PREMOTOR SYMPATHETIC CONTROL OF BLOOD PRESSURE DURING PSYCHOLOGICAL STRESS: HYPOTHALAMUS VERSUS MEDULLA.
Funder
National Health and Medical Research Council
Funding Amount
$153,616.00
Summary
Health and well being depend in large part on a strong and efficient autonomic nervous system. The autonomic nervous system controls blood pressure, heart rate, gastrointestinal function, immune responses and certain forms of pain. Negative emotions can have a strong impact on autonomic function. We have all experienced the sweaty hands, pounding heart and intestinal discomfort when the mail arrives and bad news is expected or when we face a deadline for which we are not prepared. This is known ....Health and well being depend in large part on a strong and efficient autonomic nervous system. The autonomic nervous system controls blood pressure, heart rate, gastrointestinal function, immune responses and certain forms of pain. Negative emotions can have a strong impact on autonomic function. We have all experienced the sweaty hands, pounding heart and intestinal discomfort when the mail arrives and bad news is expected or when we face a deadline for which we are not prepared. This is known as psychological stress and it is usually associated with anxiety. Unfortunately, it is also the most common form of stress in modern urban life. There are clear indications that when these autonomic changes become chronic they can lead to hypertension, weak immune responses and gastric ulcers. In people already suffering from cardiovascular diseases they can also precipitate cardiac and cerebrovascular accidents. Clearly, the link between psychological stress and the autonomic nervous system needs to be explored in more detail. This project looks at the organization of the neural network in the brain and spinal cord that controls these responses. It uses a simple model of psychological stress in the conscious rat and recent non invasive techniques to record blood pressure and look at neuronal activity. We think that we have identified a group of neurons that may be controlling very specifically this response. It is located in the hypothalamus. The aim of this project is to further test the role of these neurons and find out what is controlling them. They will also be compared to another group of neurons that also controls blood pressure but apparently not in relation to psychological stress. The possibility that the cardiovascular response to psychological stress might be mediated by a specific group of neurons in the brain is a very exciting finding. It could lead to new therapeutic applications for acting against the short and long term effects of stress.Read moreRead less
Inhibition Of Fear Memories By Extinction: Neural Substrates.
Funder
National Health and Medical Research Council
Funding Amount
$234,250.00
Summary
Anxiety disorders [e.g., Post Traumatic Stress Disorder (PTSD)] are the most prevalent type of psychopathology in the industrialised world. They are associated with characteristic behavioural (e.g., heightened startle) and autonomic (e.g., cardiovascular) reactions. These disorders are often characterised as an inability to regulate the emotion of fear. Significant progress has been made in understanding the neural and cellular processes involved in the establishment of fear memories, but relati ....Anxiety disorders [e.g., Post Traumatic Stress Disorder (PTSD)] are the most prevalent type of psychopathology in the industrialised world. They are associated with characteristic behavioural (e.g., heightened startle) and autonomic (e.g., cardiovascular) reactions. These disorders are often characterised as an inability to regulate the emotion of fear. Significant progress has been made in understanding the neural and cellular processes involved in the establishment of fear memories, but relatively little is known about the mechanisms by which fear memories can be inhibited or suppressed. Understanding this latter process is a key to the development of effective treatments for anxiety disorders such as PTSD where the patient suffers from persistent, intrusive, unwanted trauma memories. A common experimental procedure for reducing learned fear is to repeatedly expose the subject to a fear-eliciting stimulus but without any aversive outcome. This procedure leads to a progressive loss, or extinction, of the fear reactions elicited by the stimulus. Historically, the extinction of fear was thought to be due to an erasure of the fear memory. However, recent evidence shows that extinction inhibits, rather than erases, the fear memory. Because the fear memories remain intact, some structure(s) in the brain must inhibit activity in the fear pathway. This project uses extinction of conditioned fear reactions in rat subjects to determine the structure(s) in the brain that inhibit fear memories and their behavioural and cardiovascular expression. It brings together the expertise of four well-established researchers and uses a combination of behavioural, physiological, immunohistochemical, tract tracing, and lesion approaches to achieve this aim. The proposed experiments will reveal the structure(s) in the brain that control the inhibition of fear, as well as the site(s) of this inhibition in the fear pathwayRead moreRead less
