Label-free optical spectroscopy of deep brain regions towards wide volume and nanostructure-enhanced in-situ monitoring with portable optical systems

Optical approaches to monitor neural activity in vivo have drastically changed neuroscience, owing to a vast palette of genetically encoded fluorescent reporters. An emerging stream of research has recently proposed Raman spectroscopy as a complementary methodology for non-invasive tissue analysis in situ, either aiming at wide brain volumes or at neurochemical monitoring. In particular, Raman photometry has opened promising directions for improving our understanding of physiological and pathological neural mechanisms, providing label-free optical characterization of deep brain regions. This thesis explores a potential experimental strategy to perform Raman neuro-spectroscopy in physiologically relevant experiments in neuroscience laboratories. Firstly, a conventional confocal Raman microscope is employed for the characterization of the vibrational spectra of tissue samples, using a standard objective and a fiber probe. Then, design and modelling of a compact, portable optical system is addressed to facilitate the application of Raman spectroscopy through optical fibers in neuroscience laboratories, without the need for bulky and expensive microscopes.