Differentiation Of Respiratory Behaviour In The Mammalian Fetus
Funder
National Health and Medical Research Council
Funding Amount
$434,839.00
Summary
Mammalian fetuses are highly active from early in gestation, manifesting patterns of activity that are gradually transformed throughout fetal life, ultimately producing a repertoire of behaviours essential for postnatal survival. These behaviours are of fundamental importance to animals, and none more so than breathing which must perform effectively from the moment of birth. We plan to examine neural control mechanisms that transform a primitive pattern of breathing in the early gestation fetus ....Mammalian fetuses are highly active from early in gestation, manifesting patterns of activity that are gradually transformed throughout fetal life, ultimately producing a repertoire of behaviours essential for postnatal survival. These behaviours are of fundamental importance to animals, and none more so than breathing which must perform effectively from the moment of birth. We plan to examine neural control mechanisms that transform a primitive pattern of breathing in the early gestation fetus into the functional form that effectively ventilates the lungs after birth. In addition to examining the prenatal development of breathing, our program will focus on the developmental fate of a transient behaviour restricted to early development. This early behaviour plays a fundamental role in the development of the motor system before being extinguished under the influence of supraspinal inputs. This program will therefore provide a basis for understanding the mechanisms by which the brain establishes control of the motor circuits of the spinal cord during development. Further, the program is designed to provide a basis for understanding the respiratory problems so common in the preterm human infant.Read moreRead less
Current treatments for chronic pain are limited in their success. This emphasises the need for new insights into the basic mechanisms and nervous system circuitry underlying altered or chronic pain states. Work in animals and patients with chronic pain shows that certain brainstem centres communicate, via descending spinal cord pathways, with small nerve cells in the superficial dorsal horn (SDH) of the spinal cord. These SDH neurones receive and process pain-signalling information from the skin ....Current treatments for chronic pain are limited in their success. This emphasises the need for new insights into the basic mechanisms and nervous system circuitry underlying altered or chronic pain states. Work in animals and patients with chronic pain shows that certain brainstem centres communicate, via descending spinal cord pathways, with small nerve cells in the superficial dorsal horn (SDH) of the spinal cord. These SDH neurones receive and process pain-signalling information from the skin and internal organs, and receive inputs from descending pathways. This descending input can either inhibit or enhance the activity of SDH neurones and subsequent pain perception. Till now it has been difficult to directly examine how descending pain pathways influence the small SDH neurones in the spinal cord. A new approach, which has been developed in our laboratory, now allows us to record from these very small SDH neurones in the spinal cord of an intact deeply anaesthetized mouse. In addition, our technique allows us to examine the recorded SDH neurone s responses to functionally relevant stimuli (brushing or pinching the hindpaw) as well as its physiology and anatomy. This project will use our new techniques to examine the effects of activating descending brainstem pathways that alter the way painful stimuli are processed in the spinal cord. The effects of altered levels of inhibition in the spinal cord will also be studied by using mice with naturally occurring mutations in their inhibitory glycine receptors. We believe a more complete understanding of pain processing mechanisms will be achieved by examining the role of descending pathways in an intact animal preparation. Such data are essential for the development of drug therapies that can successfully target pain syndromes.Read moreRead less
INVESTIGATIONS ON THE REGULATION OF INTERVERTEBRAL DISC CELL MATRIX METALLOPROTEINASES
Funder
National Health and Medical Research Council
Funding Amount
$331,320.00
Summary
Degeneration of the intervertebral disc is a painful disabling condition with major socioeconomic consequences. Medical problems associated with disc degeneration and back-pain, of sufficient severity to warrant consultation with a physician, are experienced by 90% of the population some time during their lives. In man, back pain increases in incidence in the third and fourth decades of life, peaks in the fifties and declines thereafter. Changes in population demographics indicate this problem w ....Degeneration of the intervertebral disc is a painful disabling condition with major socioeconomic consequences. Medical problems associated with disc degeneration and back-pain, of sufficient severity to warrant consultation with a physician, are experienced by 90% of the population some time during their lives. In man, back pain increases in incidence in the third and fourth decades of life, peaks in the fifties and declines thereafter. Changes in population demographics indicate this problem will increase in severity over the next few decades. American Bureau of Census data indicate that between 1990 to 2010 the number of people >45 years will increase from 82 to 124 million, the number of elderly in emerging countries will also increase between 200 to 400% in the next 30 years. In the United States, back-pain is the second most common reason that people visit a physician and medical conditions related to back-pain account for more hospitalisations than any other musculoskeletal disorder. Despite its high incidence, associated problems of incapacity and economic implications, costed at $100 million per annum in Australia in 1992, and US$100 billion globally in 1999-2000 (Dorland Data Networks, PA, USA) the causes of low back-pain are still poorly understood. Disc disease is responsible for 23-40% of all cases of low back-pain. The management of discogenic low back-pain is currently empirical, directed either toward life-style changes to minimise symptomatology or to surgical resection or spinal arthrodesis to restrict articulation. Based on our recent findings and those of colleagues over the last 16 years, it is our strong conviction that it should be possible with a better understanding of disease mechanisms and with the use of modern technologies to inhibit, reverse or ideally prevent disc degeneration. Without such basic research there will be no scientific foundation upon which prospective therapies may be based.Read moreRead less
Investigations Of Cerebrospinal Fluid Flow In Extracanalicular Syringomyelia.
Funder
National Health and Medical Research Council
Funding Amount
$344,441.00
Summary
Cysts in the spinal cord (syringomyelia) develop in children and young adults with congenital spinal cord abnormalities such as spina bifida, and in people of all ages after spinal cord injury or meningitis. Syringomyelia causes pain and paralysis that usually does not improve even with treatment. The current lack of knowledge about the mechanism of spinal cord cyst formation and enlargement is preventing the development of effective therapy. We have previously shown that some types of spinal co ....Cysts in the spinal cord (syringomyelia) develop in children and young adults with congenital spinal cord abnormalities such as spina bifida, and in people of all ages after spinal cord injury or meningitis. Syringomyelia causes pain and paralysis that usually does not improve even with treatment. The current lack of knowledge about the mechanism of spinal cord cyst formation and enlargement is preventing the development of effective therapy. We have previously shown that some types of spinal cord cysts enlarge by the normal fluid surrounding the spinal cord being pumped around small arteries into the centre of the spinal cord. The mechanism of enlargement of post-traumatic spinal cord cysts remains unknown, and this debilitating type of syringomyelia remains difficult to treat. Our hypothesis is that post-traumatic spinal cord cysts also enlarge by fluid being pumped into them around small arteries. A further hypothesis is that reductions of arterial pulsations and of the pressure in the fluid surrounding the spinal cord will prevent or inhibit cyst enlargement. These hypotheses will be tested by examining fluid flow in models of post-traumatic syringomyelia in rats and sheep. We have established a model of post-traumatic syringomyelia in rats and the first phase of the project will be to refine and characterize this model and to reproduce it in sheep. The second phase will be to determine whether these cysts enlarge by a flow of fluid around small arteries that is driven by arterial pulsations, as they do in other types of syringomyelia. The final phase will be to determine whether reducing the pressure in the fluid around the spinal cord prevents cyst enlargement. Confirmation that these techniques prevent cyst enlargement would open up new possibilities for the treatment of human syringomyelia.Read moreRead less