Research Opportunities

OVERVIEW

LABORATORY of NEURAL STRUCTURE & FUNCTION
Injury, Disability and Chronic Pain Research
A/Prof. Kevin KEAY (Head of Discipline)

LABORATORY OF NEURAL STRUCTURE AND FUNCTION
PAIN AND NEUROIMMUNE CROSSTALK
Characterizing the effects of neuropathic pain on appetitive motivational behaviour
Dr Paul Austin

NEUROCHEMISTRY LAB
Effects of alcohol on the expressions and regulation of glutamate transporter GLAST (EAAT1)
A/Prof. Vladimir BALCAR

ANIMAL DEVELOPMENT
Gene expression during development of the sea urchin nervous system
Prof. Maria BYRNE, Dr. Demian Koop

PATHOGENESIS OF ALZHEIMER'S DISEASE
The microvasculature: degeneration, inflammation and Alzheimer’s disease
Dr. Karen CULLEN

PHYSICAL ANTHROPOLOGY & COMPARATIVE ANATOMY
Human osteology with a focus on the identification of skeletal remains
Dr. Denise DONLON

ALZHEIMER'S DISEASE CELL BIOLOGY LABORATORY
Neurodegenerative disease – dissection of mechanisms in cell models and post-mortem human brain.
Dr Claire GOLDSBURY

STUDY OF NERVE CELLS IN THE EYE
A/Prof. Ulrike GRÜNERT

EYE GENETICS RESEARCH
Novel disease gene discovery, Novel disease gene characterization, Investigation of a novel disease gene affecting the lens using a mouse model
A/Prof. Robyn JAMIESON

EMBRYOLOGY UNIT
Role of Rho GTPases in the endode| Room and endode| Room -derived organs.
Dr David LOEBEL, Prof. Patrick TAM

LENS RESEARCH LABORATORY
Normal Lens Biology, Lens Pathology (Cataract)
Prof. Frank LOVICU, Prof. John McAVOY

MOLECULAR NEUROBIOLOGY LABORATORY
Monoaminergic Dynamics following nerve injury
Dr David MOR

FEMALE REPRODUCTION and STRUCTURAL CELL BIOLOGY
Changes in the uterus during ovarian hyperstimulation
Prof. Chris MURPHY, Dr. Laura LINDSAY

ARRESTING THE SPREAD OF DEADLY GLIOBLASTOMA BRAIN TUMOURS
Mechanisms underlying the invasion of glioblastoma brain cancer cells
A/Prof Geraldine O’NEILL

REPRODUCTIVE TOXICOLOGY LABORATORY
Phenytoin and birth defects
Dr Helen RITCHIE

HYPOXIA AND CHANGES IN EMBRYONIC GENE EXPRESSION
Causes of birth defects
Dr Helen RITCHIE, Professor Sally DUNWOODIE

REGENERATIVE MEDICINE
Skin-derived neuroprecursor cells – cell therapy and disease modeling projects
Associate Professor Michael VALENZUELA


PROJECT DETAILS

LABORATORY of NEURAL STRUCTURE & FUNCTION

Injury, Disability and Chronic Pain Research

A/Prof. Kevin KEAY | Room S502, (+61 2) 9351 4132, keay@anatomy.usyd.edu.au

LABORATORY OF NEURAL STRUCTURE AND FUNCTION

Dr Paul Austin | Room E511, (+61 2) 9351 5061, paustin@anatomy.usyd.edu.au

PAIN AND NEUROIMMUNE CROSSTALK
Characterizing the effects of neuropathic pain on appetitive motivational behaviour

Chronic neuropathic pain in humans is associated with disabilities in complex behaviours. In particular, motivated behaviour is reduced, such that chronic pain interferes with work and social activities. In our laboratory we have characterised disabilities in social interactions in a subgroup of rats following chronic constriction injury, CCI, a model of chronic neuropathic pain. Rats in the subgroup displaying disabilities in social interactions also had the least tyrosine hydroxylase (TH) within the Nucleus accumbens (NAcc), a brain region critical for the expression of motivated behaviours. Since TH is the precursor enzyme for dopamine production, it is considered a marker of NAcc dopamine availability. Therefore, our previous results suggest that disability in social interactions could be due to reduced dopamine in the NAcc.

