The Structural Basis Of Direction Selectivity In The Retina
Funder
National Health and Medical Research Council
Funding Amount
$401,705.00
Summary
The retina is part of the central nervous system and there are almost one hundred types of retinal neurons which process visual information before it is passed up the optic nerve to the brain. This project examines how some of these neurons are wired together to form a simple neuronal circuit that detects the direction of a moving object. The elucidation of the cellular mechanisms of direction selectivity will provide an important paradigm of complex processing by simple neuronal circuits, with ....The retina is part of the central nervous system and there are almost one hundred types of retinal neurons which process visual information before it is passed up the optic nerve to the brain. This project examines how some of these neurons are wired together to form a simple neuronal circuit that detects the direction of a moving object. The elucidation of the cellular mechanisms of direction selectivity will provide an important paradigm of complex processing by simple neuronal circuits, with direct relevance to information processing in other parts of the central nervous system. In particular, the project may provide strong evidence for two neuronal strategies that may be of general significance. First, information may be processed at a very local level, which would greatly increase the computational power of a single neuron. Second, neurons may make selective contact with only some processes of an input neuron, which would require novel mechanisms for producing the necessary specificity.Read moreRead less
Functional And Structural Imaging Of Auditory Infomation Processing Deficits In Recent-onset And Chronic Schizophrenia
Funder
National Health and Medical Research Council
Funding Amount
$376,000.00
Summary
Abnormalities in the auditory system have long been suspected to be present among people who suffer from schizophrenia and other psychotic disorders, due in part to the high prevalence of auditory hallucinations amongst these patients. Over the last decade, a group of Australian researchers have identified an index of auditory information processing, recorded from scalp electrodes, that is abnormal in patients with schizophrenia, and their biological relatives. The present project will examine t ....Abnormalities in the auditory system have long been suspected to be present among people who suffer from schizophrenia and other psychotic disorders, due in part to the high prevalence of auditory hallucinations amongst these patients. Over the last decade, a group of Australian researchers have identified an index of auditory information processing, recorded from scalp electrodes, that is abnormal in patients with schizophrenia, and their biological relatives. The present project will examine the relationship between these electrophysiological findings, and a new non-invasive technique of functional brain imaging, looking at changes in blood flow, that can identify the specific brain regions that are active during auditory information processing, and link these to the sources of the scalp recorded measures. Both of these functional measures will be examined in relation to the volumes of brain tissue, measured from magnetic resonance imaging scans using new analysis tools, that enable the identification of subtle changes in brain anatomy. By examining patients who have recently developed schizophrenia, those who have suffered from the illness for longer periods of time, and their close relatives, this study will provide the opportunity to identify biological markers of increased vulnerability for the development of schizophrenia.Read moreRead less
The Role Of Action Potentials In Local Calcium Signalling And Induction Of Different Forms Of LTP
Funder
National Health and Medical Research Council
Funding Amount
$330,691.00
Summary
Our understanding of how the brain learns and remembers things is still limited. There is good evidence that changing the strength of the connections (synapses) between brain cells (neurons) can allow information to be stored. One type of synaptic change is called long-term potentiaton (LTP), which is a long-lasting increase in the efficacy of communication between neurons. Recently, I have described 3 different forms of LTP in a region of the brain that is known to be important for learning and ....Our understanding of how the brain learns and remembers things is still limited. There is good evidence that changing the strength of the connections (synapses) between brain cells (neurons) can allow information to be stored. One type of synaptic change is called long-term potentiaton (LTP), which is a long-lasting increase in the efficacy of communication between neurons. Recently, I have described 3 different forms of LTP in a region of the brain that is known to be important for learning and memory. These forms of LTP have different persistence characteristics - LTP 1 is relatively short-lasting, LTP 2 is of intermediate duration, and LTP 3 is very long-lasting and perhaps even permanent. Each form of LTP is selectively triggered by an increase in calcium in a different part of the neuron. In the present study, I will investigate the relationships between electrical activity in different parts of the neuron in order to define the 'rules' for triggering each form of LTP. This information is important for future studies into the specific role played by each form of LTP in learning and memory processing in the brain. A better understanding of the relationship between LTP and learning and memory will assist in developing effective treatment strategies for disorders of memory, including Alzheimer s disease, addictive bahaviour, and learning disorders.Read moreRead less
Brain Plasticity Following Changes In Sensory Input
Funder
National Health and Medical Research Council
Funding Amount
$312,576.00
Summary
The research proposed here will investigate the mechanisms our brains use to adapt to changes in sensory input, as occurs following blindness, deafness, nerve damage or loss of a limb. The information gathered will help develop treatments for diseases associated with sensory loss, as well as those associated with deficits in our ability to learn and remember, such as Alzheimer's disease.
