Super-Resolution Imaging of Subcellular Structures and Dynamics During Non-Genetic Biological Modulation

Major Goals: In funded research, we have requested an ONI imager from Oxford Nanoimaging Inc. in order to assess neuron-glial interaction and extracellular vesicles (EV) dynamics. As one of the most sensitive and multifunctional microscopes, the ONI provides the capability of high-resolution imaging, cell tracking, and single-molecule imaging of biomolecular dynamics. It has been demonstrated that glia-neuron interactions are important, but localized glia-mediated neuromodulation through physical processes (such as electrical stimulation, optical modulation, or thermal control) remains rare. In this study, we directly targeted glia with internalized nanostructures, creating subcellular glia/silicon interfaces - a hybrid cellular building block. Next, we explored several intracellular mechanisms for glial excitation using silicon. The outputs of the glia, which are endogenous chemical and bioelectric signals, were subsequently used to modulate neural activity through the natural interaction between the glia and the neurons. Currently, we are utilizing the acquired ONI system to observe the dynamics of organelles and extracellular vesicles (see below) during the triggered glia/neuron interactions. Unlike traditional neuromodulation methods, this approach differs fundamentally from them in two distinct ways. First, it is minimally invasive to neurons, since the silicon directly targets glia. Second, it explores the endogenous biological signals that traverse neurons via glia at various levels. At the same time, we are employing the ONI to study the dynamics of mitochondria in a range of mammalian cells, including glia and several cancer cell lines. Additionally, the ONI imager is being used for nanoparticle tracking analysis (NTA), a procedure that calculates the diffusion coefficient and estimations of EV sizes to resolve the dynamics within live cells. Four different fluorescent markers can be used simultaneously to measure four different colors.