Dr. Jonathan Sweedler
University of Illinois Urbana-Champaign
Department of Chemistry
Friday, October 25, 2024
12:00 Noon
Room 120 – Meyerhoff Chemistry Building
Host: Dr. Kamal Seneviratne
“Unraveling the brain’s chemistry a cell at a time using mass spectrometry”
In the postgenomic era, one expects the suite of chemical players and their spatial locations known and their functions uncovered. Perhaps surprisingly, many neurochemicals remain poorly characterized and for those that are known, their localization, dynamics and function are oftentimes unknown. A range of approaches for assaying the chemical content, location and release from brain regions down to individual brain cells are highlighted, including mass spectrometry imaging, single cell mass spectrometry and nanodialysis coupled to mass spectrometry [1-3]. Using these approaches, we measure multiple classes of analytes including lipids, fatty acids, neurotransmitters and neuropeptides, among others. The single cell assays allow differences in the metabolome and peptidome from supposedly homogeneous populations of cells to be explored, and the nanodialysis sampling provides information on their activity dependent release and thus function. Additionally, our ability to characterize the content in individual organelles such as the secretory dense core vesicles enables subclasses of organelles to be explored. Several applications of single cell chemical measurements are highlighted from the discovery of unusual metabolites to the characterization of both known and previously unknown neuropeptides and peptide hormones.