Phase Resolved Optical Coherence Tomography for Label-Free Detection of Neural Activity
- Author(s): Tong, Minh
- Advisor(s): Park, Hyle
- Adams, Micheal
- et al.
Current methods for detection of nervous system activity have been limited to electrophysiology, which requires the electrode to contact the nervous system or optical-based techniques that require incorporation of reporter agents. Both methods are golden standards but have limitations. Optical coherence tomography (OCT) is an imaging technique based on light that measures intrinsic structural changes associated with an action potential. A benefit of using OCT is that it does not require any exogenous agents and is minimally invasive. Phase-resolved OCT detects 1-30 nm swelling of an axon during neural activity. In my studies described here, phase-resolved OCT was used to detect the swelling Drosophila neurons when presented with ecdysis triggering hormone as well as a 1-3 nm swelling of a cockroach axon caused by action. However, since phase imaging is limited to one point, the dissertation ends with development of the line field swept source OCT system that can provide images of a b-line or cross-sectional image without using a scanning device.