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Quantification of neurotoxic effects on individual neuron cells using optical diffraction tomography (Conference Presentation)

Parkinson’s disease (PD) is a common neurodegenerative disease that causes symptoms of postural instability and slowness of movement. Neurodegeneration in dopaminergic neurons at the substantia nigra has been reported as pathologic features, however, detailed mechanisms underlying neurodegeneration are still remain unclear. To investigate a neurodegenerative process, various imaging tools including phase contrast microscopy, electron microscopy, and fluorescence microscopy are utilized. However, these imaging methods provide qualitative information and require invasive approaches such as the use of fluorescence agents or chemical fixation procedures that disturb normal physiological conditions of neuron cells. In order to quantify the neurodegenerative process in a non-invasive manner, we exploited optical diffraction tomography (ODT). ODT is a 3D quantitative phase imaging method that measures 3D refractive index (RI) distributions of a sample which provide quantitative structural (volume, surface area, sphericity) and biochemical (protein concentration, total cellular dry mass) information. We investigated neurotoxic effects of MPP+ on SH-SY5Y cells by using quantitative information obtained from 3D RI distributions. We also performed temporal measurements of 3D RI distributions of an individual SH-SY5Y cell to analyze neurotoxic effects on intracellular vesicle dynamics.