Simon Labrecque

EMAIL:

POSITION:

Ph.D. student in Physics (http://www.phy.ulaval.ca), Université Laval (http://www.ulaval.ca)

ACADEMIA:

M.Sc. in Physics; Optics and holography, Université Laval (http://www.ulaval.ca)

ADVISORS:

Paul De Koninck (http://www.greenspine.ca)

Réal Vallée (http://www.vrr.ulaval.ca/bd/chercheur/fiche/646.html)

RESEARCH INTERESTS:

AMPA receptors trafficking

Research Summary

In this neurophotonics project we are currently developing a technique of single particle tracking to observe the motion and recruitment of glutamatergic receptors at synapses of living neurons. Cellular and molecular imaging techniques with high spatial and temporal resolution allow us to measure the diffusion of the receptors in real time. To detect membrane receptors, we use functionalized quantum dots as fluorescent probes. Thanks to their remarkable optical properties (high intensity, resistance to photobleaching, blinking and narrow emission spectra), quantum dots allow the imaging of one neuroreceptor with a nanometric resolution and over a long time period, yet unequaled. By combining quantum dots, epifluorescence microscopy and an ultrafast CCD camera with various neuronal culture methods, we study the remodeling of the synaptic connections, which operates, in part, via the dynamic accumulation of post-synaptic receptors.

Fig. (A) Images extracted from a movie (sampling rate = 30 images/sec). The red dots are quantum dots (QD) attached via a specific antibody to AMPA receptor subunit GluR2; the green dots (Mitotracker green FM) reveal synaptic regions via the staining of mitochondria, enriched pre-synaptically. Scale bar, 4 µm.

Fig. (B) Trajectory of the quantum dot, tracked and analyzed using Metamorph 6.0 and graphed using Matlab.

Publications

De Koninck P, Labrecque S, Heyes CD, Wiseman PW. Probing synaptic signaling with quantum dots. HFSP J. 2007 May;1(1):5-10. Epub 2007 May 2. (http://www.ncbi.nlm.nih.gov/pubmed/19404455?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=2)