Toward Cell-replacement Therapy For Parkinson's Disease: Investigating Endogenous Dopamine Neurogenesis In The Adult Mouse Substantia Nigra
Funder
National Health and Medical Research Council
Funding Amount
$577,957.00
Summary
Death of a particular type of cell in the brain causes the movement symptoms of Parkinson's disease (PD) (e.g. tremor). This study investigates how these cells are normally replaced, and whether stimulating their replacement can alleviate movement symptoms in an animal model of PD. Fulfillment of these aims will deliver vital information about how we might delay and better treat the movement symptoms of PD.
A 3D Cross-Modality Atlas Of The Human Brainstem For Scientists And Clinicians
Funder
National Health and Medical Research Council
Funding Amount
$363,455.00
Summary
Recent technical advances dramatically improved imaging of the human brainstem. However, there are limited frameworks for interpreting the images. The project will address this by acquiring high quality MRI anatomical and MR microscopy data from postmortem brains and registering these with structures in Atlas of the Human Brainstem (Paxinos and Huang, 1995) where almost 500 brain areas are delineated. Our work will assist with the diagnosis of brain disorders and facilitate clinical research.
Determining Neuronal Connections Involved In Parkinson's Disease And Cocaine Addiction
Funder
National Health and Medical Research Council
Funding Amount
$343,300.00
Summary
Addictive behaviours in response to cocaine use and fine motor coordination that is affected in Parkinson's disease are both controlled by the same type of cells/neurons, i.e., dopamine neurons. However, the circuitry of these neurons varies from where they originate and the type of connections they make. By understanding the neuronal circuitry of these two circuitries in concert we will be able to gain important insight into their roles in adaptive and pathological brain function.
Differential Regulation Of Human Tyrosine Hydroxylase Isoforms And The Development Of Parkinson's Disease
Funder
National Health and Medical Research Council
Funding Amount
$325,591.00
Summary
Parkinson's disease is a common neurodegenerative disease whose major feature is loss of a dopamine containing nerves in a part of the brain called the substantia nigra. Loss of nerves within the substantia nigra is not uniform, but firstly and primarily affects the ventral cells, suggesting that particular dopaminergic neurons are more vulnerable to the disease process. A key to understanding Parkinson's disease would be to work out why these cells are more susceptible to degeneration than othe ....Parkinson's disease is a common neurodegenerative disease whose major feature is loss of a dopamine containing nerves in a part of the brain called the substantia nigra. Loss of nerves within the substantia nigra is not uniform, but firstly and primarily affects the ventral cells, suggesting that particular dopaminergic neurons are more vulnerable to the disease process. A key to understanding Parkinson's disease would be to work out why these cells are more susceptible to degeneration than other dopaminergic cells in the brain. Tyrosine hydroxylase controls the rate of dopamine synthesis. Humans are unique in that they contain four isoforms of tyrosine hydroxylase and therefore they have the potential to alter the regulation of dopamine synthesis in ways that other species do not. Recent developments in our laboratories have suggested that particular isoforms of tyrosine hydroxylase may have either a role in the susceptibility of dopaminergic neurons to degeneration in Parkinson's disease or a role in the timing of the symptoms of the disease. We have demonstrated differences in the distribution of the human TH isoforms within the substantia nigra, with certain isoforms being more prevalent in the susceptible ventral cells. We have also shown that there are major differences in the regulation of the four human tyrosine hydroxylase isoforms. Some isoforms will be more sensitive to conditions that occur with high frequency stimulation of neurons and some to low frequency sustained stimulation. This would provide a mechanism by which differential distribution of the human TH isoforms would result in altered dopamine synthesis in different parts of the human brain and this may in turn lead to either increased susceptibility to, or earlier appearance of symptoms of, Parkinson's disease.Read moreRead less
SRY: A Risk Factor For Parkinson’s Disease In Men?
Funder
National Health and Medical Research Council
Funding Amount
$514,015.00
Summary
Parkinson’s disease is a debilitating neurological disorder that affects over 70,000 Australians. This project will test the novel concept that the male sex-determination gene SRY is a risk factor for Parkinson’s disease in men. A potential implication of the work is that it will help explain why men are more susceptible to Parkinson’s disease than women, and may also provide avenues for the development of novel therapeutics for this condition.
