The goal of this Core is to provide faculty in the Center for Hearing and Balance, and associated laboratories, with access to histological equipment and expertise and assistance. The visualization and quantification of structural features that correlate with physiological, developmental, and/or plastic phenomena within the peripheral and central nervous systems provide fundamental data necessary to infer basic mechanisms of neural function. But with the increasingly specialized nature of science, the expense and difficulty of such studies can place them out of reach for most laboratories. Common resources foster collaborations between scientists with different skill sets and can be the key to implementing exciting research projects that bridge different levels of analysis. Anatomical data frequently support this bridge. The Histology Core will continue to provide assistance as well as access to, and instruction in the tools and resources required for tissue preparation and sectioning for light microscopy. This includes both plasticembedded and frozen sections. The Core provides and maintains a light/fluorescence compound microscope with digital camera for image acquisition and auxiliary workstations for analysis. In addition the Core will enable ultrastructural studies through the services of an experienced electron microsopist.