The Molecular Basis For Target Selection In The Central Nervous System By Sensory Axons
Funder
National Health and Medical Research Council
Funding Amount
$251,325.00
Summary
The normal function of the brain depends upon the specific connections that nerve cells make with each other. These connections are set up in the developing embryo when nerve cells send out long processes - axons - which grow towards their synaptic targets. How axons select their correct targets from amongst the millions of alternatives in the developing brain is unknown. A better understanding of this problem will help us develop therapies to assist regenerating axons re-establish correct conne ....The normal function of the brain depends upon the specific connections that nerve cells make with each other. These connections are set up in the developing embryo when nerve cells send out long processes - axons - which grow towards their synaptic targets. How axons select their correct targets from amongst the millions of alternatives in the developing brain is unknown. A better understanding of this problem will help us develop therapies to assist regenerating axons re-establish correct connections following injury to the brain or spinal cord. We propose to use a simple model system, the embryo of the fruitfly Drosophila, to find molecules that are involved in this process of neuron target recognition - ' axon targeting' molecules - and to study how they work. Drosophila can be genetically manipulated in ways not possible in higher animals. Furthermore the simplicity of its nervous system means that we can determine the connections of individual nerve cells with a high degree of precision. In the first part of our project, we will examine Drosophila embryos that carry mutations in genes suspected to code for targeting molecules. We will stain individual sensory nerve cells in these embryos with dyes to reveal the anatomy of their axons in the brain. If sensory axons terminate abnormally in the brain of a given mutant, the affected gene is likely to code for an axon targeting molecule. In the second part of the study, we will investigate the functions of candidate axon targeting molecules using two approaches. Firstly, we will seek to determine whether the molecule acts in the sensory axons or in their target cells. Secondly, we will use time-lapse microscopy to study how the homing behaviour of the sensory axons is affected in mutant embryos. The results of these studies will lead us closer to an answer to the question: How do axons recognise their specific target cells in the brain?Read moreRead less
The Role Of Cell Adhesion Molecules In Regulation Of Axon Advance
Funder
National Health and Medical Research Council
Funding Amount
$426,006.00
Summary
All cells contain on their surface a class of molecules, cell adhesion molecules, that enable them to adhere to other cells in tissues. Cell adhesion molecules have long been known to be involved in the guidance of axons to their targets during development. However the molecular mechanisms by which these molecules act are largely unknown. We propose to use the powerful genetic tools available in the fruitfly to dissect the mechanisms by which two cell adhesion molecules promote axon growth.
Unravelling The Molecular Basis Of Amyotrophic Lateral Sclerosis
Funder
National Health and Medical Research Council
Funding Amount
$342,325.00
Summary
The only known causes of ALS are gene mutations. State-of-the-art technologies will be used to find genetic causes of ALS to add to existing diagnostic testing and facilitate investigation into disease mechanism. ALS patients experience different disease courses, with variable age of onset, progression and duration of disease even among those with identical gene mutations. We will examine a well-characterised ALS patient cohort with differing disease manifestations to identify disease modifiers.
One Australian dies of Motor Neuron Disease (MND) every day. MND is likely to be due to a genetic susceptibility to an environmental agent such as a toxin or a virus. Recent advances in gene therapy have emphasised the urgent need to find the gene abnormalities in MND. We propose to set up an Australia-wide DNA Bank for MND to allow researchers to look for genetic abnormalities and environmental influences in this disease.
Investigation Of Dysfunction Of OPRS1, A Novel Gene Implicated In Neurodegeneration
Funder
National Health and Medical Research Council
Funding Amount
$535,471.00
Summary
A new gene has recently been discovered to play an important role in various brain and nerve degeneration disorders, including frontotemporal dementia and motor neuron disease. The aim of this project is to discover what biological processes are involved when this gene malfunctions, as this will provide knowledge important for development of new treatments for the many people worldwide affected with these disorders.
Investigation Into The Roles Of A Novel Vertebrate Gene, S52, In CNS Development And Pathogenesis
Funder
National Health and Medical Research Council
Funding Amount
$272,389.00
Summary
Developmentally regulated genes when mutated or deleted can cause a variety of diseases including neurological diseases in humans. It is therefore important to understand the fundamental molecular genetics of development. We have discovered a novel human gene, termed S52, and its equivalent gene in the mouse. The predicted protein derived from these genes would indicate that S52 protein may interact with other proteins, possibly nerve growth factors, in the body to regulate normal development an ....Developmentally regulated genes when mutated or deleted can cause a variety of diseases including neurological diseases in humans. It is therefore important to understand the fundamental molecular genetics of development. We have discovered a novel human gene, termed S52, and its equivalent gene in the mouse. The predicted protein derived from these genes would indicate that S52 protein may interact with other proteins, possibly nerve growth factors, in the body to regulate normal development and possibly facilitate the survival of nerve cells in embryos. Strikingly, the worm C. elegans, an evoluationary very distant animal, also has a very similar gene to human. The fact that the protein has been so conserved throughout evolution supports the idea that S52 function is important in development. S52 mRNA is expressed in the developing brain, particularly in a special group of cells called the floor plate. Floor plate is a tissue that has ability to organize the patterning and differentiation of cells within the developing brain. S52 is also expressed in motor neurons in early stages of development and later in a subset of dorsal spinal cord neurons. We have mapped S52 to the short arm of human chromosome 2 (2p15-22). This region of chromosome 2 is linked to several human genetic diseases with neurological defects. Based on our preliminary data, we think S52 is not only important for normal brain development but may be mutated in a human neurological disease called Spastic Paraplegia Type 4 (SPG4) which is characterized by a degeneration of nerve cells in the spinal cord. The aim of this project is to further our understanding of the function of this gene and investigate its role in disease. This knowledge will contribute to an overall increase in our understanding of the molecular basis of brain development and neurological disease in humans.Read moreRead less
Biological Characterisation Of The Opiod Receptor Sigma 1 Gene In The Frontotemporal Dementia And Motor Neuron Disease
Funder
National Health and Medical Research Council
Funding Amount
$480,211.00
Summary
Frontotemporal dementia (FTD) and motor neuron disease (MND) are the two common causes of dementia and neurodegeneration. We have identified a new genes that causes familial FTD and MND in pedigrees affected with dementia and-or MND.This project will study the expression and function of this new FTD-MND gene to determine its role in the aetiology and pathology of this complex of neurodegenerative disorders.