Article
- The EMBO Journal (2003) 22, 4656 - 4665
- doi:10.1093/emboj/cdg463
Subject Categories:
Direct imaging of lateral movements of AMPA receptors inside synapses
Catherine Tardin1,2,3, Laurent Cognet1,3, Cécile Bats2, Brahim Lounis1 and Daniel Choquet2
- Centre de Physique Moléculaire Optique et Hertzienne – CNRS UMR 5798 et Université Bordeaux 1, 351 Cours de la Libération, 33405 Talence, France
- Laboratoire de Physiologie Cellulaire de la Synapse – CNRS UMR 5091 et Université Bordeaux 2, Institut François Magendie, 1 rue Camille Saint-Saëns, 33077 Bordeaux, France
- C.Tardin and L.Cognet contributed equally to this work
Correspondence to:
Daniel Choquet, E-mail: dchoquet@u-bordeaux2.fr
Received 2 April 2003; Accepted 24 July 2003; Revised 7 July 2003
Abstract
Trafficking of AMPA receptors in and out of synapses is crucial for synaptic plasticity. Previous studies have focused on the role of endo/exocytosis processes or that of lateral diffusion of extra-synaptic receptors. We have now directly imaged AMPAR movements inside and outside synapses of live neurons using single- molecule fluorescence microscopy. Inside individual synapses, we found immobile and mobile receptors, which display restricted diffusion. Extra-synaptic receptors display free diffusion. Receptors could also exchange between these membrane compartments through lateral diffusion. Glutamate application increased both receptor mobility inside synapses and the fraction of mobile receptors present in a juxtasynaptic region. Block of inhibitory transmission to favor excitatory synaptic activity induced a transient increase in the fraction of mobile receptors and a decrease in the proportion of juxtasynaptic receptors. Altogether, our data show that rapid exchange of receptors between a synaptic and extra-synaptic localization occurs through regulation of receptor diffusion inside synapses.
Keywords:
- glutamate receptors,
- lateral diffusion,
- single-molecule fluorescence microscopy,
- synaptic transmission