This project will characterize the effect of CCI in a “reward-aversion dilemma”, which specifically tests motivation. This paradigm uses a “light-dark box”, where rats are able to receive a high sucrose reward (muesli bar), but only if they leave the safe (dark) side and enter the light side, which they find aversive. By measuring the amount of time the rat spends eating in the light side, and the total amount of muesli consumed we can assess their underlying motivational level. Initially the project will involve testing uninjured rats in this paradigm, daily for 14 days. This is essential to understand how quickly the rats learn to eat the muesli bar, but also because preliminary findings that rats split into two diverse groups (“high” versus “low” consumers) requires further characterization. The second part of the project will involve characterizing the effect of CCI on these different groups of rats, and will require daily testing for 28 days (14 pre-injury and 14 post-injury). Again from our previous studies we know CCI causes a range of behavioural disabilities across a population of rats, therefore we hypothesize the same will occur in this paradigm. The final part of the project will involve immunohistochemical analysis of brain tissue collected from all behaviourally tested rats.  Specifically, by using an antibody against TH we will target dopaminergic cells of the ventral tegmental area, as well as their terminal projections in the NAcc. Quantified TH levels will be correlated with performance in the reward-aversion dilemma, to see whether motivation to consume the high sucrose reward is related to the dopaminergic system in both uninjured and CCI rats.

NEUROCHEMISTRY LAB

A/Prof Vladimir BALCAR | Room S419, ext 12837, vibar@anatomy.usyd.edu.au          

Effects of alcohol on the expressions and regulation of glutamate transporter GLAST (EAAT1)

The second most abundant glutamate transporter in the CNS is EAAT1 (GLAST). It is located in astrocytes where it acts synergistically with the most commonly expressed glutamate transporter GLT transporting glutamate away from the extracellular space into the astrocytes. Unlike GLT, GLAST transporter seems to fo| Room transient and rather labile complexes with Na/K-ATPase. In addition, it shifts rapidly between the cytoplasm and plasma membrane depending on the demand so that it can rapidly respond to changes in glutamate concentrations outside the cell (Bauer et al 2012).

We hypothesize that alcohol disrupts the orderly shifts of GLAST from cytoplasm to the plasma membrane thus precluding the effective formation of GLAST and Na/K-ATPase complexes and impairing the GLAST function. In vivo, this would disturb the fine regulation of glutamate transport eventually leading to permanently increased extracellular glutamate (“hyperglutamatergic” state, cf. Spanagel et al. 2005). Therefore, the voluntary self-administration of alcohol (drinking) would provide less relief of craving unless the dose keeps going up (cf. Spanagel et al. 2005; for a review see Spanagel 2009). There may be a long-te| Room but, because of the disruption of the above regulatory process, less and less effective compensation by overexpression of GLAST (Flatcher-Bader and Wilce 2008). The beginnings of such process might be observable in our model if we expose the cultured astrocytes to alcohol for long enough time (hours or days) and measure the total expression of GLAST by Western blotting. We can also follow the movements of GLAST in and out of the plasma membrane in the presence of glutamate (or a more effective GLAST substrate D-aspartate) with and without alcohol. The latter methodology is based on a combination of immunocytochemistry using and deconvolution microscopy as available in our Department (Shin et al 2009, Nguyen et al 2009; 2010). GLAST antibodies have been supplied by Prof. David Pow (RMIT, Melbourne).

We also plan to look at the expression of GLAST (as well as other relevant proteins) in human alcoholic brains.

Bauer DE, Jackson JG, Genda EN, Montoya MM, Yudkoff M and Robinson MB (2012) The glutamate transporter GLAST participates in a macromolecular complex that supports glutamate metabolism. Neurochem International 61 566-574; doi: 10.1016/j.neuint.2012.01.013

Flatcher-Bader T and Wilce PA (2008) Midkine and EAAT1 in the human prefrontal cortex 

Alcoholism: Clin Exp Res 32 1849-1858

Nguyen KTD, Buljan V, Pow DV and Balcar VJ (2010) Cardiac glycosides ouabain and digoxin interfere with the regulation of glutamate transporter GLAST in astrocytes Neurochem Res 35 2062-2069

Nguyen KTD, Shin JW, Rae C, Nanitsos EL, Acosta GB, Pow DV, Buljan V, Bennett MR, Else PL and Balcar VJ (2009) Rottlerin inhibits (Na+,K+)-ATPase activity in brain tissue and alters D-aspartate dependent redistribution of glutamate transporter GLAST in cultured astrocytes Neurochem Res 34 1767-1774

