Short-term plasticity of kainate receptor-mediated EPSCs induced by NMDA receptors at hippocampal mossy fiber synapses
Journal of Neuroscience. 2007-04-11; 27(15): 3987-3993
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1. J Neurosci. 2007 Apr 11;27(15):3987-93.
Short-term plasticity of kainate receptor-mediated EPSCs induced by NMDA
receptors at hippocampal mossy fiber synapses.
Rebola N(1), Sachidhanandam S, Perrais D, Cunha RA, Mulle C.
(1)Laboratoire Physiologie Cellulaire de la Synapse, Centre National de la
Recherche Scientifique Unité Mixte de Recherche 5091, Bordeaux Neuroscience
Institute, University of Bordeaux 2, 33077 Bordeaux, France.
Kainate receptors (KARs) are heteromeric ionotropic glutamate receptors that play
a variety of functions in the regulation of the activity of synaptic networks.
Little is known about the regulation of the function of synaptic KARs in the
brain. In the present study, we found that a conditioning activation of synaptic
NMDA receptors (NMDARs) induces short-term depression of KAR-EPSCs but not of
AMPA receptor-EPSCs at synapses between mossy fibers and CA3 pyramidal cells.
Short-term depression of KAR-EPSCs by synaptic NMDARs peaked at 1 s and reversed
within 20 s, was likely induced and expressed postsynaptically, and was
homosynaptic. It depended on a rise of Ca2+ in the postsynaptic cell and on the
activation of the phosphatase calcineurin that likely binds to the GluR6b
(glutamate receptor subunit 6b) subunit splice variant allowing the
dephosphorylation of KARs and inhibition of activity. Finally, we show in the
current-clamp mode that short-term depression of KAR-EPSPs is induced by the
coincident discharge of action potentials in the postsynaptic cell together with
synaptic stimulation. Hence, this study describes a form of short-term synaptic
plasticity that is postsynaptic, depends on the temporal order of presynaptic and
postsynaptic spiking, and likely affects the summation properties of mossy fiber
PMID: 17428973 [Indexed for MEDLINE]