Respiratory-control Deficits In A Model Of Sleep Apnoea During Early Development: Mechanisms And Associations
Funder
National Health and Medical Research Council
Funding Amount
$206,717.00
Summary
A recent study showed that it is possible to induce changes in the respiratory control system of piglets after birth. This new study will examine the mechanism of that change, and develop diagnostic tools that can detect whether similar changes have occurred in babies. The results will help to diagnose the complications of respiratory problems in young babies, and will guide research regarding the potential site of the abnormalities that predispose to SIDS. Piglets have very similar development ....A recent study showed that it is possible to induce changes in the respiratory control system of piglets after birth. This new study will examine the mechanism of that change, and develop diagnostic tools that can detect whether similar changes have occurred in babies. The results will help to diagnose the complications of respiratory problems in young babies, and will guide research regarding the potential site of the abnormalities that predispose to SIDS. Piglets have very similar development of the brain and respiratory system to human infants during early development after birth. This study uses piglets to model exposure to factors that occur during infancy, and thus model some of the common respiratory diseases, including risk factors for the sudden infant death syndrome (SIDS). For example, infants may have upper-airway obstruction during sleep, or may get their face trapped in bed clothes so that they breath a mixture of lower oxygen and higher carbon-dioxide than that found in fresh air. We recently found that, during early development of piglets, repeated exposure to these types of gas mixes depressed respiratory responses tested later. Thus, respiratory responses become less vigorous over time, and this finding could explain how the exposures complicate infants' respiratory problems, or increase their risk for SIDS: Less vigorous responses mean the infant does not wake or move, the exposure becomes more severe, and may finally cause death. This study will examine piglets after such repeated exposure to: 1. find out whether heart-rate variability is reduced, in the same way as babies who later died from SIDS 2. develop a new diagnostic tool, to show the site where the abnormality is located 3. determine whether brain chemical alterations could explain the change in breathing 3. find out if exposure to cigarette smoke, known to increase respiratory problems in babies, causes even more severe disturbance of respiratory control in piglets.Read moreRead less
Previous research has shown that SIDS victims have a number of subtle abnormalities that set them apart from the normal population. These include the occurrence of upper airway obstruction in sleep, a reduced ability to awaken from sleep and abnormalities of the automatic control of heart rate and blood pressure in sleep. These body functions are controlled by a component of the brain called the autonomic nervous system which controls the heart and other internal functions by means of nerves cal ....Previous research has shown that SIDS victims have a number of subtle abnormalities that set them apart from the normal population. These include the occurrence of upper airway obstruction in sleep, a reduced ability to awaken from sleep and abnormalities of the automatic control of heart rate and blood pressure in sleep. These body functions are controlled by a component of the brain called the autonomic nervous system which controls the heart and other internal functions by means of nerves called the parasymmpathetic and sympathetic systems. The purpose of this project is to undertake studies of the autonomic system in normal infants and in those infants who are considered to be at risk for SIDS. As SIDS occurs almost exclusively in sleep it is important to study the infant?s heart rate and blood pressure responses to various challenges whilst asleep. All infants (both controls and subjects) enrolled in the protocol will therefore undergo overnight sleep studies during which their automatic responses to a variety of stimuli will be measured. Once we have established the normal response to these stimuli we can then compare them to the results of the at risk group. If, as we anticipate, there is a difference between our at risk group and the normal controls in automatic function then we will measure some of the stress hormones in the body which reflect the function of the autonomic nervous system. If there is a difference in the levels of these hormones between the normal and the at risk groups which correlates with the expected subtle abnormalities in function we may be able to devise an accessible and quantifiable measure for those infants at risk of SIDSRead moreRead less
Maternal Immune Activation And Adolescent Exposure To Cannabis In Rodents: Do Two Developmental “hits” Lead To Schizophrenia-like Changes In Brain And Behaviour?
Funder
National Health and Medical Research Council
Funding Amount
$636,711.00
Summary
The cause of schizophrenia most likely lies in early brain development due to either genetics or adverse environments. We will examine two successive environmental ‘hits’ in a rat model: infection during pregnancy followed by early adolescent cannabis use. We will track changes in the brain that occur in late adolescence and in young adults. We will also assess behaviour and brain function in adulthood to see if the animals exhibit patterns that mimic those that we see in schizophrenia.
The Effects Of Maternal Infection On Glutamate-related Behavioural, Electrophysiological And Neuropathological Measures Relevant To Schizophrenia
Funder
National Health and Medical Research Council
Funding Amount
$533,136.00
Summary
There are two well known facts about schizophrenia: maternal infection increases the risk of a schizophrenia diagnosis in adulthood and certain drugs, such as PCP, that affect particular brain chemicals induce symptoms and brain changes in healthy individuals that are similar to schizophrenia. Here we bring these two facts together by attempting to develop a maternal infection model in rodents that mimics the brain changes seen in schizophrenia, thus opening up new options for treatment.
Impaired Anticipation Of Sensory Events In Schizophrenia.
Funder
National Health and Medical Research Council
Funding Amount
$307,942.00
Summary
Schizophrenia is a mental illness that costs Australia millions of dollars and hundreds of lives every year. To address this we need to understand more about how schizophrenia develops. A brain measure (mismatch negativity) tracks biological brain changes and functional impairments in daily living that emerge in schizophrenia. It is not yet known if this measure can teach us about vulnerability to developing schizophrenia or only the effect of the disease. This study will address this question.