Role Of SOCS 3 In Regulating Oligodendroglial Phenotype In Health And Disease
Funder
National Health and Medical Research Council
Funding Amount
$419,187.00
Summary
The response of nerve cells, known as oligodendrocytes, to an inflammatory insult dictates the severity of demyelinating diseases such as multiple sclerosis (MS). We have previously discovered that a key protein in this response is the cytokine leukaemia inhibitory factor (LIF) which, by activating the LIF receptor expressed on these cells, limits their death and reduces the clinical impact on animal models of MS. However, the therapeutic benefit of LIF is incomplete and we do not completely und ....The response of nerve cells, known as oligodendrocytes, to an inflammatory insult dictates the severity of demyelinating diseases such as multiple sclerosis (MS). We have previously discovered that a key protein in this response is the cytokine leukaemia inhibitory factor (LIF) which, by activating the LIF receptor expressed on these cells, limits their death and reduces the clinical impact on animal models of MS. However, the therapeutic benefit of LIF is incomplete and we do not completely understand the mechanisms by which LIF exerts these effects. To maximise the treatment potential of LIF we need to understand how LIF receptor signaling is modulated in the nervous system. An important protein known to regulate the activity of LIF and of other cytokines in other organs of the body is the suppressor of cytokine signaling 3 (SOCS 3) molecule. We have recently shown that the expression of SOCS 3 is increased in an animal model of MS, indicating that it is likely to modulate the activity of LIF in this context. We plan to investigate the nature of this regulation. SOCS 3 might limit the efficacy of LIF but it could also limit the deleterious effect of unbridled LIF receptor signaling. To distinguish between these possibilities, we plan to study the impact of demyelinating disease in animals in which SOCS 3 is either deleted or overexpressed in oligodendrocytes. In this way, we should be able to learn how to optimise the therapeutic potential of LIF in MS and related nervous system diseases.Read moreRead less
Forebrain Neuroadaptations To Chronic Morphine Treatment
Funder
National Health and Medical Research Council
Funding Amount
$435,956.00
Summary
Drug addiction is caused by long term changes in brain areas that normally produce the drives that sustain normal behaviours such as eating, drinking and sex. Addictive drugs effectively hijack these brain areas so that behaviours relating to drug taking become associated with feeling good. In some individuals, over time the pattern of drug taking becomes compulsive and no longer can be controlled. This transition is now known to be due to drugs causing physical changes to certain groups of nerv ....Drug addiction is caused by long term changes in brain areas that normally produce the drives that sustain normal behaviours such as eating, drinking and sex. Addictive drugs effectively hijack these brain areas so that behaviours relating to drug taking become associated with feeling good. In some individuals, over time the pattern of drug taking becomes compulsive and no longer can be controlled. This transition is now known to be due to drugs causing physical changes to certain groups of nerve cells in the brain. The affected nerve cells are responsible for causing new behaviours that appear once addiction is established. Addiction is not exclusive to humans. Animals will self-inject the same addictive drugs that humans use, and show many other kinds of addictive behaviours that parallel aspects of human addiction. Studying the effects of addictive drugs on rats and other animals has been very important in working out where and how drugs work. We now have a very good idea of which parts of the brain are affected by drugs, and it turns out that most addictive drugs act in the same places. We also now know for all of the major drugs, exactly which parts of nerve cells they affect. However, this turns out to be only the first step as the nerve cells that directly respond to drugs can affect other whole networks of nerve cells. This study is going to look at how morphine, a drug that is related to heroin, affects nerve cells in a part of the brain that helps cause addiction. It is going to work out which of the many pathways in this brain region are affected by morphine treatments that cause addiction in rats. It will then see what is happening to single nerve cells in the affected pathways. If we can understand more about these processes it may become possible to come up with new ways to treat addiction. We will also understand much more about the production of powerful emotional and behavioural drives so many of us find hard to control.Read moreRead less
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.
