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
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
NPY Suppresses Seizures And Modulates Thalamocortical Activity In Animal Models Of Generalized Epilepsy
Funder
National Health and Medical Research Council
Funding Amount
$386,020.00
Summary
Epilepsy is the most common serious chronic neurological disease in the community, affecting up to 3% of the population in a lifetime and 0.5-1% at any one time. Absence epilepsy is one of the most common types of epilepsy, most frequently seen in childhood and teenage years that may persist into adulthood. Anti-epileptic drugs are effective in controlling absence seizures in most patients, however there is an important group (20-40%) of patients in whom the absence seizures remain uncontrolled ....Epilepsy is the most common serious chronic neurological disease in the community, affecting up to 3% of the population in a lifetime and 0.5-1% at any one time. Absence epilepsy is one of the most common types of epilepsy, most frequently seen in childhood and teenage years that may persist into adulthood. Anti-epileptic drugs are effective in controlling absence seizures in most patients, however there is an important group (20-40%) of patients in whom the absence seizures remain uncontrolled with current medications. Recently there has been considerable interest in the role that chemical in the brain, such as neuropeptide Y (NPY), may play in epilepsy. The research proposed will examine the role of NPY in several animal models of absence epilepsy. We have recently shown that NPY suppresses absence seizures in a rat genetic model of generalised epilepsy, and that this appears to be mediated by Y2 receptors. This work will build on these novel findings, and determine the localisation of the effect within the brain, and the underlying mechanism. We will check NPY effects across several models in different species, a genetic rat model with spontaneous seizures, and in mice treated with a chemical to induce seizures. This will determine its broad applicability. We will also determine the effects of removal of NPY or NPY receptors on the effects of NPY on seizure expression. Finally, brain recording techniques will be applied to determine the mechanism and site within the brain underlying the protective actions of NPY. The project has the potential to provide novel insights into the role of NPY in the expression and modulation of absence seizures. NPY related mechanisms might represent targets for the development of a new class of therapeutic agents for the treatment of absence epilepsy. Targets that are identified as being important in the expression of absence seizures may also prove to be relevant in other types of generalised epilepsy syndromes.Read moreRead less
A Structural Investigation Into The T-cell Response To Epstein Barr Virus Infection
Funder
National Health and Medical Research Council
Funding Amount
$549,000.00
Summary
X-ray crystallography is an essential tool for solving the three-dimensional structure of proteins. Proteins control the biological processes within the cell and it is the precise shape of proteins that determines how they function. Depending on the particular sequence of the amino acids, the so-called building unit of the proteins, the protein molecule bends and forms a distinct, complex shape. This specific three-dimensional shape allows the protein to undertake its specific function, such as ....X-ray crystallography is an essential tool for solving the three-dimensional structure of proteins. Proteins control the biological processes within the cell and it is the precise shape of proteins that determines how they function. Depending on the particular sequence of the amino acids, the so-called building unit of the proteins, the protein molecule bends and forms a distinct, complex shape. This specific three-dimensional shape allows the protein to undertake its specific function, such as binding to other proteins, acting as an enzyme or interacting with nucleic acids. To determine how a protein acts, it is vital to know the precise three-dimensional shape at the atomic level. This proposal is concerned with understanding the precise shape of proteins that control the immune response to Epstein Barr Virus. Epstein Barr Virus is an ubiquitous human pathogen that has being linked to a number of cancers. This work will further our understanding of the immune response to Epstein Barr Virus.Read moreRead less
Mechanisms Guiding Pathfinding And Positioning Of Cortical Interneurons
Funder
National Health and Medical Research Council
Funding Amount
$621,606.00
Summary
Brain disorders place an economic and social burden on Australia and the personal costs of these illnesses are immeasurable. Several brain abnormalities are caused from the failure of neurons to position themselves in the correct location when the brain develops. Our study aims to discover how neurons move and what factors influence this process. It provides an understanding of normal brain development, as well as providing insight into what may go wrong in the formation of brain diseases.
The Role Of Rnd Genes During Cortical Neurogenesis And Cell Migration
Funder
National Health and Medical Research Council
Funding Amount
$410,384.00
Summary
In order for the brain to function properly, tens of billions of neurons within it first have to be born, then find their proper location before connecting with other neurons in a highly ordered fashion. Failure of these key processes heavily impacts on subsequent brain function, and have been shown to underlie several disorders including epilepsy. This study will investigate how members of the Rnd gene family control cell production and positioning within the developing brain.
Brain Protection: A new therapeutic approach for Multiple Sclerosis In Multiple Sclerosis (MS), the immune system mistakenly attacks the brain. The immune attacks destroy myelin, the protective coat around electrical cables in the brain (demyelination). Current treatments for MS are only partially effective, and work by reducing the number and severity of these attacks. However, MS-related permanent disability in the majority of sufferers is due to the development of progressive MS, and current ....Brain Protection: A new therapeutic approach for Multiple Sclerosis In Multiple Sclerosis (MS), the immune system mistakenly attacks the brain. The immune attacks destroy myelin, the protective coat around electrical cables in the brain (demyelination). Current treatments for MS are only partially effective, and work by reducing the number and severity of these attacks. However, MS-related permanent disability in the majority of sufferers is due to the development of progressive MS, and current therapies do not reduce this progression. It is believed that one major cause of this permanent disability is permanent myelin loss. Interestingly, we have already shown that the growth factor LIF is made by the body during MS-like inflammation, and that it limits damage by directly protecting myelin-producing cells. However, the bodies own LIF production during inflammation is sub-maximal, because myelin protection can be enhanced by giving additional therapeutic LIF. This suggests that (1) The brain produces a defence response to harmful inflammation and that (2) This defence response can be enhanced therapeutically. We therefore want to define exactly how LIF enhances myelin survival. We have measured the response to LIF in myelin-producing cells, and have discovered that it strongly stimulates the production of the small protein galanin. We will now assess if galanin itself protects myelin and myelin-producing cells, and we will test this both in isolated cells and whole animal models. If galanin production is a major mechanism by which the body tries to limit the damage from abnormal inflammation during MS, then medications that mimic the action of galanin (which are already under development for different reasons) could become a major new therapy for Multiple Sclerosis.Read moreRead less
Novel Vasoactive Pathways In Liver Disease; Experimental And Clinical Studies
Funder
National Health and Medical Research Council
Funding Amount
$535,333.00
Summary
Cirrhosis of the liver due to chronic hepatitis and other common liver diseases is now a major cause of illness and death in Australia. This project will examine how a hormone system called the renin angiotensin system contributes to the development of liver damage in these diseases. We will study whether drugs targeting this system can be used to reduce liver scarring and prevent the development of cirrhosis and its complications.