Chemical Neurobiology Of Ventral Mesencephalon: Mechanisms Underlying Neuronal Death In Parkinsonism.
Funder
National Health and Medical Research Council
Funding Amount
$286,830.00
Summary
Parkinson's disease (PD) is a neurodegenerative disease which has profound effects on the Australian community. It affects about 1% of individuals aged more than 50 years and approximately 50,000 Australians. Brain cells die over many years and eventually the loss is so bad from the parts of the brain that coordinate motor control that uncontrollable motor movements occur. The cause of the condition is unknown and although drugs can control the motor disorders for some 5 years, eventually increa ....Parkinson's disease (PD) is a neurodegenerative disease which has profound effects on the Australian community. It affects about 1% of individuals aged more than 50 years and approximately 50,000 Australians. Brain cells die over many years and eventually the loss is so bad from the parts of the brain that coordinate motor control that uncontrollable motor movements occur. The cause of the condition is unknown and although drugs can control the motor disorders for some 5 years, eventually increasing disability occurs and finally complete dependency. The condition has profound effects on the families of the sufferers and the Australian health care system. Clearly, it is most important to understand how brain cells die in this debilitating neurological condition because once this death mechanism is understood then strategies can be devised to protect at risk brain cells so that new drugs can be developed to prevent the onset and progression of the disease. Since post-mortem studies on human brain suggest that cells in Parkinson's disease die by a process of programmed cell death (i.e. an unknown stimulus gives the cells a message to die by an exact mechanism involving gene activation), we shall examine the involvement of this unique form of brain cell death and attempt to determine what factors initiate the process. By establishing experimental models where rat brain cells are cultured, we plan to test how multiple factors could start the death cascade and how possible treatments may be preventitive. These assessments will be performed by measuring cellular biochemistry and electrical activity. We also hope to examine how at risk brain cells can be rescued and stimulated to grow to re-establish normal brain circuits. Overall, the programme aims to understand the disease process such that new directions for its management will be revealed.Read moreRead less
Glutathione is a natural antioxidant, which is known to protect cells in the body from chemical damage. A small part of the glutathione in cells is found in the mitochondria, a structure that is involved in producing the chemical energy needed for normal cell function. The mitochondria are also involved under some circumstances in promoting the death of cells. Although glutathione in general has been well studied, much less attention has been paid to the function of glutathione in mitochondria, ....Glutathione is a natural antioxidant, which is known to protect cells in the body from chemical damage. A small part of the glutathione in cells is found in the mitochondria, a structure that is involved in producing the chemical energy needed for normal cell function. The mitochondria are also involved under some circumstances in promoting the death of cells. Although glutathione in general has been well studied, much less attention has been paid to the function of glutathione in mitochondria, particularly in cells from the brain. Our recent studies indicate that this mitochondrial pool of glutathione is particularly important in limiting the death of cells from the brain when exposed to damaging substances that are increased in some diseases. Thus, the capacity of mitochondrial glutathione to deal with such substances might be a factor in determining the extent of cell loss in the brain, which is an important determinant of symptoms in some of the major neurological diseases. Consistent with this possibility, we have obtained evidence indicating that decreases in glutathione in the mitochondria contribute to the cell death and brain damage that results from a stroke. In our proposed studies, we will investigate the function of mitochondrial glutathione in the two major cell populations from the brain, neurons and astrocytes. We will characterise the protective role of the glutathione and investigate how it enters the mitochondria and what factors influence the amount that is present. This will provide new insights into the function of glutathione in the mitochondria and could also suggest novel approaches for manipulating this antioxidant pool. We will also study models of stroke and some related brain disorders to more directly test the role of this antioxidant in disease and to assess whether manipulating the content of glutathione in the mitochondria has the potential to reduce damage and improve function in these disordersRead moreRead less
How Does Iron Accumulation Affect Parkinson’s Disease And What Controls It?
Funder
National Health and Medical Research Council
Funding Amount
$545,517.00
Summary
Currently there is no cure for Parkinson's disease, and although we have a number of treatments to manage the disease there is an urgent need for a further understanding of the disease process. This proposal will investigate the critical role that iron plays in the cause of neuronal cell death that results in Parkinson's disease, and will investigate methods for regulating metal levels in the brain.
Neuronal Membranes And Connections In Dementia: Targets For Intervention
Funder
National Health and Medical Research Council
Funding Amount
$720,144.00
Summary
This research aims to understand why some people with Mild Cognitive Impairment (MCI) progress to dementia, whilst others do not. The fact that some people’s cognitive abilities can improve provides an opportunity to study the mechanisms that protect their brain cells from the degeneration associated with dementia. Understanding the cellular changes will lead to therapies that can be tested in the lab for individuals.
A New Function For An Old Enzyme: Src Protein Kinase Directs Excitotoxic Neuronal Death In Stroke
Funder
National Health and Medical Research Council
Funding Amount
$513,975.00
Summary
In our previous investigation of how brain cells die in patients suffering from stroke, we found that stroke causes aberrant activation of an enzyme called Src in the affected brain cells. Furthermore, this aberrantly activated Src directs the brain cells to undergo cell death. Our proposal, which aims to decipher this neurotoxic mechanism of the aberrantly activated Src will benefit development of new therapeutic strategies to reduce brain damage in stroke patients.
Deciphering How PTEN Phosphatase Mediates Excitotoxic Neuronal Death
Funder
National Health and Medical Research Council
Funding Amount
$519,715.00
Summary
In stroke patients, oxygen deprivation indirectly induces massive nerve cell death by activating a cell death-promoting enzyme called PTEN. We aim at unravelling (i) how PTEN is activated by oxygen deprivation, (ii) where the activated PTEN is localised in cells, and (iii) how the activated and optimally localised PTEN induces nerve cell death. The study will benefit development of therapeutic strategies to protect against brain damage in stroke.
Role Of Synaptogenesis In Developmental Motoneuron Cell Death
Funder
National Health and Medical Research Council
Funding Amount
$361,650.00
Summary
Naturally occurring cell death is an important and necessary event that shapes the developing embryo. It occurs in all organs of the developing body. In the nervous system about 50% of all neurons die at a time when they are making contact with one another or with their target organs. The underlying mechanisms that drive programmed neuronal cell death are not known. One possibility is that the formation of neuronal contacts (synapses) with other neurons and target cells determines the fate of a ....Naturally occurring cell death is an important and necessary event that shapes the developing embryo. It occurs in all organs of the developing body. In the nervous system about 50% of all neurons die at a time when they are making contact with one another or with their target organs. The underlying mechanisms that drive programmed neuronal cell death are not known. One possibility is that the formation of neuronal contacts (synapses) with other neurons and target cells determines the fate of a neuron. The connections of motor neurons with muscle during this period of developmental neuronal cell death is the best model to examine this phenomenon. In this grant we are in an exciting position to be able to address what causes neuronal cell death, as we have a number of mice that lack key molecules needed for the formation of specializations 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 motor neurons, counting them and screening for molecular changes in these mice, we will be able to dissect out the mechanism of how a motor neurons' fate is determined during the period of programmed cell death. The outcomes of this research will enable us to understand how the nervous system is shaped during development and will increase our knowledge about the basis of adult neurodegenerative diseases. For example, the pathology of Alzheimer's is characterised by a breakdown in neuronal connections that ultimately result in neuronal death and a loss of thought processes (cognition).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