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
Synaptic Integration And Plasticity In The Rat Piriform Cortex
Funder
National Health and Medical Research Council
Funding Amount
$250,500.00
Summary
The human cerebral cortex is the pinnacle of evolution. It is the most complex structure known, responsible for all of those skills - like language and reasoning - that make our species so remarkable. It is also a major site of many brain diseases, like schizophrenia and epilepsy. An understanding of how the cerebral cortex works would be a remarkable achievement, of immeasurable benefit to human health. How can one go about studying such a complex structure? The strategy taken in this project i ....The human cerebral cortex is the pinnacle of evolution. It is the most complex structure known, responsible for all of those skills - like language and reasoning - that make our species so remarkable. It is also a major site of many brain diseases, like schizophrenia and epilepsy. An understanding of how the cerebral cortex works would be a remarkable achievement, of immeasurable benefit to human health. How can one go about studying such a complex structure? The strategy taken in this project is to begin by studying one of the simplest regions of the cerebral cortex, the olfactory (or piriform) cortex. The olfactory cortex is an evolutionarily ancient region of cortex, with a simpler architecture than other cortical regions. Its task is to process the sense of smell, a primitive sense that is more elaborated in lower animals than in humans. The broad goal of our research is to understand, by studying the olfactory cortex of rats, how olfactory processing occurs at the level of nerve cells (neurons). We will use a number of powerful techniques - including microelectrode recording and laser microscopy - to measure the electrical properties of individual neurons. We will also study the synaptic connections between neurons, and how these connections change following memory-inducing stimuli. It is hoped that this work will shed light on how the healthy cortex is able to process and store information, and how brain diseases cause these functions to deteriorate.Read moreRead less
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 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.
Synaptic Inhibition And The Control Of Excitability In The Rodent Piriform Cortex
Funder
National Health and Medical Research Council
Funding Amount
$459,738.00
Summary
We are studying the properties of neurons (nerve cells) and brain circuits that enable mammals to recognise and remember odours. Our experiments will focus on neurons in the odour-processing region of the cerebral cortex of mice. This work will answer fundamental questions about how the brain interprets sensory inputs in order to build a coherent picture of the external world. Our findings will also provide a deeper understanding of the causes of epilepsy, leading to improved treatments.
Excitability And Hyperexcitability Of Neural Circuits In The Rodent Piriform Cortex
Funder
National Health and Medical Research Council
Funding Amount
$371,807.00
Summary
We are studying the properties of neurons (nerve cells) and brain circuits that enable mammals to recognise and remember odours. Our experiments will focus on neurons in the odour-processing region of the cerebral cortex of mice. This work will answer fundamental questions about how the brain interprets sensory inputs in order to build a coherent picture of the external world. Our findings will also provide a deeper understanding of the causes of epilepsy, leading to improved treatments.