Neuroanatomical Dynamics Of Attention In Stroke Patients And Healthy Individuals: A Magnetic Stimulation Investigation
Funder
National Health and Medical Research Council
Funding Amount
$360,363.00
Summary
Mechanisms of selective attention are of central importance in guiding human behaviour. The brain uses attention to enhance the processing of information that is behaviourally relevant, and to suppress irrelevant information. The operation of attention within sensory modalities (vision, touch, hearing) has been studied for many decades; however, little is known about how attention combines information between different senses. An understanding of 'crossmodal' attention is important for many reas ....Mechanisms of selective attention are of central importance in guiding human behaviour. The brain uses attention to enhance the processing of information that is behaviourally relevant, and to suppress irrelevant information. The operation of attention within sensory modalities (vision, touch, hearing) has been studied for many decades; however, little is known about how attention combines information between different senses. An understanding of 'crossmodal' attention is important for many reasons. First, real events in the environment provide inputs simultaneously from different locations to multiple senses, and these inputs must be integrated to yield coherent perception. Second, the most basic aspects of human perception depend upon attention; the brain implements selective mechanisms in order to filter the immense quantities of information that constantly bombard our sensory receptors. Finally, many neurological disorders are characterised by impairments of attention; these syndromes are debilitating for the patients themselves, and also place a heavy burden on caregivers and the healthcare system. This project will examine mechanisms of attention in healthy individuals and in stroke patients with attentional deficits. In all experiments, we will employ a new technique in neuroscience called 'transcranial magnetic stimulation' (TMS). TMS enables the safe and reversible stimulation of brain activity in humans. In the current project, we will use TMS with two broad objectives: (i) to determine the key brain areas involved in crossmodal attention in healthy individuals, and (ii) to treat attentional deficits that occur within and between the senses in stroke patients ('magnetic stimulation rehabilitation'). This research will provide important insights into the brain mechanisms that govern selective attention in the healthy brain, and will help guide future methods for managing and treating neurological disorders in which deficits of attention are prominent.Read moreRead less
Crossmodal Interactions In Selective Attention: A Combined Human Lesion/transcranial Magnetic Stimulation Study
Funder
National Health and Medical Research Council
Funding Amount
$188,182.00
Summary
Aspects of attention are of central importance in guiding human behaviour. The brain uses these mechanisms to enhance the processing of sensory information that is currently relevant for behaviour, and to suppress irrelevant sensory information. Although there is a considerable body of knowledge, from both animal and human research, on how attention operates within individual sensory modalities (vision, touch, hearing, etc.), very little is known about how attention integrates information across ....Aspects of attention are of central importance in guiding human behaviour. The brain uses these mechanisms to enhance the processing of sensory information that is currently relevant for behaviour, and to suppress irrelevant sensory information. Although there is a considerable body of knowledge, from both animal and human research, on how attention operates within individual sensory modalities (vision, touch, hearing, etc.), very little is known about how attention integrates information across these different modalities. An understanding of these 'crossmodal' attentional mechanisms is important for several reasons. First, much brain activity in primary sensory areas is modulated by the attentive state of the individual, so discovering how crossmodal attention works will facilitate our understanding of the neural mechanisms of sensory processing generally. Second, the most basic aspects of human perception are fundamentally dependent upon attention; without attention we would perceive inputs from the different senses as fragmentary, rather than as bound together into coherent multimodal representations. Finally, many acquired and developmental neurological disorders are characterised by debilitating impairments of attention. This project will examine crossmodal spatial attention in stroke patients with damage to an exclusively visual brain area (occipital cortex), or to a multisensory brain area (parietal cortex). It will also measure the extent of crossmodal interactions in healthy participants, using cortical transcranial magnetic stimulation (TMS) to induce reversible, 'virtual' lesions that mimic those of the stroke patients. The specific goals of the research are to explain how inputs from the senses of vision and touch interact to give rise to coherent perception; and to provide an empirical foundation for the development of more effective rehabilitative techniques for stroke patients, by exploiting any preserved crossmodal attentional mechanisms.Read moreRead less
Several members of the Flaviviridae family are major pathogens of humans including dengue (DEN), yellow fever (YF), tick-borne encephalitis (TBE), Murray valley encephalitis (MVE), Japanese encephalitis (JE), and hepatitis C virus (HCV). An Australian flavivirus Kunjin (KUN), however, appears to be naturally attenuated and does not cause an overt disease in humans. In contrast, genetically and antigenically closely related to KUN, New York strain of West Nile virus (NY WN) has already caused ~50 ....Several members of the Flaviviridae family are major pathogens of humans including dengue (DEN), yellow fever (YF), tick-borne encephalitis (TBE), Murray valley encephalitis (MVE), Japanese encephalitis (JE), and hepatitis C virus (HCV). An Australian flavivirus Kunjin (KUN), however, appears to be naturally attenuated and does not cause an overt disease in humans. In contrast, genetically and antigenically closely related to KUN, New York strain of West Nile virus (NY WN) has already caused ~500 deaths and over 20,000 registered infections since its emergence in North America in 1999, including 223 deaths and 9122 infections in 2003 alone. Recent studies with DEN indicated that flaviviruses may interfere with early steps of IFN-signalling pathway. The type I Interferon (IFN) response is the first line of defence against viral infections and many viruses have developed different strategies to counteract this response in order to ensure their survival in the infected host. In this grant we seek to exploit our extensive understanding of the molecular biology of KUN virus and the contrasting behaviour of KUN and NY WN viruses to gain an understanding of the role of flavivirus-mediated suppression of host anti-viral IFN response in virus-host relationships and its importance in determining virus virulence.Read moreRead less
SULT4A1 is not a sulfotransferase, but a sulfotransferase inhibitor. It forms high affinity heterodimers with other sulfotransferases via a conserved dimerisation site in its carboxyl terminus attenuating catalytic activity. Consequently, it is important for the metabolism of numerous important molecules including estrogens, thyroid hormones, neurotransmitters and many therapeutic agents.
Drugs are broken down in the body by the process of metabolism. Metabolism is important as both a detoxification and elimination mechanism, and determines dose rate for chronically administered drugs. Many drugs are metabolised by a reaction called glucuronidation. We will characterise the various components of the glucuronidation reaction in an integrated manner in order to understand and predict factors that influence an individual's capacity to metabolise drugs and other chemicals.
Dynamics And Mechanisms Of Immune Complex-mediated Skin Inflammation
Funder
National Health and Medical Research Council
Funding Amount
$526,467.00
Summary
Type III hypersensitivity underlies a number of common autoimmune diseases, including rheumatoid arthritis and lupus erythematosus. These diseases are caused by the deposition of immune complexes (IC) and the accumulation of neutrophils within small blood vessels. We will use real time imaging to dissect in space and time the recruitment of neutrophils and IC deposition during type III hypersensitivity reactions in order to better understand the pathogenesis of these conditions.