Shin JW, Nguyen KTD, Pow DV, Knight T, Buljan V, Bennett MR and Balcar VJ (2009) Distribution of glutamate transporter GLAST in membranes of cultured astrocytes in the presence of glutamate transport substrates and ATP Neurochem Res 34 1758-1766

Spanagel R (2009) Alcoholism: A system approach from molecular physiology to addictive behaviour

Physiol Rev 89 649-705

Spanagel R et al., (2005) The clock gene Per2 influences the glutamatergic system and modulates alcohol consumption. Nature Medicine 11 35-42

ANIMAL DEVELOPMENT

Prof. Maria BYRNE | Room S600, (+61 2) 9351 5166, mbyrne@anatomy.usyd.edu.au

Dr. Demian Koop | demian.koop@sydney.edu.au

Gene expression during development of the sea urchin nervous system

Sea urchins are a leading model for understanding the genetic networks that regulate animal development. Our lab uses Australian sea urchin species to investigate how changes to development have led to the evolution of the unique “five-rayed” organization or the sea urchin body. This will allow us to establish which parts of the genetic blueprint for development have been conserved between sea urchins and vertebrates, and will provide insights into the vertebrate ancestor. Our current ARC funding has allowed us to establish the developmental transcriptome of two local sea urchins, which we are using to investigate the genes involved in many aspects of development including axial patterning – such as Anterior-Posterior and Left-Right, genes involved in skeleton formation and genes involved in the development of the central nervous system. The projects will involve using the transcriptome to identify and characterise the genes involved in these aspects of development. This will involve expression analysis using in situ hybridization and confocal microscopy to map gene expression domains during development. The role of key signaling pathways in skeletogenesis and neurogenesis will be determined by analyzing the effects of pharmacological treatments on development of sea urchin embryos.

PATHOGENESIS OF ALZHEIMER'S DISEASE

Dr. Karen CULLEN | Room S464, (+61 2) 9351 2696, kcullen@anatomy.usyd.edu.au

The microvasculature: degeneration, inflammation and Alzheimer’s disease

The major focus of the laboratory is on the pathogenesis of Alzheimer's disease (AD).  AD is the most common fo| Room of dementia, and its prevalence is increasing as the population ages. The key lesion in the disease is breakdown of the cerebral microvasculature. Our work investigates normal and diseased microvasculature and the relationship of damaged vessels to neurodegeneration. We also examine the processes of inflammation around damaged vessels. An example of the types of projects available: Immunohistochemical study of the microvasculature and inflammation in AD brain tissue. This project involves the mapping of capillary damage and the sequence of inflammatory events from fresh microhaemorrhage to scar formation. The techniques in the lab include tissue processing, immunohistochemistry, brightfield and fluorescence microscopy. We use multidimensional analysis to examine the complex vascular network in human brain.  Additional projects on ischaemic stress in AD microlesions as well as inflammation triggers to neuronal cytoskeleton derangements are available.

PHYSICAL ANTHROPOLOGY & COMPARATIVE ANATOMY

Dr. Denise DONLON | Room W601, (+61 2) 9351 4529, ddonlon@anatomy.usyd.edu.au

Research in the Shellshear Museum focuses on human osteology with a focus on the identification of skeletal remains.  Present research focuses on discriminating between human and non-human bones, taphonomic changes to bone, the anthropometry of early British settlers in Australia and age determination using amino acid racemization of tooth enamel. Collections in the Shellshear Museum, which are available for research, include a large collection of Melanesian skulls, a collection of skeletal remains from Pella, Jordan and casts of human dentition.

ALZHEIMER'S DISEASE CELL BIOLOGY LABORATORY

Dr. Claire GOLDSBURY BMRI, (+61 2) 9351 0878, claire.goldsbury@sydney.edu.au

Neurodegenerative disease – dissection of mechanisms in cell models and post-mortem human brain.

Using cell models and post-mortem human brain tissue, this lab investigates the interactions between tau, cofilin and other proteins that are involved in generating pathological structures involved in neurodegeneration and dementia. This work will help us to understand how these structures could contribute to neurodegeneration and the resulting cognitive decline that characterizes Alzheimer’s and other neurodegenerative disease.

