Cortical Plasticity and Tinnitus

Abstract

<p>Tinnitus is an auditory disorder characterized by the perception of a ringing, hissing or buzzing sound with no external stimulus. Because the most common cause of chronic tinnitus is hearing loss, this neurological disorder is becoming increasingly prevalent in our noise-exposed and ageing society. With no cure and a lack of effective treatments, there is a need for a comprehensive understanding of the neural underpinnings of tinnitus. This dissertation outlines the development and validation of a comprehensive theoretical model of cortical correlates of tinnitus that is used to shed light on the development of tinnitus and to propose improvements to tinnitus treatment strategies.</p> <p>The first study involved the development of a computational model that predicts how homeostatic plasticity acting in the auditory cortex responds to hearing loss. A subsequent empirical study validated a more biologically plausible version of this computational model. The goal of these studies was to determine whether and how a form of plasticity that maintains balance in neural circuits can lead to aberrant activity in the auditory cortex. The final study extends the validated computational model to develop a comprehensive theoretical framework characterizing the potential role of homeostatic and Hebbian plasticity in the development of most major cortical correlates of tinnitus.</p> <p>These theoretical and empirical studies provide a novel and complete description of how neural plasticity in adult auditory cortex can respond to hearing loss and result in the development of tinnitus correlates.</p>