Mechanisms Of Cortical Plasticity And Facilitation Of Functional Recovery Following Stroke
Funder
National Health and Medical Research Council
Funding Amount
$427,500.00
Summary
Specific regions of the human brain have been shown to reorganise following damage to the brain or peripheral nerves. This reorganisation is seen in both young and older subjects and is thought to be useful in helping to restore function. For example, following a stroke a patient may, initially, be unable to move one arm. However, in the following weeks and months some function may return. A number of mechanisms may be responsible for this improvement. However, it is likely that at least some of ....Specific regions of the human brain have been shown to reorganise following damage to the brain or peripheral nerves. This reorganisation is seen in both young and older subjects and is thought to be useful in helping to restore function. For example, following a stroke a patient may, initially, be unable to move one arm. However, in the following weeks and months some function may return. A number of mechanisms may be responsible for this improvement. However, it is likely that at least some of the improvement is due to reorganisation within the sensorimotor cortex. Following the stroke the control of the arm may be taken over by adjacent undamaged regions of the brain. This reorganisation allows impressive functional recoveries to occur. We have preliminary evidence to support the idea that patterns of activity generated in peripheral nerves (afferent input) following stroke may be crucial for the development of the organisational changes seen within the brain. We have shown that by applying specific patterns of sensory input we are able to produce organisational changes within the motor cortex of control subjects. Also, we have been able to induce similar changes in stroke patients. These changes have been accompanied by improvements in motor control. These novel and exciting findings support our hypothesis that by applying certain patterns of afferent input to patients following stroke we will be able to facilitate functional recovery by maximising reoganisation within the cortex. In the present project we will establish the organisation patterns in the brain of stroke patients and contrast the findings with control subjects. Secondly we will investigate the potential for facilitating recovery of stroke patients by the application of specific patterns of afferent input. These novel experiments may lead to important therapeutic developments that will benefit the large population of patients suffering strokes.Read moreRead less
Bilateral Movement Therapy In Post-stroke Hemiparesis
Funder
National Health and Medical Research Council
Funding Amount
$265,993.00
Summary
Stroke is the leading cause of long-term disability in adults in Australia, accounting for approximately 25% of all disability. A common motor disability resulting from stroke is hemiparesis, weakness or paralysis on one side of the body. This disability severely impairs an individual's capacity to perform activities of daily living, making them dependent on relatives and health professionals for daily care. By developing effective interventions to treat stroke-induced hemiparesis both the disab ....Stroke is the leading cause of long-term disability in adults in Australia, accounting for approximately 25% of all disability. A common motor disability resulting from stroke is hemiparesis, weakness or paralysis on one side of the body. This disability severely impairs an individual's capacity to perform activities of daily living, making them dependent on relatives and health professionals for daily care. By developing effective interventions to treat stroke-induced hemiparesis both the disability caused by stroke and the associated personal and financial costs will be lessened. A number of interventions focusing on the affected side (unilateral), including active movements and muscle stimulation are being investigated as possible treatments for stroke-induced hemiparesis. Recent evidence suggests that involving the unaffected side simultaneously (bilateral therapies) could be effective, and may provide addtional benefits over unilateral therapies. The aim of this research is to thoroughly examine the effectiveness of bilateral therapies by incorporating them into established interventions. The findings from these studies will aid in the development and refinement of movement therapies aimed at promoting recovery from stroke-induced hemiparesis.Read moreRead less
The research described in this Project Grant application should help to us understand how our brains make memories. Our brains contain billions of interconnected nerve cells forming unimaginable numbers of possible networks. Previous research indicates that repetitive activation of individual networks can lead to changes in the strength of connections between nerve cells. These changes in connection strength are thought to underlie learning and memory. The experiments described in this proposal ....The research described in this Project Grant application should help to us understand how our brains make memories. Our brains contain billions of interconnected nerve cells forming unimaginable numbers of possible networks. Previous research indicates that repetitive activation of individual networks can lead to changes in the strength of connections between nerve cells. These changes in connection strength are thought to underlie learning and memory. The experiments described in this proposal will address the mechanisms underlying changes in the strength of connections between nerve cells. As most of the inputs nerve cells receive from other nerve cells are made onto their dendrites (small branching processes that extend from the cell body), the main objective is to investigate the interactions at the dendritic level responsible for changes in connection strength. The results of this work will raise our understanding of how memories are formed, which will be essential if we are to understand the cellular processes disrupted during memory dysfunction in neurological disorders such as dementia.Read moreRead less
VISUAL TESTS TO INVESTIGATE ALTERED CORTICAL FUNCTION IN MIGRAINE
Funder
National Health and Medical Research Council
Funding Amount
$293,062.00
Summary
Migraine is a very common and disabling neurological condition that often involves visual symptoms. This project will study vision in people who experience migraine, to determine whether brain function is altered by a migraine event or in between migraines. Understanding the visual consequences of migraine provides insight to the neural processes causing migraine, and also those underlying less common but more sinister outcomes of migraine such as stroke and peripheral vision loss.
