The objective of this CAREER project is to develop a method to image lipids (fatty acids) in brain cells and tissues. This capability is needed because lipids contribute to nerve generation and impulse conduction, and they are essential signaling molecules and sources of energy. The method will be demonstrated on neuronal cell and tissue samples relevant to Alzheimer’s Disease (AD). Current diagnosis methods of AD are either invasive, expensive, low-resolution, low-sensitivity, or subjective and are not capable of probing complex molecular actions down to the level needed to study neurodegenerative diseases. These limitations will be addressed by combining two existing microscopy techniques that enable precision measurements at depths not possible with current techniques. The development of the proposed technology will advance our understanding of the pathology of AD and could lead to early detection as well as better therapeutics for AD. The research objectives of the CAREER project are integrated with educational objectives to engage middle school and high school students by partnering through a local museum. Further, the project will involve students from local community colleges, minority, and underrepresented groups on brain research.
The long-term goal of the Investigator is to develop a Second Harmonic Generation (SHG) and Raman-based micro-endoscopy probe system along with statistical analysis software to perform minimally invasive imaging of lipids and metabolites in vivo at sub-millisecond time resolution. Towards this goal, the focus of this CAREER project is on pioneering a multimodal label-free approach to elucidate the spatial distribution of lipids in brain cells and tissues that will enable probing of complex molecular actions down to the synaptic level (nanoscale). Once developed, the 3D imaging platform will be used to assess the dynamics of proteins and lipids along the neuronal membrane in a mouse model of Alzheimer's Disease (AD), which could lead to improved understanding of AD pathogenesis. The Research Plan is organized under three objectives: (1) Develop a state-of-the-art nonlinear microscope system and establish a polarization activated rapid (PAR) switching of second harmonic generation (SHG) / PAR-SHG method with localize molecules with < 20 nm accuracy, depth > 1mm; (2) Utilize time-resolved high resolution SHG to image the adsorption and transport of molecules across the membrane of a single cell and to implement a novel optical biomarker identification method to perform quantitative metabolic profiling of neuronal cells; and (3) Combine high resolution SHG with Raman microscopy to perform lipidomic imaging of in vitro and in vivo samples from an AD mouse model. In the long term, the transformative approach will be able to perform super resolution in vivo imaging of living brain to study sub-cellular processes at molecular resolution. .
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.
