PROJECT SUMMARY: HISTOLOGY & PATHOLOGY SERVICE MODULE The Vanderbilt Vision Research Center (VVRC) includes faculty investigators with a strong interest in discerning structure-function relationships in the visual pathways, both in health and disease. These include inferences based on whole tissue analysis, single cell labeling, and localization of molecular components of biochemical cascades in involved in intra- and extracellular signaling. The purpose of the VVRC Histology Module is to provide a comprehensive service for all tissue preparation, sectioning and staining/labeling for investigator laboratories needing supplemental provision in these areas not covered by staff members supported by their individual grants. In the current funding period, the histology service trained 15 staff members and 9 students/fellows and contributed material for 46 publications involving 13 VVRC faculty authors. Projected use of the service module is considerable, with 12 of 16 current NEI R01 grant holders projecting moderate (6) to extensive (6) histological needs. All told, 25/52 VVRC members will have moderate to extensive use (48%), the remaining being cognitive neuroscientists or biochemists.The histology module, housed in the research space of the Department of Ophthalmology & Visual Sciences/Vanderbilt Eye Institute, is directed by VVRC Director and P30 Primary Investigator David Calkins, PhD. Using this space and personnel supported in part by this Core mechanism, the VVRC Histology Module will: (1) assist or supervise preparation of visual system tissues suitable for sectioning; provide a broad range of (2) tissue embedding capabilities and (3) sectioning of visual system structures; (4) support a diverse array of histological and immuno-labeling stains; (5) provide access to automated conventional microscopy and image processing software; and (6) train members of the vision research community on basic histological techniques. These services and resources will enhance the scope of experimentation NEI-funded VVRC investigators conduct, expand the training of students and fellows involved in vision science, and promote collaboration by providing histological support to those who otherwise would not have such capabilities, including early-career vision scientists and clinician-scientists competing for extramural funding for their laboratories.