Relationship between calcium permeability and rectification properties of AMPA receptors in cultured rat hippocampal neurons

1994 ◽  
Vol 173 (1-2) ◽  
pp. 14-16 ◽  
Author(s):  
Masae Iino ◽  
Shinobu Mochizuki ◽  
Seiji Ozawa
Physiology ◽  
1996 ◽  
Vol 11 (2) ◽  
pp. 77-82 ◽  
Author(s):  
S Ozawa ◽  
J Rossier

To trace the molecular basis of functional properties of native a-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors, we have coupled patch-clamp recordings and reverse transcription followed by polymerase chain reaction amplification. AMPA receptors lacking the GluR2 subunit in a population of hippocampal neurons exhibited a strong inward rectification and were highly permeable to Ca2+.


Neuron ◽  
1999 ◽  
Vol 23 (2) ◽  
pp. 365-376 ◽  
Author(s):  
Jacques Noel ◽  
G.Scott Ralph ◽  
Lisa Pickard ◽  
Jackie Williams ◽  
Elek Molnar ◽  
...  

2001 ◽  
Vol 85 (5) ◽  
pp. 2030-2038 ◽  
Author(s):  
Saobo Lei ◽  
Beverley A. Orser ◽  
Gregory R. L. Thatcher ◽  
James N. Reynolds ◽  
John F. MacDonald

Whole-cell or outside-out patch recordings were used to investigate the effects of protons and positive modulators of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors on the desensitization of glutamate-evoked AMPA receptor currents in isolated hippocampal CA1 neurons. Protons inhibited glutamate-evoked currents (IC50 of 6.2 pH units) but also enhanced the apparent rate and extent of AMPA receptor desensitization. The proton-induced enhancement of desensitization could not be attributed to a reduction in the rate of recovery from desensitization or to a change in the kinetics of deactivation. Non-stationary variance analysis indicated that protons reduced maximum open probability without changing the conductance of AMPA channels. The positive modulators of AMPA receptor desensitization, cyclothiazide and GT-21-005 (an organic nitrate), reduced the proton sensitivity of AMPA receptor desensitization, which suggests that they interact with protons to diminish desensitization. In contrast, the effects of wheat germ agglutinin and aniracetam on AMPA receptor desensitization were independent of pH. These results demonstrate that a reduction in the proton sensitivity of receptor desensitization contributes to the mechanism of action of some positive modulators of AMPA receptors.


2003 ◽  
Vol 358 (1432) ◽  
pp. 727-733 ◽  
Author(s):  
Dimitri M. Kullmann

At several cortical synapses glutamate release events can be mediated exclusively by NMDA receptors, with no detectable contribution from AMPA receptors. This observation was originally made by comparing the trial-to-trial variability of the two components of synaptic signals evoked in hippocampal neurons, and was subsequently confirmed by recording apparently pure NMDA receptor-mediated EPSCs with stimulation of small numbers of axons. It has come to be known as the ‘silent synapse’ phenomenon, and is widely assumed to be caused by the absence of functional AMPA receptors, which can, however, be recruited into the postsynaptic density by long-term potentiation (LTP) induction. Thus, it provides an important impetus for relating AMPA receptor trafficking mechanisms to the expression of LTP, a theme that is taken up elsewhere in this issue. This article draws attention to several findings that call for caution in identifying silent synapses exclusively with synapses without AMPA receptors. In addition, it attempts to identify several missing pieces of evidence that are required to show that unsilencing of such synapses is entirely accounted for by insertion of AMPA receptors into the postsynaptic density. Some aspects of the early stages of LTP expression remain open to alternative explanations.


2020 ◽  
Author(s):  
Jithin D. Nair ◽  
Ellen Braksator ◽  
Busra P Yucel ◽  
Richard Seager ◽  
Jack R. Mellor ◽  
...  

AbstractHere we report that sustained activation of GluK2 subunit-containing kainate receptors leads to AMPA receptor endocytosis and a novel form of long-term depression (KAR-LTDAMPAR) in hippocampal neurons. The KAR-evoked loss of surface AMPA receptors requires KAR channel activity and is occluded by the blockade of PKC or PKA. Moreover, in acute hippocampal slices, kainate invoked LTD of AMPA EPSCs. These data, together with our previously reported KAR-LTPAMPAR, demonstrate that KARs bidirectionally regulate synaptic AMPARs and synaptic plasticity.


2005 ◽  
Vol 102 (34) ◽  
pp. 12230-12235 ◽  
Author(s):  
K.-M. Noh ◽  
H. Yokota ◽  
T. Mashiko ◽  
P. E. Castillo ◽  
R. S. Zukin ◽  
...  

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