Sleep Disordered Breathing And Neurocognitive Function In Children Post-adenotonsillectomy: Three Year Follow-up
Funder
National Health and Medical Research Council
Funding Amount
$266,536.00
Summary
Snoring is very common and affects at least 10% of children, or an estimated 0.25 million children in Australia. It is associated with deficits in a wide range of neurocognitive areas including intelligence, memory, reasoning, learning and behaviour. We have recently studied a group of 53 snoring children both before and six months after removal of their tonsils and adenoids, to treat suspected upper airway obstruction associated with their snoring. We found that prior to surgery, intelligence, ....Snoring is very common and affects at least 10% of children, or an estimated 0.25 million children in Australia. It is associated with deficits in a wide range of neurocognitive areas including intelligence, memory, reasoning, learning and behaviour. We have recently studied a group of 53 snoring children both before and six months after removal of their tonsils and adenoids, to treat suspected upper airway obstruction associated with their snoring. We found that prior to surgery, intelligence, memory, reasoning, language and behaviour were significantly reduced, by up to 10% compared to 53 non-snoring control children matched by age, gender, social class and area of residence. To our great surprise, at six months after surgery we found that although sleep and behaviour improves, intelligence, memory, reasoning and language development do not. We now wish to study these same children at 3 years after tonsils and adenoids removal, as we believe that if the deficits that we described at 6 months are still present, they are likely now to be permanent. Given the degree of deficit that we have found in snoring compared to non-snoring children, even 6 months after the snoring group of children have been treated, if still present at 3 years post-surgery then it is likely that these deficits will affect the children's future learning potential and academic success. In turn, this would suggest that early identification and treatment of sleep-related upper airway obstruction is critical in preventing long-term deficits in children's daytime functioning and behaviour.Read moreRead less
Modelling Traumatic Brain Injury Using Neuropsychological, Neurosurgical, Neurochemical, And Neuroradiological Measures
Funder
National Health and Medical Research Council
Funding Amount
$403,370.00
Summary
Post mortem and brain imaging studies of patients who have had a traumatic brain injury (TBI) indicate that they sustain both focal damage and widespread diffuse damage. This diffuse damage is more difficult to detect but has been found to occur even after mild injuries and in the absence of focal brain damage. Moreover, diffuse damage is thought to contribute both to changes in a patient's level of consciousness at the time of injury and to the long-term problems experienced by patients after a ....Post mortem and brain imaging studies of patients who have had a traumatic brain injury (TBI) indicate that they sustain both focal damage and widespread diffuse damage. This diffuse damage is more difficult to detect but has been found to occur even after mild injuries and in the absence of focal brain damage. Moreover, diffuse damage is thought to contribute both to changes in a patient's level of consciousness at the time of injury and to the long-term problems experienced by patients after a TBI, suggesting that diffuse damage may provide a valuable index of the amount of brain damage that has been sustained as a result of an injury. While clinicians presently assess many cognitive abilities, they do not target the cognitive problems that are thought to arise from diffuse damage. This is largely due to an absence of validated measures and a limited understanding of the effects of diffuse damage on cognitive functioning. Consequently, we do not have a clear understanding of the extent to which diffuse damage contributes to patient outcome after a TBI. The present study is designed to provide a model of the effects of TBI that will include neuropsychological, neurosurgical, neurochemical and neuroradiological variables. The cognitive effects of diffuse damage will be assessed and related to neurochemical and brain imaging indices of diffuse damage in order to examine the relationship between brain structure and function. This study will improve our understanding of the effects of diffuse damage on cognitive functioning and will lead to the development of measures that can be used to assess the consequences of diffuse damage. In doing so, this study will improve the accuracy with which we are able to diagnose the cognitive problems of patients who have suffered a TBI. This will, in turn, reduce the public health, insurance and litigation costs associated with this type of injury.Read moreRead less
Referral Of Men Newly Diagnosed With Prostate Cancer To A Telephone-based Support Program
Funder
National Health and Medical Research Council
Funding Amount
$299,125.00
Summary
Cancer diagnosis and treatments are stressors of major proportions. There is compelling evidence that providing information, education and counselling services helps reduce emotional distress and improves quality of life among newly-diagnosed cancer patients. The public health challenge for improving the supportive care of cancer patients is to find a cost-effective way to deliver these services to this population. Our response to this challenge is to test an innovative program that involves the ....Cancer diagnosis and treatments are stressors of major proportions. There is compelling evidence that providing information, education and counselling services helps reduce emotional distress and improves quality of life among newly-diagnosed cancer patients. The public health challenge for improving the supportive care of cancer patients is to find a cost-effective way to deliver these services to this population. Our response to this challenge is to test an innovative program that involves the cancer specialist referring newly-diagnosed cancer patients to the Cancer Council Victoria's telephone information service staffed by nurse counsellors, as an integral part of the patient's treatment management. The program involves the nurse counsellor contacting patients and providing information and support at key times in the first six months after diagnosis. In this study, we will focus on prostate and male colorectal patients. The most common registrable cancers in males are prostate and colorectal cancer; male cancer patients are a group known to underutilise support services and among whom less research has been conducted on ways to improve adjustment to a cancer diagnosis and treatment. If effective, this program could provide a way for supportive care to be included among cancer patients, even those treated in rural centres, or where a multidisciplinary team is not yet available.Read moreRead less