This proposal is concerned with the development and application of methods in electrochemical extremely small environments aimed at single nerve cells. The underlying goals of the proposed work are to develop a better fundamental understanding of neurotransmission by examining exocytosis at neuronal cells bodies, mammalian cells in culture, and in single neuronal synapses. This approach combines developments in analytical measurements with experiments to investigate new aspects of neurochemistry. The methods under development use electrochemistry to probe ultrasmall environments in neuroscience. New aspects include systems to model electrochemical responses, capillary/electrochemistry measurements of vesicles, and nanometer tip electrodes for the femtoliter environment of the synapse. Neurochemical experiments are targeted at understanding exoytosis at the molecular level, discovering the neuronal rationale for neurotransmitter release at the cell body, and understanding concentration and volume effects in transmitter release during exocytosis. The later issue could be important in understanding factors involved in the treatment and/or progression of Parkinson's Disease. The specific plans of the research are: 1, to model exocytosis events measured at single electrodes; 2, to use electrochemical probes to measure plasticity mediated by the vesicular monoamine transporter; 3, to develop and apply hydrodynamic chromatography in nanometer capillaries with electrochemical detection to measure vesicle size and neurotransmitter amount for single vesicles; 4, to investigate with electrochemical and fluorescent methods the factors regulating the function of transmitter release from the neuronal cell body; and 5, to carry out electrochemical measurements in single synapses.
