Cochlear Mechanisms Of Otoacoustic Emission Generation
Funder
National Health and Medical Research Council
Funding Amount
$311,989.00
Summary
Deafness, both congenital and acquired, is likely to be one of the major causes of disability in the Australian workforce, in young Australians, and in some categories of pre-term infants in the next decade or two. While not life-threatening, hearing impairment deprives individuals of one of their most basic social needs: the ability to communicate with others. Although little can be done to recover lost hearing, it is important to detect hearing loss as early as possible in order to reduce furt ....Deafness, both congenital and acquired, is likely to be one of the major causes of disability in the Australian workforce, in young Australians, and in some categories of pre-term infants in the next decade or two. While not life-threatening, hearing impairment deprives individuals of one of their most basic social needs: the ability to communicate with others. Although little can be done to recover lost hearing, it is important to detect hearing loss as early as possible in order to reduce further loss (by behaviour modification in the case of noise-exposed adults) and to provide hearing assistance in very young children so that they may be exposed to some degree of auditory experience at as early an age as possible. To this end, the phenomenon of otoacoustic emissions, or noises from the ear, now recognised for twenty years, is likely to become even more significant in the early years of the next millennium. Otoacoustic emissions were first demonstrated as very soft echoes re-emerging from the ear after a delay of ten milliseconds or so following a click stimulus. These echoes are sounds produced by the ear as it goes about its normal function and are lost if the hearing sensitivity of the individual is below normal. Several other forms of otoacoustic emissions have been discovered and rapidly applied to the testing of hearing so that today the technique of assessing hearing status in neonates and others unable to co-operate, as well as in diagnostic applications, is widespread. The application of the technique, however, has preceded a real understanding of what otoacoustic emissions are and how they are generated, and their widespread use at the moment is somewhat akin to a car repair industry which does not understand how an engine works. This proposal intends to investigate the basic mechanisms behind otoacoustic emissions in order to improve their efficiency and accuracy of clinical interpretation.Read moreRead less
Nanoengineered Drug Delivery To The Inner Ear To Prevent Progressive Hearing Loss
Funder
National Health and Medical Research Council
Funding Amount
$479,056.00
Summary
Hearing loss is a common sensory deficit and can get progressively worse over time, eventually requiring a cochlear implant. In this project we will examine the effectiveness of a new technique that uses nanoengineered particles to provide long term and controlled delivery of drugs in order to prevent progressive hearing loss and protect residual hearing following cochlear implantation. We will develop the next generation of nanotechnology to enhance drug delivery in pathological ears.
Estimating And Alleviating The Impacts Of Age-Related Sensory Decline
Funder
National Health and Medical Research Council
Funding Amount
$323,767.00
Summary
Sensory loss and dementia disproportionately affect older adults, often co-occur, and are the two leading contributors to disability burden among older Australians. This research will investigate the consequences that hearing and vision loss have for older adult health and wellbeing, informing strategies to reduce the disability burden of age-related sensory loss. These impacts include cognitive decline and dementia, mental health, quality of life, disability and independent living.
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.
NEURAL MODULATION OF HEARING LOSSES INDUCED BY LOUD SOUND
Funder
National Health and Medical Research Council
Funding Amount
$290,500.00
Summary
Loud sounds, from occupational and recreational sources, are the most common threat to hearing and can result in temporary hearing losses (as might be experienced after an evening at a noisy pub or concert) or permanent hearing losses (after prolonged or multiple loud sounds, as for example in a noisy work environment). Noise reduction programs are either not always possible or effectively applied. A parallel strategy is the study of biological mechanisms that may ameliorate hearing damage, with ....Loud sounds, from occupational and recreational sources, are the most common threat to hearing and can result in temporary hearing losses (as might be experienced after an evening at a noisy pub or concert) or permanent hearing losses (after prolonged or multiple loud sounds, as for example in a noisy work environment). Noise reduction programs are either not always possible or effectively applied. A parallel strategy is the study of biological mechanisms that may ameliorate hearing damage, with a view to optimising such mechanisms. I propose to build on seminal Australian work to examine how one such system, nerves from the brain to the inner ear (the site of most damage from loud sounds), modulates hearing losses caused by loud sounds. Early studies indicated these nerves could protect from damage induced by short-lasting loud sound and this has led to international interest in functional applications of such protection to reduce hearing damage suffered by humans. However, my recent work indicates the nerves exert complex protective and exacerbative effects to loud sounds similar to common trauma or occurring under conditions similar to common trauma. They even exacerbate hearing losses due to loud sound, especially when there is an imbalance in hearing sensitivity in the two ears (bilateral) similar to what is common in humans. These findings make it critical that functional application be delayed until the full range of effects exerted by the nerves is understood. I propose to elucidate the novel complex effects of these nerves to loud sound. Specific aims are: (1) To understand effects of these pathways to loud sounds like those encountered by humans, (2) To investigate how chronic imbalanced bilateral hearing sensitivity, like that common in humans, alters effects of the nerves and when they change from being protective to exacerbative, (3) To adduce how an atraumatic sound affects hearing losses due to later loud sound and the role played by these nerves.Read moreRead less
Obesity In The Elderly: Impact Of Weight Loss Therapy On Physiology And Function.
