908.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
B. Barbour
An Evaluation of Synapse Independence
J. Neurosci.,
October 15, 2001;
21(20):
7969 - 7984.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. Ito
Cerebellar Long-Term Depression: Characterization, Signal Transduction, and Functional Roles
Physiol Rev,
July 1, 2001;
81(3):
1143 - 1195.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Ishikawa and T. Takahashi
Mechanisms underlying presynaptic facilitatory effect of cyclothiazide at the calyx of Held of juvenile rats
J. Physiol.,
June 1, 2001;
533(2):
423 - 431.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. Iino, K. Goto, W. Kakegawa, H. Okado, M. Sudo, S. Ishiuchi, A. Miwa, Y. Takayasu, I. Saito, K. Tsuzuki, et al.
Glia-Synapse Interaction Through Ca2+-Permeable AMPA Receptors in Bergmann Glia
Science,
May 4, 2001;
292(5518):
926 - 929.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. L. Hines and N. T. Carnevale
Neuron: A Tool for Neuroscientists
Neuroscientist,
April 1, 2001;
7(2):
123 - 135.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
M. E. Rubio and F. Soto
Distinct Localization of P2X Receptors at Excitatory Postsynaptic Specializations
J. Neurosci.,
January 15, 2001;
21(2):
641 - 653.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. G. Carter and W. G. Regehr
Prolonged Synaptic Currents and Glutamate Spillover at the Parallel Fiber to Stellate Cell Synapse
J. Neurosci.,
June 15, 2000;
20(12):
4423 - 4434.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Q. Zhou, C. C H Petersen, and R. A Nicoll
Effects of reduced vesicular filling on synaptic transmission in rat hippocampal neurones
J. Physiol.,
May 15, 2000;
525(1):
195 - 206.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Rodriguez-Moreno, J. C. Lopez-Garcia, and J. Lerma
Two populations of kainate receptors with separate signaling mechanisms in hippocampal interneurons
PNAS,
February 1, 2000;
97(3):
1293 - 1298.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|

|