Empson Lab

Associate Professor Ruth Empson

Ruth Empson

Associate Professor

Department of Physiology
Otago School of Medical Sciences
University of Otago
PO Box 913
Dunedin
New Zealand

Phone: 4797464
Fax: +64 3 479 7323

Email: ruth.empson@otago.ac.nz

Saggital section through the cerebellar cortex
Cerebellar Purkinje neuron filled with a calcium sensitive dye
Lab visit to the only Olympic-sized curling rink in the southern hemisphere, September 2011

Member of Cellular & Molecular Neuroscience and Membrane & Ion Transport.

Member of The University of Otago Brain Health Research Centre and The Australasian Winter Conference on Brain Research (AWCBR) Organising Committee.

Research interests

The research in this laboratory uses a combination of electrophysiology, live imaging and molecular approaches to better understand the consequences of modifications to neuronal circuits. Our special interest lies with those circuits, or networks that contribute to our ability to make controlled movements; those within the cerebellum and the motor cortex. This research has relevance for addressing the highly debilitating and poorly treated movement disorders such as ataxia, motor neurone disease and spinal injury. We are also becoming increasingly interested in the contribution from the cerebellum to cognitive processes and its disruption in the poorly treated disorder autism.

Keywords

Cerebellum, Motor cortex, Electrophysiology, Ca²⁺ signalling, Ataxia, PMCA2, NCX

Expertise

Patch Clamp Electrophysiology
Calcium imaging
Post-hoc neuron reconstructions
Immunohistochemistry
Western blot
PCR based genotyping; single cell PCR
MATLAB

Projects

Cellular and Network Identity in the Motor Cortex; projection neuron identity and networks
Cellular and Network Identity in the Motor Cortex; corticospinal motor neuron function
Cerebellar Circuitry - understanding modifications in the ataxic PMCA2 knockout mouse
Cerebellar Circuitry - cooperative calcium clearance mechanisms for parallel fibre function
Cerebellar Circuitry - nicotinic receptor mediated actions at cerebellar synapses

Current funding

Royal Society of New Zealand Marsden Foundation (2010-2014) The transcription factor code: maintaining neuronal identity and function in the adult brain.
University of Otago Research Grant (2013-2014) Towards the Development of an On-Demand Device to Control Epilepsy, with Assoc Profs John Reynolds (Anatomy) & Mike Paulin (Zoology)

Previous funding

New Zealand Neurological Foundation (2008-2011): Metabotropic Glutamate Receptor Signalling in Cerebellar Ataxia.
University of Otago, Otago School of Medical Sciences, Deans Bequest Funding (2007-2008). Movers and Shakers!
Otago Medical Research Foundation Cutting out the middle-man; Partner interactions for healthy synapses (2009-2010), with Dr P. Turner
HRC-JSPS Fellowhip 2008-09 to suport collaboration between our lab and Dr Thomas Knöpfel, Brain Science Institute, RIKEN, Tokyo, Japan.
BBSRC Biotechnology and Biological Sciences Research Council, UK. (2004-2009): PMCA2 (plasma membrane Ca²⁺ ATPase) - its role in synapse structure and function. Continued collaboration with Prof Philip Beesley and Prof Brian Austen, Royal Holloway University of London.
University of Otago Research Grant (2008-9) Cooperation of Ca²⁺ Recovery Mechanisms for Synapse Function
Epilepsy Research Foundation UK (2004-2007): Influence of PMCA dependent Ca²⁺ signalling during epileptogenesis.

Collaborators

Dr Stephanie Hughes, Department of Biochemistry, University of Otago, New Zealand.
Dr Natalie Medlicott, New Zealand's National School of Pharmacy University of Otago, New Zealand.
Dr Thomas Knöpfel, Laboratory of Neuronal Circuit Dynamics, RIKEN BSI, Tokyo, Japan.
Prof Emanuel Strehler & Dr Aida Filoteo, Mayo Clinic, Rochester, MN, USA.
Prof Brian Austen, Biochemistry, St George's Hospital Medical School, London, UK.
Prof Philip Beesley, School of Biological Sciences, Royal Holloway College University of London, Egham, Surrey, TW20 0EX, UK.

