Studies Of The Effects Of Asymmetric Hearing Loss On The Brain
Funder
National Health and Medical Research Council
Funding Amount
$920,076.00
Summary
Hearing loss impairs the normal development and maintenance of auditory pathways. Irreversible pathologies persist when hearing is not restored in a timely manner. While cochlear implantation is the accepted treatment for profound sensorineural hearing loss, there is significant variability in outcomes. Some of this variability is linked to the degree of hearing asymmetry. Thus, we propose to study brain changes in the auditory system that accompany asymmetric hearing impairment.
Organization Of Descending Auditory Projections From Inferior Colliculus To Cochlear Nucleus
Funder
National Health and Medical Research Council
Funding Amount
$473,121.00
Summary
Sensory information gains awareness by ascending brain pathways to reach consciousness. Descending projections, however, have grown in importance because of implications for feedback management of ascending signals. Studies of these pathways will provide insight into auditory processing with respect to selective volume control, calibration adjustments between the two ears, and the extraction of signals from background noise. The data could lead to new strategies for treating hearing disorders.
Intrinsic Hearing Protection Mechanisms: A Pathway To Prevention Of Noise-induced Hearing Loss
Funder
National Health and Medical Research Council
Funding Amount
$625,900.00
Summary
Noise-induced hearing loss (NIHL) is a significant contributor to the total burden of disease. We recently determined that when the ear is exposed to sustained noise, the cochlea is protected from damage by activation of a specific (P2X2) receptor, evident as reversible hearing adaptation. This study will determine the downstream signalling from this receptor. This will support assessment of vulnerability to NIHL and contribute to development of hearing therapeutics.
Cochlear Type II Neurons In Contralateral Suppression
Funder
National Health and Medical Research Council
Funding Amount
$459,434.00
Summary
Sound in one ear affects hearing in the other ear. This contralateral suppression is important for hearing attention and protection from noise damage. We will test the hypothesis that cochlear type II sensory neurons provide the sensory input for this process using models where neuronal development is altered, or the neurons are removed. The study addresses hearing disability in society, facilitating cochlear prosthesis development and the understanding of hearing loss.
Signals And Noise: A Study Of The Neurocognitive Mechanisms Underpinning Habituation To Noise In Normal And Damaged Hearing
Funder
National Health and Medical Research Council
Funding Amount
$408,938.00
Summary
McLachlan and Wilson recently published the first model of hearing that combines brain structure with function. This model postulates that recognition mechanisms initiate first, and then regulate the processing of other features. This project will investigate whether recognition mechanisms enable the auditory system to adapt to repetitive (background) noise by predicting and inhibiting responses to these sounds, and any changes in these mechanisms that may accompany hearing damage and tinnitus.
Bilateral Cochlear Implants: Restoring Binaural Processing By Experience And Training With Binaural Cues
Funder
National Health and Medical Research Council
Funding Amount
$968,030.00
Summary
Cochlear implantation in both ears is increasingly common and while there are benefits, performance falls short of expectations, likely due to the degradation of the long-term deaf brain’s sensitivity to small timing differences of sounds reaching each of the two ears. By confirming the hypothesis that experience with high-fidelity timing information will improve performance, this study will drive the technical innovations required to maximise the benefits and investment of bilateral implants.
A New Mouse Model That Determines The Effects Of A Unilateral Vestibular Prosthesis On Vestibular Plasticity.
Funder
National Health and Medical Research Council
Funding Amount
$455,678.00
Summary
Much like a cochlear implant restores auditory function, a vestibular prosthesis restores balance function. It is not clear whether the limited results from vestibular prostheses is due the device not stimulating one component (the otoliths) of the vestibular system essential for self-repair. We will test mutant mice that lack otoliths to determine the importance of stimulating the otoliths in restoring function. This work will shape the future direction of prosthesis development.
Neural Basis Of The Functions Of The Primary Visual Cortex: Roles Of Feedforward And Intracortical Inputs
Funder
National Health and Medical Research Council
Funding Amount
$486,280.00
Summary
Signals from the eyes undergo extensive processing at the level of the primary visual cortex so that basic features in the scene such as lines, edges, colours and movement are coded in the activity of individual neurones. This project aims to further our understanding of this process at the basic cellular level. This will not only enable interventions that would help those with poor sight but also give us an insight into basic brain circuitry and its derangement in many neurological disorders.
Mechanisms Underlying Efferent Feedback In The Vestibular System
Funder
National Health and Medical Research Council
Funding Amount
$491,475.00
Summary
The balance system has a remarkable, but poorly understood capacity for self-repair. An intrinsic feedback mechanism, the Efferent Vestibular System or EVS is thought to play a major role in this self-repair. Surprisingly, we know little about EVS function in animals or humans. We will study the EVS in mice and humans to gain a better understanding of how it works. This information will then drive the design of therapies that improve and restore balance in disease, injury, or ageing.
Information Encoding By Temporal Structure Of Afferent Spike Trains
Funder
National Health and Medical Research Council
Funding Amount
$231,175.00
Summary
Our ability to sense, discriminate and interpret touch stimuli underpins some of the most crucial functions of the human hand that relate to object exploration and manipulation. The fundamental mechanism of how nerve impulses generated by tactile receptors are interpreted by the nervous system is not understood. Only by discovering the underlying neural encoding mechanisms can we appreciate the functional impairments in patients and learn to identify them before they become widespread and irreve ....Our ability to sense, discriminate and interpret touch stimuli underpins some of the most crucial functions of the human hand that relate to object exploration and manipulation. The fundamental mechanism of how nerve impulses generated by tactile receptors are interpreted by the nervous system is not understood. Only by discovering the underlying neural encoding mechanisms can we appreciate the functional impairments in patients and learn to identify them before they become widespread and irreversible.Read moreRead less