Dysfunction of the nervous system plays an important role in the symptoms of many respiratory diseases. For example, excessive non-productive coughing, elevated mucous secretion, reduced airway patency and hyperreactivity are all characteristic symptoms of diseases such as asthma and all involve over-activity of the nervous system. This research aims to understand the neural circuitry that is involved in controlling the airways and the mechanisms that underlie how this circuitry can become dysfu ....Dysfunction of the nervous system plays an important role in the symptoms of many respiratory diseases. For example, excessive non-productive coughing, elevated mucous secretion, reduced airway patency and hyperreactivity are all characteristic symptoms of diseases such as asthma and all involve over-activity of the nervous system. This research aims to understand the neural circuitry that is involved in controlling the airways and the mechanisms that underlie how this circuitry can become dysfunctional.Read moreRead less
Role Of Load Detection And Compensation In Pathogenesis Of Obstructive Sleep Apnea.
Funder
National Health and Medical Research Council
Funding Amount
$340,867.00
Summary
This proposal will use novel techniques to explore how defective responses to the threat posed by a collapsing upper airway contribute to the Obstructive Sleep Apnea syndrome, a disease involving repetitive collapse of the upper airway in sleep. Responses to small increases in the resistance to inspiratory airflow will be examined by measuring the small electrcal responses in the brain to these loads, and the response of the muscles responsible for maintaining airway patency to the collapsing fo ....This proposal will use novel techniques to explore how defective responses to the threat posed by a collapsing upper airway contribute to the Obstructive Sleep Apnea syndrome, a disease involving repetitive collapse of the upper airway in sleep. Responses to small increases in the resistance to inspiratory airflow will be examined by measuring the small electrcal responses in the brain to these loads, and the response of the muscles responsible for maintaining airway patency to the collapsing forces induced by these loads, in both wakefulness and sleep. The brain's response to resistive loads will also be evaluated using the techique of functional magnetic resonance imaging, which demonstrates areas of the brain activated by a stimulus.Read moreRead less
Neural Circuits Producing Pelvic Vasodilation In Females
Funder
National Health and Medical Research Council
Funding Amount
$472,770.00
Summary
The reproductive organs and genitalia in males and females experience a large increase in blood flow during sexual and reproductive activity. This increased blood flow (vasodilation) is a key component of penile and clitoral erection, and enhances secretion from the lining of the internal reproductive organs. Vasodilation during sexual activity is produced by a special sets of nerves receiving signals from the genitalia and the brain. In fact, Viagra works by enhancing and prolonging the actions ....The reproductive organs and genitalia in males and females experience a large increase in blood flow during sexual and reproductive activity. This increased blood flow (vasodilation) is a key component of penile and clitoral erection, and enhances secretion from the lining of the internal reproductive organs. Vasodilation during sexual activity is produced by a special sets of nerves receiving signals from the genitalia and the brain. In fact, Viagra works by enhancing and prolonging the actions of these nerves. An important part of this neural pathway is a group of nerve cells in the spinal cord that connects the central nervous system with peripheral nerves in the reproductive organs - these are called preganglionic neurons. Recently we discovered that a major pathway from the spinal cord to the pelvic blood vessels in females leaves the spinal cord at a different level (lumbar) from that thought previously (sacral level). Currently there is no information on how these lumbar preganglionic nerves in females are connected to other nerve pathways that are active during sexual activity, and how they integrate signals from both the internal organs and the brain. We will use an array of modern cellular techniques together with direct observation of dilation in isolated uterine arteries to discover how these nerve cells are wired up in circuits in the spinal cord. This information is vital for us to understand the factors producing increased blood flow in normal sexual activity, and how these might be altered in inflammation or in conditions where there could be selective damage to one nerve pathway and not the other, such as after pelvic surgery, spinal cord damage at different levels, or stimulation of the spinal cord for treatment of chronic pain. Our study also will help understand referred pain and sensations of discomfort in abdominal and pelvic organs.Read moreRead less
Changes In Pelvic Autonomic Neurons After Spinal Nerve Injury
Funder
National Health and Medical Research Council
Funding Amount
$176,734.00
Summary