STUDY OF NERVE CELLS IN THE EYE

A/Prof. Ulrike GRÜNERT | Save Sight Institute, (+61 2) 9382 7641, ulrike.grunert@sydney.edu.au

The retina is a thin piece of nervous tissue that lines the back of the eye. It contains five major classes of neurones, which are organised in nuclear and synaptic layers. The project involves the analysis of post-mortem human retinas (obtained from donor eyes with consent from the Lions NSW Eye Bank) and post-mortem monkey retinas. High-resolution light microscopy, in conjunction with immunohistochemical methods will be used for identifying different cell types and their synaptic connectivity. Accurate knowledge of nerve cell populations and their density can allow more accurate prediction of functional properties of normal visual performance, can give a rational basis for understanding the effects of disease and degeneration, and can fo| Room a standard of normal anatomical state against which the effects of dis- ease can be measured.

Skills and knowledge you will acquire:

We are looking for an enthusiastic young scientist to learn neuroanatomical methods including cryostat and Vibratome sectioning of retinas, intracellular injections, double and triple immunofluorescence, high resolution light microscopy (deconvolution and confocal) and image analysis.

EYE GENETICS RESEARCH

A/Prof. Robyn JAMIESON | Children’s Medical Research Institute - The Children’s Hospital at Westmead and Save Sight Institute, (+61 2) 9687 2800, rjamieson@cmri.org.au

In our Eye Genetics research we are investigating the genes and pathways that are critical for normal sight, and that are abnormal in patients with blinding eye conditions such as retinitis pigmentosa, glaucoma, or cataracts.  In this work, we use whole exome and other forms of next-generation sequencing (NGS) to identify novel underlying causative disease genes.  To investigate the ways these genes and proteins contribute to normal function of the eye, we use a range of techniques and strategies including RT-PCR, in situ hybridization, immunohistochemistry, cell-based assays and examination of mouse and zebrafish model systems.  These investigations are fundamental in our work towards improved treatment for people with these blinding eye conditions. 

Projects available in the lab may include one or a combination of the following areas:

Novel disease gene discovery

We have identified a number of patients and families where the underlying disease gene is not yet known, that are suitable for next-generation sequencing investigations including exome and whole genome sequencing.  The diseases under investigation include disorders that affect the retina or lens as well as eye size and structure. This project encompasses techniques in library preparation for next-generation sequencing (NGS), bioinformatic analysis and interpretation of NGS data, PCR, and Sanger sequencing. 

Novel disease gene characterization

Novel candidate disease genes from exome sequencing studies in patients with disorders of the eye, are available for investigation to determine their role in eye development and function.   Techniques used include examination of the spatiotemporal pattern of expression of the candidate genes using RT-PCR, in situ hybridization, and immunohistochemistry.  Cell-based and animal model studies can be undertaken as appropriate for the disease gene under investigation.

Investigation of a novel disease gene affecting the lens using a mouse model

From studies of human patients with cataracts and other abnormalities of the front part of the eyes, we have identified a novel disease gene affecting the lens.  For this project, we have a mouse model with knockout of the disease gene, which leads to abnormal structure of the lens.  Little is known about the function of the encoded protein, but modeling and preliminary data suggest it may play a role in maintaining normal cell adhesion and polarity.  In this project, techniques including morphological and histological examination of the eyes, gene expression microarray, RT-PCR, in situ hybridization, immunohistochemistry and cell-based assays, will be undertaken to examine the pathways and downstream targets of the identified disease gene.

Prokudin I, Simons C, Grigg JR, Storen R, Kumar V, Phua Z, Smith J, Flaherty M, Davila S, Jamieson RV.  Exome sequencing in developmental eye disease leads to identification of causal variants in GJA8, CRYGC, PAX6 and CYP1B1.  European Journal of Human Genetics, accepted September 2013.

Skalicky SE, White AJ, Grigg JR, Martin F, Smith J, Jones M, Donaldson C, Smith JE, Flaherty M, Jamieson RV.  Microphthalmia, anophthalmia, coloboma and associated ocular and systemic features:  understanding the spectrum.  JAMA Ophthalmology, accepted April 2013.

