How Changes In The Motor Cortex And Spinal Cord With Exercise Contribute To Fatigue In Humans
Funder
National Health and Medical Research Council
Funding Amount
$311,250.00
Summary
Fatigue with exercise is a common experience in healthy people and can be a problem in many illnesses. With fatigue people are less able to produce force with their muscles. Much of this weakness occurs because of events in the muscles but some results from changes in the nervous system. The size of the contribution of the nervous system to fatigue is not known for the kinds of exercise that cause fatigue in everyday life e.g. prolonged weak contractions like holding the shopping or a plate of f ....Fatigue with exercise is a common experience in healthy people and can be a problem in many illnesses. With fatigue people are less able to produce force with their muscles. Much of this weakness occurs because of events in the muscles but some results from changes in the nervous system. The size of the contribution of the nervous system to fatigue is not known for the kinds of exercise that cause fatigue in everyday life e.g. prolonged weak contractions like holding the shopping or a plate of food, rhythmic contractions like walking or painting a wall, and more vigorous exercise that causes changes in breathing and body temperature. The behaviour of nerve cells in the brain and spinal cord is altered in fatigue but how and why many of these changes occur, and how they affect the control of movements, is poorly understood. Three approaches are planned. In the first set of studies, we will use brain and nerve stimulation to measure the impact of sustained low-level activities on people's ability to drive their muscles fully. We will identify whether such activities, as well as increased demands on other body systems, can cause fatigue in the nervous system. In the second set of studies, we will investigate whether changes in the motor areas of the brain can alter peoples' performance of fatiguing motor tasks or their perception of how much effort the tasks take. Finally, we will use stimulation of the spinal cord to work out why motor nerve cells in the spinal cord fire more slowly with fatigue. Fatigue is an important symptom which is not confined to diseases of any one system in the body. For example, it is a major complaint in multiple sclerosis, cardiac failure, chronic obstructive airway disease, depression and cancer, as well as after chemotherapy, surgery, and viral illness. The implications of better understanding of the contribution of the nervous system to fatigue range from targeting treatments in patients to improving the performance of athletes.Read moreRead less
The human mirror system and the perception of others' actions. This research will provide greater understanding of how the human mirror system operates for the perception of actions, a crucial first-step toward understanding disorders of action perception such as autism and apraxia. The research program will also contribute greatly to building national capacity in cognitive neuroscience research, using advanced brain imaging methods. The fellow actively encourages and mentors young scientists, o ....The human mirror system and the perception of others' actions. This research will provide greater understanding of how the human mirror system operates for the perception of actions, a crucial first-step toward understanding disorders of action perception such as autism and apraxia. The research program will also contribute greatly to building national capacity in cognitive neuroscience research, using advanced brain imaging methods. The fellow actively encourages and mentors young scientists, organises advanced workshops that bring brain imaging researchers around the world to Australia, and builds international collaborations based around high-field brain imaging. The Future Fellowship will substantially enhance these activities, building capacity and enhancing Australia's reputation in cognitive neurosciences.Read moreRead less
The implications of resistance training for the control of movement. Resistance training (or weight lifting) is an essential element of comprehensive rehabilitation programs in a wide range of clinical settings. However, because we know little about how the organization of the nervous system is affected by training with high loads, the consequences of resistance training for our ability to control functional movements are unclear. The ultimate goal of this research is to generate basic knowledge ....The implications of resistance training for the control of movement. Resistance training (or weight lifting) is an essential element of comprehensive rehabilitation programs in a wide range of clinical settings. However, because we know little about how the organization of the nervous system is affected by training with high loads, the consequences of resistance training for our ability to control functional movements are unclear. The ultimate goal of this research is to generate basic knowledge about the impact of resistance training on nervous system function. The research will lead to the design of injury prevention and rehabilitation programs that are maximally effective, and provide a genuine benefit to the community.Read moreRead less
Platform technology to decode motor control through ultra high-field MRI. This project aims to advance our understanding of the poorly understood neural circuits that enable fine motor control in humans. To obtain this knowledge, new platform technology will be developed to capture the full kinematics of the hand during concurrent functional magnetic resonance imaging at ultra high-field. This device will allow testing of fundamental theories describing the canonical microcircuits involved in ha ....Platform technology to decode motor control through ultra high-field MRI. This project aims to advance our understanding of the poorly understood neural circuits that enable fine motor control in humans. To obtain this knowledge, new platform technology will be developed to capture the full kinematics of the hand during concurrent functional magnetic resonance imaging at ultra high-field. This device will allow testing of fundamental theories describing the canonical microcircuits involved in hand motion. Expected outcomes include new evidence of mirror neurons and observation of predictive error signals in the motor cortex. This new knowledge paves the way towards improved computer-brain interface technology which is likely to create benefits through translation to applications such as artificial limb control.Read moreRead less
