Receptor Signalling Through Intracellular Calcium Stores In Chromaffin Cells
Funder
National Health and Medical Research Council
Funding Amount
$461,000.00
Summary
The function of cells in the body is controlled by many hormones and neurotransmitters acting on the cell's surface. Hormones and transmitters mediate their effects by producing chemical signals within the cell that regulate its activities. One key cell signalling chemical is calcium, especially in nerve cells which have developed sophisticated mechanisms for using calcium to control their function. Recently, new levels of complexity have been discovered, both in how cell calcium levels are modi ....The function of cells in the body is controlled by many hormones and neurotransmitters acting on the cell's surface. Hormones and transmitters mediate their effects by producing chemical signals within the cell that regulate its activities. One key cell signalling chemical is calcium, especially in nerve cells which have developed sophisticated mechanisms for using calcium to control their function. Recently, new levels of complexity have been discovered, both in how cell calcium levels are modified by hormones and transmitters and in how these complex calcium signals are used by cells to control their function. This project will investigate how hormones and transmitters can produce different types of calcium signals in nerve cells, and how these signals affect different aspects of the nerve cell's function. In particular, it will establish how two different types of specialised calcium stores within nerve cells are used by different classes of hormone and transmitter, and the distinct cellular functions these two calcium stores can regulate. The results will provide fundamental new information on how nerve cells control their activity and may help identify potential new targets for drugs.Read moreRead less
Post Synaptic Density Scaffold Proteins In The Growth Cone: Homer And Shank, Crucial For Calcium Signaling.
Funder
National Health and Medical Research Council
Funding Amount
$237,909.00
Summary
Our brain is a complex, yet precise electrical circuit. Understanding how the embryonic brain is wired has direct implications for all aspects of life, from the growing foetus in mother's womb, to learning algebra and for maintaining the active memories of our ageing population. This project aims to provide new insight into understanding how the embryonic brain is wired, crucial information for future pharmacological or gene therapy approaches to mental illness, ageing, and neuronal injury.
Novel Substance P Receptors On Autonomic And Sensory Neurons Regulating The Viscera
Funder
National Health and Medical Research Council
Funding Amount
$447,750.00
Summary
Potentially harmful stimulation of the skin or the internal organs activates sensory nerves that send signals to the brain. These events often are perceived as painful. One chemical messenger transmitting these signals first to the spinal cord, and then to the brain, is a neuropeptide called substance P. During many chronic inflammatory conditions, such as inflammation of the bowel, these signalling pathways are sensitised so that stimuli that previously were not painful now are perceived as pai ....Potentially harmful stimulation of the skin or the internal organs activates sensory nerves that send signals to the brain. These events often are perceived as painful. One chemical messenger transmitting these signals first to the spinal cord, and then to the brain, is a neuropeptide called substance P. During many chronic inflammatory conditions, such as inflammation of the bowel, these signalling pathways are sensitised so that stimuli that previously were not painful now are perceived as painful. This sensitisation has several different causes. One contributing factor seems to be related to a change in the receptor molecules that recognise substance P. Last year we discovered a new type of receptor for substance P, that is prominent in the nerve pathways between the gut and the spinal cord. This novel receptor has important characteristics that are different from the classical substance P receptor. However, we are still largely ignorant about how substance P interacts with these new receptors to modify the activity of nerve cells in sensory pathways. Indeed, we propose that these new receptors are likely to make a significant contribution to the sensitisation that occurs in inflammation. We will use a combination of sophisticated cellular and molecular techniques to study the way in which substance P acts on these novel receptors in nerves regulating the visceral organs. Our results are likely to make a significant contribution to the development and interpretation of rational new therapies for treating chronic diseases of the gastrointestinal tract, such as inflammatory bowel disease (IBD). Our studies will reveal signalling mechanisms that also are likely to be used by substance P more widely in the nervous system, that are relevant to other inflammatory conditions like arthritis, and even some forms of depression.Read moreRead less
Proteolytic Cleavage Of The P75 Neurotrophin Receptor Mediates Cell Death
Funder
National Health and Medical Research Council
Funding Amount
$238,500.00
Summary
