High Speed Video To Assess Eye Movements In Vestibular Dysfunction - A Validation Study
Funder
National Health and Medical Research Council
Funding Amount
$133,351.00
Summary
Dizziness affects a third of the population during their lives. Abnormal eye movements are often the best guide as to what has gone wrong in the dizzy person. The problem is that these eye movements can be difficult to see, and hence measure, as a way of diagnosing and then treating the dizziness. Video-oculography holds great promise for helping doctors identify the cause, and in many cases offer simple curative treatment, for dizziness.
Functional Interactions Between Primate Cortical Areas In Tasks Involving Attention And Short-term Memory
Funder
National Health and Medical Research Council
Funding Amount
$267,280.00
Summary
To navigate and operate in the cluttered and dynamic sensory world around us, our brains need to be able to attend to specific objects or features in the environment, identify them and also know where they exist at any one instant of time, prior to performing the appropriate action. The attention, memory, decision and motor components involved in this process possibly involve a variety of cortical areas and neuronal operations. The special primate preparation we have developed permits us to eluc ....To navigate and operate in the cluttered and dynamic sensory world around us, our brains need to be able to attend to specific objects or features in the environment, identify them and also know where they exist at any one instant of time, prior to performing the appropriate action. The attention, memory, decision and motor components involved in this process possibly involve a variety of cortical areas and neuronal operations. The special primate preparation we have developed permits us to elucidate at a neuronal level many of these brain mechanisms. By recording neuronal activities in two different cortical areas simultaneously as the monkey performs a memory task that he has been trained on, we will test the following ideas: (1) A cortical region in the dorsal, parietal stream directs spatial attention by gating other visual areas to process only a selected region of the visual world (2) A region in the ventral, temporal stream directs attention to specific features in the visual world by gating earlier cortical areas (3) The parietal cortical areas that mediate intention for action hold the relevant information in working memory till it is forwarded to the more anterior premotor areas. These experiments have the potential to reveal the basic neuronal scheme that underpins functions such as attention, visual recognition and memory, which are impaired in many neurological disorders.Read moreRead less
Analysis Of Functional Role Of The BDNF Precursor In Sensory Neurons
Funder
National Health and Medical Research Council
Funding Amount
$457,267.00
Summary
Neurotrophins, which are generated from their precursors, are essential for the survival and function of the nervous system. One of neurotrophins, brain derived neurotrophic factor (BDNF), is made in sensory neurons and transported towards nerve terminals. Mutation of a single amino acid in the precursor of BDNF disrupts this transport. This project will examine whether the precursor of BDNF has any function within sensory nerves. We will examine whether the precursor of BDNF gets into the nerve ....Neurotrophins, which are generated from their precursors, are essential for the survival and function of the nervous system. One of neurotrophins, brain derived neurotrophic factor (BDNF), is made in sensory neurons and transported towards nerve terminals. Mutation of a single amino acid in the precursor of BDNF disrupts this transport. This project will examine whether the precursor of BDNF has any function within sensory nerves. We will examine whether the precursor of BDNF gets into the nerve via its receptors and whether it plays any role in the development of pain and maintenance of neuropathic pain after nerve injury. Successful execution of the project will eludicate mechanisms of pain, especially neuropathic pain, and will provide important information to assist in the design of drugs for neurological diseases.Read moreRead less
This is a study of the senses which arise from our muscles and which tell us where our different body parts are, at any point in time. These senses, collectively called proprioception, are also involved in the automatic, unconscious control of our muscles. So, ultimately, they allow us to stand and to move freely with precision and confidence, even in the dark. One of these senses, the sense of effort or of heaviness, is believed to be generated within the brain. It intensifies when we become fa ....This is a study of the senses which arise from our muscles and which tell us where our different body parts are, at any point in time. These senses, collectively called proprioception, are also involved in the automatic, unconscious control of our muscles. So, ultimately, they allow us to stand and to move freely with precision and confidence, even in the dark. One of these senses, the sense of effort or of heaviness, is believed to be generated within the brain. It intensifies when we become fatigued. These experiments will be concerned with finding out more about how this works. We have a method that uses magnetic stimulation of the brain to change its control of our muscles. Using it we will learn how this sense is generated. When we close our eyes and move our limbs we realise that we know exactly where they are at any point in time. It remains uncertain exactly how this information is generated within the nervous system. One idea, arising from some recent experiments which we want to test, is that as we move the limb, the skin over the moving parts is stretched and stretch-sensitive nerve endings in the skin provide us with information about the movement. Alternatively, perhaps it is the effort we exert to maintain limb position against the force of gravity which tells us where the limb is. In another recent study we have found that when a muscle has become painful from excessive exercise or from some local strain injury, our ability to control the muscle and so move the limb is no longer as effective. We want to study the underlying nervous mechanisms responsible for the changes in movement control. Are they designed to spare the muscle while it recovers from injury? How are they brought about? All of this work is important for a better understanding of ourselves, for a better clinical diagnosis when something goes wrong and for improved treatment of diseased or injured muscles.Read moreRead less
