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.
Hearing Protection Conferred By P2X2 Receptor Signaling In The Cochlea
Funder
National Health and Medical Research Council
Funding Amount
$580,019.00
Summary
Hearing loss from noise damage and ageing is the principal sensory disability in our society. This project will determine the contribution of the P2X2 receptor to protection from noise-induced hearing loss. We have found that P2X2 knockout mice have minimal temporary threshold shift. We will investigate the physiological basis for this and determine why this mouse model has greater hearing loss with intense sound and faster age-related hearing loss compared with wildtype controls.
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.
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.
Gene Therapy For Preventing Progressive Sensorineural Hearing Loss And Restoring Hearing
Funder
National Health and Medical Research Council
Funding Amount
$549,848.00
Summary
This proposal aims to study the clinical feasibility and safety of gene therapy in the guinea pig cochlea for preventing progressive hearing loss and restoring hearing. Two cell survival genes (GDNF and BDNF) will be studied for preserving sensory (hair) cells and hearing nerves, while a gene called Atoh1 will be investigated for its ability to regenerate new hair cells and restore hearing after the onset of progressive hearing loss.
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.
The research will investigate the mechanisms by which our brains are able to listen selectively to sounds of interest in competing background noise. This will be investigated in normal hearing subjects, those with partial deafness and in profoundly deaf patients who use a cochlear implant. If deaf patients can learn to use cues to enhance detection of sounds of interest this could have an impact on the effectiveness of hearing aids and cochlear implants in noisy listening situations
Efferent Control Circuitry Of The Auditory Brainstem
Funder
National Health and Medical Research Council
Funding Amount
$406,306.00
Summary
Detection of important sounds within a noisy background is a crucial function of the mammalian hearing system and defects in this function impair social interaction, learning and development. In addition, activity in the brain needs to be carefully regulated by intrinsic circuitry in order to prevent excessive activity responsible for conditions such as tinnitus. The mechanisms by which the brain achieves this are poorly understood and this project aims to improve our understanding of some of th ....Detection of important sounds within a noisy background is a crucial function of the mammalian hearing system and defects in this function impair social interaction, learning and development. In addition, activity in the brain needs to be carefully regulated by intrinsic circuitry in order to prevent excessive activity responsible for conditions such as tinnitus. The mechanisms by which the brain achieves this are poorly understood and this project aims to improve our understanding of some of the brain circuits involved.Read moreRead less
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.
In the normal process of hearing, the brain actively selects sounds of interest from competing background sounds. This normal auditory function is indispensible for children and adults to cope in non-optimal listening environments, however the mechanisms by which such performance is achieved are poorly understood. This project will investigate the nerve circuits that enable this to occur and will also investigate how these circuits malfunction in various types of partial deafness. The results wi ....In the normal process of hearing, the brain actively selects sounds of interest from competing background sounds. This normal auditory function is indispensible for children and adults to cope in non-optimal listening environments, however the mechanisms by which such performance is achieved are poorly understood. This project will investigate the nerve circuits that enable this to occur and will also investigate how these circuits malfunction in various types of partial deafness. The results will improve our understanding of how we detect sounds and the impact of hearing pathologies on this process.Read moreRead less