Cell Type Specification In Developing CNS: Functional Analysis Of Sox14
Funder
National Health and Medical Research Council
Funding Amount
$468,055.00
Summary
The central nervous system (CNS) is the most complex organ in the body. The vast majority of nerve cells in the CNS are classified as 'interneurons'. These cells relay sensory information and motor commands within the CNS. Abnormal functioning of interneurons is likely to be the underlying cause of some, if not many, human nervous system diseases. However, very little is known of the precise anatomy and function of interneurons, which genes control their development, and how these functions are ....The central nervous system (CNS) is the most complex organ in the body. The vast majority of nerve cells in the CNS are classified as 'interneurons'. These cells relay sensory information and motor commands within the CNS. Abnormal functioning of interneurons is likely to be the underlying cause of some, if not many, human nervous system diseases. However, very little is known of the precise anatomy and function of interneurons, which genes control their development, and how these functions are maintained in the adult. This has been largely due to a lack of efficient and reliable methods to identify and study interneurons. We have previously discovered that a gene termed Sox14 is active in distinct interneuron groups in the embryonic brain and spinal cord. Sox14 is a member of the Sox gene family, many of which act as genetic switches to control cell and tissue development. We found that Sox14 has been extremely well conserved throughout evolution and is active in similar interneuron groups in a number of animal species. These studies led us to hypothesise that Sox14 controls a critical molecular step in the generation of certain interneurons that may be involved in reflexes, locomotion or motor coordination. In this project, we will investigate both the role of Sox14 in interneuron development and the functions of interneurons in which this gene is active. We will do so by combining modern molecular and genetic techniques with physiological approaches. This project will reveal critical molecular steps in CNS development and determine the functions of a specific group of interneurons. To this end, we will generate mouse strains in which a specific group of interneurons are genetically marked and can be manipulated during development. We envisage that these mice with 'modified brain circuits' will become unique resources for future investigations of selected interneuron types and their functions.Read moreRead less
Cell Death In The Retina: Analysing The Switch That Triggers Dependency On Target-derived Trophic Factors
Funder
National Health and Medical Research Council
Funding Amount
$428,414.00
Summary
Construction of the developing nervous system in the embryo involves the creation of nerve cells and their connections, but also involves loss of a proportion of these cells prior to maturation. We will study this process of cell death and how developing nerve cells switch on their dependency to survival factors. In so doing we will better understand what happens when brain development goes wrong and also devise new ways to protect nerve cells in the injured or degenerate adult nervous system.
Blood-brain Barrier And White Matter Damage In The Immature Rat Brain Following Systemic Inflammation
Funder
National Health and Medical Research Council
Funding Amount
$353,173.00
Summary
Clinical obstetric and paediatric studies have identified an association between intrauterine infection occurring around two thirds of the way through pregnancy, premature birth and a specific form of damage to the brain of the newborn. This damage mainly affects white matter tracts. These tracts are aggregations of nerve fibres that make the connections between different parts of the brain and may result in cerebral palsy or other neurological disorders. The association between maternal infecti ....Clinical obstetric and paediatric studies have identified an association between intrauterine infection occurring around two thirds of the way through pregnancy, premature birth and a specific form of damage to the brain of the newborn. This damage mainly affects white matter tracts. These tracts are aggregations of nerve fibres that make the connections between different parts of the brain and may result in cerebral palsy or other neurological disorders. The association between maternal infection and brain damage, one form of which is cerebral palsy, is well established from clinical epidemiological studies, but the biological mechanism of this link is unknown. The CIs' group has recently shown that the condition can be reproduced in neonatal rats at a stage of brain development in the rat that is equivalent to the critical time in human brain development when infection may be associated with brain damage. The CIs' group has shown that an induced inflammatory state similar to a bacterial infection, results in damage