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
Distribution Of Neurotransmitter Receptors On Identified Cell Populations In The Primate Retina
Funder
National Health and Medical Research Council
Funding Amount
$421,812.00
Summary
Neurons (nerve cells) communicate with each other by releasing chemicals called neurotransmitters at specialized sites called synapses. Each neuron has synaptic receptors, which determine how it will respond to neurotransmitters released by other neurons. The molecular structure and function of these receptors is well understood. Much less is known about the rules that govern which receptor types are expressed by each type of neuron, and how these receptors are distributed to the appropriate syn ....Neurons (nerve cells) communicate with each other by releasing chemicals called neurotransmitters at specialized sites called synapses. Each neuron has synaptic receptors, which determine how it will respond to neurotransmitters released by other neurons. The molecular structure and function of these receptors is well understood. Much less is known about the rules that govern which receptor types are expressed by each type of neuron, and how these receptors are distributed to the appropriate synapses so as to allow the normal function of the nervous system. We will study the distribution of neurotransmitter receptors on identified neurons in the retina. The retina is part of the central nervous system and its highly ordered structure makes it an ideal model nervous system. We will compare the distribution of receptors on neurons that play distinct functional roles in colour and movement detection. These experiments will advance our understanding of the normal functioning of the nervous system.Read moreRead less
Synaptic Connectivity Of Colour Pathways In Primate Retina
Funder
National Health and Medical Research Council
Funding Amount
$367,500.00
Summary
The first step in the visual process occurs when light enters the eye and activates specialised nerve cells called photoreceptors. The photoreceptors for daytime vision (called cones for their cone-like shape) comprise three types, which are sensitive to the long- (red), medium- (green) or short-wavelength (blue) regions of the visible spectrum. Although the properties of the cones are well known, the way in which they are functionally connected to nerve pathways for vision is not clearly unders ....The first step in the visual process occurs when light enters the eye and activates specialised nerve cells called photoreceptors. The photoreceptors for daytime vision (called cones for their cone-like shape) comprise three types, which are sensitive to the long- (red), medium- (green) or short-wavelength (blue) regions of the visible spectrum. Although the properties of the cones are well known, the way in which they are functionally connected to nerve pathways for vision is not clearly understood. Clinical research has shown that reduced sensitivity to blue light is a feature of the early stages of certain visual diseases (for example, glaucoma), so it is important to know how the short-wavelength (blue) cones contribute to visual functions such as form, motion and colour perception. Such knowledge can help to design better tests for diagnosis of visual disorders, and will improve our understanding of the normal function of the visual system in the human brain. In this project the connections of neurones in the primate retina (the nerve cells which line the back of the eye) will be analysed. The blue cones and other nerve cells will be identified using contemporary anatomical methods (double- and triple-label immunocytochemistry) combined with a new method for high-resolution light microscopy, called deconvolution microscopy. Immunocytochemistry is a method borrowed from the field of immunology, where specific antibodies are raised which bind selectively to label specific populations of neurones. Deconvolution microscopy allows rapid and simultaneous visualisation of multiple labelled cell classes, at a resolution close to the limit of the light microscope. Together, these techniques allow the wiring diagram of the blue cones within the retina to be analysed to a higher level of accuracy than previously achieved. The results will improve our understanding of the role of blue-cone circuits in normal vision and visual disorders.Read moreRead less
Identification Of Novel Regulatory Factors In Midbrain Development To Improve Cell Therapies For The Treatment Of Parkinson’s Disease
Funder
National Health and Medical Research Council
Funding Amount
$311,860.00
Summary
Cell transplantation is one of the most promising therapeutic strategies for the treatment of Parkinson’s disease. Cells are transplanted directly into the brain of the patient and can compensate for those lost to the disease. In this project we are identifying new genes that regulate the normal development of the transplanted cells in mice. We hope to use this knowledge to improve the reliability and effectiveness of the approach, bringing the therapy closer to the clinic.
Epilepsy And Stress: An Explanatory Electrophysiological Model
Funder
National Health and Medical Research Council
Funding Amount
$100,233.00
Summary
Epilepsy is one of the most common recurrent neurological disorders worldwide, affecting between 1 and 2% of the population. The cascade of events culminating in epilepsy, or the role of seizures in altering brain structures and circuits has been difficult to define. Previous work from our group has shown that stress markedly accelerates the process of epilepsy development. I am developing a model of brain functioning from observed brain cells to chart the changes associated with seizures, stres ....Epilepsy is one of the most common recurrent neurological disorders worldwide, affecting between 1 and 2% of the population. The cascade of events culminating in epilepsy, or the role of seizures in altering brain structures and circuits has been difficult to define. Previous work from our group has shown that stress markedly accelerates the process of epilepsy development. I am developing a model of brain functioning from observed brain cells to chart the changes associated with seizures, stress, and potential treatments.Read moreRead less
Neogenin: A Regulator Of Neuronal Differentiation And Migration In The Adult Brain
Funder
National Health and Medical Research Council
Funding Amount
$334,053.00
Summary
Conditions such as Alzheimer�s and Huntington�s diseases, as well as stroke, represent a major burden of disease in Australia. One goal of modern neurobiology is to harness the brain's ability to make new neurons so that we can replace those damaged by disease or injury. We will investigate how an important developmental molecule, Neogenin, promotes the production of new neurons in the adult brain. A second goal is to show that Neogenin can be activated to promote the repair of the damaged brain ....Conditions such as Alzheimer�s and Huntington�s diseases, as well as stroke, represent a major burden of disease in Australia. One goal of modern neurobiology is to harness the brain's ability to make new neurons so that we can replace those damaged by disease or injury. We will investigate how an important developmental molecule, Neogenin, promotes the production of new neurons in the adult brain. A second goal is to show that Neogenin can be activated to promote the repair of the damaged brain.Read moreRead less
Using Stem Cells And Bioengineered Scaffolds To Promote Regeneration Following Necrotic Brain Injury
Funder
National Health and Medical Research Council
Funding Amount
$710,857.00
Summary
A number of injuries, including stroke, result in tissue loss. Consequently promoting repair will require restoration of tissue structure, replacement cells and a supportive environment to promote integration of these new cells. This study will engineer and develop novel scaffolds that can replace tissue whilst additionally providing physical and chemical support for newly implanted stem cells. This work will be conducted in an animal model of stroke.
If stem cell transplantation is to be useful to repair brain injury, advancement must be made to improve the delivery, survival and differentiation of transplanted cells so that they can sufficiently integrate into the host brain. Here, self-assembling peptides will be developed to provide physical and biochemical support for stem cells and neurones in cell culture (which may be useful for drug discovery) and following transplantation into the injured brain.
Neogenin: A Molecular Determinant Of Neural Progenitor Polarity And Function
Funder
National Health and Medical Research Council
Funding Amount
$569,296.00
Summary
The neuroepithelium (NEP) contains the embryonic neural stem cells essential for the production of all neurons in the adult brain. Failure in NEP function leads to devastating neural tube defects and syndromes such as epilepsy, schizophrenia, and mental retardation. This project will identify the molecular mechanisms regulating NEP stem cell activity and the birth of new neurons in the embryonic neocortex.