The recent development of functional and mechanical utricular measures allows the differential assessment of utricular dysfunction, in vivo. Unfortunately, analogous tools have not yet been developed in the Semi-Circular Canals (SCCs) and there are no means to differentially diagnose balance dysfunction arising from SCC hair cell, nerve and mechanical abnormalities. The main aim of this project is to develop and characterize novel SCC measures, as a means to differentially assess vestibular health and disease, in vivo. A schematic of the tools to be developed and characterised over the course of this fellowship are shown above, including Semi-Circular Canal hair cell (SCC Microphonic), nerve (SCC Potential) and macromechanical measures using Laser Doppler Vibrometry (LDV).
Although reflex testing may identify the presence of a vestibular loss, they cannot determine its origin, which may arise from neural dysfunction, sensory receptor loss or mechanical abnormality. By comparison, hearing researchers have developed an array of basic techniques, which differentially assess auditory nerve, hair cell and mechanical dysfunction. These tools have progressed from basic, preclinical research measures, to indispensable clinical screening tools and have led to foundational discoveries regarding cochlear health and disease. Over the course of my PhD, I have developed several analogous techniques that allow me, for the first time, to directly measure vestibular hair cell and mechanical activity, alongside nerve function, in vivo. In this fellowship, I will build on these measures and advance the field by developing direct physiological measures of semicircular canal function in experimental animals. This will allow the differential diagnosis of peripheral vestibular dysfunction, arising from semicircular canal nerve, hair cell and mechanical abnormalities as a means to understand the causes of balance disorders, such as vertigo attacks in Meniere's disease