Funder
National Health and Medical Research Council
Funding Amount
$613,213.00
Summary
The aim of this study is to assess the safety, tolerability, weight-loss efficacy, change in lean body mass and impact of cognition of three approaches to treat obesity in the elderly. We will compare dietary advice, an energy reduced diet and a very low calorie diet. All three groups will also have an exercise program. This study will be of major assistance in developing management guidelines for obesity in the elderly, which will likely be an emerging public health issue.
Improving Weight Loss By Intermittent Use Of Very Low Energy Diet: The TANGO Diet Trial (Temporary Phases Of Accelerated Weight Loss For Noticeably Greater Outcomes)
Funder
National Health and Medical Research Council
Funding Amount
$660,736.00
Summary
Very low energy diet (VLED) is being increasingly used for the treatment of obesity, but the resultant weight loss is usually transient, partly because it induces powerful adaptive responses that inhibit weight loss and promote regain. We have shown that 'taking a break from dieting' for 2 weeks reduces these adaptive responses. In this project we will thus test whether weight loss outcomes with VLED can be improved via intermittent use, where periods on the VLED are alternated with 'breaks'.
After The Cloning Of The HMSNL Gene: Molecular Pathogenesis Of The Disease
Funder
National Health and Medical Research Council
Funding Amount
$258,564.00
Summary
We have completed an NHMRC-funded study, where we identified the gene for a severe disorder of the peripheral nervous system. The disease, hereditary motor and sensory neuropathy - Lom (HMSNL), presents with gait disturbances, difficulty in using the hands, muscle weakness and wasting and sensory loss. The concomitant impairment of the insulating myelin sheath surrounding nerve fibres (facilitating nerve conduction) and of the nerve fibres themselves suggests that the molecular defect lies in th ....We have completed an NHMRC-funded study, where we identified the gene for a severe disorder of the peripheral nervous system. The disease, hereditary motor and sensory neuropathy - Lom (HMSNL), presents with gait disturbances, difficulty in using the hands, muscle weakness and wasting and sensory loss. The concomitant impairment of the insulating myelin sheath surrounding nerve fibres (facilitating nerve conduction) and of the nerve fibres themselves suggests that the molecular defect lies in the basic mechanisms of interaction between the two main types of cell in the peripheral nervous system: the myelin-producing Schwann cell and the neuron. The two cells form the most complex system of communication in the human body, where signaling from one is vital for the development, functioning and survival of the other. Very little is known about the molecular mechanisms of this communication. At the same time, knowledge of the normal mechanisms of interaction is the key to better understanding of the mechanisms of disease in the peripheral nervous system and of the causes and possible prevention of the impairment of function. The newly identified HMSNL gene is probably involved in the signaling necessary for the development and functioning of the Schwann cell and for the survival of the nerve fibres. To gain an insight into the nature of the signaling cascade, we propose to use several complementary experimental approaches. We will create a mouse model of the human disease, to study its very early stages and subsequent evolution. In parallel, we will use molecular techniques and a yeast model, to identify other steps in the signaling cascade. The NHMRC-funded study will be part of a larger project conducted in collaboration with leading laboratories in the UK and the Netherlands, where other aspects of the molecular basis of the disease and of the role of the new gene will be examined.Read moreRead less