Participation Of Intrinsic Sensory Neurons In The Initiation Of Colonic And Gastric Reflexes
Funder
National Health and Medical Research Council
Funding Amount
$109,448.00
Summary
The gastrointestinal tract adjusts its digestive activity in response to the food that we eat. To do this, the bulk and chemical composition of the food and products of digestion must be sensed. In the small intestine, this sensing is by neurons in the wall on the intestine (intrinsic neurons) and by neurons with cells outside the intestine and endings in its wall (extrinsic neurons). There is evidence for there being intrinsic sensory neurons in the colon, subserving fewer functions than in the ....The gastrointestinal tract adjusts its digestive activity in response to the food that we eat. To do this, the bulk and chemical composition of the food and products of digestion must be sensed. In the small intestine, this sensing is by neurons in the wall on the intestine (intrinsic neurons) and by neurons with cells outside the intestine and endings in its wall (extrinsic neurons). There is evidence for there being intrinsic sensory neurons in the colon, subserving fewer functions than in the small intestine, but direct recordings from putative colonic intrinsic sensory neurons during sensory stimuli have not been made. The literature does not indicate whether there are intrinsic sensory neurons in the stomach. Some data suggests they may be present only in the antrum. It is important to determine whether there are intrinsic sensory neurons in the colon and stomach, which seems likely, to identify them morphologically and physiologically, and to investigate their responsiveness to physiological sensory stimuli. These data may be useful to understand the pathogenesis of functional bowel disorders, including delayed emptying in the stomach (which occurs in diabetes, for example) and slow transit constipation. Proper identification and characterisation of intrinsic sensory neurons might guide the development of therapies for disorders of colonic and gastric motility.Read moreRead less
Differentiation Of Multiple Phenotypes Of Rostral Ventromedial Medulla Neurons And Their Role In Pain
Funder
National Health and Medical Research Council
Funding Amount
$285,990.00
Summary
Chronic pain, defined as pain experienced in three out of a six month pre-interview period affects 17% of males and 20% of females in the Australian population. Opioid drugs such as morphine and codeine are the most effective drugs used to treat moderate to severe pain. However, the utility of these drugs is hampered by the development of a blunted response with repeated use. Furthermore, some clinically important pain states, particularly those caused by nerve injury, do not respond well to opi ....Chronic pain, defined as pain experienced in three out of a six month pre-interview period affects 17% of males and 20% of females in the Australian population. Opioid drugs such as morphine and codeine are the most effective drugs used to treat moderate to severe pain. However, the utility of these drugs is hampered by the development of a blunted response with repeated use. Furthermore, some clinically important pain states, particularly those caused by nerve injury, do not respond well to opioid drugs. Recent basic neurosceince research has identified groups of nerve cells deep within the brain that control sensitivity to pain as pain signals enter the spinal cord. Unfortunately in the presence of some chronic pain conditions, or chronic use of high doses of opioid drugs, these neurons undergo functional changes or adaptations that distort and increase the severity of pain sensation in a more or less permanent manner. This project uses electrical and chemical techniques to identify the basic physiology and pharmacology of single nerve cells in this brain region, so that their normal functions can be properly understood. We will then identify the cellular and molecular adaptations that occur in the nerve cells in animal models of chronic nerve injury and chronic morphine treatment to identify the nature of adaptations responsible for their aberrant function. We will then be in a position to rationally identify novel drug targets that can normalise the function of these nerve cells. This knowledge will provide potential targets for development of novel therapeutics to manage chronic pain.Read moreRead less
Can Human Neural Stem Cells Form Enteric Nerves In Human Hirschsprungs Disease Colon?
Funder
National Health and Medical Research Council
Funding Amount
$598,815.00
Summary
The intestine has its own nervous system which develops from cells that migrate into the intestine during early development. Sometimes this does not work and part of the bowel has no nerves and cannot function. This is treated now by cutting out this bad bowel and joining the sections of good bowel. But it may be possible to grow new nerves in the bad bowel using stem cells. This project aims to test whether this treatment, which would avoid loss of bowel, is possible.
Fainting (syncope) is a common disorder leading to blackouts, which can cause injury. Breath-holding is a related problem in younger children also resulting in blackouts. Both of these conditions can run in families but little is known about what causes these events. We will study large families to identify the genes underlying these common phenomena. This will deepen our understanding of patterns of inheritance, improve genetic counseling, and lead to better diagnostic and treatment options.
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
Migratory Behaviour And Cell Cycle Length Of Enteric Neuron Precursors
Funder
National Health and Medical Research Council
Funding Amount
$472,249.00
Summary
The activity of nerves in the intestine is essential for gastrointestinal function. Correct development of intestinal neurons requires migration of precursors to the correct location and control of proliferation to achieve correct neuron number. In this project we will identify the mechanisms regulating migration and proliferation of intestinal neuron precursors during normal development, and in mice with defects in intestinal neurons that are models of human motility disorders.
Human Hypothalamic Homologues To Autonomic Control Centres Identified In Rat And Monkey
Funder
National Health and Medical Research Council
Funding Amount
$358,770.00
Summary
The hypothalamus is a brain structure common to all mammals. Experiments on the rat have shown the hypothalamus to be fundamentally involved in cardiovascular control, fluid and electrolyte balance, food ingestion and energy metabolism, thermoregulatory and immune responses, and defensive-aggressive responses and reproduction. It is virtually impossible to perform functional studies in the human and, therefore, the human hypothalamic regions involved in these functions will be inferred from thei ....The hypothalamus is a brain structure common to all mammals. Experiments on the rat have shown the hypothalamus to be fundamentally involved in cardiovascular control, fluid and electrolyte balance, food ingestion and energy metabolism, thermoregulatory and immune responses, and defensive-aggressive responses and reproduction. It is virtually impossible to perform functional studies in the human and, therefore, the human hypothalamic regions involved in these functions will be inferred from their structural similarity to the centres identified in the rat. The present project will obtain structural-chemical data on the rat and monkey for the sole purpose of comparing these data with similar data on the human. The parts of the hypothalamus that deal with cardiovascular and other autonomic functions are expected to be similar in the rat and human and the present study will identify in the human all major regions that have been identified in the rat. The correspondence between an area in the rat brain and one in the human brain will be established primarily on the basis of chemical similarity. Corresponding areas tend to feature similar neurotransmitters, enzymes and other neuroactive substances. Some of the chemicals to be investigated are known to have a role in autonomic control. The chemical mapping study then serves two roles: (a) It permits the identification of the chemical profile (signature) of an area and consequently enables its identification in the human, and (b) it reveals the chemicals the area utilizes for possible theoretical and practical considerations. The present study will allow hypotheses derived from experimental work on the rat to be more meaningfully tested on humans. It will assist pathological and imaging investigations of the human brain.Read moreRead less