Quantitative phase imaging of neuronal movement during action potential (Conference Presentation)

Nanometer-scale deformations of the neuron accompany the action potential. These displacements are measured using a fast quantitative phase microscope and averaged in synchrony with optogenetic stimulation of cultured neurons. The phase movie is further processed by leveraging the spatial and temporal distribution of the spiking signal to detect and segment the separate action potentials in individual cells. An accompanying confocal fluorescence microscopy provides the 3-D cell shape for calibration of the refractive index to calculate the mechanical displacements from the optical phase. Together, these results illuminate the underlying mechanism of the cellular deformations and techniques for achieving all-optical single spike detection.