Increased Vulnerability To Stress During Opiate Dependence: Molecular, Anatomical, And Behavioural Correlates
Funder
National Health and Medical Research Council
Funding Amount
$272,640.00
Summary
Heroin addiction is a major health and societal problem in Australia. It is consistently associated with an adverse impact upon individual users, their families, and communities. It is a chronically relapsing condition for which few, if any effective prevention and treatment strategies exist. Moreover, why an individual initiates and maintains heroin taking remains unclear. Stress and negative emotions have a strong impact on heroin use. Stress may drive some individuals to start using heroin, s ....Heroin addiction is a major health and societal problem in Australia. It is consistently associated with an adverse impact upon individual users, their families, and communities. It is a chronically relapsing condition for which few, if any effective prevention and treatment strategies exist. Moreover, why an individual initiates and maintains heroin taking remains unclear. Stress and negative emotions have a strong impact on heroin use. Stress may drive some individuals to start using heroin, stress increases the pleasurable effects of heroin and stress increases the aversive effects of heroin withdrawal. These effects will encourage addiction and discourage addicts from seeking treatment. Stress can also cause an otherwise drug-free individual to relapse to heroin addiction despite having been drug-free for some time. In this project we will study why stress has such a large impact on heroin addicts and heroin addiction. We will test the hypothesis that heroin use actually produces profound alterations in the neural network in the brain which controls responses to stress. This project uses a simple animal model of heroin addiction whereby rats are injected with morphine to study the regulation of several genes which are important in responding to stress. We will also study how this exposure and changes in gene expression alter neurobiological, cardiovascular, and behavioural responses to stress. This project will identify parts of the brain that are altered during heroin addiction, and will also identify why heroin addicts are more vulnerable to stress than the general population. Therefore, this project will help us to identify targets for therapeutic intervention (both psychological and pharmacological) and possibly disrupt the addictive cycle.Read moreRead less
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
An FMRI Analysis Of The Functional Organization Within The Brain Of Experimental Superficial And Deep Orofacial Pain
Funder
National Health and Medical Research Council
Funding Amount
$307,526.00
Summary
This project will investigate how the human brain processes a number of important aspects of human jaw muscle pain that are clinically relevant but poorly understood. For example, we do not understand why jaw muscle pain has such different behavioural effects to skin pain. Jaw muscle pain is associated with a significant emotional component not seen in with skin pains. Also, skin pain usually has a sharp or burning quality, is well-localized and is readily treated, while jaw muscle pain is a dee ....This project will investigate how the human brain processes a number of important aspects of human jaw muscle pain that are clinically relevant but poorly understood. For example, we do not understand why jaw muscle pain has such different behavioural effects to skin pain. Jaw muscle pain is associated with a significant emotional component not seen in with skin pains. Also, skin pain usually has a sharp or burning quality, is well-localized and is readily treated, while jaw muscle pain is a deep pain that has a dull, aching quality that may be referred to related sites of the face, head and neck. It is also not known why jaw muscle pain is more common in females in comparison to males. Chronic jaw muscle pain is a major symptom of patients with Temporomandibular Disorders, the most common form of non-dental orofacial pain and that involves pain in or about the jaw joint and-or jaw muscles, and often limitation of jaw movement. Chronic jaw muscle pain can have a severe effect on quality of life but its diagnosis and management is difficult. Despite the widespread prevalence of chronic orofacial pains, we have little information on the central processing of chronic human orofacial pain. This proposal will improve our fundamental understanding of how jaw muscle pain is processed in the brain. The way that the central nervous system processes and represents jaw muscle pain will help explain why these pains present differently in the clinic and should provide important information on the differences between females and males in the representation of jaw muscle pain. This information on the central processing of chronic orofacial pain is crucial to inform the direction of novel or specific management strategies. Our long-term goal is to improve the diagnosis and management of patients with Temporomandibular Disorders, and the present application represents a major new direction of research.Read moreRead less
Glycine Transporters regulate the concentration of glycine in the spinal cord and brain. It has been suggested that elevating glycine levels in these regions may be useful in treating pain and schizophrenia. This project will provide the basis for the development of new glycine transport inhibitors that may be used to treat these conditions.