to blood vessels in the white matter and is associated with changes in white matter, as occurs in affected babies. The purpose of this study is to understand the nature of the damage to white matter blood vessels and the mechanisms by which materials in blood, which in the normal brain do not pass from the blood to the brain across the blood-brain barrier, are able to do so via the inflammation damaged blood vessels. The study also aims to show whether it is components of the blood entering the brain via the damaged blood vessels that are responsible for the damage to white matter in the immature brain. The outcome should lead to development of ways to improve clinical care of women who acquire infections during pregnancy.Read moreRead less
Schizophrenia is a group of brain disorders that affects approximately 1 in 100 people. The symptoms can include delusions (false beliefs), hallucinations (e.g., hearing voices), blunted emotions, poor planning ability and reduced motivation. Because these disorders often start in early adulthood, and can be chronic, schizophrenia contributes substantially to the burden of disease across the globe. The causes of schizophrenia are poorly understood, but it is clear that both genetic factors and e ....Schizophrenia is a group of brain disorders that affects approximately 1 in 100 people. The symptoms can include delusions (false beliefs), hallucinations (e.g., hearing voices), blunted emotions, poor planning ability and reduced motivation. Because these disorders often start in early adulthood, and can be chronic, schizophrenia contributes substantially to the burden of disease across the globe. The causes of schizophrenia are poorly understood, but it is clear that both genetic factors and environmental factors can contribute to the risk of developing schizophrenia. As part of an integrated program of research searching for novel environmental risk factors for schizophrenia, this application examines the impact of low prenatal vitamin D on brain development. Vitamin D is a steroid hormone mostly derived from the action of bright sunshine on the skin. Our past research (based on population studies, cell culture studies and animal experiments) have provided tantalizing clues about the impact of low prenatal vitamin D on brain development. This project will explore two important areas. We will explore mechanims by which LOW vitamin D may cause LESS programmed cell death (apoptosis). Programmed cell death is a crucial feature in brain development, and any alteration to the orderly sequence of brain development may leave the person vulnerable to adult-onset brain disorders like schizophrenia. Secondly, we will compare the behaviour and brain markers of adult rats born of mothers depleted of vitamin D versus normal mothers. Finally, we will examine the impact of vitamin D on neural tissue cultures obtained from nasal biopsy. If low prenatal vitamin D is a risk factor for schizophrenia, then it may be possible to reduce the incidence of schizophrenia by providing pregnant women with a safe and cheap vitamin tablet (similar to how folate supplements have reduced the incidence of spina bifida) .Read moreRead less
Molecular Definition Of Neural Pathways In The Embryo And Adult Mouse
Funder
National Health and Medical Research Council
Funding Amount
$401,000.00
Summary
It is our objective to gain insight into the role of the Stem Cell leukaemia (SCL) gene in the central nervous system (CNS). SCL is known to play a crucial role in blood cell development and if aberrantly expressed can lead to T-cell leukemia. Although we do know that SCL is expressed in the brain, its role in the CNS has not been addressed so far and it is of great interest to us to study its potential function in neural development. We have designed a series of experiment in mice to elucidate ....It is our objective to gain insight into the role of the Stem Cell leukaemia (SCL) gene in the central nervous system (CNS). SCL is known to play a crucial role in blood cell development and if aberrantly expressed can lead to T-cell leukemia. Although we do know that SCL is expressed in the brain, its role in the CNS has not been addressed so far and it is of great interest to us to study its potential function in neural development. We have designed a series of experiment in mice to elucidate the expression pattern of SCL in the CNS, to identify the phenotype of neural cells that express SCL in different regions of the mouse brain, and to ablate the SCL gene at different time points during life (during embryonic development, just after birth and during adulthood). These experiments will be performed in conditional transgenic mice that have unique and precisely defined genetic alteration and are generated by us specifically for our research on the SCL-gene. This genetic approach is used to define the neuroanatomical and molecular bases of SCL-function in the brain.Read moreRead less
Intraocular Transplantation And Regeneration Of Retinofugal Pathways In Rodents
