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The organization of AMPA receptor subunits at the postsynaptic membrane
Author(s) -
Jacob Amanda L.,
Weinberg Richard J.
Publication year - 2015
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/hipo.22404
Subject(s) - ampa receptor , silent synapse , neuroscience , synapse , synaptic plasticity , excitatory postsynaptic potential , postsynaptic potential , neurotransmission , excitatory synapse , biology , long term potentiation , synaptic pharmacology , chemistry , synaptic augmentation , glutamate receptor , receptor , inhibitory postsynaptic potential , biochemistry
AMPA receptors are the principal mediators of excitatory synaptic transmission in the mammalian central nervous system. The subunit composition of these tetrameric receptors helps to define their functional properties, and may also influence the synaptic trafficking implicated in long‐term synaptic plasticity. However, the organization of AMPAR subunits within the synapse remains unclear. Here, we use postembedding immunogold electron microscopy to study the synaptic organization of AMPAR subunits in stratum radiatum of CA1 hippocampus in the adult rat. We find that GluA1 concentrates away from the center of the synapse, extending at least 25 nm beyond the synaptic specialization; in contrast, GluA3 is uniformly distributed along the synapse, and seldom extends beyond its lateral border. The fraction of extrasynaptic GluA1 is markedly higher in small than in large synapses; no such effect is seen for GluA3. These observations imply that different kinds of AMPARs are differently trafficked to and/or anchored at the synapse. © 2014 Wiley Periodicals, Inc.