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Peter Magill "Dopamine Dependency of Neuronal Oscillations in the Cerebral Cortex and Basal Ganglia"

Abstract :

Studies in the cerebral cortex, particularly the hippocampus,
have suggested that the brain may employ a ‘temporal code’ to represent information. In particular, the precise temporal structure offered by regular fluctuations in activity, or oscillations, maybe important for the encoding and retrieval of information in networks of neurons. Thus, it is possible that disturbances in network oscillations might also underlie brain dysfunction in disease. For example, the chronic loss of dopamine from the basal ganglia and cortex, such as occurs in Parkinson’s disease and its animal models, results in profound changes in neuronal oscillations in these structures.

In this seminar, I will first present evidence that coordinated network oscillations exist in the healthy basal ganglia and cortex. I will then describe the hallmarks of supposed pathological oscillatory activity in the brain in Parkinson’s disease and its models, and explore how these phenomena might contribute to disease symptoms. Finally, I will highlight how animal models of Parkinson’s disease can be exploited to give valuable insight into the mechanisms underlying the pathological brain oscillations observed in patients.

Selected publications

Sharott, A., Magill, P.J., Harnack, D., Kupsch, A., Meissner, W. and Brown, P. (2005)Dopamine depletion increases the power and coherence of -oscillations in the cerebral cortex and subthalamic nucleus of the awake rat. European Journal of Neuroscience, 21, pp1413-1422.
Magill, P.J., Sharott, A., Bolam, J.P. and Brown, P. (2004) Brain state-dependency of coherent oscillatory activity in the cerebral cortex and basal ganglia of the rat. Journal of Neurophysiology, 92, pp2122-2136.
Magill, P.J., Sharott, A., Bevan, M.D., Brown, P. and Bolam, J.P. (2004) Synchronous unit activity and local field potentials evoked in the subthalamic nucleus by cortical stimulation. Journal of Neurophysiology, 92, pp700-714.
Ungless, M.A., Magill, P.J. and Bolam, J.P. (2004) Uniform inhibition of dopamine neurons in the ventral tegmental area by aversive stimuli. Science, 303, pp2040-2042.

Thomas Boraud