Position: Research Associate
Academia: PhD – Physics, Institut Fresnel,   Aix-Marseille University
Advisor: Daniel Côté

Research Interestsrelation between molecular architecture, biological function and biomechanics in neurodegenerative disseases, physics of light-matter interaction at the microscale, advanced technological developments in optics for live imaging.

My motivation is driven first and foremost by the needs to identify microscopic biomarkers of the state of multiple sclerosis that lie below detection limits of MRI, at cellular and molecular levels and to monitor these biomarkers in vivo through the progression of disease. Recently developped Switching LAser mode Coherent anti-Stokes Raman Scattering (SLAM-CARS) microscopy pushes the limits of the spatial resolution and contrast of optical microsocpy [1]. SLAM-CARS, applied to image myelin in the brain and spinal cord, allows for differentiating axons otherwise unresolved using standard vibrational microscopy (CARS) and provides a better measure of the thickness of the myelin sheath surrounding the axons. This result is of significance to morphological studies in MS, since the thickness of myelin is arguably one of the most important parameter considered when evaluating the pathology of demyelinating disease. On the other hand, Polarization Resolved Microscopy, a unique method for monitoring the local molecular orientational behaviour in lipid membranes [2], allows to characterise molecular organisation in tissue at submicroscopic scales and detect nano-lesions otherwise not detectable with any other optical method. Performing in vivo measurements in living animals using these two complementary techniques allows to map out the thickness, volume and density of myelin at the molecular level and detect the earliest signs of lesions.

[1] A. Gasecka, A. Daradich, H. Dehez, M. Piché, and D. Côté, “Resolution and contrast enhancement in coherent anti-Stokes Raman-scattering microscopy,” Opt Lett, vol. 38, no. 21, pp. 4510–4513, Nov. 2013.

[2]  A. Gasecka, T-J. Han, C. Favard, B.R. Cho, and S. Brasselet, “Quantitative Imaging of Molecular Order in Lipid Membranes Using Two-Photon Fluorescence Polarimetry”, Biophys J., Nov 15, 97, pp. 2854