Understanding how the brain grows and is organised is one of the great challenges of science. This project seeks to identify key regulators of neural progenitors as these are the building blocks from which all brains cells are derived. This knowledge may also identify new avenues through which to manipulate neural progenitor function. This has implications not only for normal brain development but also potential therapies for neural disorders and disease.
The Development Of Glial Cells In The Sympathetic Nervous System
Funder
National Health and Medical Research Council
Funding Amount
$372,025.00
Summary
Nervous system development entails the co-ordinated multiplication of a small number of founder cells to give the millions of cells of the mature nervous system. Each founder generates a many different cell types. Understanding how this is controlled is among the most challenging problems in modern biology. We will show how the development of the two basic cell types (neurons and glia), is controlled in a part of the nervous system that is relatively simple and accessible for manipulation.
The Role Of GRHL-3, A Mammalian Homologue Of Drosophila Grainyhead, In Neural Tube Development
Funder
National Health and Medical Research Council
Funding Amount
$496,500.00
Summary
Spina bifida and anencephaly are two common human congenital malformations that form part of a wide spectrum of mutations known collectively as neural tube defects (NTDs). Patients with the most severe form of spina bifida have a failure of the vertebral column and skin to close over the spinal cord and therefore suffer from limb paralysis and marked bladder and bowel dysfunction. Infants with anencephaly have an open cranial vault and failure of normal brain development and die within the first ....Spina bifida and anencephaly are two common human congenital malformations that form part of a wide spectrum of mutations known collectively as neural tube defects (NTDs). Patients with the most severe form of spina bifida have a failure of the vertebral column and skin to close over the spinal cord and therefore suffer from limb paralysis and marked bladder and bowel dysfunction. Infants with anencephaly have an open cranial vault and failure of normal brain development and die within the first few hours of life. These abnormalities occur frequently (1-1000 live births) and are a direct result of failure of the neural tube to close during embryogenesis. NTDs are influenced by both environmental and genetic factors. The best characterised environmental factor is the dietary supplement folate, which when administered before conception results in a reduction in the incidence of spina bifida. The genetic complexity is evidenced by the array of mouse genetic mutations that give rise to NTDs. One of these mouse mutations, known as Curly tail (ct), has served as the major animal model of human NTDs. This is because the ct mice are resistant to folate administration (like most of the cases of spina bifida currently seen in patients) and because the mice seem to have normal development in virtually all other organ systems. Ironically, the genetic mutation that causes the curly tail phenotype has remained undiscovered for over 50 years. We have now identified the gene mutated in the curly tail mice. This gene is highly conserved in humans suggesting that it will play a similar role in neural tube development in man. The gene, known as GRHL-3, is a descendant of a fly gene critical for development of the nervous system in that organism. The studies we propose here will examine the developmental pathways involved in normal neural tube closure in mice and humans and will impact on our understanding of these devastating congenital malformations.Read moreRead less
MEASURING AND MODELLING VISUAL CORTICAL PLASTICITY
Funder
National Health and Medical Research Council
Funding Amount
$612,693.00
Summary
We are the product of both our genes and our environment. Scientists have already shown that the physical structure of our brain can be changed by our experiences. But how much can it be changed? Our experiments will address this question for a particular case: how far our visual experiences can affect the structure of the part of our brain that processes visual images. This will help us understand the delicate balance between our genes and our environment in shaping who we are.
Neural Crest Stem Cell Therapy For Absence Of Intestinal Nerves In Hirschsprungs Disease
Funder
National Health and Medical Research Council
Funding Amount
$504,377.00
Summary
Hirschsprung's disease is acommon birth defect caused by failure of nerve cells to get into the colon. This results in intractable often fatal constipation. Current treatment is surgical removal of the affected colon soon after birth but often problems persist. These nerves might be rebuilt using nerve stem cells, but not all stem cells have this capacity. And is not known if this can be achieved after birth: This project will define which stem cell populations to use and in what age of bowel.
