FIBER-OPTIC BUNDLE FLUORESCENCE MICROSCOPY FOR FUNCTIONAL BRAIN ACTIVITY MAPPING

Fiber-optic microscopy;Brain imaging;Freely moving animals;Electrical Engineering

Cha, JaepyeongKang, Jin U. ;

Johns Hopkins University

关键词: Fiber-optic microscopy;    Brain imaging;    Freely moving animals;    Electrical Engineering;   

Others  :  https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/44627/CHA-DISSERTATION-2016.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: JOHNS HOPKINS DSpace Repository

【 摘 要 】

Understanding the relationship between cellular activities in the animal brain and the emerging patterns of animal behavior is a critical step toward completing the Brain Activity Map. This dissertation describes the development of fiber-bundle microscopy capable of high-resolution cellular imaging, for mapping of functional brain activity in freely moving mice. As a part of this work, several fiber-bundle microscope systems and image processing algorithms were proposed and developed. These optical imaging methods and system performance were tested and evaluated by performing in vivo animal brain imaging.Several fiber-bundle imaging devices, including a dual-mode confocal reflectance and fluorescence micro-endoscope, a single ball-lens imaging probe, and a spatially multiplexed fiber-bundle imager, were designed and developed for high-resolution imaging of brain cells and visualization of brain activity. A dual-mode micro-endoscope, simultaneously achieving laser scanning confocal reflectance and fluorescence imaging, was developed to quantitatively assess gene transfection efficacy using human cervical cancer cells. A single ball-lens integrated imaging probe was designed for endoscopic brain imaging. Lastly, a spatially multiplexed fiber-bundle imager that allows concurrent monitoring of astrocytic activities in multiple brain regions and enables optical manipulation with cell-specific targeting was proposed and experimentally demonstrated.Novel image-processing algorithms were used along with the developed imaging systems. Structured illumination employing a digital micro-mirror device (DMD) was integrated into the system to achieve depth-resolved imaging with a wide-field illumination fiber-bundle microscope. Data from super-resolution fiber-bundle microscopy based on the linear structured illumination were numerically processed to extend the lateral resolution beyond the diffraction limit. To evaluate the performance of the developed fiber-bundle microscope systems and image reconstruction algorithms, the systems and methods were each tested and validated on in vivo animal models, namely transgenic mice expressing a genetically encoded Calcium indicator (GCaMP3) within astrocytes. We showed that locomotion triggers simultaneous activation of astrocyte networks in multiple brain regions in mice. We have also demonstrated real-time cellular-resolution dual-color functional brain imaging in mice. Finally, we established a platform that allows real-time and non-invasive imaging of the intact central nervous system of freely behaving mice. Using this platform, we observed, for the first time, physiologically relevant activation of astrocytes during behaviorally relevant tasks and in the natural setting. In addition, we present a proof-of-concept study by using a fiber-bundle ring light-guided portable multispectral imaging (MSI) platform capable of tissue characterization and preoperative surgical planning for intestinal anastomosis.