Studying The Interaction Of Reelin Deficiency And Environmental Factors In The Development Of Schizophrenia Using Animal Behavioural Models
Funder
National Health and Medical Research Council
Funding Amount
$438,695.00
Summary
Schizophrenia is caused by an interaction of genetic predisposition and environmental risk factors such as stress or drug abuse. Reelin is a protein involved in the normal development of the brain but its levels are markedly reduced in schizophrenia. We will use mice with low levels of reelin in their brain and assess the effect of environmental stress and drugs of abuse. These studies could elucidate gene-environment interaction in schizophrenia and lead to new treatment strategies.
Assessing The Role Of The N-terminus Of The Prion Protein, Emphasising Constitutive Cleavage, In Normal Function And Pathogenesis, As Well As Defining The Relationship Between Intensity Of Surveillance And Sporadic CJD Incidence.
Funder
National Health and Medical Research Council
Funding Amount
$387,469.00
Summary
As a neurologist undertaking research into prion diseases over an extended period, I have been able to lead and participate in many projects that have made significant contributions, such as validation of new diagnostic tests for Creutzfeldt-Jakob disease (CJD), assessment of potential therapeutics, provide insights into the normal function of the prion protein and the underlying pathways causing cellular damage and determine the real significance of apparent clusters of sporadic CJD.
The Role Of Down Syndrome Candidate Region 1 (DSCR1) In Neurotransmitter Release, Vesicle Recycling And Down Syndrome.
Funder
National Health and Medical Research Council
Funding Amount
$352,318.00
Summary
Individuals with Down syndrome (DS) have three copies of human chromosome 21 (HSA21), rather than the normal two. The symptoms observed in DS individuals are therefore due to the overexpression of HSA21 genes. Since all individuals with DS develop symptoms in the brain similar to those see in Alzheimer's disease (AD), there may be a common mechanism that can be traced to the extra gene dosage from HSA21. We are interested in one of these genes, Down syndrome candidate region 1 (Dscr1), which is ....Individuals with Down syndrome (DS) have three copies of human chromosome 21 (HSA21), rather than the normal two. The symptoms observed in DS individuals are therefore due to the overexpression of HSA21 genes. Since all individuals with DS develop symptoms in the brain similar to those see in Alzheimer's disease (AD), there may be a common mechanism that can be traced to the extra gene dosage from HSA21. We are interested in one of these genes, Down syndrome candidate region 1 (Dscr1), which is overexpressed in both DS and AD brains. We hypothesise that Dscr1 has a role in regulating exocytosis, a process in which chemical messengers are released from cells. Exocytosis is highly specialised in the brain where neurotransmitters are released from neuronal synapses in a process known as synaptic transmission. Reduced synaptic transmission is one of the earliest hallmark of DS and AD occurring long before the classical neurological traits of DS and AD such as plaque formation and dementia. We propose that alterations in Dscr1 expression are responsible for the reduced neuronal exocytosis observed in the early stages of DS and AD. We have generated mice in which Dscr1 expression is altered, as occurs in DS and AD brains, and our preliminary studies indicate that exocytosis is reduced in these mice. We now wish to find the intracellular changes responsible for regulating exocytosis when Dscr1 expression is altered. We also aim to compare this to exocytosis in classical DS mouse models which have an extra chromosome 21 and in similar DS mouse models which have normal levels of Dscr1. This project will uncover the currently unknown functions of Dscr1 in exocytosis in an animal model, allow us to gauge whether Dscr1 is solely responsible for altering exocytosis in DS amongst other HSA21 genes, enable us to better understand the mechanisms initiating DS and AD and possibly lead to new targets of early intervention in these diseases.Read moreRead less
Astrocyte-Neuron Communication: Unravelling The Role Of Astrocytes In The Modulation Of Neuronal Circuits
Funder
National Health and Medical Research Council
Funding Amount
$403,064.00
Summary
Astrocytes, a type of glial cell, are the most numerous cell type in the brain. They outnumber their neuronal counterparts by ten times and make up almost 90% of adult brain weight. They were originally thought to have only a supportive role in brain metabolism and the regulation of brain blood flow. It is now known that they also modulate neurons and their synapses through release of vesicles containing specific substances and have key roles in some neuropathic (e.g. pain and epilepsy) and neur ....Astrocytes, a type of glial cell, are the most numerous cell type in the brain. They outnumber their neuronal counterparts by ten times and make up almost 90% of adult brain weight. They were originally thought to have only a supportive role in brain metabolism and the regulation of brain blood flow. It is now known that they also modulate neurons and their synapses through release of vesicles containing specific substances and have key roles in some neuropathic (e.g. pain and epilepsy) and neurodegenerative states (e.g. Alzheimer's disease, Parkinson's disease, and multiple sclerosis). Many of these diseases are associated with a pathological astrocyte process known as 'reactivity'. This process remains enigmatic, resulting in so-called reactive gliosis, a reaction characterized by changes in gene expression, cell enlargement and changes in cell shape, and, in some cases, cell division. Most of the research on astrocyte reactivity has focused on the impairment of astrocyte metabolic activities. Comparatively little is known about the effect of reactive gliosis on so called 'newer' astrocyte roles such as their ability to interact with each other and nearby neurons using exocytosis of gliotransmitters (GTs: glutamate and ATP) and neurotrophic factors (NTFs: glial and brain derived neurotrophic factors). This project will both further investigate the normal mechanisms of astrocyte-neuron communication, and examine the effects of astrocyte reactivity on these mechanisms. The aim is to identify possible therapeutic targets to ameliorate the detrimental affects of neurodegeneration.Read moreRead less