Speech and chewing are accomplished automatically by the jaw muscles which have both the power to chew meat and even bone, and the precision to make extremely fine adjustments to the shape of the mouth that enable speech. The brain needs constant inputs from sensory receptors in and around the mouth to control these muscles. We will investigate how these sensory mechanisms automatically fine-tune the activity of the jaw muscles and the mechanisms that keep the jaw in its normal position when the ....Speech and chewing are accomplished automatically by the jaw muscles which have both the power to chew meat and even bone, and the precision to make extremely fine adjustments to the shape of the mouth that enable speech. The brain needs constant inputs from sensory receptors in and around the mouth to control these muscles. We will investigate how these sensory mechanisms automatically fine-tune the activity of the jaw muscles and the mechanisms that keep the jaw in its normal position when the subject is sitting quietly, or when the head is moving up and down during running. This normal rest position of the jaw is a vital point of reference for dentists who are making false teeth and for surgeons who are restoring damaged faces, but it is not known what mechanisms are responsible for it. Anyone who has experienced a sore tooth or sore jaw muscles will know that pain adversely affects normal chewing. A common symptom is limitation of jaw movements. We will determine how pain affects the control of jaw muscles. This is important for people with chronic facial pain from arthritis of the jaw joint or from grinding their teeth while they are asleep. Even if it is not possible to eliminate their pain, we hope to suggest approaches which will alleviate its effects. Another part of our study involves a computer model of the chewing system. Computer models enable scientists to examine the effect of various interventions such as surgery or orthodontics on a model before these are tried on humans. It is also possible to use such a virtual patient to answer important functional questions that cannot be examined in humans because the methods are unavailable, or because the procedures would be ethically unacceptable. The current version of the computer model is quite sophisticated anatomically, but lacks important information on the control systems that activate the muscles. We will collaborate with the developers of the model by providing this information.Read moreRead less
My work investigates the neural output to human inspiratory muscles and how it is related to mechanical effectiveness for breathing. The aim is to discover how this relationship can change with respiratory disorders such as chronic obstructive pulmonary disease and obstructive sleep apnoea. I also examine the changes in breathing muscle control in people with spinal cord injury. This work promises new understanding of the basic control of respiration and how it changes with disease.
Central, Reflex And Mechanical Factors In The Control Of Human Breathing Muscles.
Funder
National Health and Medical Research Council
Funding Amount
$497,968.00
Summary
We will study the neural output to human inspiratory muscles and how it is related to mechanical effectiveness for breathing and then how this relationship can change with respiratory disorders such as chronic obstructive pulmonary disease and obstructive sleep apnoea. We will also examine the spinal reflex connections of human breathing muscles in people with spinal cord injury. This work promises new understanding of the basic control of respiration and how it changes with disease.
How Neural Impairment Affects Respiratory Motor Function In Chronic Obstructive Pulmonary Disease And Healthy Ageing
Funder
National Health and Medical Research Council
Funding Amount
$762,797.00
Summary
With chronic obstructive pulmonary disease (COPD) and ageing, respiratory muscles are weak and the mechanics of the chest and lungs are altered. Our proposal will examine the contribution of impaired neural control to muscle weakness with the aim to identify new targets for therapy to reduce respiratory morbidity in ageing and patients with COPD.
High Field Magnetic Resonance Evaluation Of Cerebral And Brainstem Dysfunction In Obstructive Sleep Apnea.
Funder
National Health and Medical Research Council
Funding Amount
$335,175.00
Summary
BACKGROUND: Obstructive Sleep Apnea (OSA) is a condition where repetitive obstruction of the upper airway occurs during sleep. This occurs in susceptible patients when the muscles which normally hold the upper airway open relax with sleep onset. During these interruptions to breathing (apneas) oxygen levels can fall significantly and repetitive awakenings from sleep result. Patients with sleep apnea are often sleepy during the day and experience difficulties with concentration on complex or bori ....BACKGROUND: Obstructive Sleep Apnea (OSA) is a condition where repetitive obstruction of the upper airway occurs during sleep. This occurs in susceptible patients when the muscles which normally hold the upper airway open relax with sleep onset. During these interruptions to breathing (apneas) oxygen levels can fall significantly and repetitive awakenings from sleep result. Patients with sleep apnea are often sleepy during the day and experience difficulties with concentration on complex or boring tasks. Recent improvements in magnetic resonance imaging (MRI) technology allow targeting very small areas of the brain, such as the brainstem, the region of the brain which contols the upper airway muscles. MRI can detect subtle signs of damage to brain cells, and can assess brain activation induced by a task, such as moving the tongue . AIM 1. To identify the presence and patterns of damage to brain cells in patients with OSA by MRI scanning. 2. To examine whether patients with the most severe patterns of injury are also those with the greatest difficulties with sleepiness and concentration. 3. To determine whether these brain abnormalities improve after 6 months of treatment of OSA. 4. To assess activity of the brainstem in wakefulness in OSA patients and compare this to the activity in subjects without OSA. SIGNIFICANCE: This project will advance our understanding of the causes of obstructive sleep apnea. We anticipate it will provide a new method for investigating injury to brain cells in this disease. It will also provide a new means for investigating the causes of OSA and for evaluating novel therapies aimed at enhancing the activity of upper airway muscles and preventing obstruction during sleep.Read moreRead less
Clinical And Physiological Features Of Obstructive Sleep Apnoea Phenotypes
Funder
National Health and Medical Research Council
Funding Amount
$117,331.00
Summary
Obstructive sleep apnoea has variable causes and clinical effects in different patient groups. My research will quantify the contribution of various physiological processes to the development of upper airway obstruction in different sub-types of sleep apnoea and to determine how this affects clinical presentation. I will be measuring a number of physiological parameters, and finding out how sleep apnoea manifests in terms of symptomatology and adverse health effects.
The Role Of Lung Volume In The Pathogenesis And Treatment Of Obstructive Sleep Apnea.
Funder
National Health and Medical Research Council
Funding Amount
$337,691.00
Summary
Obstructive sleep apnea (OSA) is a common disorder of repetitive upper airway collapse during sleep. Reducing the volume of air in the lungs increases airway collapsibility. Lung volume is therefore likely important in OSA but has not been investigated thoroughly. Also, whether raising lung volume during sleep can be used to treat OSA is unknown. The aim of this grant is therefore to investigate the role, and therapeutic potential, of lung volume in OSA.