The Role Of Netrin-DCC In The Development Of The Corpus Callosum
Funder
National Health and Medical Research Council
Funding Amount
$512,065.00
Summary
During embryonic development neurons send out axons that connect to other target neurons within the brain. The proper connectivity of these axons is vital to brain function. The largest axon tract in the brain is called the corpus callosum and connects neurons in the left and right cerebral hemispheres. When the corpus callosum does not form, significant cognitive, motor and sensory deficits occur in patients. This condition, known as agenesis of the corpus callosum (ACC), is associated with ove ....During embryonic development neurons send out axons that connect to other target neurons within the brain. The proper connectivity of these axons is vital to brain function. The largest axon tract in the brain is called the corpus callosum and connects neurons in the left and right cerebral hemispheres. When the corpus callosum does not form, significant cognitive, motor and sensory deficits occur in patients. This condition, known as agenesis of the corpus callosum (ACC), is associated with over 50 different human congenital syndromes. Thus understanding how the genes and molecules involved in the formation of the corpus callosum function in normal development can provide the basis for our understanding of what goes wrong in ACC. In this proposal we will investigate the role of the axon guidance molecule Netrin1, and its receptor DCC, in development of the corpus callosum in both a mouse model and in humans with malformations of the corpus callosum. Although Netrin1-DCC signalling has traditionally been associated with mechanisms of axon guidance, we hypothesize that these molecules may play a different role, specifically in cellular adhesion and ultimately in the fusion of the two cerebral hemispheres, in a manner that allows the corpus callosum to form. A second role for Netrin1-DCC signalling may be in the guidance of these axons once the midline has fused correctly and we investigate this in Aim 2 of the proposal. Finally, we are collaborating with a paediatric neurologist at UCSF, who has identified several mutations in the DCC gene in patients with ACC. In Aim 3 we test whether these mutations disrupt the function of DCC in callosal axon pathfinding. Understanding how these genes function during development of the brain and how their function may be altered in ACC is crucial to providing a proper diagnosis and prognosis for these patients. Ultimately, understanding more about how these genes function could also lead to prevention of these disorders.Read moreRead less
Characterisation Of Neuregulin-2 Function In The Nervous System.
Funder
National Health and Medical Research Council
Funding Amount
$183,250.00
Summary
The Neuregulins (NRG's) are a family of four structurally related growth factors expressed in the developing and adult brain. NRG-1 is essential for life and has been implicated in the development and maintenance of both neurons and glial cells, as well as being essential for normal heart formation. NRG-2 was identified by us and others as being closely related to NRG-1 and, like NRG-1, it is also expressed predominantly in neuronal populations of the brain. One striking feature of NRG-2 express ....The Neuregulins (NRG's) are a family of four structurally related growth factors expressed in the developing and adult brain. NRG-1 is essential for life and has been implicated in the development and maintenance of both neurons and glial cells, as well as being essential for normal heart formation. NRG-2 was identified by us and others as being closely related to NRG-1 and, like NRG-1, it is also expressed predominantly in neuronal populations of the brain. One striking feature of NRG-2 expression in the adult brain is its localisation to regions associated with neurogenesis (renewal of neurons from stem cell precursors). Outside the nervous system Neuregulin-2 can stimulate the proliferation and differentiation of epithelial cells. However, little is known about the activity of Neuregulin-2 in the brain. This grant proposal aims to study the biological functions of Neuregulin-2 in the developing and adult central nervous system. The experimental design is based on characterisation of mice that do not contain the Neuregulin-2 gene. We will also look specifically at the action of Neuregulin-2 on discrete populations of neuronal cells, grown in tissue culture. We expect that these studies will provide valuable insight into the role of NRG-2 in the brain and that they will be the basis for defining the mechanisms by which NRG-2 activity differs to that of the NRG family members. By studying factors that are involved in the development of the nervous system it is hoped that valuable insights will be made regarding repair and regeneration in the adult brain.Read moreRead less