Potential For Creatine Or Melatonin As Dietary Supplements In Pregnancy To Prevent Perinatal Brain Damage
Funder
National Health and Medical Research Council
Funding Amount
$483,217.00
Summary
Brain damage in the newborn - particularly in prematurely born infants - remains a significant health problem. At present there are very few treatments that can be used to minimize damage when it becomes apparent in the newborn, and none that can be used PROSPECTIVELYduring pregnancy to protect the developing brain from damage. The most likely cause of damage to the fetal brain during pregnancy or at birth is global ASPHYXIA, either by itself or in association with other problems of pregnancy su ....Brain damage in the newborn - particularly in prematurely born infants - remains a significant health problem. At present there are very few treatments that can be used to minimize damage when it becomes apparent in the newborn, and none that can be used PROSPECTIVELYduring pregnancy to protect the developing brain from damage. The most likely cause of damage to the fetal brain during pregnancy or at birth is global ASPHYXIA, either by itself or in association with other problems of pregnancy such as infection, preterm birth, or fetal growth retardation. In this project we propose that providing extra amounts of the dietary constituent creatine, or of the hormone melatonin, to the pregnant animal in late gestation, will provide NEUROPROTECTION to the developing brain in the face of an asphyxial challenge that otherwise causes damage. We will use pregnant sheep to investigate the effects of asphyxia in utero on the fetal brain using techniques that allow us to monitor metabolic changes within the brain in real time. In addition, we will use the pregnant Spiny Mouse to investigate the effects of birth asphyxia on the postnatal brain structure and behavioral development. We will study groups of animals fed a normal diet, and compare then to animals that receive additional amounts of creatine or melatonin. We expect to determine if either of these treatments have the potential to protect the developing brain from asphyxial damage, and to recommend if similar treatments could be used in pregnant women where the obstetrician suspects the baby's brain is at risk of damage.Read moreRead less
Contribution Of Disturbed Blood Flow And Cerebral Metabolism To White Matter Damage In The Perinatal Brain
Funder
National Health and Medical Research Council
Funding Amount
$369,375.00
Summary
It has been known for some time that the white matter regions of the developing brain are particularly vulnerable to damage. These regions are deep in the brain near the ventricles, and are rich in myelin sheaths wrapped around the nerve fibres running from cell-rich areas in the outer layers of the brain to other regions, and down into the spinal cord. Damage to white matter usually leads to behavioural, learning and motor problems in the newborn infant - in its severest form, seen as cerebral ....It has been known for some time that the white matter regions of the developing brain are particularly vulnerable to damage. These regions are deep in the brain near the ventricles, and are rich in myelin sheaths wrapped around the nerve fibres running from cell-rich areas in the outer layers of the brain to other regions, and down into the spinal cord. Damage to white matter usually leads to behavioural, learning and motor problems in the newborn infant - in its severest form, seen as cerebral palsy. Such outcomes are often associated with the presence of asphyxia and infection during pregnancy, leading to the belief that the damage first arises while the baby is still in utero. In this application we suggest that asphyxia and-or infection during pregnancy cause prolonged disturbances in the regulation of blood flow and integrity of the blood-brain barrier in the developing brain, together with changes in metabolism that result in accumulation of prostaglandins and the toxic hydroxyl radical, leading irreversibly to cell death. If this series of events proves to be true, we have suggested and will test several protocols for protecting the fetal brain, which should be readily translatable to clinical practice.Read moreRead less
Using Astrocytes To Protect The Brain From Injury: Investigating Mechanisms And Therapeutic Strategies.
Funder
National Health and Medical Research Council
Funding Amount
$374,310.00
Summary
Brain damage caused by hypoxia (lack of oxygen) is a common problem in babies and can lead to outcomes ranging from cerebral palsy to death. We have a limited understanding of the mechanisms that cause damage, and thus very limited treatments. This project will investigate the role of cells called astrocytes in brain injury and identify novel therapeutic strategies to prevent or reverse brain damage. The outcomes of this research will ultimately lead to new treatments for hypoxic brain injury.
