Freund Wolfgang, Stuber Gregor, Wunderlich Arthur P, Schmitz Bernd
Department of Diagnostic and Interventional Radiology, University Hospital, Ulm, Germany.
Somatosens Mot Res. 2007 Dec;24(4):203-12. doi: 10.1080/08990220701723636.
Two neuroimaging studies using fMRI were conducted in order to assess the cortical processes involved in the perception and suppression of pain. In the first study, 15 healthy subjects were stimulated with variable intensities of electrical pulses during a discrimination task. In the second study, the same subjects had to try to suppress the feeling of pain during tonic stimulation. The discrimination task resulted in cortical activation of contralateral SI, corresponding in extent to the intensity of the stimulus. Activation of contralateral operculum/posterior insula (SII) and non-dominant dorsolateral prefrontal cortex (DLPFC) with non-painful stimuli changed to activations of non-dominant anterior insula upon painful stimulation. In the second study, all subjects succeeded in suppressing the feeling of pain during previously painful levels of stimulation. During this suppression task, activations changed from anterior to posterior insula; also there was a suppression of activity in the anterior cingulated cortex (ACC) and caudate nucleus. Subjects seem to be able to suppress to a certain degree the feeling of pain under constant (and previously painful) stimulation. The cortical correlate seems to be a shift of cerebral activation from anterior to posterior right insula and a suppression of activity in the ACC and caudate nucleus.
为了评估参与疼痛感知和抑制的皮质过程，进行了两项使用功能磁共振成像（fMRI）的神经影像学研究。在第一项研究中，15名健康受试者在辨别任务期间接受不同强度的电脉冲刺激。在第二项研究中，相同的受试者必须在持续性刺激期间尝试抑制疼痛感觉。辨别任务导致对侧初级体感皮层（SI）的皮质激活，其范围与刺激强度相对应。非疼痛刺激时对侧岛盖/后岛叶（SII）和非优势背外侧前额叶皮质（DLPFC）的激活在疼痛刺激时转变为非优势前岛叶的激活。在第二项研究中，所有受试者在先前疼痛的刺激水平期间均成功抑制了疼痛感觉。在该抑制任务期间，激活从前岛叶转移至后岛叶；前扣带回皮质（ACC）和尾状核的活动也受到抑制。受试者似乎能够在持续（且先前疼痛）的刺激下一定程度地抑制疼痛感觉。皮质相关表现似乎是大脑激活从右侧前岛叶转移至后岛叶以及ACC和尾状核活动的抑制。
