Cortical Spreading Depressions: Effects On Intracellular Ca2+ Concentration And Mechanisms Of Propagation
Funder
National Health and Medical Research Council
Funding Amount
$185,604.00
Summary
Human neuropathologies such as migraine, stroke, focal epilepsy and head injury all appear to involve an event called cortical spreading depression (CSD). This is characterised by a transient loss of excitability of cells that slowly spreads from a site of initiation out across the cortical surface. In normal brain tissue CSDs do not kill cells but in tissue with less than optimal energy supply CSDs do kill cells. This project is designed to understand the mechanisms contributing to CSD-induced ....Human neuropathologies such as migraine, stroke, focal epilepsy and head injury all appear to involve an event called cortical spreading depression (CSD). This is characterised by a transient loss of excitability of cells that slowly spreads from a site of initiation out across the cortical surface. In normal brain tissue CSDs do not kill cells but in tissue with less than optimal energy supply CSDs do kill cells. This project is designed to understand the mechanisms contributing to CSD-induced cell death. It is widely accepted that a high intracellular concentration of calcium ions is lethal to a cell. Thus, the proposed experiments are expected to show that a single episode of CSD in normal brain tissue induces only small changes in the intracellular calcium ion concentration but if repeated episodes of CSD occur, and if they take place in tissue with a compromised energy supply, then the calcium concentration rises to detrimental levels. Little is known about the mechanisms which underlie the propagation of CSD and therefore experiments will also be undertaken to investigate whether release of a messenger into the extracellular space is important or if there is a role for release of calcium from intracellular stores.Read 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.
Word finding difficulties are the most common type of language impairment following stroke, causing considerable frustration and distress for the individual and their family and friends. Current available language therapies are not always effective. This project aims to (1) develop and test new language treatments for stroke sufferers, and (2) find out how language therapy works in the brain. Outcomes will include improved treatment of communication disorders after stroke.