Plasticity of gastrointestinal vagal afferents. The aim of this project is to identify how leptin modulates specific subtypes of vagal afferent within the gut and the plasticity of this system under different dietary conditions. This proposed project will substantially increase understanding of the interactions between leptin, known to influence food intake, and vagal afferent satiety signals. It will also increase understanding of how these interactions alter in obesity and ultimately provide t ....Plasticity of gastrointestinal vagal afferents. The aim of this project is to identify how leptin modulates specific subtypes of vagal afferent within the gut and the plasticity of this system under different dietary conditions. This proposed project will substantially increase understanding of the interactions between leptin, known to influence food intake, and vagal afferent satiety signals. It will also increase understanding of how these interactions alter in obesity and ultimately provide targets and/or concepts for the pharmacotherapy of obesity.Read moreRead less
Listen and learn - statistical learning and the adapting auditory brain. This project aims to explore the link between rapid neural adaptation - a form of learning referred to as statistical learning - and human listening performance in noisy environments. The project aims to generate a new understanding of mechanisms that contribute to listeners' abilities to understand speech in noise, and to complex communication disorders such as dyslexia. Expected outcomes will include increased capacity to ....Listen and learn - statistical learning and the adapting auditory brain. This project aims to explore the link between rapid neural adaptation - a form of learning referred to as statistical learning - and human listening performance in noisy environments. The project aims to generate a new understanding of mechanisms that contribute to listeners' abilities to understand speech in noise, and to complex communication disorders such as dyslexia. Expected outcomes will include increased capacity to investigate a broad range of cognitive and communication functions. Benefits will include potential technologies and algorithms to assist listening (in devices such as hearing aids), language development and reading.Read moreRead less
Central pathways regulating visceral pain. This project aims to investigate the neural pathways within the spinal cord and brain processing colorectal pain perception. The project aims to identify the spinal cord neurons relaying colorectal signalling into the brain and the influence of descending modulation from the brainstem upon these pathways. The outcomes will greatly benefit fundamental understanding of the central pathways processing visceral pain.
Central Representation of Electroacoustic Stimuli. Cochlear implantation, initially only provided to profoundly deaf individuals, is now routine in people with substantial residual hearing. Although stimulation via a cochlear implant and hearing aid in the same ear has been shown to improve speech understanding, particularly in noise, and to increase the aesthetic quality of sound, almost nothing is known about the physiological mechanisms underlying these benefits. The broad aim of our project ....Central Representation of Electroacoustic Stimuli. Cochlear implantation, initially only provided to profoundly deaf individuals, is now routine in people with substantial residual hearing. Although stimulation via a cochlear implant and hearing aid in the same ear has been shown to improve speech understanding, particularly in noise, and to increase the aesthetic quality of sound, almost nothing is known about the physiological mechanisms underlying these benefits. The broad aim of our project is to address this deficiency by measuring the patterns of neural activity evoked by speech sounds across the tonotopic axis in the inferior colliculus and auditory cortex and assess the extent to which the pattern of neural activity allows discrimination between the different speech sounds.Read moreRead less
Identifying the basis for perceptual stability and perceptual omission during saccadic eye movements. The ability to explore the world via eye movements is an important feature of visual capabilities. This project will establish how the brain maintains the perception of a stable and stationary world despite the several eye movements made each second. This knowledge will fill a conspicuous gap in the understanding of the human visual system.
Relationship of the functional architecture of the mammalian brain to its microcircuitry. The project seeks to understand a very fundamental issue in neuroscience: how the connectivity and architecture of the cortex are related to the functions of neurones in that area? This will be investigated by imaging the surface of the visual cortex of anaesthetised cats and monkeys as special visual patterns are shown to the eye/s. The overall picture gained of the active and inactive cortical areas will ....Relationship of the functional architecture of the mammalian brain to its microcircuitry. The project seeks to understand a very fundamental issue in neuroscience: how the connectivity and architecture of the cortex are related to the functions of neurones in that area? This will be investigated by imaging the surface of the visual cortex of anaesthetised cats and monkeys as special visual patterns are shown to the eye/s. The overall picture gained of the active and inactive cortical areas will be related to the properties of neurones in those areas and to those of individual input and output fibres. An optical imaging equipment will be acquired in 2004 using a recently awarded LIEF grant to the CI.Read moreRead less