I am a molecular physiologist investigating the structure and function of the inhibitory neurotransmitter glycine receptor (GlyR) and GABA type- A receptor (GABAAR) chloride channels. We are interested in understanding how these receptors open and close
Molecular Determinants Of Inhibitory Synaptic Function Studied Using Mutant And Transgenic Mice
Funder
National Health and Medical Research Council
Funding Amount
$496,500.00
Summary
Communication between nerve cells is the key to effective brain function and when disturbed, pathological states such as epilepsy, schizophrenia, fear and anxiety, spasticity and motor disorders ensue. This project is based on new data which suggests that the site of this communication, called the synapse, is a much more dynamic structure than previously thought. Based on our work to date, where we have demonstrated the recruitment of selected classes of neurotransmitter receptors into synapses, ....Communication between nerve cells is the key to effective brain function and when disturbed, pathological states such as epilepsy, schizophrenia, fear and anxiety, spasticity and motor disorders ensue. This project is based on new data which suggests that the site of this communication, called the synapse, is a much more dynamic structure than previously thought. Based on our work to date, where we have demonstrated the recruitment of selected classes of neurotransmitter receptors into synapses, our aim is to use a range of naturally occuring mice mutants, as well as transgenic mice to modulate the receptor levels and so to examine the role of synaptic function and synaptic dynamics. The outcomes of this project will provide fundamental new knnowledge aimed at understanding how communication in the nervous system works and may suggest ways in which modulation of this information flow could be used to treat disorders of brain function.Read moreRead less
Absence epilepsy is the commonest form of idiopathic generalized epilepsy. It can lead to hundreds of seizures per day, and mainly affects children between the ages of four and eight. Its cause is in most cases unknown. In this study we will use a rat model of absence epilepsy to investigate the cellular basis of this disease. Preliminary work indicates that a particular protein - HCN1 - is reduced in the cortex of rats with absence epilepsy. This protein codes for a pore in the membrane of nerv ....Absence epilepsy is the commonest form of idiopathic generalized epilepsy. It can lead to hundreds of seizures per day, and mainly affects children between the ages of four and eight. Its cause is in most cases unknown. In this study we will use a rat model of absence epilepsy to investigate the cellular basis of this disease. Preliminary work indicates that a particular protein - HCN1 - is reduced in the cortex of rats with absence epilepsy. This protein codes for a pore in the membrane of nerve cells, which acts like a switch. We have preliminary evidence that in rats with absence epilepsy this switch does not work properly. We wish to investigate how this influences the activity of nerve cells in rats with absence epilepsy. Furthermore, as absence epilepsy is an inherited disease, we wish to track down the genetic basis of this disease. This will give us clues as to the cause of the disease in this rat model. This research will shed light on the potentially important role of the HCN1 protein in absence epilepsy, which may represent an potentially new therapeutic target for the development of drugs for the treatment of absence epilepsy.Read moreRead less
Therapeutic Potential Of Glycine Receptors In Pain Sensory Pathways
Funder
National Health and Medical Research Council
Funding Amount
$292,223.00
Summary
Inflammation caused by infection or injury leads to a heightened sensation of pain and can convert non-painful stimuli (e.g., touch) into painful stimuli. This effect is mediated by the production of prostaglandins both in peripheral tissues and in the spinal cord. Prostaglandins have recently been shown to decrease the magnitude of the inhibitory neurotransmission that normally occurs onto pain sensing neurons in the spinal cord. This has the effect of raising the excitability of these neurons, ....Inflammation caused by infection or injury leads to a heightened sensation of pain and can convert non-painful stimuli (e.g., touch) into painful stimuli. This effect is mediated by the production of prostaglandins both in peripheral tissues and in the spinal cord. Prostaglandins have recently been shown to decrease the magnitude of the inhibitory neurotransmission that normally occurs onto pain sensing neurons in the spinal cord. This has the effect of raising the excitability of these neurons, thereby making it easier for weak pain stimuli to be relayed to the brain. Inhibitory neurotransmission onto pain sensing neurons is largely mediated by the alpha3 glycine receptor subunit that is not found anywhere else in the body. Very little is known about the physiological and pharmacological properties of these receptors. We hypothesise that drugs that increase the activation of alpha3 glycine receptors may provide a novel treatment for pain. This project will firstly identify new drugs that can increase the activation of these receptors. It will then test whether these drugs are likely to work in vivo. The project will also establish why these receptors are found only on pain neurons. Together, this information will establish whether alpha3 glycine receptors represent a promising new therapeutic target for inflammatory pain, and will place us in an excellent position to begin the next step of identifying novel therapeutic lead compounds.Read moreRead less
The neocortex is the region of the brain that underlies all cognitive functions. Mental disorders, such as schizophrenia, occur when the communication between nerve cells in the neocortex breaks down. We propose to make electrical measurements from the thin processes of neurons that receive input from widely separated neocortical areas to understand how areas of the neocortex are functionally interlinked, with the ultimate aim to identify how these processes are disturbed in mental disorders.
