The measurement of neurotransmitter secretions by living cells, both in living organisms or in preparations, constitutes an enduring and vexing problem for neuroscientists due to the large number of substances involved at very low concentrations. An ability to correlate neurotransmitter secretions with various factors including organismic behavior would greatly advance our understanding of the organization and functioning of central nervous systems. This, in turn, has many important

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... for the diagnosis and treatment of disorders of central nervous systems (mainly in humans) as well as for the design and implementation of information processing and control systems. The work presented here was undertaken in order to explore a novel approach to this demanding problem. The objective was to develop a probe capable of measuring neurotransmitter secretions in real time, at physiologically relevant concentrations, and non-invasively in situ. Data were obtained using an ultraviolet resonance Raman spectroscopic analytical technique performed via optical fibers, and were analyzed primarily with artificial neural networks. To this end, a prototype tunable ultraviolet resonance Raman system was designed, assembled, comissioned and employed. A general introduction to the problem and a discussion of existing techniques for neurotranmitter measurement are given in Part I. In Part n, the analytical method was shown to allow discrimination between several different neurotransmitters and some of their precursors, both on the basis of their spectra and the selective resonance enhancement of their spectra. Optical fibers were characterized with regard to their suitability for use with pulsed ultraviolet radiation in Part III and on the basis thereof selected for the construction of optical fiber probes. It was found that the performance of optical fibers varied greatly when subjected to pulsed ultraviolet radiation, making the selection of fibers a crucial factor in probe construction. Various desig [...]