Format

Send to

Choose Destination
See comment in PubMed Commons below
J Neurosci. 2007 Sep 19;27(38):10165-75.

NMDA receptor surface trafficking and synaptic subunit composition are developmentally regulated by the extracellular matrix protein Reelin.

Author information

  • 1Physiologie Cellulaire de la Synapse, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5091, 33077 Bordeaux, France. laurent.groc@u-bordeaux2.fr

Abstract

During postnatal development, changes in the subunit composition of glutamate receptors of the NMDA subtype (NMDARs) are key to the refinement of excitatory synapses. Hypotheses for maturation of synaptic NMDARs include regulation of their expression levels, membrane targeting, and surface movements. In addition, several members of extracellular matrix (ECM) proteins such as Reelin are involved in synaptic plasticity. However, it is not known whether and how ECM proteins regulate synaptic NMDAR maturation. To probe the participation of NMDARs to synaptic currents and NMDARs surface dynamics, we used electrophysiological recordings and single-particle tracking in cultured hippocampal neurons. Our results show that, during maturation, Reelin orchestrates the regulation of subunit composition of synaptic NMDARs and controls the surface mobility of NR2B subunits. During postnatal maturation, we observed a marked decrease of NR1/NR2B receptor participation to NMDAR-mediated synaptic currents concomitant with the accumulation of Reelin at active synapses. Blockade of the function of Reelin prevented the maturation-dependent reduction in NR1/NR2B-mediated synaptic currents. The reduction of NR1/NR2B receptors was not inhibited by blocking synaptic activity but required beta1-containing integrin receptors. Single-particle tracking showed that inhibition of Reelin decreased the surface mobility of native NR2B-containing NMDARs, whereas their synaptic dwell time increased. Conversely, recombinant Reelin dramatically reduced NR2B-mediated synaptic currents and the time spent by NR2B subunits within synapses. Our data reveal a new mode of control of synaptic NMDAR assembly at postnatal hippocampal synapses and an unprecedented role of ECM proteins in regulating glutamate receptor surface diffusion.

[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk