Titre : New Analytical Tools for the Cell by Cell Chemical Characterization of the Brain.
Endroit : Pavillon J-A.-Bombardier, salle 1035 à 11 h.
Hôte : Professeur Pierre Thibault.
Cette conférence sera prononcée par le professeur Jonathan Sweedler du Département de chimie de l'University of Illinois at Urbana-Champaign.
Résumé : In the postgenomic era, one expects the suite of chemical players in a brain region to be known and their functions uncovered. However, many cell-to-cell signaling molecules remain poorly characterized and for those that are known, their localization and dynamics are oftentimes unknown. A suite of small-scale bioanalytical approaches are described that allow the investigation of individual neurons and small brain regions; these approaches include capillary scale separations coupled to mass spectrometry and direct mass spectrometric-based profiling and mass spectrometry imaging. A key to successful measurement involves optimized tissue and cell sampling protocols. Depending on the sample being assayed and metabolites being measured, we use mechanical isolation, optical tweezers, patch pipettes, dialysis probes and microfluidics, all of which have advantages for specific sample types. Several applications of single cell microanalysis are highlighted including the discovery of unusual metabolites to characterizing the peptides in single cells. Imaging mass spectrometry and dynamic sampling of the extracellular environment are used for elucidating novel cell to cell signaling molecules in a range of neuronal model systems. Current technology efforts involve extending the depth of metabolome coverage and adapting our approaches to high throughput single cell assays. Our overarching goal is to uncover the complex chemical mosaic of the brain and pinpoint key cellular players in physiological and pathological processes.
