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
Cellular Mechanisms Controlling Neural Crest Cell Migration Along The Developing Gut
Funder
National Health and Medical Research Council
Funding Amount
$368,895.00
Summary
Within the wall of the gut, there are a large number of neurons, probably more than are in the spinal cord. These enteric neurons play an essential role in controlling a number of gut functions including peristalsis (the propulsion of contents along the gut). Most of the neurons in the gut, including those in the large intestine, arise from precursors that emigrate from the hindbrain, and then migrate into and along the gastrointestinal tract during development. The colonization of the gut by ne ....Within the wall of the gut, there are a large number of neurons, probably more than are in the spinal cord. These enteric neurons play an essential role in controlling a number of gut functions including peristalsis (the propulsion of contents along the gut). Most of the neurons in the gut, including those in the large intestine, arise from precursors that emigrate from the hindbrain, and then migrate into and along the gastrointestinal tract during development. The colonization of the gut by neuron precursors takes 5 days in mice and 6 weeks in humans. Studies of the mechanisms controlling the migration of neuron precursors along the gut have provided fundamental information about cell migration in general. Genetic studies in humans and mice have identified some of the genes that are necessary for the migration of neuron precursors along the gastrointestinal tract, but for some of the key genes, their precise role is unknown. We have recently developed a method for imaging living neuron precursors migrating through explants of embryonic mouse gut. In the current proposal we will meld imaging and genetic studies to understand how mutations in particular genes lead to migration defects. In particular, how do particular mutations affect the migratory behaviour of enteric neural precursors? We have also previously shown that neuron precursors migrate along the gut in close association with axons. We will examine the nature of these interactions - in particular, who is following whom, and what happens when cell migration and axon growth are uncoupled? These studies, which will investigate a number of critical aspects of the migration of neural precursors into and along the developing gut, are central to understanding how the enteric nervous system is established along the gastrointestinal tract.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.
The Role Of Microglia In Early Diabetic Retinopathy
Funder
National Health and Medical Research Council
Funding Amount
$665,582.00
Summary
Diabetic retinopathy is one of the most feared complications of diabetes. This project will examine the role that retinal immune cells called microglia have in causing early changes in the vasculature. We will examine whether diabetes changes the way neurons communicate with blood vessels, opening up a possible treatment target that could prevent the progression to more advanced disease.
Axon Degeneration And Axon Protection In CNS Disease And Injury
Funder
National Health and Medical Research Council
Funding Amount
$389,120.00
Summary
One of the major reasons for the clinical symptoms of neurological diseases such as Alzheimer’s disease and Motor Neuron Disease is the loss of connections between the nerve cells. Nerve cells are connected by specialized processes called axons. In disease these processes can breakdown. This project specifically looks at how axons break down in disease and tests therapeutic strategies to protect them.
The Role Of Excitotoxicity In Mediating Distal Axonal Degneration In ALS
Funder
National Health and Medical Research Council
Funding Amount
$392,952.00
Summary
Amyotrophic lateral sclerosis (ALS), the major cause of motor neuron disease, is a devastating diseasse for which there is no cure. There have been significant advances in understanding the pathology of ALS yet we still don’t know what causes the dying back of spinal motor neurons. We have new evidence that suggests that ALS may, in part, be caused by excitotoxcity - or over stimulation - of neurons in the spinal cord. We will follow this lead using a range of cutting edge experimental models.
BRAIN-MEND: Biological Resource Analysis To Identify New Mechanisms And Phenotypes In Neurodegenerative Diseases
Funder
National Health and Medical Research Council
Funding Amount
$861,866.00
Summary
Current classification of neurodegenerative diseases (ND) based on clinical phenotypes does not take into account underlying disease heterogeneity, or overlapping disease mechanisms, thus hindering therapy development. Segregation and re-classification of ND phenotypes is urgently needed. BRAIN-MEND will reclassify existing phenotypic classifications using using pathway and network analyses within and across complex NDs.
Frontotemporal Dementia And Motor Neurodegenerative Syndromes
Funder
National Health and Medical Research Council
Funding Amount
$11,583,107.00
Summary
Frontotemporal degeneration of the brain is a leading cause of morbidity. It is a pathologically heterogeneous group of rapidly-progressive disorders with behavioural, language and motor deficits. This research program brings together international leaders in clinical, pathological and biological research of these syndromes, aiming to fast track new knowledge and innovations to develop the necessary tools and therapies to effectively diagnose, manage and treat these disorders.
The Mechanism Of HSV-1 Transport In Sensory Axons And Its Unique Assembly At The Axon Terminus
Funder
National Health and Medical Research Council
Funding Amount
$670,284.00
Summary
Herpes simplex viruses 1 and 2 cause common diseases such as genital herpes and, occasionally, neonatal deaths and encephalitis and predisposes to HIV infection. New antiviral strategies are required for resistant viruses for control. These aims will be facilitated by understanding how HSV is transported down nerves and across into skin. In this study, we will define how a key viral protein plays a major role in assembly of the virus at the tip of the nerve before it enters skin.
Frontotemporal Dementia And Motor Neurodegenerative Syndromes
Funder
National Health and Medical Research Council
Funding Amount
$17,069,580.00
Summary
Frontotemporal degeneration of the brain is a leading cause of morbidity due to a pathologically heterogeneous, rapidly-progressive group of disorders with behavioural, language and motor deficits. Our internationally recognized team will continue to develop the necessary tools and therapies to effectively diagnose, manage and treat these disorders. Our focus in this program is to understand the unusual genetics underpinning these disorders, and to fast track any potential treatments.