Determining The Electrical Stimulation Parameters Required To Program The Bionic Eye To Effect Vision.
Funder
National Health and Medical Research Council
Funding Amount
$458,449.00
Summary
Our eyes are invaluable organs that we use for nearly all daily tasks. Loss of vision is devastating but, unfortunately, little can be done at this time. One strategy to restore vision is through a prosthetic to stimulate the retina. For a prosthetic to work, however, we must first understand how the retina encodes the visual image. Our research seeks to decode the retinal signals and determine how a Bionic Eye could be programmed to mimic them.
The Cellular Organisation Of Interneurones In Human Retina
Funder
National Health and Medical Research Council
Funding Amount
$526,454.00
Summary
Our goal is to determine the numbers and types of nerve cells in the human retina: the part of the eye where visual processing starts. This data will serve as a baseline against which effects of visual disease can be measured.
The broad aim of this project is to understand how the eye receives visual signals and sends them to the brain. Our experimental goal is to study the structure of neural connections in a poorly understood division of the visual system, called the koniocellular pathway. The cells of the koniocellular pathway make up close to 10 percent of all projections from the eye to the brain, but their functions are almost completely unknown. The fovea is a specialised region of the retina (the nerve cells w ....The broad aim of this project is to understand how the eye receives visual signals and sends them to the brain. Our experimental goal is to study the structure of neural connections in a poorly understood division of the visual system, called the koniocellular pathway. The cells of the koniocellular pathway make up close to 10 percent of all projections from the eye to the brain, but their functions are almost completely unknown. The fovea is a specialised region of the retina (the nerve cells which line the back of the eye). It is characterised by a very high density of cone photoreceptors, and is essential for high-acuity vision. This makes the fovea the most important part of the primate retina, but the high density of nerve cells there is thought to be the reason why the fovea is especially vulnerable to disease and age-related degeneration. Our aim is to analyse, using high-resolution microscopic techniques, the connections of koniocellular-pathway cells within the retina. We specifically aim to discover whether the koniocellular pathway contributes to foveal vision. Recent work from our and other laboratories has shown that many koniocellular-pathway cells receive functional connections from short-wavelength sensitive (blue) cone photoreceptors. Thus, our study will provide new insights into the connectivity of blue-cone pathways in the fovea. Although these experiments address basic scientific questions, they can lead to improved clinical practice. Understanding the wiring diagram of the retina can inform clinical studies of conditions such as glaucoma, and helps to give a rational basis for development of treatments. For example, dysfunction in blue-cone pathways is an early sign of glaucoma, so understanding the connections of blue-cone pathways in the fovea can lead to improved methods for early detection of this leading cause of blindness.Read moreRead less
Muller Cell Reactivity During Diabetic Retinopathy
Funder
National Health and Medical Research Council
Funding Amount
$258,000.00
Summary
Diabetes is the leading cause of blindness in the working population. In some patients with diabetes, blood vessels within the retina proliferate, haemorrhage or cause retinal detachment. The underlying changes within the retina that lead to the proliferation of blood vessels are not well understood. One of the factors that leads to changes in retinal blood vessels is an increase in growth factors from cells within the retina called Muller cells. Muller cells are vital for the normal function of ....Diabetes is the leading cause of blindness in the working population. In some patients with diabetes, blood vessels within the retina proliferate, haemorrhage or cause retinal detachment. The underlying changes within the retina that lead to the proliferation of blood vessels are not well understood. One of the factors that leads to changes in retinal blood vessels is an increase in growth factors from cells within the retina called Muller cells. Muller cells are vital for the normal function of the retina and are known to be abnormal late in diabetes. They may also be dysfunctional early in diabetes and could play a significant role in causing the early changes seen in diabetes. Therefore a good understanding of how Muller cells change and the time at which they change is vitally important to gain a better understanding of the defects that are associated with diabetes. Furthermore, an understanding of the basic underlying cellular changes that occur in dibaetes will aid the development of more specific therapeutic agents in the future.Read moreRead less
Generation Of Complex Responses In Retinal Ganglion Cells
Funder
National Health and Medical Research Council
Funding Amount
$490,500.00
Summary
The retinal ganglion cells, whose axons form the optic nerve, comprise numerous distinct types, which respond to visual stimuli in either a simple or complex manner. The project will investigate how the complex responses of the direction-selective ganglion cells (DSGCs) and the local-edge-detector ganglion cells (LEDs) are generated. It appears that the retinal neurons providing inhibitory input to DSGCs and LEDs use different neurotransmitters, and the project will investigate how this shapes t ....The retinal ganglion cells, whose axons form the optic nerve, comprise numerous distinct types, which respond to visual stimuli in either a simple or complex manner. The project will investigate how the complex responses of the direction-selective ganglion cells (DSGCs) and the local-edge-detector ganglion cells (LEDs) are generated. It appears that the retinal neurons providing inhibitory input to DSGCs and LEDs use different neurotransmitters, and the project will investigate how this shapes the response properties of the ganglion cells. This will be done both by recording the visually evoked responses of the ganglion cells in an isolated preparation of the retina and by using two-photon laser-scanning microscopy to functionally image the neuronal interactions between the neurons that inhibit the DSGCs.Read moreRead less
The superior colliculus is a brain centre which uses visual information from the eyes and other sensory information, such as sound, to direct the head and eyes towards objects of interest. This project will use current advancements in optogenetics to activate connections to this brain region in order to understand its role in coordinating head and eye movements. This will advance our understanding of how the brain collects and processes visual information to subserve behavioural functions.
The retina lines the back of the eye and sends multiple movies of the visual world to the brain. This project aims to investigate how these multiple information channels are created. Descriptions of the basic pattern of wiring in the healthy retina will help clinical researchers to understand the disruptions that occur in visual disease. The precision of normal retinal wiring also delineates the precision required to restore normal function to a diseased or degenerating eye.