The Extinction Of Conditioned Fear And Its Implications For Cue Exposure Therapy
Funder
National Health and Medical Research Council
Funding Amount
$322,430.00
Summary
This project studies extinction of Pavlovian conditioned fear reactions in rats. Extinction of these reactions is an animal model for exposure therapy used in the treatment of anxiety disorders in people. In exposure therapy, the patient, aided by the clinician, confronts trauma-related cues in the absence of any overt danger. The intention of this therapy is to reduce the ability of the trauma-related cues to provoke the fear reactions that are undermining the patient's quality of life. In Pavl ....This project studies extinction of Pavlovian conditioned fear reactions in rats. Extinction of these reactions is an animal model for exposure therapy used in the treatment of anxiety disorders in people. In exposure therapy, the patient, aided by the clinician, confronts trauma-related cues in the absence of any overt danger. The intention of this therapy is to reduce the ability of the trauma-related cues to provoke the fear reactions that are undermining the patient's quality of life. In Pavlovian conditioning, subjects (typically rats) are exposed to a signaling relation between an initially neutral stimulus (e.g., a noise) and a feared outcome (e.g., foot shock). When later repeatedly exposed to the initially neutral but now feared stimulus (the noise) in the absence of the feared outcome, the fear reactions it acquired progressively decline until eventually it fails to elicit any such reactions. The fear reactions are said to have been extinguished. There has been significant progress in understanding the psychological processes and neural mechanisms underlying the acquisition of fear reactions, but much less is known about the processes and mechanisms underlying the extinction of these reactions. The project has two general objectives. The first is to determine the conditions of extinction training that promote long-term loss of fear reactions. The second objective is to determine how the brain controls this extinction of learned fear. Achieving these aims will be significant for two reasons. First, it will contribute to understanding the mechanisms by which animals (including people) learn to adjust their behaviour to bring it into line with the current relations that exist between events in the world. Second, it will provide important information about how such adjustment is facilitated or impaired across extinction training and, thereby, contribute towards understanding both the successes and failures of cue exposure therapy for fear-related disorders.Read moreRead less
Cognitive Enhancement In Schizophrenia Via Selective Oestrogen Receptor Modulator.
Funder
National Health and Medical Research Council
Funding Amount
$396,380.00
Summary
Cognitive dysfunction in schizophrenia is resistant to treatment and related to poor community functioning and quality of life. In spite of the widely appreciated magnitude of the problem, there is still a critical gap in our knowledge concerning treatments to reverse these cognitive deficits. The proposed research is significant because it will clarify the role of hormones and genes in relation to cognitive deficits in schizophrenia and it may help patients improve their level of functioning.
The Role Of GRHL-3, A Mammalian Homologue Of Drosophila Grainyhead, In Neural Tube Development
Funder
National Health and Medical Research Council
Funding Amount
$496,500.00
Summary
Spina bifida and anencephaly are two common human congenital malformations that form part of a wide spectrum of mutations known collectively as neural tube defects (NTDs). Patients with the most severe form of spina bifida have a failure of the vertebral column and skin to close over the spinal cord and therefore suffer from limb paralysis and marked bladder and bowel dysfunction. Infants with anencephaly have an open cranial vault and failure of normal brain development and die within the first ....Spina bifida and anencephaly are two common human congenital malformations that form part of a wide spectrum of mutations known collectively as neural tube defects (NTDs). Patients with the most severe form of spina bifida have a failure of the vertebral column and skin to close over the spinal cord and therefore suffer from limb paralysis and marked bladder and bowel dysfunction. Infants with anencephaly have an open cranial vault and failure of normal brain development and die within the first few hours of life. These abnormalities occur frequently (1-1000 live births) and are a direct result of failure of the neural tube to close during embryogenesis. NTDs are influenced by both environmental and genetic factors. The best characterised environmental factor is the dietary supplement folate, which when administered before conception results in a reduction in the incidence of spina bifida. The genetic complexity is evidenced by the array of mouse genetic mutations that give rise to NTDs. One of these mouse mutations, known as Curly tail (ct), has served as the major animal model of human NTDs. This is because the ct mice are resistant to folate administration (like most of the cases of spina bifida currently seen in patients) and because the mice seem to have normal development in virtually all other organ systems. Ironically, the genetic mutation that causes the curly tail phenotype has remained undiscovered for over 50 years. We have now identified the gene mutated in the curly tail mice. This gene is highly conserved in humans suggesting that it will play a similar role in neural tube development in man. The gene, known as GRHL-3, is a descendant of a fly gene critical for development of the nervous system in that organism. The studies we propose here will examine the developmental pathways involved in normal neural tube closure in mice and humans and will impact on our understanding of these devastating congenital malformations.Read moreRead less
Hedgehog Signalling In Limb And Craniofacial Development And Disease
Funder
National Health and Medical Research Council
Funding Amount
$494,544.00
Summary
Anomalies of the face and limbs are amongst the most common features of human birth defects, and their frequent association suggests that the same genes are involved in governing the development of the limbs and face during embryogenesis. We have used a genomics-based approach to identify genes involved in limb development based on their alteration in a mouse model which develops extra fingers and toes. Defects in this mouse result from changes in Gli3, a gene which is known to be important in b ....Anomalies of the face and limbs are amongst the most common features of human birth defects, and their frequent association suggests that the same genes are involved in governing the development of the limbs and face during embryogenesis. We have used a genomics-based approach to identify genes involved in limb development based on their alteration in a mouse model which develops extra fingers and toes. Defects in this mouse result from changes in Gli3, a gene which is known to be important in both limb and face development. Based on the organs in which our genes of interest are active, we believe that they will also play key roles in embryonic development of the limbs, face and other organs. We now plan to investigate the regulation of a subset of these genes based on analysis in mouse models of limb and face development. In addition, we have chosen to further analyse the function of a completely novel gene we have identified which our preliminary studies suggest may play a role in the normal development of the lip and palate. These studies have the potential to shed light on the processes governing how organs develop, as well as on the molecular basis of common birth defects such as polydactyly (extra fingers and toes) and cleft palate.Read moreRead less
Hospital Admission, Cerebral Palsy, Intellectual Disability And Birth Defects In Assisted Conception Infants.