A common sub-cortical system for human eye and limb control. This project aims to discover how the human brain controls reaching movements via structures and control mechanisms used for rapid eye movements, and for prey capture by lower vertebrates such as fish. Fast and accurate visually-guided movement was crucial for survival long before animals evolved a cerebral cortex, suggesting that basic control systems may be conserved across species. The notion that primitive sub-cortical systems can ....A common sub-cortical system for human eye and limb control. This project aims to discover how the human brain controls reaching movements via structures and control mechanisms used for rapid eye movements, and for prey capture by lower vertebrates such as fish. Fast and accurate visually-guided movement was crucial for survival long before animals evolved a cerebral cortex, suggesting that basic control systems may be conserved across species. The notion that primitive sub-cortical systems can control complex, human limb movements challenges conventional thinking about movement-related brain activity, and has important implications for the design of human-machine interfaces and training protocols in rehabilitation, industry and sport.Read moreRead less
Cortical, Descending And Reflex Control Of Human Inspiratory Muscles
Funder
National Health and Medical Research Council
Funding Amount
$324,500.00
Summary
Of all the skeletal muscles, the breathing muscles perform the most crucial action, that is, they maintain ventilation. The neural control of respiratory muscles must be finely integrated to maintain ventilation while we are awake, asleep, exercising, eating and talking. The neural circuitry for the respiratory muscles is unique. Control of respiratory muscles differs from that of limb muscles because the respiratory motoneurones are activated rhythmically but are controlled via two descending p ....Of all the skeletal muscles, the breathing muscles perform the most crucial action, that is, they maintain ventilation. The neural control of respiratory muscles must be finely integrated to maintain ventilation while we are awake, asleep, exercising, eating and talking. The neural circuitry for the respiratory muscles is unique. Control of respiratory muscles differs from that of limb muscles because the respiratory motoneurones are activated rhythmically but are controlled via two descending pathways. During automatic breathing, descending neural drive arises from the central respiratory pattern generator in the brainstem. Through this system, disturbances are reflexly compensated for without conscious effort. However, in addition, to automatic control, respiration can also be controlled voluntarily from the motor cortex, for example during speech or a breath hold. However, in humans the neural connections and interactions between these two centres are poorly understood. In addition to descending signals, the activity of inspiratory muscles is affected by sensory reflex inputs. The proposed studies will investigate three aspects of the control of human inspiratory muscles that act to 'pump' air into the lungs and upper airway 'dilator' muscles that act to keep the airway open. Because expiration is usually passive during quiet breathing we will focus on the neural control of inspiration. First, we will investigate some of the reflex connections of human 'pump' and 'dilator' muscles in people with and without obstructive sleep apnoea. Second, we will study the descending control of inspiratory muscles using single motor unit recordings. In addition, we will make the first detailed analysis of single motor unit activity from the tongue. This muscle critically helps preserve breathing when we sleep. Finally, we will examine the interactions between the motor cortex and medulla in the control of breathing about which relatively little is known in awake humans.Read moreRead less
The structure and function of the human spinal connectome. This project will use complex network analysis to map the interactions between the brain and body, to understand how the central nervous system controls our movements. The project will provide fundamental insights into mechanisms that coordinate activity in the human motor system, and how the breakdown of coordination may lead to movement disorders. By integrating advanced computational analyses with state-of-the-art recording techniques ....The structure and function of the human spinal connectome. This project will use complex network analysis to map the interactions between the brain and body, to understand how the central nervous system controls our movements. The project will provide fundamental insights into mechanisms that coordinate activity in the human motor system, and how the breakdown of coordination may lead to movement disorders. By integrating advanced computational analyses with state-of-the-art recording techniques, the project will generate new knowledge of the neural basis of human motor coordination. Expected outcomes may support future applications to restore motor function through brain stimulation, prosthetics and robotics design.Read moreRead less
Competing demands on the axial muscles: Effects, consequences, compensations and mechanisms. Back and neck pain are major health issues and are associated with considerable cost to society and an individual's quality of life. A major issue is to identify factors that increase the chance of developing pain. This project will investigate a novel and innovative possibility; that competition between the many functions of the trunk muscles may increase the possibility for injury. We will study how th ....Competing demands on the axial muscles: Effects, consequences, compensations and mechanisms. Back and neck pain are major health issues and are associated with considerable cost to society and an individual's quality of life. A major issue is to identify factors that increase the chance of developing pain. This project will investigate a novel and innovative possibility; that competition between the many functions of the trunk muscles may increase the possibility for injury. We will study how the nervous system coordinates functions as diverse and movement of the spine, breathing, and control of head and eye movement. A key issue will be to identify whether situations arise in which control of the spine is compromised, potentially leading to increased risk of pain and injury. Such data can aid prevention and rehabilitation.Read moreRead less