疼痛性冷刺激和非痛温热刺激口腔时对大脑皮层反应强度的影响

Effects of noxious coldness and non-noxious warmth on the magnitude of cerebral cortex activation during intraoral stimulation with water

目的探索疼痛性冷刺激和非痛温热刺激口腔时对大脑皮层反应强度的影响。方法选取6名健康志愿者,采用组块设计方法,利用水传递装置分别用冷水(4℃)和温水(23℃)刺激其口腔,采集全脑血氧水平依赖对比的功能性磁共振成像(f MRI)扫描数据进行分析。结果冷水和温水刺激共同激活了左侧中央前后回、岛叶/岛盖、前扣带回(ACC)、眶额皮层,右侧中脑红核和丘脑。此外,冷水刺激还激活了左侧枕叶、运动前皮层布罗德曼分区(BA)6、右侧BA44、舌回,以及顶叶BA7和BA40,初级躯体感觉皮层SⅠ。疼痛性冷水刺激激活的脑区多于无痛温水,而激活脑区的强度小于温水,但是疼痛冷水刺激在ACC的激活强度明显大于无痛温水刺激。结论大脑皮层对疼痛性冷刺激口腔时反应的脑区的激活强度小于非痛性温热水刺激,但是ACC脑区的激活强度大于非痛性温水刺激。

Objective We used functional magnetic resonance imaging（f MRI） to explore the effects of noxious coldness and non-noxious warmth on the magnitude of cerebral cortex activation during intraoral stimulation with water.Methods Six male and female subjects were subjected to whole-brain f MRI during the phasic delivery of non-noxious hot（23 ℃） and noxious cold（4 ℃） water intraoral stimulation.A block-design blood oxygenation level-dependent f MRI scan covering the entire brain was also carried out.Results The activated cortical areas were as follows：left pre-/post-central gyrus,insula/operculum,anterior cingulate cortex（ACC）,orbital frontal cortex（OFC）,midbrain red nucleus,and thalamus.The activated cortical areas under cold condition were as follows：left occipital lobe,premotor cortex/Brodmann area（BA） 6,right motor language area BA44,lingual gyrus,parietal lobule（BA7,40）,and primary somatosensory cortex SⅠ.Comparisons of the regional cerebral blood flow response magnitude were made among stereotactically concordant brain regions that showed significant responses under the two conditions of this study.Compared with non-noxious warmth,more regions were activated in noxious coldness,and the magnitude of activation in areas produced after non-noxious warm stimulation significantly increased.However,ACC only significantly increased the magnitude of activation under noxious coldness stimulation.Conclusion Results suggested that a similar network of regions was activated common to the perception of pain and nopain produced by either non-noxious warmth or noxious coldness stimulation.Non-noxious warmth also activated more brain regions and significantly increased the response magnitude of cerebral-cortex activation compared with noxious coldness.Noxious coldness stimulation further significantly increased the magnitude of activation in ACC areas compared with noxious warmth.