Brain Plasticity Following Changes In Sensory Input
Funder
National Health and Medical Research Council
Funding Amount
$312,576.00
Summary
The research proposed here will investigate the mechanisms our brains use to adapt to changes in sensory input, as occurs following blindness, deafness, nerve damage or loss of a limb. The information gathered will help develop treatments for diseases associated with sensory loss, as well as those associated with deficits in our ability to learn and remember, such as Alzheimer's disease.
The human brain has many subdivisions (�areas�) that are dedicated to vision, but in many cases their functions remain unclear. This project will study an area located deep in the brain, about which very little is known, and which appears to be affected from early stages in conditions such as Alzheimer�s disease. By understanding the patterns of electrical activity of cells in this region, and their connections with other brain areas, we hope to decipher their contribution to sensory cognition.
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
The Role Of Adipokines In Modulation Of Gastric Vagal Afferent Satiety Signals
Funder
National Health and Medical Research Council
Funding Amount
$624,535.00
Summary
When we feel full after a meal it is the result of a variety of different nerve signals from the gut in response to distension of the stomach and specific nutrients. These signals are disordered in obesity and may be influenced by factors released from fat stores in the body. The aim of this project is to determine how these factors interact with gastric nerve satiety signals and thus identify targets for the pharmacological treatment of obesity.
Cochlear Mechanisms Of Otoacoustic Emission Generation
Funder
National Health and Medical Research Council
Funding Amount
$311,989.00
Summary
Deafness, both congenital and acquired, is likely to be one of the major causes of disability in the Australian workforce, in young Australians, and in some categories of pre-term infants in the next decade or two. While not life-threatening, hearing impairment deprives individuals of one of their most basic social needs: the ability to communicate with others. Although little can be done to recover lost hearing, it is important to detect hearing loss as early as possible in order to reduce furt ....Deafness, both congenital and acquired, is likely to be one of the major causes of disability in the Australian workforce, in young Australians, and in some categories of pre-term infants in the next decade or two. While not life-threatening, hearing impairment deprives individuals of one of their most basic social needs: the ability to communicate with others. Although little can be done to recover lost hearing, it is important to detect hearing loss as early as possible in order to reduce further loss (by behaviour modification in the case of noise-exposed adults) and to provide hearing assistance in very young children so that they may be exposed to some degree of auditory experience at as early an age as possible. To this end, the phenomenon of otoacoustic emissions, or noises from the ear, now recognised for twenty years, is likely to become even more significant in the early years of the next millennium. Otoacoustic emissions were first demonstrated as very soft echoes re-emerging from the ear after a delay of ten milliseconds or so following a click stimulus. These echoes are sounds produced by the ear as it goes about its normal function and are lost if the hearing sensitivity of the individual is below normal. Several other forms of otoacoustic emissions have been discovered and rapidly applied to the testing of hearing so that today the technique of assessing hearing status in neonates and others unable to co-operate, as well as in diagnostic applications, is widespread. The application of the technique, however, has preceded a real understanding of what otoacoustic emissions are and how they are generated, and their widespread use at the moment is somewhat akin to a car repair industry which does not understand how an engine works. This proposal intends to investigate the basic mechanisms behind otoacoustic emissions in order to improve their efficiency and accuracy of clinical interpretation.Read moreRead less
Interactions Of Gastric Hormones With Vagal Afferent Pathways And The Role Of This System In Obesity
Funder
National Health and Medical Research Council
Funding Amount
$550,918.00
Summary
When we feel full after a meal it is the result of a variety of different nerve signals from the gut in response to distension of the stomach and specific nutrients. These signals are disordered in obesity and this project aims to find out how to correct this problem in this modern day epidemic.
Mechanisms Of Cortical Plasticity And Facilitation Of Functional Recovery Following Stroke
Funder
National Health and Medical Research Council
Funding Amount
$427,500.00
Summary
Specific regions of the human brain have been shown to reorganise following damage to the brain or peripheral nerves. This reorganisation is seen in both young and older subjects and is thought to be useful in helping to restore function. For example, following a stroke a patient may, initially, be unable to move one arm. However, in the following weeks and months some function may return. A number of mechanisms may be responsible for this improvement. However, it is likely that at least some of ....Specific regions of the human brain have been shown to reorganise following damage to the brain or peripheral nerves. This reorganisation is seen in both young and older subjects and is thought to be useful in helping to restore function. For example, following a stroke a patient may, initially, be unable to move one arm. However, in the following weeks and months some function may return. A number of mechanisms may be responsible for this improvement. However, it is likely that at least some of the improvement is due to reorganisation within the sensorimotor cortex. Following the stroke the control of the arm may be taken over by adjacent undamaged regions of the brain. This reorganisation allows impressive functional recoveries to occur. We have preliminary evidence to support the idea that patterns of activity generated in peripheral nerves (afferent input) following stroke may be crucial for the development of the organisational changes seen within the brain. We have shown that by applying specific patterns of sensory input we are able to produce organisational changes within the motor cortex of control subjects. Also, we have been able to induce similar changes in stroke patients. These changes have been accompanied by improvements in motor control. These novel and exciting findings support our hypothesis that by applying certain patterns of afferent input to patients following stroke we will be able to facilitate functional recovery by maximising reoganisation within the cortex. In the present project we will establish the organisation patterns in the brain of stroke patients and contrast the findings with control subjects. Secondly we will investigate the potential for facilitating recovery of stroke patients by the application of specific patterns of afferent input. These novel experiments may lead to important therapeutic developments that will benefit the large population of patients suffering strokes.Read moreRead less