Laurent Bourdieu, Ecole Normale Supérieure, France
Friday, August 24, 2012, 2:00 PM to 4:00 PM
Location: E2-280
Hosted By Joel Kubby

Bio

Dr. Laurent Bourdieu received his PhD in Condensed Matter from the University Pierre et Marie Curie (Paris) and worked during his postdoc at Princeton University. Since then, he served as a research scientist at the CNRS in France, first in Strasbourg and now at the Biology Department of the Ecole Normale Supérieure (Paris). Dr. Bourdieu has contributed to the study of mechanical and dynamical properties of biological molecules (DNA, F-actin) interacting with proteins. He is now studying by optical methods (two-photon microscopy) the integrative properties of neurons in the rodent somato-sensory cortex.  He is also involved in the improvement of these optical techniques in terms of depth penetration and temporal resolution.

Abstract

"Measuring and Correcting Aberrations in the Rat Brain"

Aberrations limit the resolution, signal intensity and achievable imaging depth in microscopy. In neurosciences, two-photon microscopy allows e.g. the study of neuron integrative properties, but only within the layers II/III of the cortex. I will first show that compensation of the defocus aberration due to refractive index mismatch in full-field Optical Coherence Tomography (ff-OCT) improves significantly its depth penetration. Application to myelin imaging in the rodent cortex will be shown. I will then describe a method that allows the fast measurement of aberrations in scattering samples, referred as Coherence-Gated Wavefront Sensing (CGWS). I will show that known aberrations can be reliably measured using CGWS in the rat brain despite of multiple scattering. CGWS performance will be compared to image-based methods.