Biological Sciences Division
Published July 27, 2017 | Version v1
Journal article Open

Super-resolution imaging of synaptic and extra-synaptic AMPA receptors with Different-Sized fluorescent probes

Creators

  • 1. University of Illinois, Urbana-Champaign
  • 2. University of Chicago
  • 3. University at Buffalo

Description

Previous studies tracking AMPA receptor (AMPAR) diffusion at synapses observed a large mobile extrasynaptic AMPAR pool. Using super-resolution microscopy, we examined how fluorophore size and photostability affected AMPAR trafficking outside of, and within, post-synaptic densities (PSDs) from rats. Organic fluorescent dyes (≈ 4 nm), quantum dots, either small (≈ 10 nm diameter; sQDs) or big (>20 nm; bQDs), were coupled to AMPARs via different-sized linkers. We find that >90% of AMPARs labeled with fluorescent dyes or sQDs were diffusing in confined nanodomains in PSDs, which were stable for 15 min or longer. Less than 10% of sQD-AMPARs were extrasynaptic and highly mobile. In contrast, 5-10% of bQD-AMPARs were in PSDs and 90-95% were extrasynaptic as previously observed. Contrary to the hypothesis that AMPAR entry is limited by the occupancy of open PSD 'slots', our findings suggest that AMPARs rapidly enter stable 'nanodomains' in PSDs with lifetime ≥15 min, and do not accumulate in extrasynaptic membranes.

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Additional details

Identifiers

DOI
10.7554/eLife.27744
Other
oai:uchicago.tind.io:9946

Related works

Is supplement to
https://doi.org/10.7554/eLife.33413 (URL)

Funding

National Institutes of Health
NIH NS090903
National Science Foundation
PHY-1430124
National Science Foundation
CBET-1264051
National Institutes of Health
NIH NS100019

UChicago Information

Division(s)
Biological Sciences Division
Department(s)
Neurobiology