This project, carried out by Professor J. Sweedler of the University of Illinois, and supported by the Analytical and Surface Chemistry Program, will develop the analytical instrumentation and methodology capable of identifying and quantifying neuropeptides from single cells, and those neuropeptides involved in cellular processes. The model system Aplysia californica is used as a test bed to demonstrate these new and improved capabilities, and to elucidate the fundamental aspects of peptidergic transmission. Matrix-assisted laser desorption ionization mass spectrometry is used to image intact ganglion sections with molecular specificity and subcellular resolution. Capillary electrophoretic methods are used to analyze sub-nanoliter volumes of samples derived from these systems. Electrospray ionization mass spectrometry is used to monitor peptide releases from a single cell under precisely controlled stimulation conditions.
Professor Sweedler will use advanced analytical methods to identify and quantify the peptides released from individual nerve cells on stimulation, and to image the distribution of these compounds within the cell itself. Signal transmission between cells depends on the release and uptake of these small peptides. Careful study of the model system will provide, for the first time, a complete understanding of the fundamentals of nerve impulse transmission. This example can then be used as a starting point for the study of nerve impulse transmission in more complex organisms.
