The Role Of Ten-m3 In Patterning Ipsilateral Retinal Projections
Funder
National Health and Medical Research Council
Funding Amount
$453,042.00
Summary
The normal functioning of the brain depends on connections of billions of nerve cells or neurons. We have found that a protein called Ten_m3 plays a very important role in specifying the way that neurons from the eye connect to the brain. The role of this protein is so important that mice which lack the protein behave as if they are blind. The aim of this project is to understand how this protein controls the development of the visual system.
Network Properties Of Colour Pathways In Primates.
Funder
National Health and Medical Research Council
Funding Amount
$594,891.00
Summary
This project concerns the way in which the eye and brain work together, to enable perception of the colour, form, and movements of objects in the visual world. It is thought that these different attributes of the visual environment are signalled by several parallel nerve pathways in the visual system, but the nature of the neuronal code carried by these pathways remains poorly understood. The aim of our project is to address this basic question, in experimental studies of the intact primate visu ....This project concerns the way in which the eye and brain work together, to enable perception of the colour, form, and movements of objects in the visual world. It is thought that these different attributes of the visual environment are signalled by several parallel nerve pathways in the visual system, but the nature of the neuronal code carried by these pathways remains poorly understood. The aim of our project is to address this basic question, in experimental studies of the intact primate visual system. We plan two sets of experiments. Firstly, we will test the hypothesis that signals for both high-acuity form vision and red-green colour vision can be carried along a single neuronal pathway. We will determine whether response timing in nerve pathways provides a clue by which colour and brightness variation in the environment can be discriminated. Secondly, we will study the segregation of colour and acuity-related signals in the brain, using the method of functional optical imaging. This method, which allows nerve activity to be monitored at high resolution, over relatively large areas of the brain surface (cortex), will allow us test the hypothesis that colour signals are segregated to distinct regions of the visual cortex. These experiments address basic questions, but have application to human vision and visual dysfunction. Good acuity is essential for everyday tasks such as reading, and specific defects in colour vision are used for early detection of neurological dysfunction in diseases such as glaucoma and multiple sclerosis. Understanding the properties of neurons which underlie visual perception can thus help us to understand normal visual performance, and to develop better methods for detection and treatments for such disorders.Read moreRead less
A Study Of The Role Of Voltage-gated Potassium Channels In The Process Of Phototransduction, In The Setting Of Photoreceptor Sensitivity Levels And Response Times, And In The Progression Of A Distinctive Form Of Inherited Retinal Dystrophy
Funder
National Health and Medical Research Council
Funding Amount
$360,371.00
Summary
Inherited retinal disease is a major cause of blindness but the genetic basis is extremely heterogeneous. One such disorder, cone dystrophy with supernormal rod ERG, arises from mutations in KCNV2 that encodes a potassium voltage-gated channel protein. The objective of the project is to use animal models of the disease to determine the role of this channel protein in normal visual function and to assess the impact of loss of function on retinal development and function.
The Role Of Dopamine And Other Neuromodulators As Light Signals In The Inner Retina: A Link To Night Blindness Disorders
Funder
National Health and Medical Research Council
Funding Amount
$250,250.00
Summary
Although most human activities can be performed at night as efficiently as during daytime due to the use of artificial light, normal function of the circuits underlying night vision is critical. For example, when driving at night in a poorly illuminated road where the region illuminated by the headlights is processed by the cone circuit that serves daylight in the retina whilst the peripheral areas are processed by the rod driven nighttime circuit. Impairment of night vision and of the dark-ligh ....Although most human activities can be performed at night as efficiently as during daytime due to the use of artificial light, normal function of the circuits underlying night vision is critical. For example, when driving at night in a poorly illuminated road where the region illuminated by the headlights is processed by the cone circuit that serves daylight in the retina whilst the peripheral areas are processed by the rod driven nighttime circuit. Impairment of night vision and of the dark-light switch can have fatal consequences. Night blindness is a symptom characterised by reduced vision in the dark and slow adaptation to dim light. Some congenital night blindness disorders are caused by mutations in the photoreceptor calcium channels which mediate signal transmission. Additionally, patients treated with neuroleptics, a group of drugs which affect the dopaminergic system, suffer night vision disorders. Dopamine acts as a light signal in the retina. AII amacrine cells are pivotal neurones for night vision segregating two channels (ON and OFF) which convey visual information. AII cells are modulated by dopamine and thus, represent interesting targets to study the role of dopamine in the dark-light switch. Much is know about the action of dopamine on transmission of ON signals channelled by AII cells. However, its action on the OFF channel is largely unknown. We believe that some night vision disorders originate by imbalance in the dopaminergic system in the retina and its effects on AII cells. We will test our hypothesis by studying the modulatory effect of dopamine on calcium dependent signal transmission between AII cells and their partners in the OFF channel. Our hypothesis will be further tested by using animal models in which dopamine receptor function is altered. The results of these studies will provide us with an invaluable model to understand the physiological basis of the dark-light switch and of the role of dopamine in night vision disorders.Read moreRead less
Thalamic inputs and cortical microcircuitry underlying the functional architecture of the visual cortex. This project seeks to reveal the fundamental circuitry of the visual cortex that enables visual perception. Such understanding is essential not only for explaining many perceptual disturbances, but also for providing a neuronal basis for developing functionally useful prostheses for the blind.
