Central, Reflex And Mechanical Factors In The Control Of Human Breathing Muscles.
Funder
National Health and Medical Research Council
Funding Amount
$497,968.00
Summary
We will study the neural output to human inspiratory muscles and how it is related to mechanical effectiveness for breathing and then how this relationship can change with respiratory disorders such as chronic obstructive pulmonary disease and obstructive sleep apnoea. We will also examine the spinal reflex connections of human breathing muscles in people with spinal cord injury. This work promises new understanding of the basic control of respiration and how it changes with disease.
My work investigates the neural output to human inspiratory muscles and how it is related to mechanical effectiveness for breathing. The aim is to discover how this relationship can change with respiratory disorders such as chronic obstructive pulmonary disease and obstructive sleep apnoea. I also examine the changes in breathing muscle control in people with spinal cord injury. This work promises new understanding of the basic control of respiration and how it changes with disease.
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 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
Experimental and computational assessment of the mechanical, musculo-skeletal and neuromuscular contributions to rhythmic multi-joint arm movements. The human body is a complex mechanical system that is controlled by a vast neural network comprising many millions of connections. To date, realistic descriptions of the interactions between these neuro-mechanical features have proved elusive. This project seeks to develop a mathematical model that accurately describes the essential features of the ....Experimental and computational assessment of the mechanical, musculo-skeletal and neuromuscular contributions to rhythmic multi-joint arm movements. The human body is a complex mechanical system that is controlled by a vast neural network comprising many millions of connections. To date, realistic descriptions of the interactions between these neuro-mechanical features have proved elusive. This project seeks to develop a mathematical model that accurately describes the essential features of the control system for human movement, and yet is simple enough to inform the design of artificial devices to generate or assist movement. The knowledge derived should improve mechanical and neural prosthetic systems, and guide rehabilitation protocols. The work will ultimately provide a considerable benefit to the community by reducing the social cost of a range of movement disorders.Read moreRead less
An inverse control approach to resolving the neural basis of spatial and muscular dependencies in coordinated multi-limb movements. Each year 48,000 Australians suffer from stroke with many survivors left with problems that limit limb function. With reduced duration of hospital care, the opportunities for retraining in the period immediate following stroke are rapidly diminishing. Effective and efficient strategies of rehabilitation that will maximise the level of recovery following stroke will ....An inverse control approach to resolving the neural basis of spatial and muscular dependencies in coordinated multi-limb movements. Each year 48,000 Australians suffer from stroke with many survivors left with problems that limit limb function. With reduced duration of hospital care, the opportunities for retraining in the period immediate following stroke are rapidly diminishing. Effective and efficient strategies of rehabilitation that will maximise the level of recovery following stroke will result in benefits expressed in terms of enhanced quality of life and functional life-span, as well as significantly reduced costs of health care. In understanding the fundamental principles underlying the stability and adaptability of movement coordination, this research is likely to make a significant contribution to the design of programs for movement rehabilitation.Read moreRead less
Cortical Mechanisms Mediating Bilateral Interactions Between the Upper Limbs. Each year 40,000 Australians suffer from stroke with many survivors left with problems that limit limb function. With reduced duration of hospital care, the opportunities for retraining in the period immediate following stroke are rapidly diminishing. Effective and efficient strategies of rehabilitation that will maximise the level of recovery following stroke will result in benefits expressed in terms of enhanced qual ....Cortical Mechanisms Mediating Bilateral Interactions Between the Upper Limbs. Each year 40,000 Australians suffer from stroke with many survivors left with problems that limit limb function. With reduced duration of hospital care, the opportunities for retraining in the period immediate following stroke are rapidly diminishing. Effective and efficient strategies of rehabilitation that will maximise the level of recovery following stroke will result in benefits expressed in terms of enhanced quality of life and functional life-span, as well as significantly reduced costs of health care. In understanding the fundamental principles underlying the stability and adaptability of movement coordination, this research is likely to make a significant contribution to the design of programs for rehabilitation of the upper limb.Read moreRead less
The neural basis of interlimb coordination. The aims of the proposed research program are to increase our understanding the control of voluntary movement. It is expected that the outcomes of this research program will have eventual application to a number of acquired movement deficits, in particular those arising from spinal cord and brain injury. This research will also be of diagnostic value in determining the integrity of the motor pathways, in both acquired and developmental movement disorde ....The neural basis of interlimb coordination. The aims of the proposed research program are to increase our understanding the control of voluntary movement. It is expected that the outcomes of this research program will have eventual application to a number of acquired movement deficits, in particular those arising from spinal cord and brain injury. This research will also be of diagnostic value in determining the integrity of the motor pathways, in both acquired and developmental movement disorders.Read moreRead less
Spatio-Temporal Precision of Interceptive Action. Interceptive actions like hitting a moving target require precise, accurate positioning and timing. This project aims to empirically document how spatial and temporal constraints affect performance of interceptions and to quantify the speed-accuracy trade-off for interceptions. The speed-accuracy trade-off for movements aimed at stationary targets has been extensively documented - slower movements are more accurate. There has been no correspondin ....Spatio-Temporal Precision of Interceptive Action. Interceptive actions like hitting a moving target require precise, accurate positioning and timing. This project aims to empirically document how spatial and temporal constraints affect performance of interceptions and to quantify the speed-accuracy trade-off for interceptions. The speed-accuracy trade-off for movements aimed at stationary targets has been extensively documented - slower movements are more accurate. There has been no corresponding documentation for interception. This project will fill the gap and provide a rich data set for developing an understanding of interception through modeling work. An understanding of the factors governing interception has potential applications in road safety, sports and neurological rehabilitation.Read moreRead less
Interceptive Action: Performance, Neuromotor Control and Learning. Natural, everyday environments are dynamic. People, animals and other objects move around and human behaviour must be geared to these motions: people must anticipate where things are going and when they will get there so that undesirable collisions and contacts can be avoided and desirable ones achieved. This project investigates basic modes of interacting with dynamic environments - intercepting and evading objects in motion. T ....Interceptive Action: Performance, Neuromotor Control and Learning. Natural, everyday environments are dynamic. People, animals and other objects move around and human behaviour must be geared to these motions: people must anticipate where things are going and when they will get there so that undesirable collisions and contacts can be avoided and desirable ones achieved. This project investigates basic modes of interacting with dynamic environments - intercepting and evading objects in motion. The aim is to extend our understanding of the principles, control mechanisms and brain structures involved. Such understanding has the potential to contribute to areas such as road safety, autonomous robotics, sports training and neurological rehabilitation.Read moreRead less