I am a medically trained physiologist studying how the brain controls the delivery of oxygen to the body, the removal of carbon dioxide and the maintenance of normal acid level in the blood. This branch of physiology is well known to anyone who has studied 'ABC' in a first aid programme. My work concerns the coordination of the breathing and blood pressure centres in the brain. It is crucial in the understanding of diseases such as obstructive sleep apnoea and hypertension.
Cell-selective Deletion Of Brain AT1A Receptors In Hypertension: Effect On Blood Pressure, Increased ROS Production And Inflammation.
Funder
National Health and Medical Research Council
Funding Amount
$578,268.00
Summary
Angiotensin is important for normal regulation of blood pressure but is also involved in cardiovascular diseases. Interruption of angiotensin’s actions is a common treatment of these diseases. Functional deletion of angiotensin receptors decreases blood pressure. Surprisingly the site(s) in the body responsible for this decrease are not known. We will examine the role of angiotensin receptors in the brain in the control of blood pressure in health and in cardiovascular disease.
Reduced Baroreceptor Reflex Control Of Heart Rate In Chronic Renal Failure
Funder
National Health and Medical Research Council
Funding Amount
$490,288.00
Summary
People with kidney disease are more likely to die of heart disease than their ailing kidneys. One reason is because their hearts do not respond properly to changes in blood pressure, as the nerve circuits controlling the heart become dysfunctional. We will examine where and why components of this circuit are unable to respond to changes in blood pressure. This will help guide new treatments to reduce the incidence of heart disease and risk of death associated with kidney disease.
Cardiac Sympathetic Nerve Activity: Understanding Normal Control And The Causes Of The Increase In Heart Failure
Funder
National Health and Medical Research Council
Funding Amount
$531,125.00
Summary
Heart failure is a condition in which the heart muscle becomes weak and is unable to pump sufficient blood around the body to provide adequate perfusion of the organs. This results in breathlessness, lethargy, fatigue, mental confusion and eventually death. At present the life expectancy of patients with heart failure is poor, with a 5 year survival of 25% in men and 38% in women. It is the only form of heart disease that is increasing, the reason being that thousands of patients who have surviv ....Heart failure is a condition in which the heart muscle becomes weak and is unable to pump sufficient blood around the body to provide adequate perfusion of the organs. This results in breathlessness, lethargy, fatigue, mental confusion and eventually death. At present the life expectancy of patients with heart failure is poor, with a 5 year survival of 25% in men and 38% in women. It is the only form of heart disease that is increasing, the reason being that thousands of patients who have survived heart attacks or had coronary bypass operations go on to develop heart failure. In heart failure there is a very large increase in the activity of the nerves that stimulate cardiac rate and contractility, the cardiac sympathetic nerves. This increase in activity is detrimental, higher levels of activity predict greater morbidity and a reduced life span. The mechanisms causing the increase in cardiac sympathetic nerve activity are unknown, but greater understanding is essential if new and improved treatments are to be developed for patients with heart failure. Only two groups in the world measure cardiac nerve activity in conscious animals, neither is studying heart failure. We therefore have a unique opportunity to investigate the factors that control the activity of the cardiac nerves in the healthy state and to establish the causes of the increase in activity in heart failure. In particular, we will investigate how reflex control mechanisms, circulating hormones that are increased in heart failure and specific mechanisms in the brain act to control cardiac nerve activity in the normal state and what changes in these mechanisms lead to the preferential increase in cardiac nerve activity in heart failure. These findings will provide a detailed understanding of the mechanisms controlling cardiac nerve activity in the normal healthy state and increased knowledge of the factors that lead to the preferential activation of the cardiac nerves in heart failure.Read moreRead less
THE BAROREFLEX IN SNORING AND THE OBSTRUCTIVE SLEEP APNOEA HYPOPNOEA SYNDROME
Funder
National Health and Medical Research Council
Funding Amount
$436,261.00
Summary
The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including snoring and cessation of breathing for short periods of time. OSAHS is amongst the commonest of chronic disorders of adult males, occuring in 5% of men over the age of 45 years. It is now recognised that one of the major complications of OSAHS is the development of high blood pressure and heart disease. In the proposed studies, we ....The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including snoring and cessation of breathing for short periods of time. OSAHS is amongst the commonest of chronic disorders of adult males, occuring in 5% of men over the age of 45 years. It is now recognised that one of the major complications of OSAHS is the development of high blood pressure and heart disease. In the proposed studies, we will examine the proposal that snoring alone, without significant associated OSAHS, can also lead to high blood pressure in habitual snorers both awake and asleep. In particular, we will explore the hypothesis that chronic snoring transmits a pressure wave through the tissues of the neck to the carotid artery which is the main blood supply to the brain. We propose that the chronic vibration of this artery can alter pressure sensors in the artery wall, which then results in the persistance of high blood pressure. Our studies will help to prove that this is a mechanism whereby both snoring and OSAHS may contribute to the development of high blood pressure. The recognition of snoring as an independent risk factor for high blood pressure will clearly have important and wide ranging implications for the future management of snoring in the prevention of high blood pressure.Read moreRead less
I am a cardiorespiratory neuroscientist. My work aims to discover what determines central respiratory and sympathetic activity and how this controls breathing and the circulation in health and disease