We are able to identify and discriminate objects in the world because of exquisitely detailed and rapid processing of sensory information by neurons in the cortex of the brain. In this project we will examine these operations in neurons in the cortex that receive input from the large face whiskers of the rat. These whiskers are used for fine-grain discrimination and for gauging distance. They are deflected by being actively moved, under muscle control, over objects (active touch) or by being pas ....We are able to identify and discriminate objects in the world because of exquisitely detailed and rapid processing of sensory information by neurons in the cortex of the brain. In this project we will examine these operations in neurons in the cortex that receive input from the large face whiskers of the rat. These whiskers are used for fine-grain discrimination and for gauging distance. They are deflected by being actively moved, under muscle control, over objects (active touch) or by being passively deflected by objects. Deflection results in inputs to the brain that are processed to form the neural basis for very finely detailed perceptual behaviour. In rats, with impoverished visual and auditory senses, the whiskers are the major sensory system for interacting with the world, and are used in navigating the environment and in finding and distinguishing foods. Thus they contribute strongly to the remarkable success of this species. This elegant sensory system has a number of advantages that make it a very good model for the study of brain mechanisms responsible for active fine-grain sensory function. We plan to take advantage of the unique features of this system to define the information processing that occurs in the cortex in this elegantly complex system. This will address an issue relevant to all sensory systems - namely the neural basis of complex fine grain perceptual behaviour. Understanding the mechanisms underlying active tactile perception also has relevance to clinical conditions involving deficits in active touch e.g., in diabetic polyneuropathy (which eventually affects ~50% of diabetics), in leprosy (in which an early sign is damage to active touch). Knowledge of the core brain processes in active touch gained in this study could eventually underpin the ameliorative technologies for such deficits.Read moreRead less
Neural Circuits For Residual Vision After Damage To Striate Cortex
Funder
National Health and Medical Research Council
Funding Amount
$662,220.00
Summary
Brain cells have the ability to rearrange their connections to create alternate pathways, which compensate for loss of function following brain damage. To understand why some people become blind after damage to the visual cortex, and some don't, we will determine how neural connections change following lesions in different stages of life. The project will provide important information that may allow future development of treatments for blindness due to stroke or traumatic brain injury.
The Orexin System: A Link Between Addiction And Depression
Funder
National Health and Medical Research Council
Funding Amount
$378,426.00
Summary
Relapse represents the most significant barrier to the successful treatment of addiction Interestingly, relapse rates are significantly higher amongst addicts with a concurrent mood disorder such as depression. This fellowship will use a number of cutting-edge techniques to explore the role of a hypothalamic peptide called 'orexin' in both relapse and depression and will thereby guide translational research aimed at developing pharmacotherapies designed to treat these disorders.
Neural Circuits For Active Vision In The Primate Cerebral Cortex
Funder
National Health and Medical Research Council
Funding Amount
$632,938.00
Summary
This project will try to understand how we use visual information to identify objects by their shape and motion, in natural situations in which the eyes are moving all the time. This will be accomplished by recording the electrical activity of brain cells while a trained animal is performing different types of tasks, such as tracking a moving object or exploring a scene with its eyes.
Down syndrome (DS) individuals have 3 copies of chromosome 21. I am proposing to do my PhD to investigate the role of a gene existing on chromosome 21 called Intersectin 1. This gene, when over-expressed might be responsible for manifestation of intellectual impairment in Down syndrome. I will be examining the consequence of altered/over-expression of this gene in receptor trafficking, cell signalling and histology of the brain to identify the differences between affected individuals and the nor ....Down syndrome (DS) individuals have 3 copies of chromosome 21. I am proposing to do my PhD to investigate the role of a gene existing on chromosome 21 called Intersectin 1. This gene, when over-expressed might be responsible for manifestation of intellectual impairment in Down syndrome. I will be examining the consequence of altered/over-expression of this gene in receptor trafficking, cell signalling and histology of the brain to identify the differences between affected individuals and the normal population.Read moreRead less
Sensory Coding Mechanisms in Rat Somatosensory System; A Combined Behavioural and Electrophysiological Approach. This inter-disciplinary project spans behavioural sciences, neurophysiology and computational neuroscience. It investigates fundamental questions such as how different aspects of stimuli are presented in sensory areas of the brain and how the animal interprets the neuronal activity in such areas to generate the relevant behaviour. A major problem with making prosthetic sensory devices ....Sensory Coding Mechanisms in Rat Somatosensory System; A Combined Behavioural and Electrophysiological Approach. This inter-disciplinary project spans behavioural sciences, neurophysiology and computational neuroscience. It investigates fundamental questions such as how different aspects of stimuli are presented in sensory areas of the brain and how the animal interprets the neuronal activity in such areas to generate the relevant behaviour. A major problem with making prosthetic sensory devices is the way by which these devices can communicate with the brain. Research into the coding of different features of simple stimuli will provide basic knowledge which can be implemented in prosthetic sensory devices. Read moreRead less
Understanding Cortical Circuitry Underlying Sensory Integration And The Consequence Of Its Developmental Disruption
Funder
National Health and Medical Research Council
Funding Amount
$527,395.00
Summary
The mammalian neocortex is organised into six layers with a systematic pattern of wiring that relies on normal development and balanced activity of neurons. This project combines developmental, electrophysiological, optogenetic behavioural, and computational methods to establish how the properties of the precise structure of cortical circuits impact their function and how disruptions in the balanced activity during development affect circuit formation and function in the mature brain.
How The Lateral Habenula Integrates Behavioral And Autonomic Functions: The VTA Dopamine Connection
Funder
National Health and Medical Research Council
Funding Amount
$819,904.00
Summary
When adverse events occur, the lateral habenula, an old brain nucleus, helps calculate the wisest corrective action by contributing to the “brake” that controls the brain’s dopamine reward system. Our research will show how the lateral habenula links corrective changes in behavior with coordinated changes in temperature. Understanding this link will greatly contribute to understanding the brain mechanisms that regulate our physiology during stressful situations and as part of mental illness.
Chromatic Inputs to Cortical Receptive Fields in Primates. The human eye contains three kinds of receptors for daytime vision, named blue, green and red cones for their sensitivity to different regions of the visible spectrum. It is known that blue cones contribute to brain pathways for colour vision, but recent data suggest there is also 'cross-talk' of blue cone signals to pathways for motion and high-acuity vision. This project comprises precise measurement of blue cone signals, and anatomica ....Chromatic Inputs to Cortical Receptive Fields in Primates. The human eye contains three kinds of receptors for daytime vision, named blue, green and red cones for their sensitivity to different regions of the visible spectrum. It is known that blue cones contribute to brain pathways for colour vision, but recent data suggest there is also 'cross-talk' of blue cone signals to pathways for motion and high-acuity vision. This project comprises precise measurement of blue cone signals, and anatomical tracing of blue cone pathways, in a primate model for human vision. The data will improve our basic knowledge of how the brain processes sensory signals.Read moreRead less
Neuronal Activity And Functional Magnetic Resonance Imaging (fMRI)
Funder
National Health and Medical Research Council
Funding Amount
$367,561.00
Summary
How does brain activity relate to perception and behaviour? How does functional magnetic resonance imaging (fMRI) of the brain, which measures changes in blood oxygen, relate to the activity of single cells? I will address these questions, comparing electrical measurements of single cells and functional images, and advance our understanding of the brain in health and disease.