Time Course of Activity in Itch-Related Brain Regions: A Combined MEG-fMRI Study
Time Course of Activity in Itch-Related Brain Regions: A Combined MEG-fMRI Study
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DOI：
10.1152/jn.00460.2009
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发表时间：
2009-11-01
影响因子：
2.5
通讯作者：
Kakigi, Ryusuke
中科院分区：
文献类型：
--
作者：
Mochizuki, Hideki;Inui, Koji;Kakigi, Ryusuke
Mochizuki H，Inui K，Tanabe HC，Akiyama LF，Otsuru N，Yamashiro K，Sasaki A，Nakata H，Sadato N，Kakigi R。瘙痒相关脑区活动的时间进程：MEG-fMRI联合研究。神经生理学杂志102：2657-2666,2009。2009年8月26日首次出版；DOI：10.1152/jn.00460.2009。功能神经成像研究已经确定了与瘙痒相关的大脑区域。然而，还没有研究调查与瘙痒相关的大脑处理的时间方面。在这里，我们用电诱发的瘙痒对10名健康成年人进行了研究。刺激左手腕，用脑磁图(MEG)和功能磁共振成像(FMRI)测量脑电活动。在脑磁图实验中，观察到瘙痒刺激引起的对侧和同侧额颞区的磁反应。在fMRI实验中，与磁反应相关的偶极子主要位于对侧(9名受试者)和同侧(8名受试者)次级躯体感觉皮质(SII)/岛叶，它们也被瘙痒刺激激活。我们还观察到6名受试者在中央顶区后部出现与瘙痒相关的磁反应。脑磁图和功能磁共振数据显示，该区域的磁反应主要与楔前叶瘙痒相关的激活有关。同侧的潜伏期明显长于对侧的SII/岛，提示这种差异可能与其在膝状体纤维中的传递有关。楔前叶激活的时间介于对侧和同侧SII/岛之间。其他来源位于运动前、初级运动和前扣带回皮质(各一名受试者)。这项研究首次证明了与瘙痒有关的大脑处理的部分时间进程。结合高时间和空间分辨率的方法(如脑磁图和功能磁共振成像)将有助于研究瘙痒脑机制的时间方面。
Mochizuki H, Inui K, Tanabe HC, Akiyama LF, Otsuru N, Yamashiro K, Sasaki A, Nakata H, Sadato N, Kakigi R. Time course of activity in itch-related brain regions: a combined MEG-fMRI study. J Neurophysiol 102: 2657-2666, 2009. First published August 26, 2009; doi: 10.1152/jn.00460.2009. Functional neuroimaging studies have identified itch-related brain regions. However, no study has investigated the temporal aspect of itch-related brain processing. Here this issue was investigated using electrically evoked itch in ten healthy adults. Itch stimuli were applied to the left wrist and brain activity was measured using magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI). In the MEG experiment, the magnetic responses evoked by the itch stimuli were observed in the contralateral and ipsilateral frontotemporal regions. The dipoles associated with the magnetic responses were mainly located in the contralateral (nine subjects) and ipsilateral (eight subjects) secondary somatosensory cortex (SII)/insula, which were also activated by the itch stimuli in the fMRI experiment. We also observed an itch-related magnetic response in the posterior part of the centroparietal region in six subjects. MEG and fMRI data showed that the magnetic response in this region was mainly associated with itch-related activation of the precuneus. The latency was significantly longer in the ipsilateral than that in the contralateral SII/insula, suggesting the difference to be associated with transmission in the callosal fibers. The timing of activation of the precuneus was between those of the contralateral and ipsilateral SII/insula. Other sources were located in the premotor, primary motor, and anterior cingulate cortices (one subject each). This study is the first to demonstrate part of the time course of itch-related brain processing. Combining methods with high temporal and spatial resolution (e.g., MEG and fMRI) would be useful to investigate the temporal aspect of the brain mechanism of itch.