The p75 neutrotophin receptor (p75NTR) is a major inducer of nerve cell death, and is active in a wide range of neurodegenerative conditions, including Alzheimer's disease, motor neuron disease, multiple sclerosis, stroke and nerve trauma. This study aims to understand and to characterise the events that regulate this receptor. In particular, we will investigate the role that cleavage or controlled breakdown of the receptor plays in mediating its cell death activity. A fundamental aspect of this ....The p75 neutrotophin receptor (p75NTR) is a major inducer of nerve cell death, and is active in a wide range of neurodegenerative conditions, including Alzheimer's disease, motor neuron disease, multiple sclerosis, stroke and nerve trauma. This study aims to understand and to characterise the events that regulate this receptor. In particular, we will investigate the role that cleavage or controlled breakdown of the receptor plays in mediating its cell death activity. A fundamental aspect of this proposal is determining whether cleavage is due to presenilin-dependent activity, given that presenilin mutations have been demonstrated in most familial Alzheimer s disease cases. While this will increase our understanding of one of factors contributing to Alzheimer's disease, it also has much broader implications. A wide range of pharmaceuticals which regulate presenilin cleavage are already being developed and clinically tested for their efficacy in the treatment of Alzheimer s disease. Should our research demonstrate that p75NTR cleavage is the key process that regulates neuronal degeneration it will have major ramifications for approaches to the treatment of other p75NTR-associated neurodegenerative conditions.Read moreRead less
Modulation Of Calcium Signalling By Acetylcholine In The Basolateral Amygdala
Funder
National Health and Medical Research Council
Funding Amount
$266,748.00
Summary
The amygdala is an area of the brain involved in assigning emotional significance to sensory stimuli. This grant examines the cellular processes involved in making these associations. Specifically, it studies the relationship between two signalling molecules implicated in association learning, acetylcholine and calcium. This research will test hypotheses of memory formation and provide insight into disorders linked to detrimental emotional associations, such as anxiety and addiction.
Neogenin Regulates Progenitor Division And Interneuron Migration In The Developing Forebrain
Funder
National Health and Medical Research Council
Funding Amount
$526,878.00
Summary
In humans, mutations in genes controlling the production of new neurons in the embryonic brain result in severe disruption of the adult cortex. This project tests the hypothesis that one cell surface molecule, Neogenin, regulates the birth of new neurons and their subsequent travels through the developing brain to form the neocortex. The outcome of these studies will provide fundamental insights into the aberrant processes that underlie human mental retardation, epilepsy, dyslexia and autism.
Regulation Of P75 Death Signalling: How Neurotransmitter- And Neurotrophic- Signals Determine Cell Survival
Funder
National Health and Medical Research Council
Funding Amount
$292,216.00
Summary
Nerve cell survival is dependent on trophic support in the form of growth factors and synaptic input, both of which promote recovery after nerve injury. The survival pathways activated by growth factors are generally well characterised, whereas survival signals activated by synaptic activity are largely unexplored. This proposal aims to discover how synaptic activity prevents nerve cell death by looking at how synaptic activity inhibits the processes active in dying nerve cells.
Dissecting The Molecular Mechanisms Driving Cell Migration During Neurulation Triggered By The Netrin Receptor, Neogenin
Funder
National Health and Medical Research Council
Funding Amount
$432,750.00
Summary
In humans, abnormalities in brain and spinal cord formation during early embryogenesis result in congenital syndromes such as spina bifida and anencephaly. These defects occur at a rate of 1-1000 pregnancies and are therefore a major contributor to pre- and perinatal deaths. In the early embryo, the brain and spinal cord begin as a hollow tube of cells (the neural tube) that subsequently expands into the complex structures seen at birth. It is known that the neural tube is formed by a complex pr ....In humans, abnormalities in brain and spinal cord formation during early embryogenesis result in congenital syndromes such as spina bifida and anencephaly. These defects occur at a rate of 1-1000 pregnancies and are therefore a major contributor to pre- and perinatal deaths. In the early embryo, the brain and spinal cord begin as a hollow tube of cells (the neural tube) that subsequently expands into the complex structures seen at birth. It is known that the neural tube is formed by a complex process in which early neural cells migrate toward the midline of the embryo and subsequently coalesce. This project seeks to determine the function of one molecular signaling pathway (the neogenin pathway) that has been implicated in driving these cell migration events. We will initially use the frog, Xenopus laevis, as our embryonic model since the developmental processes that form the Xenopus neural tube closely parallel those ocurring in the human embryo. This model will allow us to identify the molecules in the neogenin signaling pathway. We will also create mice that carry a mutation in the neogenin gene so that we can study neogenin function in the mammal. We anticipate that these studies will provide important insights into the development of the central nervous system and also into the aberrant molecular processes underlying neural tube defects in man.Read moreRead less