Funder
National Health and Medical Research Council
Funding Amount
$115,110.00
Summary
We have recently completed a study examining the prevalence of birth defects in assisted conception infants born in Western Australia from 1993-1997. Contrary to reassuring claims by other researchers in this area, we found that assisted conception infants have a two-fold increased risk of being diagnosed with a major birth defect by one year of age. We now propose to examine other long-term health outcomes in these children. This study involves record linkage between the WA Reproductive Technol ....We have recently completed a study examining the prevalence of birth defects in assisted conception infants born in Western Australia from 1993-1997. Contrary to reassuring claims by other researchers in this area, we found that assisted conception infants have a two-fold increased risk of being diagnosed with a major birth defect by one year of age. We now propose to examine other long-term health outcomes in these children. This study involves record linkage between the WA Reproductive Technology Register and four other population-based databases. The prevalence of cerebral palsy, intellectual disability, hospital admission and birth defects in assisted conception children born in WA between 1993 and 2001 will be compared to that seen in all other Western Australian children born over the same time period. The collection of information on risks associated with assisted conception treatment is vital to allow adequate counselling of couples considering fertility treatment. Cerebral palsy, intellectual disability, birth defects and hospital admission are all serious adverse health outcomes and, despite the introduction of IVF to most Western countries twenty years ago, there are limited data in the literature concerning the occurrence of these conditions in assisted conception infants. Quantifying the contribution of assisted conception treatment to neonatal, infant and childhood morbidity and mortality is also important for the planning of health service provision. Although assisted conception births represent only a small proportion of total births in Australia, these infants may require a disproportionate level of health care services, such as neonatal intensive care treatment due to complications associated with preterm or multiple birth. The wide application of assisted conception treatment in Australia and the increased number of pregnancies achieved by these means reinforce the urgent need for valid data on the health of children born after these procedures.Read moreRead less
Ascending Control Of Behavioural State And Cognition - Role Of Nucleus Incertus And Relaxin-3 Transmission
Funder
National Health and Medical Research Council
Funding Amount
$540,356.00
Summary
Mental illness and dementia are significant social and economic burdens worldwide and knowledge of their underlying causes and more effective therapies are required. Our research aims to use pre-clinical models to characterize a little studied neuronal network implicated in control of brain theta rhythm activity, which could lead to improved treatment of neuropsychiatric diseases such as anxiety and depression, and degenerative cognitive decline.
Investigating The Role Of The UPF3B Gene And Nonsense Mediated RNA Decay (NMD) Process In Mental Retardation.
Funder
National Health and Medical Research Council
Funding Amount
$572,710.00
Summary
Intellectual disability is a frequent and important medical problem. Genetic and environmental factors contribute about equally to the aetiology of intellectual disability. Estimated 1-3% of population suffer from a form of intellectual disability. Among the genetic factors contributing to intellectual disability are genes, and their mutations, on one of the human chromosomes, chromosome X. We have been studying human X-chromosome genes for many years and discovered in excess of 20 novel genes c ....Intellectual disability is a frequent and important medical problem. Genetic and environmental factors contribute about equally to the aetiology of intellectual disability. Estimated 1-3% of population suffer from a form of intellectual disability. Among the genetic factors contributing to intellectual disability are genes, and their mutations, on one of the human chromosomes, chromosome X. We have been studying human X-chromosome genes for many years and discovered in excess of 20 novel genes causing various forms of intellectual disability. Surprisingly the number of genes, in which mutations cause various forms of intellectual disability is unexpectedly high. Just on the human X-chromosome we expect in excess of 200 such genes, which is nearly 30% of the gene content of this chromosome. We propose to study a novel gene, UPF3B, we recently identified to be mutated in a form of intellectual disability. The normal function of this gene and its protein is known to a certain extent. The UPF3B protein plays a role of a guardian of other genes in human (and also other species) cells. The role of the UPF3B protein is to prevent erroneous genetic information to be used for the building of proteins with potentially toxic effects to the organism. In our patients this process clearly malfunctions as a consequence of the damaged UPF3B gene. We propose to shed some more light in to the molecular intricacies of this process with the aim to better understand the mechanics of the process. Families, which participate in our studies and have this gene involved will benefit from the availability of direct test. Multiple other families around the world are also likely to benefit, now or in the future.Read moreRead less