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Optical imaging of nociception in primary somatosensory cortex of nonhuman primates

Li-Min CHEN, Robert M. Friedman, Anna W. Roe

Departments of 1Radiology and Radiological Science and Psychology； Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232, USA

摘要

While the activation of primary somatosensory (SI) cortex during pain perception is consistently reported in functionalimaging studies on normal subjects and chronic pain patients, the specific roles of SI, particularly the subregions within SI, in theprocessing of sensory aspects of pain are still largely unknown. Using optical imaging of intrinsic signal (OIS) and single unitelectrophysiology, we studied cortical activation patterns within SI cortex (among Brodmann areas 3a, 3b and 1) and signal amplitudechanges to various intensities of non-nociceptive, thermal nociceptive and mechanical nociceptive stimulation of individual distalfinerpads in anesthetized squirrel monkeys. We have demonstrated that areas 3a and 1 are preferentially involved in the processing ofnociceptive information while areas 3b and 1 are preferentially activated in the processing of non-nociceptive (touch) information.Nociceptive activations of individual fingerpad were organized topographically suggesting that nociceptive topographic map exits inareas 3a and 1. Signal amplitude was enhanced to increasing intensity of mechanical nociceptive stimuli in areas 3a, 3b and 1. Withinarea 1, nociceptive response co-localizes with the non-nociceptive response. Therefore, we hypothesize that nocicepitve informationis area-specifically represented within SI cortex, in which nociceptive inputs are preferentially represented in areas 3a and 1 while nonnociceptiveinputs are preferentially represented in areas 3b and 1.

关键词： nociception; optical imaging; primates; hand; primary somatosensory cortex

Optical imaging of nociception in primary somatosensory cortex of nonhuman primates

Li-Min CHEN, Robert M. Friedman, Anna W. Roe

Departments of 1Radiology and Radiological Science and Psychology； Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232, USA

Abstract

While the activation of primary somatosensory (SI) cortex during pain perception is consistently reported in functionalimaging studies on normal subjects and chronic pain patients, the specific roles of SI, particularly the subregions within SI, in theprocessing of sensory aspects of pain are still largely unknown. Using optical imaging of intrinsic signal (OIS) and single unitelectrophysiology, we studied cortical activation patterns within SI cortex (among Brodmann areas 3a, 3b and 1) and signal amplitudechanges to various intensities of non-nociceptive, thermal nociceptive and mechanical nociceptive stimulation of individual distalfinerpads in anesthetized squirrel monkeys. We have demonstrated that areas 3a and 1 are preferentially involved in the processing ofnociceptive information while areas 3b and 1 are preferentially activated in the processing of non-nociceptive (touch) information.Nociceptive activations of individual fingerpad were organized topographically suggesting that nociceptive topographic map exits inareas 3a and 1. Signal amplitude was enhanced to increasing intensity of mechanical nociceptive stimuli in areas 3a, 3b and 1. Withinarea 1, nociceptive response co-localizes with the non-nociceptive response. Therefore, we hypothesize that nocicepitve informationis area-specifically represented within SI cortex, in which nociceptive inputs are preferentially represented in areas 3a and 1 while nonnociceptiveinputs are preferentially represented in areas 3b and 1.

Key words: nociception; optical imaging; primates; hand; primary somatosensory cortex

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通讯作者：Li-Min CHEN　　E-mail: limin.chen@vanderbilt.edu

引用本文：

Li-Min CHEN, Robert M. Friedman, Anna W. Roe. Optical imaging of nociception in primary somatosensory cortex of nonhuman primates[J]. 生理学报 2008; 60 (5): 664-668.

Li-Min CHEN, Robert M. Friedman, Anna W. Roe. Optical imaging of nociception in primary somatosensory cortex of nonhuman primates. Acta Physiol Sin 2008; 60 (5): 664-668 (in Chinese with English abstract).