P 227. Ultramicroscopy (UM) in neurobiology

Abstract

UM is a prime example for an interdisciplinary research field invention. It enables researchers to obtain high-resolution 3D-reconstructions of organ systems in different animal models. Knowledge about the interconnections of the neuronal network to the vascular system is often essential neurobiological research. Ultramicroscopy (UM) is a light sheet based fluorescence microscopy. This novel bioimaging technique allows the 3D-visualization of cm-sized biological specimens with μm-resolution ( [Dodt et al., 2007] , [Jährling, 2011] ). Artifacts of conventional microscopy such as distortion of the tissue are avoided. It is due to optical sectioning instead of mechanical sclicing ( [Jährling and Saghafi, 2011] , [Jährling, 2011] ). In UM, a specimen is illuminated by a thin sheet of laser light, formed by one or more cylindrical lenses ( [Jährling and Saghafi, 2011] , [Jährling, 2011] ). To generate a light sheet distribution in the standard UM, we basically employ a single cylindrical lens placed in front of a variable rectangular slit aperture ( [Jährling and Saghafi, 2011] , [Jährling, 2011] ). Lectinis are proteins that bind to sugar complexes, which are attached to proteins and lipids. We employed an approach using fluorescent conjugated lectins during the transcardial perfusion of mice to contrast the endothelium building up the vascular system ( [Jährling, 2011] , [Jährling et al., 2009] ). Biological samples are prepared chemically to become as transparent as possible ( Jährling, 2011 ). In this study the architecture of the blood vessel system of whole organs of animal models is visualized ( [Jährling, 2011] , [Jährling et al., 2009] ). By combining light sheet based UM with lectin-labelling, 3D reconstructions of vascular structures of the mouse spinal cord can be generated. Alteration in optics, morphological analysis of neurobiological disorders, multiple labeling, improving histology of clearing procedure, the analysis of brain tumors are subjects of interests are subjects of interests in our future work.