Imaging exocytosis via a combined fluorescence and amperometry approach

University Of Missouri-Columbia, Columbia MO

Investigators

Abstract

With the support of the Chemistry of Life Processes (CLP) Program in the Division of Chemistry, Professors Timothy Glass and Kevin Gillis of the University of Missouri are studying how neurotransmitters are released into synapses. Neurotransmitters are critical to the regulation of the nervous system and control a number of functions such as learning, memory, sleep, and movement. Understanding the machinery of synaptic release, and the chemical activity of neurotransmitters is vital to understanding both normal and atypical neuronal processes. Furthermore, understanding the basic mechanisms of synaptic vesicle fusion and transmitter release via exocytosis is of broad significance because it will not only aid in the development of therapies for diseases where release of neurotransmitters is compromised, but it will also advance our understanding of FDA-approved treatments that modulate transmitter release, such as botulinum toxin A and B. As part of the broader impacts of this work, a new robotics camp for underserved high school students will be held. It has been demonstrated that activities such as these camps enhances the likelihood that participants pursue STEM (science, technology, engineering and mathematics) coursework during their secondary education. This project involves the preparation and evaluation of fluorescent chemical sensors for catecholamines with a view toward the fluorescent detection of neurotransmitters. These sensors are related to the NeuroSensor class of probes developed in PI Glass’s lab, which have already been used to detect norepinephrine in isolated chromaffin cells. Sensors will be developed that produce fluorescence enhancements upon exocytosis. The sensors will be used in combination with novel transparent electrodes developed in PI Gillis’ lab to study mechanisms of exocytosis via fluorescence imaging in combination with amperometric measurements. These combination experiments will measure both release and retention of catecholamine from individual vesicles to test the hypothesis that the amount of catecholamine released from a vesicle is modulated by the stimulus intensity. This project is expected to result in the development and application of a new set of important chemical biology tools for the study of neurochemistry with potentially broad scientific impact. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.