Stark Z, Storen R, Bennetts B, Savarirayan R, Jamieson RV.  Isolated hypogonadotropic hypogonadism with SOX2 mutation and anophthalmia/microphthalmia in offspring.  European Journal of Human Genetics, 2011 Feb 16.

 WeavingL, Mihelec M, Storen R, Sosic D, Grigg J, Tam P, Jamieson RV. Twist2: role in corneal stromal keratocyte proliferation and corneal thickness.  Investigative Ophthalmology and Visual Science, 2010, 51: 5561-5570.

EMBRYOLOGY UNIT

Dr David LOEBEL  | Children’s Medical Research Institute - Westmead, (+61 2) 8865 2953, dloebel@cmri.org.au

Prof. Patrick TAM | Children’s Medical Research Institute - Westmead, (+61 2) 8865 2800, ptam@cmri.org.au

Role of Rho GTPases in the endode| Room and endode| Room -derived organs.

This project addresses a fundamental issue in biology: the formation of tissues and organs from their basic components. Members of the family of small GTPase proteins related to Rho and Cdc42 play multiple roles in regulating cell and tissue architecture and differentiation. This project focuses on the role of Rho GTPase proteins and the proteins they interact with in the acquisition and maintenance of cell and tissue architecture during early development of the embryonic ge| Room layers and organs. This research makes use of conditional mouse mutants that enable us to study loss of gene function, in addition to cell culture bases experiments using in vitro models of epithelium formation. This research will provide novel insights into the mechanisms of formation of major body parts in the early embryo.

LENS RESEARCH LABORATORY

Prof. Frank LOVICU | Room S252, (+61 2) 9351 5170, frank.lovicu@sydney.edu.au

Prof. John McAVOY | Save Sight Institute, (+61 2) 9382 7369, johnm@eye.usyd.edu.au

Research in our laboratory is directed at identifying the molecular mechanisms that regulate eye lens development, growth and pathology. Our research group has two major laboratories, one situated in the Anderson Stuart Building on the main University campus and the other at the Save Sight Institute, Sydney Eye Hospital on Macquarie Street. Using a range of techniques (including tissue culture, immunohistochemistry, in situ hybridisation, PCR, chromatography, Western blotting, light and electron microscopy, in vitro biological assays and transgenic mouse strategies), we investigate the expression, effects and function of different growth factors and their receptors as well as the regulation of their intracellular signalling, both in normal lens development and pathology. To date, we have shown that members of the fibroblast growth factor (FGF) and Wnt families are important regulators of lens epithelial cell proliferation, migration and differentiation and are important for the normal development and maintenance of the lens. Our other studies have also shown that growth factors such as transforming growth factor ß (TGF-ß), induce the formation of fibrotic plaques that lead to cataract (loss of lens transparency), similar to that found in humans.

Students that undertake Honours projects in our laboratory can expect to be exposed to a wide array of techniques, encompassing cellular, developmental and molecular biology, and can carry out a project in one or a combination of the following areas:

Normal Lens Biology

*Investigate the role of growth factors (FGF, PDGF, IGF, EGF, BMPs) and their signalling pathways in regulating lens cell proliferation and fibre differentiation using lens epithelial explants and/or transgenic mouse models.

*Identify factors (related to Wnt signalling) that promote fibre cell alignment and orientation so that lens develops its highly ordered three-dimensional cellular architecture.

*Identify factors that maintain the normal lens epithelial phenotypic characteristics including cell-cell and cell-matrix adhesion and communication.

*Use transgenic mice and in vitro assays to determine the role of novel genes (Crim1, Sef, Sprouty1/2, Spreds1/2/3) thought to be involved in regulation of growth factor bioavailability and signalling.

*Use electron microscopy and tissue culture to identify the molecules in the ocular fluid that are important for lens cell differentiation and how this contributes to lens transparency.

Lens Pathology (Cataract)

*Use transgenic mouse models to understand how TGFß induces and regulates cataract formation.

*Use lens explant cultures to determine how TGFß disrupts normal lens signalling pathways and induces an epithelial-mesenchymal transition, characteristic of cataract.

*Use lens explant cultures to identify putative inhibitors of TGFß signalling as a means of preventing cataract.