This project is about the effects of spinal injury on autonomic neurons that control the bladder, lower bowel and reproductive organs. One of the consequences of some types of spinal injury is that there are no signals being sent from the spinal cord to the nerve cells outside the cord, and this leads to poor bladder control, impotence, etc. We are mimicking this problem experimentally by damaging the spinal nerves that carry these signals. We have found that after this type of damage the pelvic ....This project is about the effects of spinal injury on autonomic neurons that control the bladder, lower bowel and reproductive organs. One of the consequences of some types of spinal injury is that there are no signals being sent from the spinal cord to the nerve cells outside the cord, and this leads to poor bladder control, impotence, etc. We are mimicking this problem experimentally by damaging the spinal nerves that carry these signals. We have found that after this type of damage the pelvic autonomic neurons make many new connections between each other, and the types of new connections depend on which spinal nerves have been injured. This leads to the question: are these new connections good or bad? ie are they helpful in trying to get organ control back to normal or will they stop the correct connections from the spinal cord from being made in the future? This project addresses these questions by using sophisticated techniques for staining and visualising individual nerve fibres growing out from the spinal cord. We will track how well these fibres grow back and connect with the pelvic autonomic neurons. In particular, we will see whether they make correct connections, and if these connections are influenced by the new fibres that have grown between the autonomic neurons in the interim period. We will also do physiological tests to see if the new connections have the correct function. The ultimate aim of these studies is not only to understand more about regeneration, but to see what determines whether the correct connections have been made - and ideally, to give us insight into how we can make regeneration work more quickly and accurately. We believe that this work is an important adjunct to other studies on spinal injury, which mostly focuses on regaining voluntary motor control (e.g. walking); however loss of bladder, bowel and reproductive function is another important quality of life issue for spinal injury patients.Read moreRead less
The final and most effective means that we have to stop a fall is the stepping reflex, which is an automatic response when the body topples. For many elderly and others, this reflex does not work effectively and leads to falls and injuries. Although we know a lot about human balance and standing, we know little about this stepping reflex. This project investigates the basic physiology of the stepping reflex and how it is affected by age with the aim of preventing falls and injuries.
The Role Of Coronary Artery Baroreceptors In Cardiopulmonary Reflexes
Funder
National Health and Medical Research Council
Funding Amount
$361,018.00
Summary
The blood vessels and heart contain sensors that report on the state of the circulation to the brain. Blood vessel sensors send information about the level of blood pressure to the brain, and the brain coordinates appropriate changes in the activity of the heart and blood vessels so that blood pressure stays within narrow limits and blood flow to the brain is protected. Heart sensors send information to the brain about pressures in the heart and the release of chemicals during heart pain. Specia ....The blood vessels and heart contain sensors that report on the state of the circulation to the brain. Blood vessel sensors send information about the level of blood pressure to the brain, and the brain coordinates appropriate changes in the activity of the heart and blood vessels so that blood pressure stays within narrow limits and blood flow to the brain is protected. Heart sensors send information to the brain about pressures in the heart and the release of chemicals during heart pain. Specialized pressure receptors, like the receptors on blood vessels, have recently been reported to exist on the main blood vessels in the heart and, although not extensively studied, likely send information to the brain to participate in blood pressure regulation and to protect the supply of blood to the heart. These heart receptors normally work in concert with, and overshadowed by, the blood vessel receptors. In cardiovascular disease this concerted and complimentary interaction may be lost, resulting in contradictory signals being sent to the brain and inappropriate regulatory responses occurring. To study the functions of these heart receptors we will compare the number and types of nerves going to the heart receptors with the nerves that go to the blood vessel receptors to tell us whether their functions are likely to be similar. We will activate the heart receptors in healthy conscious animals to see what happens to blood pressure, heart rate, breathing patterns and blood flow to different organs. Finally we will use brain mapping techniques to see which brain cells are excited when the heart receptors are excited, and brain cell recording techniques to determine how individual brain cells respond to heart or vessel information. These studies will provide important new information about heart sensors, and help us understand the role these sensors have in heart disease or heart attack. This knowledge will aid the development of effective new ways of treating heart disease.Read moreRead less
Whether holding the arm still or standing, the brain uses a silent proprioceptive sense that unconsciously detects and controls our movements. Key sensory receptors for this sense are located within the muscles that are also contracting. This is a project to discover how proprioception is affected by muscle contraction and how this affects postural control. This will improve the management of many common disorders that affect movement and balance.