Mechanisms And Pathways Leading To Saccadic Suppression In Primate Brain
Funder
National Health and Medical Research Council
Funding Amount
$858,086.00
Summary
Only the central few degrees of the visual field are viewed in high resolution. Consequently, the eyes must be pointed at targets of interest using saccadic eye movements. Each saccade generates potentially disturbing image motion but this is never perceived: saccadic suppression. This project aims to characterise the neural basis of saccadic suppression using modern techniques. As a result, a prime question in Neuroscience for over 100 years can now be answered.
Visuomotor Integration In The Medial Parietal Cortical Areas
Funder
National Health and Medical Research Council
Funding Amount
$665,163.00
Summary
This project will find out how the electrical activity of brain cells is used to direct the arms to a specific position in the space around a person's body. By understanding the code used by brain cells to perform this control of the arms, we will be able to "read" the brain activity directly, and use it to allow control of artificial arms by people who have been paralysed or had amputations.
A decade ago the adult brain was thought of as a structurally-fixed organ. Against this are well-documented cases of slow recovery after massive injuries or stroke. Simple models of brain injury using the tactile, visual and auditory systems of animals as models have now revealed multiple stages of recovery (plasticity). Some of these are inbuilt into the wiring of the neural systems such that functional plasticity can result without the need for any structural or cellular changes. A second grou ....A decade ago the adult brain was thought of as a structurally-fixed organ. Against this are well-documented cases of slow recovery after massive injuries or stroke. Simple models of brain injury using the tactile, visual and auditory systems of animals as models have now revealed multiple stages of recovery (plasticity). Some of these are inbuilt into the wiring of the neural systems such that functional plasticity can result without the need for any structural or cellular changes. A second group of plastic phenomena depend upon minute changes in the connections between neurons and these are invoked in the first few days following an injury (synaptic plasticity; changes in the pattern and strength of the connections between neurons). Aside from being model systems, there are also parallels of this plasticity with clinical situations such as losses in hearing and sight, and of the adaptations made by the brain in response to prosthetics (e.g. bionic ear) and resorative surgery but the degree of relevance for these situations is unclear. An intriguing aspect of the experiments on auditory and visual systems is that neurons with inputs from both ears, or both eyes, undergo the plastic changes when the relevant sense organ on only one side is damaged but the other is intact. In fact, on the basis of the limited available evidence, it appears that the changes are independent of there being a normal input from the other side. This is difficult to explain in terms of the modern understanding neuronal plasticity at a cellular level. It is thus proposed to study both auditory and visual models of this brain plasticity with stimuli which are systematically varied to extract the extent of bilateral interaction in the induced plasticity. This will enable prediction of how these plasticity mechanisms will be involved in adaptations made to prosthetics and surgical corrections.Read moreRead less
Understanding The Brain In The Transition From Acute To Chronic Low Back Pain
Funder
National Health and Medical Research Council
Funding Amount
$107,049.00
Summary
A critical question in treating low back pain (LBP) is why some people get better after hurting their back while others do not. Physiological mechanisms, such as brain plasticity and central sensitisation, are believed to underpin the transition to persistent pain. This is the first study to evaluate these mechanisms longitudinally and their relationship with LBP outcomes. The result of this research will provide better understanding of pain mechanisms of LBP and assist to develop novel therapy.
Understanding The Organisation Of The Medial Parietal Cortex: Sensorimotor Integration For Goal-directed Behaviour
Funder
National Health and Medical Research Council
Funding Amount
$551,862.00
Summary
Reaching and grasping are of obvious significance for a productive life, and many of the brain areas known to be involved in the direction of arm movements are located in the parietal lobe. Stroke affecting this part of the brain causes disability, as people become unable to reach accurately, or to close their hands around objects with appropriate strength. This project will combine modern physiological and anatomical methods to reveal the brain circuitry responsible for such crucial skills.
Combining input from vision and hearing greatly enhances perception when information from one of these senses is degraded or incomplete, such as when tracking objects in foggy, dark or noisy places. This enhancement is of considerable importance because degraded input is the daily situation faced by many people with hearing or vision impairment. We will study the neural processes underlying our ability to combine vision and hearing to create a more reliable and accurate perception of the world.
One of the main trends in the evolution of the primate brain was the huge expansion of the cortical areas devoted to visual processing. However, the exact role of individual areas remains highly controversial, making detailed physiological and anatomical studies in suitable primate models a key step to elucidating their function in the human brain. We will address one particular aspect of this problem, namely the organisation of the cortical areas that provide visual control for skilled movement ....One of the main trends in the evolution of the primate brain was the huge expansion of the cortical areas devoted to visual processing. However, the exact role of individual areas remains highly controversial, making detailed physiological and anatomical studies in suitable primate models a key step to elucidating their function in the human brain. We will address one particular aspect of this problem, namely the organisation of the cortical areas that provide visual control for skilled movements. It is proposed that there are two parallel brain circuits involved in the analysis of motion, one tracking the movement of objects, and the other analysing a person s self-motion. Consider, for example, the task of a tennis player who has to return a serve. In order to achieve this, the brain must precisely integrate information about the ball s motion, as well as information about the player s speed and direction. This requires precise control of eye movements (to keep the eyes on the ball), as well as the ability to control the limb and trunk muscles. The aim of this study will be to map the anatomical framework underlying our ability to process all the relevant visual motion information, and to coordinate the appropriate motor responses. Such work is fundamental for understanding the functional organisation of the brain. It also has the potential to lay the groundwork for developments in areas of applied research, including medicine (e.g. the design of better rehabilitation strategies for people with brain damage), robotics- artificial intelligence (e.g. the improvement of artificial systems capable of vision), and the cognitive sciences (e.g. a better understanding of factors that limit human responses to visual stimuli).Read moreRead less
Neural Circuits For Odour-processing In The Rodent Piriform Cortex 'in Vivo'
Funder
National Health and Medical Research Council
Funding Amount
$488,817.00
Summary
We are studying the brain circuits that enable mammals to recognise odours. We will apply puffs of odorants to the nose of an anaesthetised mouse while measuring electrical signals in the odour-processing region of its cerebral cortex. Our work will answer fundamental questions about how the brain interprets sensory inputs in order to build a coherent picture of the world. This is basic research that will, in the longer term, shed light on the disturbances that occur during mental illness.