Funder
National Health and Medical Research Council
Funding Amount
$370,937.00
Summary
In the adult human brain and spinal cord there is little or no intrinsic capacity for replacement of lost or dying neurons, and there is minimal spontaneous repair of nerve fibre pathways. Thus traumatic injuries, stroke, or loss of neurons due to chronic degenerative disease result in functional impairments that are usually severe and long-lasting. The personal, social and economic costs associated with these neurological problems are enormous. New ways must be found of protecting and-or replen ....In the adult human brain and spinal cord there is little or no intrinsic capacity for replacement of lost or dying neurons, and there is minimal spontaneous repair of nerve fibre pathways. Thus traumatic injuries, stroke, or loss of neurons due to chronic degenerative disease result in functional impairments that are usually severe and long-lasting. The personal, social and economic costs associated with these neurological problems are enormous. New ways must be found of protecting and-or replenishing nerve cells in damaged CNS gray matter, and new methods are also required to help reconstruct fibre tracts after injury. Using the visual system as an experimental model, the aims of the proposed work are to develop novel transplantation and surgical strategies to: (i) Incorporate new cells into retinae that have been selectively depleted of endogenous neurons (ii) Promote the effective regeneration of large numbers of adult retinal axons through prosthetic peripheral nerve bridging grafts and into host CNS distal to the injury. The results obtained from the first series of studies will not only be of direct relevance to the future treatment of human retinal degenerative disorders, but will also increase our overall understanding of how best to ensure the differentiation and stable integration of different types of transplanted cells within the compromised host CNS. The second series of experiments should lead to an entirely new approach to nerve pathway reconstruction, relevant to both brain and spinal cord injuries. The ultimate aim of this experimental work is to improve the management and treatment of human CNS injury and disease, leading to better functional recovery and rehabilitation.Read moreRead less
The Structural Basis Of The Interaction Of Human Relaxins With Their Receptors.
Funder
National Health and Medical Research Council
Funding Amount
$489,000.00
Summary
Human Gene 2 (H2) relaxin is a peptide hormone structurally related to insulin and has numerous biological actions related to its roles during pregnancy. It exerts these primarily by inducing the breakdown of collagen and the formation of new blood vessels while simultaneously stimulating tissue growth and inhibiting cell death. Its functions have led to several potential therapeutic roles for relaxin being explored. These include the treatment of fibrotic disorders and peripheral vascular disea ....Human Gene 2 (H2) relaxin is a peptide hormone structurally related to insulin and has numerous biological actions related to its roles during pregnancy. It exerts these primarily by inducing the breakdown of collagen and the formation of new blood vessels while simultaneously stimulating tissue growth and inhibiting cell death. Its functions have led to several potential therapeutic roles for relaxin being explored. These include the treatment of fibrotic disorders and peripheral vascular disease. H2 relaxin is the principal expression product in vivo and has been shown to exert a wide range of physiological responses beyond those normally associated with pregnancy. We have recently discovered another human - H3 - relaxin that is expressed primarily in the brain which strongly suggests a neuropeptide role. Surprisingly, H2 and 3 relaxins each act via different G-protein coupled receptors. We will perform detailed structure-function studies to determine how these relaxins impart their specific biological actions. Modern chemical synthesis protocols will be used to prepare each of these complex peptides in adequate quantities for detailed secondary and tertiary structural study. Analogues containing modified residues and global domains will be prepared and assayed for characteristic relaxin agonist and antagonist activity. Sophisticated biomolecular interaction analyses will be used to identify differences in receptor binding regions for the two relaxins. The results, together with those obtained by three-dimensional structural analysis using NMR spectroscopy, will allow us to ultimately define the key features of the H2 and 3 hormones that are responsible for selective receptor binding and specific relaxin activity. We will then be able to design smaller, more stable, orally active relaxin mimetics. Such compounds will have great potential for therapeutic application in the treatment of fibrosis or as biological and pharmacological probes of relaxin action.Read moreRead less