MOLECULAR NEUROBIOLOGY LABORATORY

Dr David MOR | david.mor@sydney.edu.au

Monoaminergic Dynamics following nerve injury

A significant proportion of patients who have suffered traumatic nerve injury, following accident or surgery, subsequently experience disability, characterised by anxiety, depression and disturbances in cognition and sleep cycles. The main focus of this lab is on the alterations caused by the nerve injury within the neural network that regulates behavioural and physiological responses to stress and pain. We specifically study differences in serotonergic and dopaminergic neurotransmissions from selected midbrain and brainstem nuclei into two brain regions within this network: the nucleus accumbens and the prefrontal cortex (PFC). The nucleus accumbens is important for regulation of motivational drive. The PFC is considered an executive regulator of the coping responses. Its function is to incorporate and assess information from the environment and responsible for decision making of which behaviour to produce. The project involves identifying individual differences in the regulation these monoaminergic projections that are specific to the expression of disability following a nerve injury. Techniques used will include behavioural testing of rats following a nerve injury, molecular techniques analysing epigenetic differences as well as gene and protein expression, and immunohistochemistry.

FEMALE REPRODUCTION and STRUCTURAL CELL BIOLOGY

Prof. Chris MURPHY | Room N364, (+61 2) 9351 4128, histology@medsci.usyd.edu.au

Dr. Laura LINDSAY | Room N364, (+61 2) 9351 2508, laural@anatomy.usyd.edu.au

The work in this lab is centred around reproductive biology and medicine and in particular the biology of the uterus, uterine receptivity for blastocyst implantation and hormonal influences on the uterus. We are interested in how it is that the uterus manages to tightly regulate those times during the reproductive cycle when it will allow the blastocyst to attach but to prevent attachment and the beginning of a pregnancy at other times. We are particularly interested in uterine epithelial cells and the molecular interactions that occur between the surface of these cells and the implanting blastocyst. A variety of methods are available including light & electron microscopy, immunohistochemistry, Western blotting and PCR. The work uses both animal and human tissues and involves basic cell biological research as well as work on human tissues of direct relevance to the human menopause and to In vitro fertilisation (IVF) programmes. The laboratory also has extensive contacts with The School of Biological Sciences and the Electron Microscope Unit (EMU) which involves a major project on the evolution of viviparity (live birth) and the development of the placenta. This work involves study on mammals and lizards in particular but also other animals to understand the biology of different types of placentas. We also have an interest in one of the major diseases of the uterus which affects over a million Australian women endometriosis - and have collaborations with Westmead hospital to study this disease. We would accept students interested in mammalian reproduction and/or students interested in working on an aspect of the evolution of live birth and placentation. An honours place in conjunction with the EM Unit could also be arranged. We are particularly interested in accepting Honours students who may be interested in progressing to a PhD and have laboratory-funded top-up scholarships available for such students.

 Changes in the uterus during ovarian hyperstimulation

Controlled ovarian hyperstimulation (COH) is part of the in vitro fertilisation (IVF) protocol to harvest multiple eggs from a woman. It has been known for many years that the drugs used in COH leads to a decrease in uterine receptivity, however there is currently no known mechanism of how this occurs. We use a rat ovarian hyperstimulation model (OH) to investigate changes in the rat uterus during OH pregnancy, especially at the time of blastocyst implantation. We use several molecular and histochemical techniques to investigate changes in protein localisation and expression, such as immunofluorescence microscopy, western blotting and ELISAs. We also use a range of microscopy techniques such as light microscopy, transmission electron microscopy and scanning electron microscopy. The ultimate aim of this project is to identify factors or proteins associated with the decreased uterine receptivity in women undergoing ovarian hyperstimulation. A more detailed understanding of these factors may increase the pregnancy rate in IVF procedures.

ARRESTING THE SPREAD OF DEADLY GLIOBLASTOMA BRAIN TUMOURS

A/Prof Geraldine O’NEILL | Children's Cancer Research Unit - Children’s Hospital at Westmead, geraldine.oneill@health.nsw.gov.au

Our lab investigates the mechanisms underlying the invasion of glioblastoma brain cancer cells. Unfortunately, there are currently no successful treatments for this cancer and there have been no improvements for patient survival over the last 20 years. One of the main difficulties in treating brain cancer is the rogue cancer cells that have already escaped the primary tumour at diagnosis and cannot be detected by current imaging technologies. These escaped cells inevitably lead to recurrence of the tumour. Our goal is to understand how the glioblastoma cells so readily invade the normal brain tissue. In particular we focus on how the mechanical features of the normal brain tissue contribute to the invasive journey taken by the brain cancer cells. To investigate these questions we use a range of cell biology approaches and cell culture models that recapitulate the biophysical characteristics and composition of the brain. Techniques employed include fluorescence microscopy, time-lapse microscopy and cell tracking and molecular biology and biochemistry.

