From Single-Cell to Whole-Body: Developing a Molecular Neuroscience Toolkit

Citation

Flytzanis, Nicholas C. (2019) From Single-Cell to Whole-Body: Developing a Molecular Neuroscience Toolkit. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/S28C-DJ17. https://resolver.caltech.edu/CaltechTHESIS:10122018-165154970

Abstract

Throughout my Ph.D. I have worked on technology development, at first to answer basic scientific questions and eventually for therapeutic applications. This technology development applied to a variety of fields, from neuroscience to development to gene therapy, and acted upon biological systems in a wide range of scale, from the single-cell monitoring to organism-wide gene-transfer. My graduate research began with the engineering of microbial rhodopsin spectral properties and fluorescence. By making use of their ability to absorb light and emit fluorescence in a voltage-dependent manner, I aimed to interrogate neuronal activity during behavior at the single-cell level. That line of research ended with publication of the voltage-sensor Archer, which I used to track activity of a single cell in vivo in awake, behaving worms. I then shifted from tracking activity at the single cell level, to visualizing entire organisms, by developing clearing techniques that enable a high-resolution, three-dimensional analysis of a diverse range of tissues. I began by optimizing tissue-clearing parameters for various tissue types and a wide variety of experimental needs. I then took that knowledge and applied it to visualizing and tracking the developing neural crest in cleared, whole-mount chicken embryos, discovering some unexpected derivates. Finally, I became interested not only in visualizing entire organisms, but in developing technologies to facilitate gene transfer throughout the body. The rapidly growing field of gene therapy is in constant need of new tools that target specific tissues, avoiding off-target effects. The end of my Ph.D. has been spent engineering viruses that can be delivered body-wide, but target only specific areas of therapeutic interest, like the brain and lungs.

Thesis Files