My group works on the neurons and circuits in the brain that underlie the sense of smell.  In particular, we focus on the olfactory cortex, a brain region that is responsible for our ability to recognise and remember odours.  By studying this cortex, we hope to elucidate how the brain processes sensory information in order to form a coherent picture of the outside world.  This kind of fundamental research is important for an eventual understanding of how brain circuits become dysfunctional in certain mental disorders, like schizophrenia and autism.  The olfactory cortex is also highly susceptible to epilepsy, Alzheimer's Disease and Parkinson's Disease, and the study of this cortex may reveal new understanding and therapies for these devastating and surprisingly common neurological disorders.

Born in Barcaldine, western Queensland, Australia.
Grew up in Darwin and Brisbane, Australia.

Tertiary education:
Griffith University, Brisbane - BSc (Hons 1) physics
Manchester University, UK - MSc history & philosophy of science
Cambridge University, UK - PhD neuroscience

Postdoctoral training:
Yale University School of Medicine, New Haven, CT, USA
Salk Institute, La Jolla, CA, USA

Honours & Awards:
Griffith University Medal
Commonwealth Scholarship to the UK
Gedge Prize in Biology, Cambridge University
Queen Elizabeth II Research Fellowship
Alexander von Humboldt Research Fellowship
Award for Education in Neuroscience, US Society for Neuroscience

Interests:
hiking/bushwalking
French language & literature

1. Excitability and hyperexcitability of neural circuits in the rodent piriform cortex (NHMRC Project Grant):
This project uses patch clamping, calcium imaging and molecular genetic approaches to study the spread of electrical activity in the piriform cortex (PC) of mice. The PC is a phylogenetically-ancient cortical region with a much simpler structure than other sensory cortices. This comparative simplicity means that it is an ideal system in which to study fundamental questions about normal and abnormal brain function. Surprisingly, the PC has been little-studied. Major aims of this project are: 1. To use functional calcium imaging to track the spread of electrical excitability through identified microcircuits in different layers of acute slices of the mouse PC following stimulation of inputs from the olfactory bulb. This is done under both normal and epileptic conditions. 2. To use a novel transgenic mouse to selectively manipulate electrical activity in layer II semilunar cells using optogenetic techniques. This is a collaboration with Sacha Nelson, Brandeis University, USA.

2. Neural circuits for odour-processing in the rodent piriform cortex 'in vivo' (NHMRC Project Grant):

This project uses 'blind' and two-photon targeted patch clamping in vivo to measure the responses of identified neurons in the piriform cortex to odour application. This work will allow us to examine the functional roles of the different classes of glutamatergic and GABAergic neurons that we have identified in slices of the piriform cortex. The project will also use a 'periscope' method to image changes in intracellular calcium across the full thickness of the piriform cortex when applying odours to the nose. This should allow us to study the mechanisms giving rise to beta oscillations in electrical activity during odour processing. This work is a collaboration with Matthew Larkum, Charite Medical University, Germany.

3. Persistent firing in cortical interneurons: Mechanisms and potential anticonvulsant role (NHMRC Project Grant):
This project uses whole-cell patch clamping and voltage imaging to study the mechanisms and possible functions of a recently-discovered phenomenon called persistent firing, which is found in some classes of cortical interneurons.  Persistent firing is a state of heightened excitability, in which neurons slowly integrate excitatory inputs until eventually (after a few seconds) they start to fire action potentials at a high frequency, even after the initiating excitation is stopped.  We hypothesise that persistent firing is an adaptation to counter undesirable cortical hyperexcitability, such as occurs during epileptic seizures.  This idea will be tested.  The project also involves developing computational models to test our ideas about how persistent firing affects neuronal networks.  This work is a collaboration with Mark McDonnell, University of South Australia.

Here are some ideas for possible research projects for students wishing to join the Laboratory.

1. Development of a cultured slice preparation of the piriform cortex and olfactory bulb, to be used to address a number of questions that involve applying molecular genetic approaches to the study of olfactory circuitry.

2. 'In vivo' patch clamp and calcium imaging of identified GABAergic interneurons in the piriform cortex during responses to odours.

3. Investigation of the cellular mechanisms responsible for the hyperexcitability of 'area tempestas', a region in deep piriform cortex and the endopiriform nucleus that is an important site for the initiation of epileptic seizures.