With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Jonathan V. Sweedler and his research group at the University of Illinois at Urbana-Champaign are developing new measurement technologies (based on mass spectrometry imaging and chemical separations) to probe the chemical composition of individual cells in a high throughput manner. In a test application, the new methods are used to analyze and classify all the cells within the central nervous system of the marine sea slug, Aplysia californica, an important neuroscience/physiological animal model. This research promises to provide the most complete description of cellular chemistry of the brain for any animal model, providing fundamental details linking neurochemistry to brain function. This proof-of-concept study is ultimately expected to lead to measurement of more complex brains. The interdisciplinary research bridges the worlds of analytical chemistry and cellular neurobiology. The broad-based dissemination of the results through scientific and lay publications, conferences, high school and open house outreach programs, and training across multiple disciplines assures that this research advances NSF's mission in science education and research.
The analytical platform being developed integrates mass spectrometry-based chemical imaging, capillary electrophoresis separations hyphenated to mass spectrometry, and optical microscopy to enable high-throughput characterization of tens of thousands of cells at the single-cell level, with an aim of global characterization of the chemical constituents of complex tissues such as the brain. The first goal is to create novel cell isolation approaches and then high-throughput, multiplex single-cell chemical analyses based on laser desorption/ionization and secondary ionization mass spectrometry imaging to examine individual cells within larger cell populations. An enhanced method of off-line coupling of selected cells of interest to a capillary electrophoresis mass spectrometry system is used to perform follow-up assays. In a model test system, the experiments provide detailed information on the cell types and chemical heterogeneity within the Aplysia central nervous system. Undergraduate and graduate students with diverse backgrounds are actively involved in these interdisciplinary efforts, and are involved in multiple outreach programs in both public and educational settings.
