CAREER: Understanding calcium communication in neurons with nanomagnetic forces and engineered network patterns

Montana State University, Bozeman MT

Investigators

Abstract

Calcium ions are essential signals to regulate communication and function in cells, which are the basic biological units of living systems. Within the central nervous system, physiological levels of calcium play an important role in neural activity and in transporting signals across neuronal networks. In contrast, highly elevated levels of calcium ions are associated with dysfunctional communication and can lead to the degeneration of the neuronal network. Recently, it has been demonstrated that magnetic nanoparticles can be used to mechanically open calcium channels allowing calcium ions to enter neurons through the cell membrane. How this intentional, force-mediated influx of calcium ions interacts with structures inside neurons and how it spreads within a neuronal network is highly important for understanding force-mediated brain cell communication and degenerative diseases. This award will fund a research program that links nanomaterials to neurobiological systems and aims to capture and to quantify calcium signal transport in experimentally grown, controlled neuronal networks. Both graduate and undergraduate students involved in the project will benefit from an enhanced research infrastructure combining nanotools and neuroengineering. These nanotools will also become available to a broader research community interested in analyzing changes in communication patterns during degeneration or stem cell development. Finally, the project will involve the creation of an interdisciplinary bio micro-electro-mechanical system (BioMEMS) course to advance the STEM workforce in Montana, and science communication summer workshops for students specifically interested in transforming engineering data into visual arts. Stimulation through nanomagnetic forces is a tool that operates magnetic nanoparticles within magnetic fields to impose a mechanical force on associated objects. Within a biological context, this project considers brain cells that express mechanically sensitive ion channels and receptors as the target for nanomagnetic stimulation. Applying nanomagnetic forces to the membrane of neural networks in vitro has been shown to trigger an influx of calcium ions, recently. How the force stimulation relates to other neurophysiological events, however, remains unknown. In particular, the integration of subcellular biomechanics with innovative neuronal cell screening platforms has not been used in combination with nanomagnetic force stimulation, previously. This knowledge gap currently limits the broader experimental applicability of nanomagnetic stimulation. Hence, this project addresses current limitations of nanomagnetic force stimulation by unraveling how neuron-to-neuron communication is impacted by force-mediated intracellular changes in calcium signaling. The proposed work will systematically analyze how fast this force-mediated calcium influx in neuronal networks occurs, and how the architecture of a neuronal network impacts the spatial transport of evoked signals. Calcium fluorometry will be employed in combination with electrophysiology to assess the spatiotemporal aspects of subcellular calcium stimulation in rodent primary neurons. Furthermore, this project develops highly parallelized arrays of cell nano-manipulation and assessment tools with low-resolution live-cell calcium imaging to map calcium signal propagation across neuronal cultures. Research results from this proposal will pave the way to future use of mechanical stimulation as a precise neurophysiological tool. Based on this knowledge, the project will develop design guidelines for future neuro-therapeutics using magnetic nanoparticle-mediated force stimulation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.