Diffusional Trapping of GluR1 AMPA Receptors by Input-Specific Synaptic Activity

Michael D. Ehlers, Martin Heine, Laurent Groc, Ming-Chia Lee, Daniel Choquet
Neuron. 2007-05-01; 54(3): 447-460
DOI: 10.1016/j.neuron.2007.04.010

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1. Neuron. 2007 May 3;54(3):447-60.

Diffusional trapping of GluR1 AMPA receptors by input-specific synaptic activity.

Ehlers MD(1), Heine M, Groc L, Lee MC, Choquet D.

Author information:
(1)Department of Neurobiology, Howard Hughes Medical Institute, Duke University
Medical Center, Durham, NC 27710, USA.

Synaptic activity regulates the postsynaptic accumulation of AMPA receptors over
timescales ranging from minutes to days. Indeed, the regulated trafficking and
mobility of GluR1 AMPA receptors underlies many forms of synaptic potentiation at
glutamatergic synapses throughout the brain. However, the basis for
synapse-specific accumulation of GluR1 is unknown. Here we report that synaptic
activity locally immobilizes GluR1 AMPA receptors at individual synapses. Using
single-molecule tracking together with the silencing of individual presynaptic
boutons, we demonstrate that local synaptic activity reduces diffusional exchange
of GluR1 between synaptic and extraynaptic domains, resulting in postsynaptic
accumulation of GluR1. At neighboring inactive synapses, GluR1 is highly mobile
with individual receptors frequently escaping the synapse. Within the synapse,
spontaneous activity confines the diffusional movement of GluR1 to restricted
subregions of the postsynaptic membrane. Thus, local activity restricts GluR1
mobility on a submicron scale, defining an input-specific mechanism for
regulating AMPA receptor composition and abundance.

DOI: 10.1016/j.neuron.2007.04.010
PMCID: PMC1993808
PMID: 17481397 [Indexed for MEDLINE]

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