The 'Pain Matrix' Reloaded

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• Dr Giandomenico Iannetti, Department of Neuroscience, Physiology and Pharmacology University College London (UK)
• Friday 15 July 2011, 15:00-16:00
• Room 611.

If you have a question about this talk, please contact Danilo Mandic.

Brief radiant laser pulses activate cutaneous Aδ and C nociceptors selectively, and elicit reliable EEG and fMRI brain responses in a wide network of cortical areas. As this network of brain areas is assumed to be uniquely or preferentially involved in processing nociceptive input, it has been christened the ‘pain matrix’, and laser-evoked EEG and fMRI responses have been used extensively in the past 30 years to gain knowledge about the cortical mechanisms underlying nociception and pain perception in humans. In this talk I will illustrate some experimental results showing that, in contrast with this dominant view, the brain responses elicited by a selectively nociceptive stimulus do not reflect nociceptivespecific neural activities, but are entirely explained by a combination of multimodal neural activities (i.e. activities also elicited by stimuli belonging to other sensory modalities) and somatosensoryspecific neural activities (i.e. activities elicited by both nociceptive and tactile somatosensory stimuli). By showing that pain-evoked brain responses are not specific for the perception of pain, these results indicate that it is incorrect to refer to these responses as originating from a “pain matrix”, and question the appropriateness of relying on them to build models of where and how nociceptive input is processed in the human brain.

References: GD Iannetti, MC Lee, NP Hughes, A Mouraux. The determinants of laser-evoked EEG responses: pain perception or stimulus saliency? Journal of Neurophysiology 2008, 100: 815-828. GD Iannetti, A Mouraux. From the neuromatrix to the pain matrix (and back). Review. Exp Brain Res 2010, 205: 1-12. A Mouraux, GD Iannetti. Nociceptive laser-evoked brain potentials do not reflect nociceptive-specific neural activity. Journal of Neurophysiology, 2009, 101:3258-69. MC Lee, A Mouraux, GD Iannetti. Characterizing the cortical activity through which pain emerges from nociception. Journal of Neuroscience 2009, 29: 7909-16.

Bio: Giandomenico Iannetti was born in Rome in 1974. He graduated in Medicine and Surgery from “La Sapienza” University of Rome, where he obtained his MD in 1999, and his PhD in Neuroscience in 2003. During his PhD he has been working in the laboratory of Giorgio Cruccu, investigating the brainstem neural circuits subserving trigemino-facial reflexes in humans, by using electrophysiological recording and MR imaging, as well as the cortical responses to selective stimulation of the nociceptive system, by recording scalp electroencephalographic (EEG) responses to radiant laser stimuli (laser-evoked potentials, LEPs). In 2003 he moved to Oxford and joined, as Post Doctoral Research Fellow, the laboratory of Irene Tracey, to investigate further the central nervous system responses to nociceptive stimuli in humans. In Oxford he set up the technique to record laser-evoked potentials, which he used to achieve novel physiological information about spatial-temporal summation of nociceptive inputs and perceptual-related activity of cortical nociceptive areas. He also successfully combined the recording of EEG and functional MRI responses to laser stimulation in humans. Part of his research activity has been devoted to the pharmacological modulation of central nervous system responses to nociceptive stimuli; this research has lead to a better understanding of the brain deactivations in response to external stimuli, in the wider context of the field investigating the brain activity at rest. In 2005 he was Visiting Scientist at the National Institutes of Health (NIH) in the United States, where he applied the technique of functional MRI to investigate quantitatively the neural activity in the spinal cord during voluntary movement. In 2006 Dr Iannetti was awarded a University Research Fellowship of the Royal Society and joined St. Catherine’s College as Fellow by Special Election. The Royal Society Fellowship allowed him to build his own research group, which has been initially based in Oxford. Dr Iannetti’s current research focuses on the neurophysiology of sensory systems in humans, with particular interest on the somatosensory system. His research group is currently based at the Department of Neuroscience, Physiology and Pharmacology of University College London.

This talk is part of the COMMSP Seminar series.

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• COMMSP & CP list
• COMMSP Seminar
• Room 611
• SAP Talks

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