Dynamic Aspects Of Inhibitory Synaptic Transmission And Modulation By Neuroactive Drugs
Funder
National Health and Medical Research Council
Funding Amount
$370,500.00
Summary
Information moving through the brain is typically encoded as brief bursts of signals. These signals travel along the microscopic wiring that connect the brain's nerve cells into complex circuits. Information is encoded in the frequency of the signals within a burst, and the duration of each burst. This frequency-coded information is processed at the contact points between nerve cells (synapses). Almost all neuroactive drugs target synapses, where they alter information processing. Most of the in ....Information moving through the brain is typically encoded as brief bursts of signals. These signals travel along the microscopic wiring that connect the brain's nerve cells into complex circuits. Information is encoded in the frequency of the signals within a burst, and the duration of each burst. This frequency-coded information is processed at the contact points between nerve cells (synapses). Almost all neuroactive drugs target synapses, where they alter information processing. Most of the information about how neuroactive drugs work has been acquired from experiments performed under steady-state conditions. Typically, drugs are applied at a constant concentration and a synapse is stimulated at an unrealistically low frequency. The data obtained under these conditions are very useful, but tell only part of the story. For example, during an extended burst of signals, some neuroactive drugs may be displaced from their synaptic binding sites, reducing their effectiveness. In contrast, other drugs can only bind when synapses are active, and their effectiveness will increase during a burst of signals. For optimal drug design and delivery, it is important to understand how drugs work during bursts of activity. To date, the highly dynamic, non-equilibrium conditions encountered at central synapses have not been extensively studied. The central goal of this research proposal is to investigate the dynamic properties of synapses, and the drugs that modulate them. The results will provide insights into information processing in the brain, and will have significant implications for the development and targeting of clinically relevant neuropharmacological compounds.Read moreRead less
Chronic inflammation underlies common and debilitating diseases and causes pain by unknown mechanisms. There is an urgent need to gain a deeper understanding of the mechanisms of chronic pain, which will allow the development of improved therapies with fewer side-effects. Our research program investigates the mechanisms of pain that are associated with inflammatory bowel disease and irritable bowel syndrome, with the goal of developing more effective and selective therapies.
Discovery And Development Of Better Pain Treatments
Funder
National Health and Medical Research Council
Funding Amount
$9,613,850.00
Summary
Many forms of pain remain poorly treated, leading to significant quality of life and economic losses. This Program grant will discover and characterise new peptides from cone snails and spiders that modulate specific channels in nerves that are critical to the transmission of pain signals to the brain. Using advanced chemical and structural approaches, promising leads will be optimised for potency and stability and evaluated in disease and pathway-specific models of pain to establish their clini ....Many forms of pain remain poorly treated, leading to significant quality of life and economic losses. This Program grant will discover and characterise new peptides from cone snails and spiders that modulate specific channels in nerves that are critical to the transmission of pain signals to the brain. Using advanced chemical and structural approaches, promising leads will be optimised for potency and stability and evaluated in disease and pathway-specific models of pain to establish their clinical potential.Read moreRead less
Opioids are the most important drugs used to treat moderate to severe pain, however the development of tolerance limits their usefulness. In addition, clinically important pain states, particularly neuropathic pain, are insensitive to opioid treatment. Human and animal studies indicate that the active ingredient of the plant cannabis sativa, THC, and a number of synthetic cannabinoids also have analgesic, or pain relieving properties. Of particular interest is the finding that cannabinoids enhan ....Opioids are the most important drugs used to treat moderate to severe pain, however the development of tolerance limits their usefulness. In addition, clinically important pain states, particularly neuropathic pain, are insensitive to opioid treatment. Human and animal studies indicate that the active ingredient of the plant cannabis sativa, THC, and a number of synthetic cannabinoids also have analgesic, or pain relieving properties. Of particular interest is the finding that cannabinoids enhance the analgesic actions of opioids. Several brain regions are known to play a pivotal role in the analgesic actions of both opioids and cannabinoids. In previous studies I have identified the cellular and molecular mechanisms by which opioid drugs produce their analgesic effects in single brain cells. However, the cellular mechanisms underlying cannabinoid induced analgesia within the brain are poorly understood. In addition, the cellular actions of cannabinoids and opioids in neuropathic pain states are unknown. The proposed study will determine the cellular and molecular mechanisms underlying the analgesic actions of cannabinoids and opioids in single brain neurons in normal and neuropathic pain states. These techniques have the potential to identify antinociceptive combinations between cannabinoids and other agents with enhanced efficacy and reduced side effects.Read moreRead less
Regulation Of Synaptic Vesicle Biogenesis For Synaptic Transmission
Funder
National Health and Medical Research Council
Funding Amount
$339,115.00
Summary
The overall aim is to better understand the molecular processes of nerve cell communication during learning, memory and abnormal brain activity that cause neurological diseases. The supply and generation (biogenesis) of synaptic vesicles (SVs) in nerve cells is critical to sustain neurotransmission. It requires complex protein interactions and signalling. Thus modulation of SV biogenesis at the molecular level will allows future development of new targeted treatments for neurological diseases.