Investigation Of A Novel Role For Factor XIII In Regulating The Adhesive Function Of Platelets
Funder
National Health and Medical Research Council
Funding Amount
$243,000.00
Summary
Platelets are small specialised blood cells that are extremely important for the normal formation of blood clots and for the repair of injured blood vessels. We are studying the processes that allow platelets to stick to the site of vessel injury and to each other to form stable blood clots. If this process proceeds unchecked, harmful blood clots can form which block blood vessels and cause heart attacks and strokes. There are many factors, both inside and outside platelets, which control how bi ....Platelets are small specialised blood cells that are extremely important for the normal formation of blood clots and for the repair of injured blood vessels. We are studying the processes that allow platelets to stick to the site of vessel injury and to each other to form stable blood clots. If this process proceeds unchecked, harmful blood clots can form which block blood vessels and cause heart attacks and strokes. There are many factors, both inside and outside platelets, which control how big and how fast a blood clot grows and whether it becomes harmful enough to cause a blood vessel blockage. One of these factors is the level of platelet 'stickiness' or 'reactivity'. We are working towards a better understanding of how platelet reactivity is regulated. Specifically, we believe we have identified a new factor which keeps blood clots at a size that is not harmful to cause blood vessel blockade. This information will not only increase our knowledge of blood clot formation in health and disease but also may help in the development of new therapies for the prevention of heart attack and stroke.Read moreRead less
Cardiovascular Responses To Stress And Arousal: Hypothalamic And Brainstem Mechanisms
Funder
National Health and Medical Research Council
Funding Amount
$566,468.00
Summary
Stressful episodes in everyday life cause increases in blood pressure, mainly via activation of nerves that constrict blood vessels and increase heart rate. This in turn increases the risk of heart attacks, strokes, or other cardiovascular diseases. This project aims to identify the brain mechanisms that cause these stress-evoked effects. This knowledge may lead to much more effective ways of minimising stress-evoked responses, and thus reduce the risk of cardiovascular disorders.
A Randomised Controlled Trial Of Internet-based Therapy For Panic Disorder.
Funder
National Health and Medical Research Council
Funding Amount
$202,575.00
Summary
Approximately 9.7% of the adult population have an anxiety disorder with one of the more common, panic disorder, often with agoraphobia, afflicting 2.4% of the community. Around 8% of patients consulting a GP also have panic disorder (PD). A further 10% of the community experience spontaneous panic, but do not have full PD (termed non-clinical panic). People with PD frequently experience clinical depression, about 15% abuse alcohol and non-prescription drugs and PD is associated with an increase ....Approximately 9.7% of the adult population have an anxiety disorder with one of the more common, panic disorder, often with agoraphobia, afflicting 2.4% of the community. Around 8% of patients consulting a GP also have panic disorder (PD). A further 10% of the community experience spontaneous panic, but do not have full PD (termed non-clinical panic). People with PD frequently experience clinical depression, about 15% abuse alcohol and non-prescription drugs and PD is associated with an increased risk of suicide. Over time people with PD appear to have an increased risk of heart problems. They also have substantial financial burdens through multiple attendances at doctors' rooms and through restricted employment opportunities. Only just over one in four people with an anxiety disorder consults a health professional for their problems, with most going to their GP. It has been estimated that less than 10% of these people seek the services of a mental health specialist such as a clinical psychologist or psychiatrist. Therefore because of blocks to do with access, cost or embarrassment, many people with mental health problems do not seek face-to-face specialised mental health treatment. People in rural and regional Australia are particularly disadvantaged by limited access to these specialists. We have developed an internet-based treatment program on panic and anxiety for people in the community, and particularly in regional Australia. Early evaluation of this program has found it is more effective than other types of therapist-assisted self-help treatment. The aim of this research project is to compare it to best-practice face-to-face psychological and pharmacological treatment for PD. If the effectiveness of our internet-based treatment is comparable to best-practice face-to-face treatment, its availability will assist the many Australians who suffer from debilitating panic but who are unable to access specialised mental health assistance.Read moreRead less