ORCID Identifier(s)


Graduation Semester and Year




Document Type


Degree Name

Doctor of Philosophy in Electrical Engineering


Electrical Engineering

First Advisor

Digant P Dave

Second Advisor

Weidong Zhou


We describe an optical technique for label-free detection of the action potential in cultured mammalian neurons. Induced morphological changes due to action potential propagation in neurons are optically interrogated with a phase sensitive interferometric technique. Optical recordings composed of signal pulses mirror the electrical spike train activity of individual neurons in a network. The optical pulses are transient nanoscale oscillatory changes in the optical path length of varying peak magnitude and temporal width. Exogenous application of glutamate to cortical neuronal cultures produced coincident increase in the electrical and optical activity; both were blocked by application of a Na-channel blocker, Tetrodotoxin. The observed transient change in optical path length in a single optical pulse is primarily due to physical fluctuations of the neuronal cell membrane mediated by a yet unknown electromechanical transduction phenomenon. Our analysis suggests a traveling surface wave in the neuronal cell membrane is responsible for the measured optical signal pulses. In addition, we describe various optical techniques that may be used to design and create a neural circuit, and manipulate it with various inputs to decode the transfer function of the circuit. Together, these techniques, with the proposed optical detection technique can help understand the neural signaling in simple neural networks.


Optical detection, Label free, Interferometry, Action potential, Neuroscience, Spectral interferometry


Electrical and Computer Engineering | Engineering


Degree granted by The University of Texas at Arlington