Blood-brain Barrier And White Matter Damage In The Immature Rat Brain Following Systemic Inflammation
Funder
National Health and Medical Research Council
Funding Amount
$353,173.00
Summary
Clinical obstetric and paediatric studies have identified an association between intrauterine infection occurring around two thirds of the way through pregnancy, premature birth and a specific form of damage to the brain of the newborn. This damage mainly affects white matter tracts. These tracts are aggregations of nerve fibres that make the connections between different parts of the brain and may result in cerebral palsy or other neurological disorders. The association between maternal infecti ....Clinical obstetric and paediatric studies have identified an association between intrauterine infection occurring around two thirds of the way through pregnancy, premature birth and a specific form of damage to the brain of the newborn. This damage mainly affects white matter tracts. These tracts are aggregations of nerve fibres that make the connections between different parts of the brain and may result in cerebral palsy or other neurological disorders. The association between maternal infection and brain damage, one form of which is cerebral palsy, is well established from clinical epidemiological studies, but the biological mechanism of this link is unknown. The CIs' group has recently shown that the condition can be reproduced in neonatal rats at a stage of brain development in the rat that is equivalent to the critical time in human brain development when infection may be associated with brain damage. The CIs' group has shown that an induced inflammatory state similar to a bacterial infection, results in damage to blood vessels in the white matter and is associated with changes in white matter, as occurs in affected babies. The purpose of this study is to understand the nature of the damage to white matter blood vessels and the mechanisms by which materials in blood, which in the normal brain do not pass from the blood to the brain across the blood-brain barrier, are able to do so via the inflammation damaged blood vessels. The study also aims to show whether it is components of the blood entering the brain via the damaged blood vessels that are responsible for the damage to white matter in the immature brain. The outcome should lead to development of ways to improve clinical care of women who acquire infections during pregnancy.Read moreRead less
Neuroactive Steroids In The Developing Brain: Potential For Preventing Perinatal Brain Damage
Funder
National Health and Medical Research Council
Funding Amount
$481,500.00
Summary
Complications during pregnancy, birth asphyxia or premature birth can lead to serious neurological impairment in the newborn. Despite excellent neonatal care many of these babies go on to have serious handicaps. Neuroactive steroids are a group of neuromodulators that are derived from the hormone progesterone. These steroids fall into two groups, those that appear to protect brain cells from damage caused by an inadequate supply of oxygen and those that may increase cell death. We have shown tha ....Complications during pregnancy, birth asphyxia or premature birth can lead to serious neurological impairment in the newborn. Despite excellent neonatal care many of these babies go on to have serious handicaps. Neuroactive steroids are a group of neuromodulators that are derived from the hormone progesterone. These steroids fall into two groups, those that appear to protect brain cells from damage caused by an inadequate supply of oxygen and those that may increase cell death. We have shown that protective neuroactive steroids are present in very large amounts in the fetal brain. Steroids produced by the placenta are converted to these neuroactive products by enzymes in the brain leading to the high levels that are seen during fetal life. Certain adverse conditions during pregnancy as well as preterm birth may cause marked changes in the balance of steroids that could increase susceptibility to brain injury. We have found that areas of the brain, where damage most often occurs, normally contain the highest amount of protective steroids, but only in late pregnancy. This suggests that disturbances that lower steroid production in these areas could contribute to the death of cells, particularly in mid-pregnancy and after premature birth. In the proposed studies, we will examine whether a toxic balance of steroids develops following adverse events in pregnancy as well as the areas of the brain where this is most pronounced. We will examine the changes in the expression of enzymes that can potentially cause the accumulation of protective steroids in the brain. We will then examine treatments that can raise the concentration of steroids and determine which combination of steroids best reduces cell death and brain injury following complications during pregnancy. The findings of this work will indicate the best therapeutic approach that may be adopted to modify the concentration of certain steroids so as to reduce the risk of brain damage in the fetus and neonate.Read moreRead less
Neurosteroid Mediated Protection After Birth: Approaches For Maximising Protective Steroid Levels In The Neonatal Brain
Funder
National Health and Medical Research Council
Funding Amount
$450,703.00
Summary