The Role Of Afferent Input In The Development Of Focal Task Specific Dystonia
Funder
National Health and Medical Research Council
Funding Amount
$213,000.00
Summary
The term dystonia is used to describe a condition that is characterised by abnormal muscle activation patterns. This leads to impaired control of voluntary movements. Depending upon which part of the body is affected, dystonia may be classified as generalised (affecting two or more body segments), hemi (involving one side), segmental (involving adjacent body parts or a segment), or focal (affecting one part of the body). Many of the focal dystonias are also task specific and the aim of this prop ....The term dystonia is used to describe a condition that is characterised by abnormal muscle activation patterns. This leads to impaired control of voluntary movements. Depending upon which part of the body is affected, dystonia may be classified as generalised (affecting two or more body segments), hemi (involving one side), segmental (involving adjacent body parts or a segment), or focal (affecting one part of the body). Many of the focal dystonias are also task specific and the aim of this proposal is to investigate these task-specific focal dystonias. Task-specific focal dystonia is common in the community and causes considerable suffering and loss of productivity. For example, writer's cramp (a common form of task specific focal dystonia) is probably the commonest cause of writing difficulty in patients in whom this is the sole complaint. No treatment regimen has been shown to be effective in alleviating it's often debilitating symptoms. The aim of these studies is to further define the pathophysiological changes seen in task-specific dystonia and investigate the mechanisms responsible for their generation. Using the techniques of transcranial magnetic stimulation and peripheral nerve stimulation we will investigate the organisation of the motor cortex in this condition and examine the influence of afferent input on intrinsic cortical circuitry. We hypothesise that the motor regions of the brain are more sensitive to the particular repeated patterns of sensory information reaching the brain during repetitive movement and this results in abnormal alterations in organisation that may be responsible for the symptoms of dystonia. Additionally, we predict that it may be possible to reverse these organisational changes by applying novel patterns of nerve stimulationRead moreRead less
Plasticity Of Sensorimotor Representations In Adult Primate Cortex
Funder
National Health and Medical Research Council
Funding Amount
$554,656.00
Summary
Cells in some regions of the brain, collectively known as the sensorimotor cortex, control our capacity to purposefully move the arms and hands. Damage to these regions in adults causes severe deficits. However, rehabilitative training can restore some control over the muscles. To understand how the brain circuits change to compensate for injury, and what effect rehabilitation may have on these changes, I will study cellular alterations in the movement control pathways in the cerebral cortex.
Representation Of Spatial Coordinate Systems Within Posterior Parietal Cortex And Hippocampus
Funder
National Health and Medical Research Council
Funding Amount
$43,759.00
Summary
To accurately reach for an object or walk from one room to another, our brains need to be able to locate objects around us and detect obstacles in our path. Our amazing ability to make an accurate eye movement directly towards an object such as a cup of tea and move our hand smoothly and directly to the cup is something we all take for granted. However, this ability requires enormous computational complexity which our brains have evolved to handle with ease. We plan to determine the parts of the ....To accurately reach for an object or walk from one room to another, our brains need to be able to locate objects around us and detect obstacles in our path. Our amazing ability to make an accurate eye movement directly towards an object such as a cup of tea and move our hand smoothly and directly to the cup is something we all take for granted. However, this ability requires enormous computational complexity which our brains have evolved to handle with ease. We plan to determine the parts of the brain that perform these computations by using a relatively new technique called functional magnetic resonance imaging or fMRI. This is a non-invasive technique that requires a person to lie in an MRI scanner and perform simple eye movement tasks while the scanner takes images of the brain. With this technology we are able to determine which regions of the brain are most active during the performance of each task, thereby giving us an insight into how the brain works. An area of the brain called the parietal lobe is thought to be involved in the localization of objects, such as reaching for a cup of tea. We will study this area using fMRI to determine how a map of space is represented within the parietal lobe. This region of the brain communicates with another region, the hippocampus which is thought to be involved in navigation, such as walking about the house or driving in the city. Functional MRI will be used to study the hippocampus of our subjects while they perform simple navigational tasks through a maze which is simulated on a computer screen. This will reveal the role hippocampus plays in navigation and the relationship between the parietal lobe and hippocampus. We hope that the greater understanding of hippocampus that will arise from this study will enable us to devise a robust method for imaging hippocampal function with fMRI. We expect that these techniques will aid in the diagnosis of hippocampal abnormalities in patients with temporal lobe epilepsy.Read moreRead less
Molecular And Cellular Changes Following A Cortical Injury: What Role Do They Play In Regeneration?
Funder
National Health and Medical Research Council
Funding Amount
$499,625.00
Summary
Damage to the visual areas of the brain is common after, for example stroke, neurotrauma or hypoxia. The injury often manifests in the form of a scar caused by a specific type of brain cell (astrocyte). This scar acts as a barrier to the cells which transmit information (neurones), preventing re-establishment of connectivity, thus functional recovery. We will see if we can reduce this scar and enhance re-connectivity after injury by blocking some of the molecules that brain cells express.