Vasomotor Ganglionic Transmission: The Preganglionic Peptide And The Second Gear
Funder
National Health and Medical Research Council
Funding Amount
$451,896.00
Summary
Blood pressure depends on nerve signals that travel from the central nervous system to blood vessels. In the middle of this pathway is a relay station - the sympathetic ganglion cell. Transmission through this relay station has recently been shown to have not only a fixed but also a variable component - the 'second gear'. The project tests if and how three likely candidate peptide molecules, one in the nerves, two in the bloodstream, control this 'second gear' and hence regulate blood pressure.
A novel sensory neural circuit has been identified innervating the airways and lungs. The anatomical organisation of this circuit has been described to some extent in previous studies, however there is a significant gap in knowledge with respect to its functional importance. This project will develop methods to address this knowledge gap and in doing so the project will firstly describe how this circuit controls breathing under normal conditions and secondly how this becomes dysregulated during
Network Interactions Between Cardiovascular Control Neurons In The Brainstem Underlie Sympathetic Tone
Funder
National Health and Medical Research Council
Funding Amount
$268,328.00
Summary
High blood pressure is a very significant risk factor for many common cardiovascular diseases. Blood pressure is normally tightly regulated by groups of neurons in the brainstem; although we know that this part of the brain becomes dysfunctional in patients with high blood pressure, we do not understand why. We have recently discovered that cardiovascular control neurons can influence each other. The project will determine the effect of such communication in the control of blood pressure.
Regeneration Of Pelvic Autonomic Axons After Injury
Funder
National Health and Medical Research Council
Funding Amount
$457,267.00
Summary
This project is focused on the problem of erectile dysfunction, especially the common situation where this is caused by injury to the penile nerves. These nerves are part of the parasympathetic nervous system . Nerve injury-induced erectile dysfunction is a common problem for prostatectomy patients, with recovery of normal erections occurring slowly, partially or not at all. There is currently no therapy to improve regeneration of these nerves, and this is partly because very little is known abo ....This project is focused on the problem of erectile dysfunction, especially the common situation where this is caused by injury to the penile nerves. These nerves are part of the parasympathetic nervous system . Nerve injury-induced erectile dysfunction is a common problem for prostatectomy patients, with recovery of normal erections occurring slowly, partially or not at all. There is currently no therapy to improve regeneration of these nerves, and this is partly because very little is known about effects of injury on any parasympathetic neurons, and especially for those that are essential for erection. The first aim of this study is to define the key structural and functional changes occurring in penile parasympathetic neurons during regeneration after injury. This fundamental neurobiological knowledge is essential to develop and optimise an future growth treatments. The second aim of the study is to define the effects of a protein, neurturin, on axonal regeneration of penile pro-erectile neurons. Our evidence so far strongly suggests that it is necessary for the early stages of injury responses. Our studies will be performed in mice, where we also have colonies of knockout animals to study the effect of removing neurturin from the regeneration process. Our experiments will include neuroanatomical studies of injured and growing nerves, pharmacology studies on penile smooth muscle (corpus cavernosum) innervation and responsiveness, and tissue culture studies. We will investigate not only the changes that occur following injury to penile nerves, but also the way in which undamaged nerves may assist in returning erectile function.Read moreRead less
Gastrointestinal Signals And Cardiovascular Regulation- Implications For Obesity-related Hypertension.
Funder
National Health and Medical Research Council
Funding Amount
$486,886.00
Summary
Obesity is reaching epidemic proportions, and obesity-related hypertension is the leading cause of serious cardiovascular complications. Hormones released from the gut have been implicated in obesity, but their contribution to hypertension has not been studied. Preliminary studies in our laboratory have shown that these hormones participate in signals related to cardiovascular control by acting locally to relay signals to the brain, and may be more important in obesity than previously thought.
Sympathetic Nervous System Activation In Renal Failure. Its Contribution To Pathogenesis And Progression.
Funder
National Health and Medical Research Council
Funding Amount
$490,796.00
Summary
Cardiovascular morbidity and mortality is exceedingly high in patients with chronic renal failure and particularly end stage renal disease. Recent studies suggest that sympathetic activation contributes substantially to the development of hypertension, progression of renal disease and cardiovascular prognosis in these patients. Increased sympathetic nerve firing has been demonstrated in end stage renal disease by the use of clinical microneurography, which has been attributed to uremia-related t ....Cardiovascular morbidity and mortality is exceedingly high in patients with chronic renal failure and particularly end stage renal disease. Recent studies suggest that sympathetic activation contributes substantially to the development of hypertension, progression of renal disease and cardiovascular prognosis in these patients. Increased sympathetic nerve firing has been demonstrated in end stage renal disease by the use of clinical microneurography, which has been attributed to uremia-related toxins. However, renal transplant recipients with excellent graft function and no signs of uremia still exhibit increased sympathetic nerve firing. Most interestingly, bilateral nephrectomized patients have nerve firing rates comparable to that of normal control subjects without renal disease. These data suggest that the diseased kidneys exert excitatory effects on the sympathetic nervous system independent of correction of uremia. The proposed study aims to comprehensively investigate the pattern of sympathetic activation both centrally (microneurography) and regionally (radiotracer dilution methodology) in patients with chronic renal failure and end stage renal disease . The effect of the centrally acting sympatholytic drug rilmenidine on sympathetic activity in the setting of renal disease will be assessed. Patients with ESRD waitlisted for kidney transplantation will be studied before and after transplantation. Some of the transplant recipients will also have undergone uni- or bilateral nephrectomy before transplantation which will enable us to further explore the role of the diseased kidneys in sympathetic activation. The results of this study may prove to have significant implications for treatment and prevention of cardiovascular morbid events frequently associated with renal disease.Read moreRead less
Investigations Of Mechanisms Underlying Autonomic Cardiovascular Regulation In Medial Temporal Lobe Epilepsy.
Funder
National Health and Medical Research Council
Funding Amount
$311,860.00
Summary
People with epilepsy often show disturbed cardiovascular function which may increase mortality risk. This may reflect seizure related disturbances in the autonomic circuitry regulation of the cardiovascular system. We apply advanced brain imaging analysis of altered neural structure, circuit connectivity and function within medial temporal lobe and mid brain, combined with clinical assessment of autonomic function to provide important new insights into cardiac disturbances in epilepsy.
How Intestinal Motility Activates Sensory Pathways
Funder
National Health and Medical Research Council
Funding Amount
$555,875.00
Summary
Pain and discomfort from the gut are common and unpleasant. We understand how gut sensory nerve cells work, at the cellular, molecular and genetic level. However, movement of the gut wall and contents are the major cause of activation of sensory neurons. We know little about which particular patterns of movement cause pain. This is crucial information for accurately diagnosing human gut disorders, for monitoring effectiveness of treatments and for identifying potential new drug targets.
Unravelling The Neuropathological Basis Of The Gastrointestinal Manifestations Of Parkinson’s Disease
Funder
National Health and Medical Research Council
Funding Amount
$822,957.00
Summary
Parkinson’s Disease occurs in about 1% of the population. It is a distressing, progressive disease that places a severe burden on patients, families and carers. 80-90% of Parkinson’s Disease patients have constipation which causes substantial distress to patients, their families and carers. We have a rational path to therapy for constipation of Parkinson’s Disease that will be pursued in this project