New Dopaminergic Neurons In The Parkinson's Disease Striatum: Establishment Of Phenotype, Function And Origin.
Funder
National Health and Medical Research Council
Funding Amount
$156,493.00
Summary
Parkinson s disease is usually associated with loss of dopamine cells that send nerves from the substantia nigra to the striatum. However, we have found large numbers of apparently new dopaminergic cells in post mortem tissue from the striatum of 10 patients with Parkinson s disease but not in 5 age-matched controls. Our aims are firstly to determine whether these cells are indeed dopaminergic neurons by establishing their neurochemical and morphological profiles. This is required to determine w ....Parkinson s disease is usually associated with loss of dopamine cells that send nerves from the substantia nigra to the striatum. However, we have found large numbers of apparently new dopaminergic cells in post mortem tissue from the striatum of 10 patients with Parkinson s disease but not in 5 age-matched controls. Our aims are firstly to determine whether these cells are indeed dopaminergic neurons by establishing their neurochemical and morphological profiles. This is required to determine whether these apparently dopaminergic cells do indeed produce the neurotransmitter dopamine and to determine to what class of neuron they belong. The latter is important to establish whether they act locally in the striatum or extend their influence over a larger area of the brain. Secondly we shall assess their function in human and rat tissue. We shall determine whether their number is related to the severity of damage in Parkinson s disease, or whether L-DOPA therapy, which most patients receive, plays any role in their appearance. These experiments will lay the ground work to allow us to determine whether these cells are beneficial or harmful. Lastly, we shall determine where these cells come from. We shall determine whether they have always been present but have taken on a new function, or whether they are in fact new cells which have been born recently. This knowledge is essential if we are to be able to change their numbers to improve treatment of Parkinson s disease. We estimate that there are up to 66,000 of these dopaminergic cells in each striatum of patients with Parkinson s disease. This is enough to have a significant impact on the manifestation of the disease. These cells might be beneficial, allowing the brain to maintain essential functions for longer or they might be harmful playing a role in either development of Parkinson s disease itself or the harmful side effects of L-DOPA therapy.Read moreRead less
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
Development Of An In Vivo Pharmacokinetic-pharmacodynamic Model For Evaluation Of Antimalarial Drug Therapy Combinations
Funder
National Health and Medical Research Council
Funding Amount
$120,604.00
Summary
The World Health Organization currently estimates that there are 300-500 million cases of malaria annually, with 1.5-2.7 million deaths. These are staggering data, given that almost 20 antimalarial drugs are now in regular clinical use. Multi-drug resistance is present in most tropical countries where malaria is endemic and there has been a rapid escalation in cases of malaria in developed countries over recent decades (imported by travellers). Clearly, there is a need to ensure that current and ....The World Health Organization currently estimates that there are 300-500 million cases of malaria annually, with 1.5-2.7 million deaths. These are staggering data, given that almost 20 antimalarial drugs are now in regular clinical use. Multi-drug resistance is present in most tropical countries where malaria is endemic and there has been a rapid escalation in cases of malaria in developed countries over recent decades (imported by travellers). Clearly, there is a need to ensure that current and new treatment and prevention strategies are rational and effective. This project is based on the premise that improvements can be made in the in vitro testing process of antimalarial drugs. The experiments will be conducted using mice and a form of malaria that is specific to mice but closely resembles human malaria. In the first stage, the relationship between the amount of a new antimalarial drug (dihydroartemisinin) in the body and the effectiveness of the dose will be tested. These experiments will be repeated using conventional antimalarial drugs such as mefloquine. Information from these studies will subsequently be used to evaluate combinations of antimalarials. The results will be used as the basis of extensive, collaborative clinical studies in South-East Asia that are beyond the scope of this project. The methods used for this research will be important for future testing of new antimalarial drugs or combinations of drugs for the treatment and prophylaxis of malaria.Read moreRead less
I am a lab-based neurochemist-cell biologist with expertise in protein chemistry and pharmacology. My research focuses on the dynamin family of proteins in the endocytosis of synaptic vesicles and in the molecular mechanisms of synaptic transmission in th
Development Of A Simple Chemical Test For Detecting DNA-interacting Compounds For Medical And
Funder
National Health and Medical Research Council
Funding Amount
$315,450.00
Summary
The project exploits a simple chemical reaction to detect and measure the interaction of compounds with DNA. The test will be useful in the early screening of drug candidates for genotoxicity, identifying new anticancer drugs and also find application in the environmental, cosmetic and food industries. Work will focus on establishing peak conditions for the test, determining the scope of application, testing a panel of control compounds and performing a blind study to provide proof of concept.
NADPH Oxidase In Pathological Angiogenesis In Solid Tumours And Retina
Funder
National Health and Medical Research Council
Funding Amount
$581,989.00
Summary
Understanding blood vessel growth has profound clinical implications for many diseases. Blocking vessel growth is a promising strategy for treatment of cancer and eye complications accompanying diabetes, whereas treatments to stimulate new vessel growth will treat ischemic disorders ie. heart attack and stroke. Here we investigate whether targeting an enzyme that grows blood vessels has potential for making drugs to stop tumor growth or eye damage that occurs with diabetes and premature births.