Sympathetic Control Of Cutaneous Blood Flow And Blood Pressure In Human Spinal Cord Injury
Funder
National Health and Medical Research Council
Funding Amount
$242,002.00
Summary
While spinal cord injury can cause devastating changes in the nervous system paralysis and loss of sensation relatively little is known about changes to the sympathetic nervous system. The sympathetic nervous system is intimately involved in the ongoing control of blood pressure, blood flow and temperature control. Loss of sympathetic control can occur following spinal cord injury. Interruption of descending pathways can result in partial or complete loss of sympathetic outflow from the thoracol ....While spinal cord injury can cause devastating changes in the nervous system paralysis and loss of sensation relatively little is known about changes to the sympathetic nervous system. The sympathetic nervous system is intimately involved in the ongoing control of blood pressure, blood flow and temperature control. Loss of sympathetic control can occur following spinal cord injury. Interruption of descending pathways can result in partial or complete loss of sympathetic outflow from the thoracolumbar segments. Complete decentralization can result in autonomic dysreflexia (autonomic hyperreflexia), in which sensory stimuli originating below the lesion evoke a reflex increase in sympathetic drive to the blood vessels, causing them to constrict. Because of this, blood pressure may rise suddenly and remain at such high levels that stroke and (occassionally) cardiac arrest may occur. This phenomenon, autonomic dysreflexia, is considered a medical emergency. The typical subjective signs of autonomic dysreflexia include a throbbing headache, tingling in the head or nasal congestion; sweating and flushing above the lesion are clinical signs that prompt medical staff to measure blood pressure and to locate the source of sensory irritation (usually a distended bladder or impacted colon, sometimes a pressure sore or ingrown toenail). Commonly, however, subclinical episodes go undetected, and this phenomenon of silent dysreflexia is of increasing concern. This project will develop means of assessing the integrity and state of the sympathetic nervous system below a lesion in patients with spinal cord injury and characterize the firing properties of reflexly activated sympathetic neurones.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
Mapping the connectome that controls blood pressure. The connections that an individual brain cell receives from other cells ultimately determines its behaviour. Using a revolutionary new technique, the project will create a map of the brain cells that control blood pressure.
Unravelling The Behavioural And Brain Mechanisms Of Compulsive Disorders, And New Ways To Treat Them
Funder
National Health and Medical Research Council
Funding Amount
$635,076.00
Summary
Disorders of compulsion, such as obsessive-compulsive disorder and substance use disorder, are chronic, debilitating, and present a significant cost to the individual and to society. Together, these disorders affect more than 10% of the population. Moreover, 40-60% of these individuals are resistant to current treatment. The current project is aimed at improving the preclinical research underlying our understanding the behavioural and brain mechanisms of such disorders and how to treat them.
Prion-like Behaviour In Immunity: Super-sized Signalling Platforms?
Funder
National Health and Medical Research Council
Funding Amount
$611,995.00
Summary
Prions have been mostly associated with pathologies but recent discoveries show that prion-like behaviour may be beneficial, enhancing our immune response for example. To test this, we want to systematically explore all human proteins involved in the defence against pathogens, find new prion-like trends and probe their role in the innate immune response.
Rhombomeric Topography of Structures in the Adult Mouse: Evidence from Avian Homologies and Transgenic Mice. The brainstem of birds has been shown to be formed by a line of segments, like carriages of a train. The same arrangement exists in the embryos of mammals, but is hidden in the adult mammalian brain. We will transfer our detailed knowledge of bird brains to make a maps of the brainstem segments in adult mice. We will then test this map with special gene markers which will reveal the occul ....Rhombomeric Topography of Structures in the Adult Mouse: Evidence from Avian Homologies and Transgenic Mice. The brainstem of birds has been shown to be formed by a line of segments, like carriages of a train. The same arrangement exists in the embryos of mammals, but is hidden in the adult mammalian brain. We will transfer our detailed knowledge of bird brains to make a maps of the brainstem segments in adult mice. We will then test this map with special gene markers which will reveal the occult segmental pattern in adult mice. This work will give us a new way of understanding the organisation of brainstem centres that control breathing, cardiovascular functions and emotional states.Read moreRead less
Towards a continuum model of orienting and defensive responses. Orienting (OR) and Defensive Responses (DR) underlie important survival functions of attending to unexpected stimuli and avoiding harm.We will establish the first integrative profile of human OR/DR function, using simultaneous recording of brain activity and 'body' responsivity. Given sex and age variation in OR/DRs, both males and females spanning six decades will be studied. OR/DR abnormalities are associated with major disorders ....Towards a continuum model of orienting and defensive responses. Orienting (OR) and Defensive Responses (DR) underlie important survival functions of attending to unexpected stimuli and avoiding harm.We will establish the first integrative profile of human OR/DR function, using simultaneous recording of brain activity and 'body' responsivity. Given sex and age variation in OR/DRs, both males and females spanning six decades will be studied. OR/DR abnormalities are associated with major disorders of attention and stress, which also vary with sex and age. We will examine relationships between OR/DR function and proneness to these disorders in healthy individuals. The results will provide a framework for developing prevention and intervention strategies.Read moreRead less
Signalling Pathways And Fungal Virulence – The Inositol Polyphosphate Kinase Pathway In Cryptococcus Neoformans
Funder
National Health and Medical Research Council
Funding Amount
$545,189.00
Summary
Bloodstream fungal infections kill millions of people per year world-wide and are costly to treat. A potentially fruitful strategy for developing new, urgently-needed drugs to fight these infections, is to target signalling pathways, which in fungi, are essential for establishing infection. This proposal investigates how one such pathway, the inositolpolyphosphate kinase pathway, allows fungi to establish infection and will determine which components are suitable targets for drug development.
Exploring the brain mechanisms underlying hyperactivity in Attention-Deficit/Hyperactivity Disorder. Attention-deficit/Hyperactivity Disorder (AD/HD) is the most common psychiatric disorder affecting children, resulting in substantial costs (both human and financial) to the child, their family and Australian society. The outcomes of this project will provide a better foundation for understanding dysfunctional brain mechanisms in AD/HD, which is expected to lead to better diagnosis, treatment, an ....Exploring the brain mechanisms underlying hyperactivity in Attention-Deficit/Hyperactivity Disorder. Attention-deficit/Hyperactivity Disorder (AD/HD) is the most common psychiatric disorder affecting children, resulting in substantial costs (both human and financial) to the child, their family and Australian society. The outcomes of this project will provide a better foundation for understanding dysfunctional brain mechanisms in AD/HD, which is expected to lead to better diagnosis, treatment, and community support. Ultimately this will contribute to a healthy start to life for these children. This project will also demonstrate how an integrated Australian approach can lead the research agenda in both basic neuroscience, at the interface of psychology and physiology, and its applications in health.Read moreRead less
Invasive fungal infections are a serious, escalating health issue. They cause severe disease with high death rates and are very costly to the health system. Current drugs often have suboptimal efficacy and cause side effects. New drugs are needed urgently. Many fungi, including the AIDS-related pathogen, Cryptococcus neoformans, secrete phospholipase B (Plbp) to facilitate infection. We will identify and investigate the Plbp secretion pathway as a novel anti-fungal drug target.