Dynamic ocular imaging: New tools to study neurodegenerative disease. Neurovascular uncoupling occurs when blood supply and energy production is no longer responsive to the metabolic of nervous tissue. Neurovascular uncoupling is thought to be a key mechanism in the development of debilitating neurodegenerative diseases such as Alzheimer’s disease and glaucoma. This project will be the first study to develop, validate and employ a comprehensive suite to simultaneously image blood flow, oxygen sa ....Dynamic ocular imaging: New tools to study neurodegenerative disease. Neurovascular uncoupling occurs when blood supply and energy production is no longer responsive to the metabolic of nervous tissue. Neurovascular uncoupling is thought to be a key mechanism in the development of debilitating neurodegenerative diseases such as Alzheimer’s disease and glaucoma. This project will be the first study to develop, validate and employ a comprehensive suite to simultaneously image blood flow, oxygen saturation, metabolic activity and retinal function to understand neurovascular uncoupling in aging and age-related neurodegeneration. Read moreRead less
Histamine and non-visual regulation of retinal signalling. This project is internationally competitive, asking basic biological questions about the brain and vision. Of direct national benefit, the new knowledge generated may alter the way we understand how vision works. Ultimately this knowledge may give insight into particular health issues, such as the persistence of visual memory in Post Traumatic Stress Disorder, and age related diseases such as Alzheimer's disease. Further this new kno ....Histamine and non-visual regulation of retinal signalling. This project is internationally competitive, asking basic biological questions about the brain and vision. Of direct national benefit, the new knowledge generated may alter the way we understand how vision works. Ultimately this knowledge may give insight into particular health issues, such as the persistence of visual memory in Post Traumatic Stress Disorder, and age related diseases such as Alzheimer's disease. Further this new knowledge will flow directly into the reputation of our major institutes of higher education and strengthen their place on the world stage. Through both CIs, this research will contribute to the education of both undergraduate and postgraduate science students at The University of Melbourne. Read moreRead less
Using the eye as a window to the central nervous system for improved drug testing. The annual cost of treating brain illnesses is US$250 billion. Each new drug costs about US$900 million to develop. This research will give Pfizer Pty Ltd, the project’s industry partner, a more efficient and direct way of testing whether drugs can get into and affect the brain. This will reduce the cost of drug development, which ultimately means cheaper drugs. The project will develop new technologies to put Aus ....Using the eye as a window to the central nervous system for improved drug testing. The annual cost of treating brain illnesses is US$250 billion. Each new drug costs about US$900 million to develop. This research will give Pfizer Pty Ltd, the project’s industry partner, a more efficient and direct way of testing whether drugs can get into and affect the brain. This will reduce the cost of drug development, which ultimately means cheaper drugs. The project will develop new technologies to put Australia at the forefront of neuropharmaceutical and neuroscience research. A new research platform will foster collaborations with the pharmaceutical industry both within Australia and overseas. This industrial link will promote a unique post-graduate experience by providing exposure to academic and industrial environments for Australian scientists.Read moreRead less
Functional pathways in primate retina. When light enters the eye, specialised nerve cells called photoreceptors transform the light signal into nerve signals. These signals are processed in the retina by two groups of neurones, bipolar and ganglion cells before being sent to higher brain centres. Bipolar and ganglion cells can be subdivided into several types. We will measure which types communicate with each other and which proteins (neurotransmitter receptors) are involved at the site of commu ....Functional pathways in primate retina. When light enters the eye, specialised nerve cells called photoreceptors transform the light signal into nerve signals. These signals are processed in the retina by two groups of neurones, bipolar and ganglion cells before being sent to higher brain centres. Bipolar and ganglion cells can be subdivided into several types. We will measure which types communicate with each other and which proteins (neurotransmitter receptors) are involved at the site of communication between these nerve cells. This study will improve our knowledge of the basis of functional subspecialisation at the earliest stages of the visual process.Read moreRead less
Centre-surround interactions in ageing human vision. Australia has a rapidly ageing population. This project will study how ageing affects the visual perception of objects presented on non-uniform backgrounds. Our ability to discriminate objects from their backgrounds is key to most natural visual tasks. The visual processes involved are known as centre-surround interactions, and are considered fundamental building blocks to human perception. This project will significantly advance our knowledge ....Centre-surround interactions in ageing human vision. Australia has a rapidly ageing population. This project will study how ageing affects the visual perception of objects presented on non-uniform backgrounds. Our ability to discriminate objects from their backgrounds is key to most natural visual tasks. The visual processes involved are known as centre-surround interactions, and are considered fundamental building blocks to human perception. This project will significantly advance our knowledge of which spatial visual mechanisms are altered due to age, supplying key information for understanding and improving visual environments for the elderly, as well as increasing knowledge of the brain mechanisms susceptible to the ageing process.Read moreRead less