Advisor: Dr. Hang Lu, School of Chemical & Biomolecular Engineering Georgia Institute of Technology

Committee members:
Dr. Jennifer Curtis, School of Physics, Georgia Institute of Technology
Dr. Phillip Santagelo, School of Biomedical Engineering, Georgia Institute of Technology
Dr. Athanassios Sambanis, School of Chemical & Biomolecular Engineering Georgia Institute of Technology
Dr. Alexander Gottschalk, Institute of Biochemistry and Frankfurt Institute for Molecular Life Sciences (FMLS)
The field of neuroscience has recently seen optogenetics emerge as a highly utilized and powerful method of non-invasive neural activation and inhibition. As optogenetics becomes a highly utilized method to probe neural circuits and function, a great amount of research has been dedicated to advancing and enhancing the optogenetic toolbox. Thus far, much effort has been devoted to the optogenetic reagents themselves: increasing sensitivity, altering ion channel/pump properties and selectivity, and altering the activity spectrum. While important, improvements of the hardware and software used in optogenetic experiments must also be improved; the methods of illumination must be made more specific to target specific areas, supporting methods must be developed to increase the processing power of optogenetic screens, and software for control of developed hardware must be made flexible and approachable for all users.

Due to its relative neural simplicity, and the wealth of resources available, C. elegans is a popular model organism for neuroscience research. The use of optogenetics in C. elegans research has seen a vast increase over the past several years and has been utilized to study synaptic function, neural basis of behavior, transfer characteristics of synaptic connections, mating behavior, among several of areas of neurobiology. Thus, optogenetics is a powerful and rapidly emerging technique for investigations of the nervous system in C. elegans. These studies will only increase in sensitivity, complexity, and throughput as corresponding advances in the hardware and software is developed.

This thesis seeks to enhance the optogenetic toolbox through the design, construction, and evaluation of a number of hardware and software modules for research in C. elegans neuroscience. In the first aim, we combine optogenetics, microfluidics, and automated image processing, to create a system capable of high-throughput analysis of synaptic function. Furthermore, the system was further enhanced by combining it with a commonly used liquid handling system for increased processing power. In the second aim, we develop a multi-modal illumination system for the manipulation of optogenetic reagents. The system is capable of multi-spectral illumination in definable patterns, with the ability to dynamically alter the intensity, color, and shape of the illumination. The illumination system is controlled by a set of software programs introduced in aim three, and is demonstrated through a set of experiments in aim four where we selectively activate and inhibit specific neural nodes expressing optogenetic reagents in freely moving C. elegans. With the ability to target specific nodes in a freely moving animal, we can determine correlations of neural activity to specific behaviors and gives researchers the ability to dissect neural circuits. Taken together, the developed technologies for optogenetic researchers will allow for experimentation with previously unattainable speed, precision and flexibility.