Signals And Noise: A Study Of The Neurocognitive Mechanisms Underpinning Habituation To Noise In Normal And Damaged Hearing
Funder
National Health and Medical Research Council
Funding Amount
$408,938.00
Summary
McLachlan and Wilson recently published the first model of hearing that combines brain structure with function. This model postulates that recognition mechanisms initiate first, and then regulate the processing of other features. This project will investigate whether recognition mechanisms enable the auditory system to adapt to repetitive (background) noise by predicting and inhibiting responses to these sounds, and any changes in these mechanisms that may accompany hearing damage and tinnitus.
The Role Of Corticothalamic Feedback On The Response Dynamics Of Thalamic Neurons
Funder
National Health and Medical Research Council
Funding Amount
$351,852.00
Summary
A fundamental question in neuroscience is how the brain selectively processes sensory information to generate a reliable representation of the world. Positioned in the centre of the brain, the thalamus plays a key role in sensory processing. This project investigates how the interaction between thalamus and cortex shapes the selection and gating of sensory information. This is a fundamental question in basic neuroscience with the potential to increase our knowledge about attentional deficits.
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
Central pathways regulating visceral pain. This project aims to investigate the neural pathways within the spinal cord and brain processing colorectal pain perception. The project aims to identify the spinal cord neurons relaying colorectal signalling into the brain and the influence of descending modulation from the brainstem upon these pathways. The outcomes will greatly benefit fundamental understanding of the central pathways processing visceral pain.
Cochlear Type II Neurons In Contralateral Suppression
Funder
National Health and Medical Research Council
Funding Amount
$459,434.00
Summary
Sound in one ear affects hearing in the other ear. This contralateral suppression is important for hearing attention and protection from noise damage. We will test the hypothesis that cochlear type II sensory neurons provide the sensory input for this process using models where neuronal development is altered, or the neurons are removed. The study addresses hearing disability in society, facilitating cochlear prosthesis development and the understanding of hearing loss.
Plasticity of gastrointestinal vagal afferents. The aim of this project is to identify how leptin modulates specific subtypes of vagal afferent within the gut and the plasticity of this system under different dietary conditions. This proposed project will substantially increase understanding of the interactions between leptin, known to influence food intake, and vagal afferent satiety signals. It will also increase understanding of how these interactions alter in obesity and ultimately provide t ....Plasticity of gastrointestinal vagal afferents. The aim of this project is to identify how leptin modulates specific subtypes of vagal afferent within the gut and the plasticity of this system under different dietary conditions. This proposed project will substantially increase understanding of the interactions between leptin, known to influence food intake, and vagal afferent satiety signals. It will also increase understanding of how these interactions alter in obesity and ultimately provide targets and/or concepts for the pharmacotherapy of obesity.Read moreRead less
Assembly of neural circuits during development. This program aims to understand how nerve cells wire up accurately during development. Specifically, the program will determine how neuronal connections are established in the retina to produce a sensory structure essential for vision. The program will also generate innovative tools for watching in live animals, the making and breaking of connections during normal and abnormal development. Discoveries will not only significantly increase our knowle ....Assembly of neural circuits during development. This program aims to understand how nerve cells wire up accurately during development. Specifically, the program will determine how neuronal connections are established in the retina to produce a sensory structure essential for vision. The program will also generate innovative tools for watching in live animals, the making and breaking of connections during normal and abnormal development. Discoveries will not only significantly increase our knowledge base of how the nervous system develops or degenerates, but the results will provide crucial information for future studies based on genetic approaches, drug therapies and bioengineering technology to repair the injured nervous system.Read moreRead less
Microglia and the inflammation spectrum - not just good or bad. Cell-mediated tissue clearance following brain injury is a universal mechanism. However, our understanding of the cells that perform these tasks is very limited. Our project will characterise this inflammatory response at a single-cell level using the zebrafish spinal cord as a versatile experimental model. The project is expected to strongly contribute to the molecular understanding of the mechanisms underlying debris removal and w ....Microglia and the inflammation spectrum - not just good or bad. Cell-mediated tissue clearance following brain injury is a universal mechanism. However, our understanding of the cells that perform these tasks is very limited. Our project will characterise this inflammatory response at a single-cell level using the zebrafish spinal cord as a versatile experimental model. The project is expected to strongly contribute to the molecular understanding of the mechanisms underlying debris removal and will advance innovative technologies that facilitate intellectual progress in neuroscience. It will produce new insights into the process of neuronal degeneration, promote Australia’s growing reputation as a global leader in neuroscience, and provide high quality training for early career researchers.Read moreRead less
THE AUTONOMIC, SOMATIC AND CENTRAL NEURAL RESPONSES TO DEEP AND SUPERFICIAL PAIN IN HUMAN SUBJECTS
Funder
National Health and Medical Research Council
Funding Amount
$375,750.00
Summary
Pain is a subjective experience, the intensity of which can be readily influenced by personal experience. Despite this, pain originating from a particular part of the body will usually be described by all individuals as having similar character. For example, pain arising from the skin is commonly described as being sharp or burning and is usually easy to localise, whereas pain arising from muscle is commonly dull, throbbing and diffuse. In addition to producing sensory changes, pain also evokes ....Pain is a subjective experience, the intensity of which can be readily influenced by personal experience. Despite this, pain originating from a particular part of the body will usually be described by all individuals as having similar character. For example, pain arising from the skin is commonly described as being sharp or burning and is usually easy to localise, whereas pain arising from muscle is commonly dull, throbbing and diffuse. In addition to producing sensory changes, pain also evokes changes in blood pressure, heart rate and motor activity (often in an attempt to remove the source of the pain). The proposed research aims to characterise the cardiovascular and motor patterns associated with pain originating in skin and in muscle and to examine the brain regions that produce these changes. More specifically, microelectrodes will be used to investigate changes in peripheral nerve activity during transient painful skin and muscle events in awake human subjects. In a separate investigation functional magnetic resonance imaging will be used to determine brain sites that are activated by skin or muscle pain.Read moreRead less
Operation of nerve cell networks in the neocortex. In humans, intellectual disabilities occur when nerve cells in the neocortex, the most complicated area of the brain, fail to function correctly. The goal of this project is to understand how neocortical areas communicate and how changes in the structure of neurons disturb their function; work that will lead to a better understanding of the operation of the neocortex.