Secretion Of Alpha-synuclein: A Diagnostic Marker For Parkinsons Disease And A Clue To Its (patho)physiology
Funder
National Health and Medical Research Council
Funding Amount
$634,051.00
Summary
We have found that a protein, alpha-synuclein is low in people with Parkinson's Disease. We wish to see if this can be used as a diagnostic test for the condition. Alpha-Synuclein is thought to be important in causing Parkinson's Disease. We suspect that by finding out why less of this protein enters the blood stream in Parkinson's Disease, we may discover clues as to how alpha-synuclein causes problems in this condition.
Neuropathways And Synaptic Adaptations Underlying Drug Addiction In Central Dopamine Systems
Funder
National Health and Medical Research Council
Funding Amount
$184,812.00
Summary
There is a rising trend in addiction to drugs, such as opioids (heroin) and stimulants (methamphetamine and ecstasy). A key feature of this addiction is intensified craving for the drug with repeated use. A major brain component thought to mediate drug-craving is the dopamine (DA) neurotransmitter system, consisting of cells in the midbrain that project nerve terminals to forebrain structures involved in reward-based learning. DA cells undergo long-term depression (LTD) and potentiation (LTP) of ....There is a rising trend in addiction to drugs, such as opioids (heroin) and stimulants (methamphetamine and ecstasy). A key feature of this addiction is intensified craving for the drug with repeated use. A major brain component thought to mediate drug-craving is the dopamine (DA) neurotransmitter system, consisting of cells in the midbrain that project nerve terminals to forebrain structures involved in reward-based learning. DA cells undergo long-term depression (LTD) and potentiation (LTP) of synaptic strength when excitatory inputs to DA cells are stimulated. These findings are important to drug addiction as amphetamine has been shown to block LTD and enhance LTP in brain slices of DA cells. Thus, changes in LTD and LTP by illicit drugs may underlie the conditions necessary for expression of drug-induced behavioural sensitisation, the best-accepted model of drug-craving in human addiction. To date, these studies have all been conducted in brain slices. Therefore, the functional importance of this synaptic plasticity in midbrain DA cells has yet to be shown in terms of changes in DA release in forebrain terminals in the living animal. For the first time we will address this issue by recording DA cell firing activity together with DA release using a newly developed technique that permits DA release to be monitored in the living brain in 'real-time' (100,000 samples-sec). This will allow us to identify the origin (cortical excitatory inputs) and receptor mechanisms that mediate LTP and LTD in DA cells and their effects on DA release. Recording DA cell activity with real-time measurement of DA release will promote a new cutting-edge technology to the Australian Neurosciences. These data will provide 'first of its kind' evidence of the functional anatomy and receptor mechanisms underlying synaptic plasticity in DA neurons associated with repeated drug use and ultimately enhance our basic understanding of the neural mechanisms of human drug addiction.Read moreRead less
In Parkinson's disease only specific brain cells die, these cells are unusual in that they contain a dark coloured pigment called neuromelanin. The presence of this pigment is thought to play a role in the death of these cells. Evidence from many different diseases has demonstrated that a type of cell damage called oxidative damage is caused by an increase in tissue iron levels. Iron levels are increased in the brains of persons who have died with Parkinson's disease but only in the part of the ....In Parkinson's disease only specific brain cells die, these cells are unusual in that they contain a dark coloured pigment called neuromelanin. The presence of this pigment is thought to play a role in the death of these cells. Evidence from many different diseases has demonstrated that a type of cell damage called oxidative damage is caused by an increase in tissue iron levels. Iron levels are increased in the brains of persons who have died with Parkinson's disease but only in the part of the brain which contains neuromelanin. This increase in iron is thought to lead to oxidative damage and thus cell death in Parkinson's disease. Why iron should be increased specifically in this part of the brain is unknown but it has been shown that neuromelanin binds tissue iron and that the interaction between iron and neuromelanin can result in tissue damage. These events are suggested to underlie the specific vulnerability of the neuromelanin-containing cells in Parkinson's disease. However as yet very little is known about this pigment or how it interacts with iron. This research investigates neuromelanin in the normal brain and in the brain of persons who have died with Parkinson's disease. The project aims to demonstrate how neuromelanin interacts with iron and how neuromelanin, both in the presence and absence of iron, can influence oxidative cell damage. The use of human neuromelanin makes this research unique and it will provide important and novel information regarding the role of this pigment in the aetiology of this devastating disease.Read moreRead less