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
The mammalian cerebral cortex is an area of the brain responsible for all higher order cognitive processes. I investigate how connections from between the two cerebral hemispheres during embryonic and foetal development, thus enabling the brain to coordinate information from the two sides of the body. Malformations of these connections cause mental retardation and sensory and motor deficits. I want to understand how these brain defects occur and how best to treat them.
Associate Professor Bourne’s research will involve learning how the infant brain has an enhanced capacity to repair its own neocortex following an injury and to translate these findings into the development of brain regenerative therapies.
Targeting Of Callosal Axons To Duplicate Cortical Areas In The Contralateral Hemisphere
Funder
National Health and Medical Research Council
Funding Amount
$600,785.00
Summary
The two sides of the brain communicate via a large fibre tract called the corpus callosum. This proposal investigates how the corpus callosum is formed during embryonic and postnatal development. Specifically, we investigate how the axons that make up the corpus callosum are able to locate their precise target in the contralateral hemisphere so that the brain circuit they form will be functional. We have developed a new mouse model to discover the fundamental mechanisms regulating how the brain ....The two sides of the brain communicate via a large fibre tract called the corpus callosum. This proposal investigates how the corpus callosum is formed during embryonic and postnatal development. Specifically, we investigate how the axons that make up the corpus callosum are able to locate their precise target in the contralateral hemisphere so that the brain circuit they form will be functional. We have developed a new mouse model to discover the fundamental mechanisms regulating how the brain is wired in order to function correctly.Read moreRead less
Guidance Mechanisms Regulating The Development Of Axonal Projections From The Cingulate Cortex.
Funder
National Health and Medical Research Council
Funding Amount
$484,236.00
Summary
The corpus callosum is the largest fibre tract in the brain and connects neurons in the left and right cerebral hemispheres. A subpopulation of callosal axons arise from neurons in the cingulate cortex and are the first to cross the midline. Defects in activation or wiring of the cingulate cortex are strongly implicated in acute pain, schizophrenia and bipolar disorder. This proposal investigates how the commissural projections of the cingulate cortex become wired up during development.
Cellular And Molecular Regulation Of Interhemispheric Fusion
Funder
National Health and Medical Research Council
Funding Amount
$449,489.00
Summary
In the developing brain, the two cerebral hemispheres undergo interhemispheric fusion to allow commissural fibres to cross the midline. Lack of interhemispheric fusion results in agenesis of the corpus callosum and may manifest as an interhemispheric cyst in acallosal patients. This project will investigate the cellular and molecular mechanisms that regulate interhemispheric fusion, including removal of the leptomeninges, astroglial differentiation and the formation of adherens junctions at the ....In the developing brain, the two cerebral hemispheres undergo interhemispheric fusion to allow commissural fibres to cross the midline. Lack of interhemispheric fusion results in agenesis of the corpus callosum and may manifest as an interhemispheric cyst in acallosal patients. This project will investigate the cellular and molecular mechanisms that regulate interhemispheric fusion, including removal of the leptomeninges, astroglial differentiation and the formation of adherens junctions at the interhemispheric fissure to mediate fusion.Read moreRead less
Molecular And Activity Dependent Mechanisms Regulating The Targeting Of Corpus Callosum Axons In The Contralateral Hemisphere.
Funder
National Health and Medical Research Council
Funding Amount
$413,266.00
Summary
The brain is made up of circuits of neurons that process specific information. For example, the somatosensory cortex receives and sends connections to other somatosensory areas, including the contralateral cortex, but how these systems are wired up is not known. We will investigate whether information about the size and position of the cortical areas and activity-matching of the somatosensory information received by each hemisphere are used to guide callosal axons to their targets.
The Modulation Of Neuronal Activity By Inter-cortical Sensory Input
Funder
National Health and Medical Research Council
Funding Amount
$638,771.00
Summary
For any given behaviour, the brain must merge information from all different sensory systems to generate a coherent representation of the external world. How this is achieved is largely unknown and is the basis of this research proposal. Here, using cutting edge recording techniques, the activity of brain cells within the cortex will be measured during the activation of multiple sensory systems. This research will provide insight into therapeutic approaches to local brain damage.
Sensory Cortex Processing Changes Underlying Brain And Behaviour Deficits Caused By Traumatic Brain Injury
Funder
National Health and Medical Research Council
Funding Amount
$576,795.00
Summary
Traumatic brain injury (TBI) from physical head trauma causes behavior and cognitive deficits. The burden for victims, families and the community is enormous: total life-time expenses in moderate-to-severe TBI are estimated to be $8.6 billion in Australia. We aim to elucidate whether changes in how the brain processes sensory information could underlie TBI-induced deficits in complex behaviour and whether these changes will be ameliorated by the three currently-most-promising treatments for TBI.