Lab personnel

Emma Deeney

Manju Ganesh

Mohamed Ibrahim

Javier Jiminez Martin

Kyoko Potapov

Daniil Potapov

Emmet Power

Aisha Sati

Previous lab personnel

Dr Chris Roome (now with Dr Bernd Kuhn, Okinawa Institute of Technology, Japan)
Dr Raghu Nagaraja (now with Assoc Prof John Reynolds, Dept of Anatomy and Structural Biology, University of Otago)
Miss Helena Huang (now a PhD candidate with Assoc Prof John Bekkers, ANU, Australia).
Mr Daniil Potapov (now with Dr István Ábrahám, Department of Physiology)
Dr Tom Jensen (now with Prof Dimitri Rusakov, Institute of Neurology, Queen Square, London, UK).

Selected publications

Ruth M. Empson, Helena Huang, Raghavendra Y. Nagaraja, Chris J. Roome and Thomas Knöpfel Enhanced synaptic inhibition in the cerebellar cortex of the ataxic PMCA2-/- knockout mouse The Cerebellum Mar 21 2013 In press DOI 10.1007/s12311-013-0472-0.
Roome CJ, Power EM, Empson RM. Transient Reversal of the Sodium-Calcium Exchanger Boosts Presynaptic Calcium and Synaptic Transmission at a Cerebellar Synapse. J Neurophysiol. 2013 Mar 109(6):1669-80. Impact Factor 3.3.
Chris J. Roome & Thomas Knöpfel & Ruth M. Empson Functional contributions of the plasma membrane calcium ATPase and the sodium–calcium exchanger at mouse parallel fibre to Purkinje neuron synapses Pflugers Archiv European Journal of Physiology 2013 465(2):319-31. doi: 10.1007/s00424-012-1172-1.
Empson RM, Knöpfel T. Functional integration of calcium regulatory mechanisms of Purkinje neuron synapses. The Cerebellum. 2012 Sep;11(3):640-50. doi: 10.1007/s12311-010-0185-6.
Roome CJ, Empson RM. Assessment of the contribution of the plasma membrane calcium ATPase, PMCA, calcium transporter to synapse function using patch clamp electrophysiology and fast calcium imaging. Methods Mol Biol. 637:343-60 (2010).
Helena Huang, Raghavendra Y. Nagaraja, Molly L. Garside, Walther Akemann, Thomas Knöpfel and Ruth M. Empson The Contribution of Plasma Membrane Ca²⁺ ATPase (PMCA2) to Cerebellar Synapse Function World Journal of Biological Chemistry (5):95 -102 doi:10.4331/wjbc.v1.i5.95 Published online May 26 2010.
Ruth M. Empson, Paul R. Turner, Raghavendra Y. Nagaraja, Philip W. Beesley, Thomas Knöpfel Reduced PMCA2 Reduced expression of the Ca²⁺ transporter protein PMCA2 slows Ca²⁺ dynamics in mouse cerebellar Purkinje neurones and alters the precision of motor coordination. J Physiol 588 (6) 907-922 (2010).
Garside, M., Turner, P.R., Austen, B.A., Strehler, E.E., Beesley, P.W, Empson, R.M., Molecular interactions of the plasma membrane calcium ATPase PMCA2 at pre- and post-synaptic sites in rat cerebellum. Neuroscience, 162(2):383-95 (2009).
Jensen, T.P., Buckby, L.E., Empson, R.M., Reduced expression of the "fast" calcium transporter PMCA2a during homeostatic plasticity. Molecular Cellular Neurosci. 41(3):364-72 (2009)
Empson RM, Garside ML, Knöpfel T. Plasma membrane Ca²⁺ ATPase 2 contributes to short-term synapse plasticity at the parallel fiber to Purkinje neuron synapse. J Neurosci. Apr 4;27(14): 3753-8 (2007).

Teaching

PHSL341 - Cellular Communication; Calcium and synaptic signalling
HUBS191 - Membrane Bioelectricity
PHSL231 - Electrical Signalling; Membrane excitability, action potentials and synapses
PHSL474 - Research Topics
PHSL472 - Cellular and Molecular Physiology
Convenor HUBS191 Health Sciences First Year