Presynaptic NMDA receptors - dynamics and distribution in developing axons in vitro and in vivo

Ishwar Gill, Sammy Droubi, Silvia Giovedi, Karlie N. Fedder, Luke A.D. Bury, Federica Bosco, Michael P. Sceniak, Fabio Benfenati, Shasta L. Sabo

Research output: Contribution to journalArticlepeer-review

24 Scopus citations

Abstract

During cortical development, N-methyl-D-aspartate (NMDA) receptors (NMDARs) facilitate presynaptic terminal formation, enhance neurotransmitter release and are required in presynaptic neurons for spike-timing-dependent long-term depression (tLTD). However, the extent to which NMDARs are found within cortical presynaptic terminals has remained controversial, and the sub-synaptic localization and dynamics of axonal NMDARs are unknown. Here, using live confocal imaging and biochemical purification of presynaptic membranes, we provide strong evidence that NMDARs localize to presynaptic terminals in vitro and in vivo in a developmentally regulated manner. The NR1 and NR2B subunits (also known as GRIN1 and GRIN2B, respectively) were found within the active zone membrane, where they could respond to synaptic glutamate release. Surprisingly, NR1 also appeared in glutamatergic and GABAergic synaptic vesicles. During synaptogenesis, NR1 was mobile throughout axons - including growth cones and filopodia, structures that are involved in synaptogenesis. Upon synaptogenic contact, NMDA receptors were quickly recruited to terminals by neuroligin-1 signaling. Unlike dendrites, the trafficking and distribution of axonal NR1 were insensitive to activity changes, including NMDA exposure, local glutamate uncaging or action potential blockade. These results support the idea that presynaptic NMDARs play an early role in presynaptic development.

Original languageEnglish
Pages (from-to)768-780
Number of pages13
JournalJournal of Cell Science
Volume128
Issue number4
DOIs
StatePublished - 2015

Keywords

  • NMDA receptor
  • Presynaptic
  • Receptor trafficking
  • Synapse development
  • Synaptosome

Fingerprint

Dive into the research topics of 'Presynaptic NMDA receptors - dynamics and distribution in developing axons in vitro and in vivo'. Together they form a unique fingerprint.

Cite this