REPRODUCTIVE TOXICOLOGY LABORATORY

Dr Helen RITCHIE | Room S449, (+61 2) 9351 9476, helen.ritchie@sydney.edu.au

Phenytoin and birth defects

Our laboratory is interested in why some drugs taken during pregnancy cause birth defects. We use rat models to answer this question. Phenytoin is a drug used to control epilepsy. However it causes cleft lip in humans if taken during pregnancy. The mechanism by which phenytoin causes birth defects remains unknown but there is a strong hypothesis that phenytoin that crosses the placenta slows the embryonic heart causing the fetus to become hypoxic for some hours. If this hypoxia occurs during critical periods of facial development it is thought to induce abnormal development. We are going to test this hypothesis by examining the heart rate of the embryo in vivo by ultrasound and in vitro by embryo culture. There is an alternate hypothesis which proposes that the malformations are caused by hyperglycaemia. We will test this hypothesis by measuring the glucose levels in pregnant rats following a teratogenic dose of phenytoin.

HYPOXIA AND CHANGES IN EMBRYONIC GENE EXPRESSION

Dr Helen RITCHIE | Room S449, (+61 2) 9351 9476, helen.ritchie@sydney.edu.au

Professor Sally DUNWOODIE | Victor Chang Cardiac Research Institute, s.dunwoodie@victorchang.edu.au

Our laboratory is interested in the causes of birth defects. We use animal models to address this issue. Dofetilide is a drug used to control human cardiac arrhythmia. In laboratory animals dofetilide causes birth defects, thus there is a risk that it might cause similar malformations in humans if taken during pregnancy. In rats we have shown that dofetilide slows the fetal heart and causes arrhythmia, leading to fetal hypoxia for some hours (Ritchie et al 2013). We have also established that mouse embryos exposed to 8 hours of hypoxia, half way through gestation, develop defects of the vertebral column (Sparrow et al 2012). We hypothesis that hypoxia induced by dofetilide, will lead to vertebral column defects in mice. To test this hypothesis we will administer dofetilide to pregnant mice and determine the extent to which dofetilide causes hypoxia in embryos. Embryo hypoxia will be determined using two markers, hypoxyprobe (via western blot) and HIF1a expression (via in situ immunofluorescence). We will also examine the effect of dofetilide on the heart rate of embryos exposed to dofetilide in vitro by embryo culture. We have shown that gene-environment interaction causes developmental defects in mice (Sparrow et al 2012). Specifically, embryos genetically susceptible to vertebral column defects develop such defects, when exposed to hypoxia during gestation. We will test if similar interaction occurs between these genetically susceptible embryos and the hypoxia induced by dofetilide.

REGENERATIVE MEDICINE

Associate Professor Michael Valenzuela | BMRI - Building K Level 4, (+61 2) 9114 4136, michael.valenzuela@sydney.edu.au

Skin-derived neuroprecursor cells – cell therapy and disease modeling projects

Neural stem cells (NSCs) can divide indefinitely and under controlled conditions differentiate into the brain’s three main cell types – neurons, glia and oligodendrocytes. Currently, there are three main strategies for obtaining NSCs: from the brain’s neurogenic niches that persist into adulthood, from culture of embryonic stem cells or from genetic engineering of embryonic stem cell-like induced pluripotential cells. Each of these approaches present non-trivial challenges for clinical application and in vitro disease modeling. Our laboratory has therefore developed a protocol for generating skin-derived neural precursors (SKNs) from a small biopsy of mature adult skin. SKNs are most likely of neural crest origin and are both rate- and fate- restricted, capable of 3-5 cells divisions and differentiate almost exclusively into neuron. In culture, SKNs have a strong gabaergic bias that stimulates interest in modeling of neuropsychiatric disorders. SKNs also survive, migrate, elaborate dendrites and display network functionality after hippocampal transplantation in an ageing rodent model, resulting in rescue of memory dysfunction. Honors projects will continue to progress this research and combine both in vitro and in vivo neuroscience techniques.