Molecular And Cellular Mechanisms Of Vertebrate Brain Development
Funder
National Health and Medical Research Council
Funding Amount
$586,428.00
Summary
The essential steps in forming a normal functioning brain occur during life as an embryo. If these processes go haywire, there can be serious repercussions for life after birth. This project seeks to understand how the brain forms during embryonic stages so that better treatments and procedures can be developed to deal with developmental problems.
Discovering Molecules And Mechanisms Regulating Dendrite Formation
Funder
National Health and Medical Research Council
Funding Amount
$517,989.00
Summary
Dendrites are neuronal projections necessary to receive stimuli from other neurons or the external environment. Abnormalities in dendrite development associate with mental retardation and other human conditions such as Down syndrome, Rett syndrome and Fragile-X syndrome. The studies presented in this proposal, using the powerful genetic and molecular tools available for the nematode C. elegans, will provide new insight into the cellular and molecular mechanisms regulating dendrite development.
Role Of Chemokines And Interferons In Neural Progenitor Cell Function
Funder
National Health and Medical Research Council
Funding Amount
$521,178.00
Summary
Regeneration of the central nervous system following disease or injury is extremely limited and frequently results in substantial impairment. A potential therapy to replace damaged or killed nervous system cells is the use of neural stem cells. Neural stem cells are present in the central nervous system and frequently attempt, but fail to repair nervous system damage. This project aims to examine factors that regulate neural stem cell function including factors that may regulate their ability to ....Regeneration of the central nervous system following disease or injury is extremely limited and frequently results in substantial impairment. A potential therapy to replace damaged or killed nervous system cells is the use of neural stem cells. Neural stem cells are present in the central nervous system and frequently attempt, but fail to repair nervous system damage. This project aims to examine factors that regulate neural stem cell function including factors that may regulate their ability to migrate or become appropriate neural cell types. Of particular interest are factors known as chemokines that regulate cell migration as well as have a variety of other effects. In addition, interferons, which are inflammatory molecules present in the damaged nervous system and that we have shown affect neural stem cell function, may interact with chemokines and will also be examined. In addition to examining the effects of these factors on neural stem cells, the signalling pathways they use in these cells will also be determined.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 Central And Peripheral Synaptic Activity In The Developmental Death Of Motoneurons.
Funder
National Health and Medical Research Council
Funding Amount
$463,145.00
Summary
Information processing in the nervous system relies on the effective communication between neurons and their target cells which make up our neuronal circuitry. At the centre of all this is the synapse, the specialized contact between a neuron and its target cell, be it another neuron in the brain or a target organ such as skeletal muscle. Our primary goal is to determine how the formation of synaptic connections during development regulates neuronal survival. In this proposal we have focussed on ....Information processing in the nervous system relies on the effective communication between neurons and their target cells which make up our neuronal circuitry. At the centre of all this is the synapse, the specialized contact between a neuron and its target cell, be it another neuron in the brain or a target organ such as skeletal muscle. Our primary goal is to determine how the formation of synaptic connections during development regulates neuronal survival. In this proposal we have focussed on the neuromotor system as it is a well characterised part of the nervous system. During development, 50% of motoneurons die at a time when they are making contact with skeletal muscle, and when contacts onto motoneurons by other neurons are being established. We believe that the formation of effective synaptic contacts onto motoneurons, as well as connections by motoneurons onto muscle are the key regulators of motoneuron survival. We are in a position to be able to address what regulates motoneuron death; as we have a number of mice which lack key molecules needed for the formation of specialisations that allow neuronal contacts to be made between motor neurons and their muscle, and with other neurons within the spinal cord. By examining the function of motoneurons, counting them and screening for molecular changes in these mice, we will be able to dissect out the mechanism of how a motoneurons' fate is determined during developmental motoneuron death. This research could help in developing strategies aimed at improving neuronal connections to improve neuronal viability. Our research will have important implications for our understanding about the basis of adult neuro-degenerative diseases, such as motor neuron disease and Alzheimer's, which are in part characterised by a molecular breakdown in neuronal connections that ultimately result in neuronal death.Read moreRead less
Migration And Differentiation Of Enteric Neuron Precursors
Funder
National Health and Medical Research Council
Funding Amount
$385,116.00
Summary
There are many millions of nerve cells within the wall of the intestine, and they control many intestinal functions, including motility. During development, these nerve cells arise from cells which migrate away from the developing brain and first enter the stomach. The migratory cells are called neural crest cells. After entering the stomach, neural crest cells migrate within the wall of the gastrointestinal tract, until they reach the far (anal) end. In embryonic mice, this colonisation of the ....There are many millions of nerve cells within the wall of the intestine, and they control many intestinal functions, including motility. During development, these nerve cells arise from cells which migrate away from the developing brain and first enter the stomach. The migratory cells are called neural crest cells. After entering the stomach, neural crest cells migrate within the wall of the gastrointestinal tract, until they reach the far (anal) end. In embryonic mice, this colonisation of the entire small and large intestines by neural crest cells takes over 4 days, and in humans the process probably takes at least one week. It is essential that the neural crest cells colonise the entire gastrointestinal tract, since regions of intestine lacking neural crest cells (and hence nerve cells) cannot function and intestinal contents build up in front of the region lacking nerve cells. This condition is found in some babies (Hirschsprung's disease), and it can only be treated by surgically removing the region lacking nerve cells. It is therefore essential that migratory neural crest cells colonise the entire gastrointestinal tract. Currently, little is known about the mechanisms controlling the migration of neural crest cells, and whether a) particular molecules within the gut wall are important for migration, and-or b) the migratory behaviour of the neural crest cells is regulated mostly by the neural crest cells themselves. In this study we will take time-lapse images of neural crest cells migrating through the gut of embryonic mice to identify the factors that are important for the migration. After the neural crest cells have colonised the entire intestine, they develop into different types of nerve cells. We will also examine some of the factors affecting the development of different types of nerve cells.Read moreRead less
Role Of The Hypothalamus, Oxidative Stress And Angiotensin In Chronic Stress
Funder
National Health and Medical Research Council
Funding Amount
$535,333.00
Summary
Stress can trigger life threatening cardiovascular events and its impact is much greater when blood pressure is raised. We seek to determine which chemical type of brain neuron and which region is responsible for amplifying the responses to repeated stress in an animal model that closely resembles the human form of the disease. We will focus specifically on the hypothalamus which controls the sympathetic nervous system.