THE ROLE OF CHANGES IN THE HIPPOCAMPAL SEROTONIN TRANSPORTER IN THE PATHOLOGY OF SCHIZOPHRENIA
Funder
National Health and Medical Research Council
Funding Amount
$340,317.00
Summary
Schizophrenia is a serious mental illness that affects approximately 1% of the Australian population. The cause of the illness remains unknown but many lines of evidence suggest that changes in the function of a chemical neurotransmitter, serotonin, are involved in the disease process. We have shown a change in the serotonin transporter, a critical component of the brain which controls the actions of serotonin, in the an area of the brain called the hippocampus in subjects with schizophrenia. Th ....Schizophrenia is a serious mental illness that affects approximately 1% of the Australian population. The cause of the illness remains unknown but many lines of evidence suggest that changes in the function of a chemical neurotransmitter, serotonin, are involved in the disease process. We have shown a change in the serotonin transporter, a critical component of the brain which controls the actions of serotonin, in the an area of the brain called the hippocampus in subjects with schizophrenia. This proposal seeks to elucidate the mechanisms by which a change in the serotonin transporter may affect other important molecules in the hippocampus. In addition, we will continue our research designed to assess the usefulness of the 5,7-dihydroxytryptamine treated rat as a possible tool for the study of changes in the serotonin transporter.Read moreRead less
A Study Of The Medial Temporal Lobe In High-risk And Established Schizophrenia Using T2 Relaxometry
Funder
National Health and Medical Research Council
Funding Amount
$358,245.00
Summary
Neurodevelopmental models of schizophrenia suggest that this disorder is associated with a structural brain abnormality present from very early life. This model predicts that brain changes are present before the onset of schizophrenia, and do not change. Our work supports the idea that damage is present from the outset of illness - however, this damage was not evident in a high-risk group of individuals who later developed psychosis. When these patients were rescanned after the onset of the illn ....Neurodevelopmental models of schizophrenia suggest that this disorder is associated with a structural brain abnormality present from very early life. This model predicts that brain changes are present before the onset of schizophrenia, and do not change. Our work supports the idea that damage is present from the outset of illness - however, this damage was not evident in a high-risk group of individuals who later developed psychosis. When these patients were rescanned after the onset of the illness, they exhibited reductions in the volumes of structures that are regarded as critical to the symptoms of schizophrenia. The lack of structural changes in this group before the onset of psychosis may have a number of possible explanations. However, it may be that a number of factors produce the observed changes in the temporal lobe in schizophrenia. Thus, high-risk subjects may have a vulnerability to hippocampal damage that becomes apparent during the transition to psychosis. In order to explore this, our study will examine changes in the hippocampi in three groups of patients, and compare them with matched normal control subjects. The patient groups are: (i) individuals at high-risk, (ii) first-episode psychosis patients and (iii) patients with chronic schizophrenia. The study will rescan the high-risk group to examine hippocampal changes once they have become psychotic. T2 relaxometry is a non-invasive way to examine whether changes in the brain are present in patients with schizophrenia from the outset of illness. T2 will also let us examine the high-risk individuals to see whether such changes are also apparent premorbidly. Using T2 we will be able to examine the nature of these structural changes and assess what processes are in evidence. Our MRI findings present a challenge to the neurodevelopmental hypothesis of schizophrenia. The use of T2 in this study will allow a thorough examination of these findings and will have major implications for this hypothesis.Read moreRead less