Tim Aumann
BSc (Hons) PhD (Monash)
Brain Injury and Repair Group
Neurodegeneration Laboratory
Contact Details
Email: | |
Phone: | +61 (0)3 8344 7335 |
Fax: | +61 (0)3 9348 1707 |
Research Interests
Our laboratory is investigating how dopamine synthesis is regulated in adult brain cells. Abnormal dopamine neurotransmission is associated with several prominent brain and mind disorders including Parkinson's disease, schizophrenia, drug addiction, attention deficit and hyperactivity disorder. Current treatments involve administering drugs which mimic or inhibit dopamine's actions in the brain. However, these treatments cause severe side-effects. It is likely these side-effects can be abrogated by altering the number of dopamine-synthesising cells in the brain. In this way the amount of dopamine can be normalised whilst retaining normal dopamine neurotransmission. Furthermore, regulating dopamine synthesis in a patient's own cells avoids problems associated with transplanting foreign dopamine cells into a patient's brain, as is being trialed for treating Parkinson's disease.
We’ve found that by changing the electrical activity of cells in the substantial nigra pars compacta we can bidirectionally alter the number of dopamine-synthesising cells and alter the amount of dopamine synthesised by cells. This may be useful for treating disorders of too much dopamine, such as schizophrenia or drug addiction, as well as disorders of too little dopamine such as Parkinson's disease. The electrical activity of cells can be altered in many different ways which opens a wide array of potential therapeutic strategies.
Currently we are testing the therapeutic potential of various ion-channel agonists and antagonists to recruit new dopamine cells and alleviate motor symptoms in rodent models of Parkinson's disease. In addition we are investigating: (1) how changes in electrical activity lead to increased or decreased dopamine synthesis in substantia nigra pars compacta cells; (2) the identity of recruitable midbrain cells; and (3) the role of neurogenesis in this process.
Laboratory Techniques
- Electrophysiology (in vivo & in vitro)
- Neurosurgery
- Animal behaviour
- Immunohistochemistry
- Cell culture
- Calcium imaging
- PCR & Western blot
Publications and Articles
Aumann, T.D., Rawson, J.A., Finkelstein, D.I. and Horne, M.K. (1994) Projections from the lateral and interposed cerebellar nuclei to the thalamus of the rat: a light and electron microscopic study using single and double anterograde labeling. J. Comp. Neurol. 349:165-181.
Aumann, T.D., Rawson, J.A., Pichitpornchai, C. and Horne, M.K. (1996) Projections from the cerebellar interposed and dorsal column nuclei to the thalamus in the rat: a double anterograde labeling study. J. Comp. Neurol. 368:608-619.
Aumann, T.D. and Horne, M.K. (1996) Ramification and termination of single axons in the cerebello-thalamic pathway of the rat. J. Comp. Neurol. 376:420-430.
Aumann, T.D. and Horne, M.K. (1996) A comparison of the ultrastructure of synapses in the cerebello-rubral and cerebello-thalamic pathways in the rat. Neuroscience Letters 211:175-178.
Churchward, P.R., Butler, E.G., Finkelstein, D.I., Aumann, T.D., Sudbury, A. and Horne, M.K. (1997) A comparison of methods used to detect changes in neuronal discharge patterns. J. Neurosci. Meth. 76:203-210.
Aumann, T.D., Rawson, J.A. and Horne, M.K. (1998) The relationship between monkey dentate cerebellar nucleus activity and kinematic parameters of wrist movement. Exp. Brain Res. 119:179-190.
Aumann, T.D., Ivanusic, J. and Horne, M.K. (1998) Arborization and termination of single motor thalamo-cortical axons in the rat. J. Comp. Neurol. 396:121-130.
Aumann, T.D. and Horne, M.K. (1999) Ultrastructural change at rat cerebello-thalamic synapses associated with volitional motor adaptation. J. Comp. Neurol. 409:71-84.
Aumann, T.D., Redman, S.J. and Horne, M.K. (2000) Long-term potentiation across rat cerebello-thalamic synapses in vitro. Neuroscience Letters 287:151-155.
Aumann, T.D. (2002) Cerebello-thalamic synapses and motor adaptation. The Cerebellum 1:69-77.
Aumann, T.D. and Fetz, E.E. (2004) Oscillatory activity in forelimb muscles of behaving monkeys evoked by microstimulation in the cerebellar nuclei. Neuroscience Letters 361:106-110.
Aumann, T.D., Gantois, I., Egan, K., Vais, A., Tomas, D., Drago, J.D. & Horne, M.K. (2008) SK channel function regulates the dopamine phenotype of neurons in the substantia nigra pars compacta. Exp Neurol 213:419-430.
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