Investigation Of A Novel Sympathetic Vasomotor Pathway
Funder
National Health and Medical Research Council
Funding Amount
$354,586.00
Summary
Blood pressure is regulated by sympathetic nerves to the heart and blood vessels, and it is believed that overactive sympathetic nerves contribute to many cases of hypertension. Overactive sympathetic nerves also contribute to, and worsen the disease process, in heart failure as well as other cardiovascular diseases. The regulation of sympathetic nerves is thus central to the understanding and treatment of cardiovascular disorders. The present proposal is specifically relevant to the hypertensio ....Blood pressure is regulated by sympathetic nerves to the heart and blood vessels, and it is believed that overactive sympathetic nerves contribute to many cases of hypertension. Overactive sympathetic nerves also contribute to, and worsen the disease process, in heart failure as well as other cardiovascular diseases. The regulation of sympathetic nerves is thus central to the understanding and treatment of cardiovascular disorders. The present proposal is specifically relevant to the hypertension which accompanies airway obstruction during sleep (obstructive sleep apnoea - OSA). We plan to study a novel class of sympathetic nerves ('accessory' sympathetic nerves), which are likely to be centrally involved in the hypertension of OSA, and probably also other conditions where sympathetic nerve activity is pathologically raised. 'Accessory' sympathetic nerves can cause a long-lasting amplification of the activity in the 'regular' sympathetic nerve pathway, enhancing its actions on the heart and blood vessels. The brain pathways that drive 'accessory' sympathetic nerves are essentially unknown. We seek to find out those pathways, study how they amplify the activity in the 'regular' pathway and explore their significance in an animal model of OSA. The outcomes of this study will be first, essential basic knowledge of a novel, but probably important, mechanism whereby the brain controls the cardiovascular system in health and disease. Second, the relevance of that mechanism to a specific type of neurogenic hypertension will have been defined.Read moreRead less
How Does The Central Respiratory Generator Amplify Sympathetic Activity In Hypertension?
Funder
National Health and Medical Research Council
Funding Amount
$290,113.00
Summary
High blood pressure causes many life-threatening cardiovascular diseases, including heart failure and stroke. The cause of most high blood pressure is not known. Using an animal model of high blood pressure we have shown that an interaction, in the brain, between the nerve pathways that generate respiratory activity and regulate blood pressure is altered. This occurs early in life and our evidence strongly suggests this may be a cause of high blood pressure.
Nerve pathways exist that carry information from the highest parts of the brain to the peripheral hearing organ, the inner ear. These descending control pathways have the potential to affect the hearing process in a number of ways; protecting from loud sounds, improving the detection of signals in noisy backgrounds, selecting stimuli of interest and regulating a variety of aspects of inner ear function. Abnormal function of these pathways can affect hearing sensitivity and may be important in ph ....Nerve pathways exist that carry information from the highest parts of the brain to the peripheral hearing organ, the inner ear. These descending control pathways have the potential to affect the hearing process in a number of ways; protecting from loud sounds, improving the detection of signals in noisy backgrounds, selecting stimuli of interest and regulating a variety of aspects of inner ear function. Abnormal function of these pathways can affect hearing sensitivity and may be important in phenomena such as tinnitus and other disorders of hearing. This project will investigate the subtle effects that selective activation of these pathways has on inner ear function and will attempt to unravel the different influences that subcomponents of the pathways have on the different aspects of hearing.Read moreRead less
Respiratory Modulation Of RVLM Premotor Neurons: Role In The Sympathetic Over-activity Of Hypertension.
Funder
National Health and Medical Research Council
Funding Amount
$338,605.00
Summary
Hypertension is a common health disorder in all societies and is a major risk factor for the development of life threatening cardiovascular diseases, including heart failure and stroke. Whilst some effective therapies are available, many patients are not adequately treated or have reduced quality of life due to serious side effects. There is a great need for alternative therapies. The central nervous system is clearly involved in hypertension although the level of that involvement is not well un ....Hypertension is a common health disorder in all societies and is a major risk factor for the development of life threatening cardiovascular diseases, including heart failure and stroke. Whilst some effective therapies are available, many patients are not adequately treated or have reduced quality of life due to serious side effects. There is a great need for alternative therapies. The central nervous system is clearly involved in hypertension although the level of that involvement is not well understood- i.e. is it a causal factor or just a contributor to the maintenance of established hypertension? The experiments outlined in this application are based on the observation that modulation of nervous activity to blood vessels is more influenced by the respiratory system in people with high blood pressure, than in normotensive people. We aim to test whether this increased respiratory modulation might be involved in the generation of the high blood pressure.Read moreRead less
Understanding Factors Involved In The Development Of Hypertension
Funder
National Health and Medical Research Council
Funding Amount
$757,492.00
Summary
High blood pressure is a major cause of cardiovascular diseases. Currently intervention occurs after the cardiovascular system is damaged. Our interest is in the development of high blood pressure, to determine whether early intervention could stop its progression. We identified that excitation of the sympathetic nervous system by the circuits that control breathing is important. We seek to further understand this interaction to identify novel approaches to treat high blood pressure.
Role Of The Area Postrema In Determining The Increased Cardiac Sympathetic Nerve Activity In Heart Failure
Funder
National Health and Medical Research Council
Funding Amount
$489,912.00
Summary
In heart failure there is a large increase in sympathetic nerve activity to the heart that has detrimental effects on the heart and can induce sudden death. The areas in the brain causing the increased nerve activity are unknown. We will investigate the role of the area postrema, which is a window to the brain for hormones in the blood. We have evidence that this brain site maintains the high level of nerve activity in heart failure, possibly stimulated by hormones circulating in the blood.
Mechanisms Responsible For Neurogenic Hypertension: A Novel Interaction Between GABAergic Modulation Of Amygdalo-hypothalamic Pathways And MicroRNA Regulation Of Renin
Funder
National Health and Medical Research Council
Funding Amount
$340,220.00
Summary
A genetic model of hypertension will be used to understand the interrelated role of the brain, nervous system and kidney. The proposed studies will test the hypothesis that disruption of inhibitory neurochemicals in specific regions of the brain, leads to greater nervous system activation of the kidney, which in turn decreases an inhibitory molecule, ultimately resulting in greater activation of a hormonal system responsible for raising blood pressure.
The human mirror system and the perception of others' actions. This research will provide greater understanding of how the human mirror system operates for the perception of actions, a crucial first-step toward understanding disorders of action perception such as autism and apraxia. The research program will also contribute greatly to building national capacity in cognitive neuroscience research, using advanced brain imaging methods. The fellow actively encourages and mentors young scientists, o ....The human mirror system and the perception of others' actions. This research will provide greater understanding of how the human mirror system operates for the perception of actions, a crucial first-step toward understanding disorders of action perception such as autism and apraxia. The research program will also contribute greatly to building national capacity in cognitive neuroscience research, using advanced brain imaging methods. The fellow actively encourages and mentors young scientists, organises advanced workshops that bring brain imaging researchers around the world to Australia, and builds international collaborations based around high-field brain imaging. The Future Fellowship will substantially enhance these activities, building capacity and enhancing Australia's reputation in cognitive neurosciences.Read moreRead less