Peter Santi, Principal Investigator

Computer Image Analysis of Macromolecular Arrays in the Cochlear Extracellular Matrix

The extracellular matrix is one of the basic constituents of the cochlea. It plays an important structural and mechanical role and is involved in transduction of sound-induced mechanical stimuli into electrical signals. Structural abnormalities of the matrix may lead to different types of hearing disorders. The overall goal of this project is to study the structure of symmetric macromolecular arrays in the cochlea. The project contains two specific aims:

• To determine the ultrastructure of the cochlear extracellular matrix. Supramolecular organization of collagen, fibronectin, tenascin, and other molecules may provide a foundation upon which micromechanical models of the cochlea can be constructed. The researchers are focusing on the ultrastructure of proteoglycans arrays in different types of cochlear basement membranes.
• To determine the structure of the outer hair cell stereocilia links. The structure of periodically arranged side links, rotationally distributed “attachment links” and helical organization of the tip-links are being investigated to find a relationship between the structure and role of these symmetric arrays. The tip-links play an important role in mechano-electrical transduction of the sound waves, and a substantial part of this project includes the study of its helical structure found recently in these links.