THE AUTONOMIC, SOMATIC AND CENTRAL NEURAL RESPONSES TO DEEP AND SUPERFICIAL PAIN IN HUMAN SUBJECTS
Funder
National Health and Medical Research Council
Funding Amount
$375,750.00
Summary
Pain is a subjective experience, the intensity of which can be readily influenced by personal experience. Despite this, pain originating from a particular part of the body will usually be described by all individuals as having similar character. For example, pain arising from the skin is commonly described as being sharp or burning and is usually easy to localise, whereas pain arising from muscle is commonly dull, throbbing and diffuse. In addition to producing sensory changes, pain also evokes ....Pain is a subjective experience, the intensity of which can be readily influenced by personal experience. Despite this, pain originating from a particular part of the body will usually be described by all individuals as having similar character. For example, pain arising from the skin is commonly described as being sharp or burning and is usually easy to localise, whereas pain arising from muscle is commonly dull, throbbing and diffuse. In addition to producing sensory changes, pain also evokes changes in blood pressure, heart rate and motor activity (often in an attempt to remove the source of the pain). The proposed research aims to characterise the cardiovascular and motor patterns associated with pain originating in skin and in muscle and to examine the brain regions that produce these changes. More specifically, microelectrodes will be used to investigate changes in peripheral nerve activity during transient painful skin and muscle events in awake human subjects. In a separate investigation functional magnetic resonance imaging will be used to determine brain sites that are activated by skin or muscle pain.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
NPY Suppresses Seizures And Modulates Thalamocortical Activity In Animal Models Of Generalized Epilepsy
Funder
National Health and Medical Research Council
Funding Amount
$386,020.00
Summary
Epilepsy is the most common serious chronic neurological disease in the community, affecting up to 3% of the population in a lifetime and 0.5-1% at any one time. Absence epilepsy is one of the most common types of epilepsy, most frequently seen in childhood and teenage years that may persist into adulthood. Anti-epileptic drugs are effective in controlling absence seizures in most patients, however there is an important group (20-40%) of patients in whom the absence seizures remain uncontrolled ....Epilepsy is the most common serious chronic neurological disease in the community, affecting up to 3% of the population in a lifetime and 0.5-1% at any one time. Absence epilepsy is one of the most common types of epilepsy, most frequently seen in childhood and teenage years that may persist into adulthood. Anti-epileptic drugs are effective in controlling absence seizures in most patients, however there is an important group (20-40%) of patients in whom the absence seizures remain uncontrolled with current medications. Recently there has been considerable interest in the role that chemical in the brain, such as neuropeptide Y (NPY), may play in epilepsy. The research proposed will examine the role of NPY in several animal models of absence epilepsy. We have recently shown that NPY suppresses absence seizures in a rat genetic model of generalised epilepsy, and that this appears to be mediated by Y2 receptors. This work will build on these novel findings, and determine the localisation of the effect within the brain, and the underlying mechanism. We will check NPY effects across several models in different species, a genetic rat model with spontaneous seizures, and in mice treated with a chemical to induce seizures. This will determine its broad applicability. We will also determine the effects of removal of NPY or NPY receptors on the effects of NPY on seizure expression. Finally, brain recording techniques will be applied to determine the mechanism and site within the brain underlying the protective actions of NPY. The project has the potential to provide novel insights into the role of NPY in the expression and modulation of absence seizures. NPY related mechanisms might represent targets for the development of a new class of therapeutic agents for the treatment of absence epilepsy. Targets that are identified as being important in the expression of absence seizures may also prove to be relevant in other types of generalised epilepsy syndromes.Read moreRead less
Hydrostatic Pressure Distributions In Peri-pharyngeal Tissues : Impact On Upper Airway Patency
Funder
National Health and Medical Research Council
Funding Amount
$508,935.00
Summary
The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSAHS affects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in ~4% of men over the age of 45 years. In the proposed studies we will develop a computer model of the function of the throat during breathing. A particular focus of our mo ....The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSAHS affects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in ~4% of men over the age of 45 years. In the proposed studies we will develop a computer model of the function of the throat during breathing. A particular focus of our model will be the influence of the properties of the tissue that form the walls of the throat. Our goal is to construct a computer model that will be useful in identifying specific features of throat function that make people susceptble to the development of OSAHS. In this manner we hope to provide a tool that can be used to develop new approaches to the treatment and prevention of OSAHS.Read moreRead less
The Role Of The Intrauterine (pro) Renin-(pro)renin Receptor System In Prostaglandin Synthesis In Pregnancy.
Funder
National Health and Medical Research Council
Funding Amount
$488,478.00
Summary
Preterm birth is associated with a very high incidence of infant disability and mortality. This has long term economic and social costs to the Australian people. We will demonstrate that in late gestation, the intrauterine (pro)renin renin receptor system controls prostaglandin synthesis by the fetal membranes and the placenta. Prostaglandins can cause premature labour.