Complications during pregnancy, birth asphyxia or premature birth can lead to neurological impairment in the newborn. Despite excellent neonatal care many of these babies go on to have serious handicaps. Neurosteroids are a group of steroids that regulate brain activity. These steroids protect brain cells from damage caused by an inadequate supply of oxygen by suppressing toxicity caused by excessive activity. We have shown that the levels of these protective steroids are remarkably high in the ....Complications during pregnancy, birth asphyxia or premature birth can lead to neurological impairment in the newborn. Despite excellent neonatal care many of these babies go on to have serious handicaps. Neurosteroids are a group of steroids that regulate brain activity. These steroids protect brain cells from damage caused by an inadequate supply of oxygen by suppressing toxicity caused by excessive activity. We have shown that the levels of these protective steroids are remarkably high in the fetal brain and levels rise further in response to fetal stress. The placenta contributes steroid precursors that help maintain these high neurosteroid levels. This placenta-fetal brain interaction comprises an internal mechanism that protects the fetal brain from adverse events during pregnancy. At birth, however, there is a dramatic decline in neurosteroid concentrations in the brain after the loss of the placental precursor supply. The fall in concentrations is even greater in animals that are born growth restricted. This suggests that newborns, particularly those from compromised pregnancies, are at increased risk of brain damage due to low neurosteroid levels. We believe that certain commonly used steroid therapies may also lower steroid levels in the brain and result in increased vulnerability to brain damage during birth or in the early neonatal period. Alternatively, we propose that replacement of neurosteroid precursors in the newborn may raise brain neurosteroid levels and protect against brain damage. In the proposed studies we will evaluate treatments that can raise the concentration of steroids and determine the best strategy for reducing brain injury following complications during pregnancy, at birth and during the early newborn period. This work will determine the best therapeutic approaches for maximising neurosteroid-induced brain protection and for reducing the risk of brain damage.Read moreRead less
Cerebrovascular Effects Of Intrauterine Hypoxia: Contribution To Perinatal Brain Injury
Funder
National Health and Medical Research Council
Funding Amount
$579,138.00
Summary
During pregnancy, delivery of oxygen and nutrients to the growing fetus is sometimes disturbed, and can lead to injury of the developing brain. In this project we investigate the idea that low oxygen (hypoxia) causes brain demage to blood vessels in the fetal brain, and new blood vessesl produced in an attempt to repair this damage are fragile and prone to rupture, explaining the high incidence of bleeding in the brain of prematurely-born and full term infants that experience birth hypoxia.
Mechanisms Contributing To Long-term Neuronal Loss After Hypoxia-ischemia In The Premature Neonate Brain.
Funder
National Health and Medical Research Council
Funding Amount
$432,535.00
Summary
A lack of oxygen (hypoxia) and blood flow to the brain (ischemia) around the time of birth can cause brain injury that perists into adulthood. The burdens on financial, educational and healthcare resources are enormous. We will improve our understanding of what parts of the brain are injured and the mechanisms contributing to on-going brain injury after hypoxia-ischemia.This is important to devise treatments and to provide a healthy start to life for neonates.
Role Of Kynurenine Metabolites In Causing And Preventing Excitotoxic Brain Damage In The Fetus.
Funder
National Health and Medical Research Council
Funding Amount
$92,815.00
Summary
Brain damage is present in some babies at birth, and recent epidemiological and clinical studies strongly suggest that this either occurs some time during the pregnancy, or the conditions are such that the fetal brain is particularly vulnerable to the stresses that are present during labor and birth. In this project we propose that hypoxic (low oxygen) conditions in the womb, either alone or in combination with substances released because of maternal infection, cause accumulation of a neurotoxic ....Brain damage is present in some babies at birth, and recent epidemiological and clinical studies strongly suggest that this either occurs some time during the pregnancy, or the conditions are such that the fetal brain is particularly vulnerable to the stresses that are present during labor and birth. In this project we propose that hypoxic (low oxygen) conditions in the womb, either alone or in combination with substances released because of maternal infection, cause accumulation of a neurotoxic substance - QUINOLINIC ACID - in the fetal brain and circulation. The increased production of QUINOLINIC ACID occurs because certain cells react to the low oxygen and infectious conditions - these cells include MICROGLIA, a cell type in the brain. Little is currently known about MICROGLIA in the developing brain. We will therefore study the effects of hypoxia and infection in fetal sheep, and we will determine how these conditions affect MICROGLIA and the synthesis of QUINOLINIC ACID in the fetal brain. The capacity of the brain to produce QUINOLINIC ACID is closely related to the dietary intake of the essential amino acid TRYPTOPHAN, and it is decreased when synthetic analogues of tryptophan are infused. Therefore, we have devised a treatment regime using these tryptophan analogues to prevent increases of QUINOLINIC ACID concnetrations in the fetal brain, and we propose that a simple treament is at hand to reduce the incidence of perinatal brain damage in human pregnancies.Read moreRead less