The Biology of Human Cortical Pain Related Activity

描述（由申请人提供）：这些研究的长期目标是了解急性疼痛的感觉和情感维度的人类皮质机制。对于接受伤害性输入的人类皮层结构的具体功能、它们与疼痛的各个维度的关系、注意力对这些输入的调节，或者可能连接这些结构的相互作用，我们知之甚少。在初步研究中，我们使用皮肤激光刺激产生一个纯粹的疼痛感觉，通过选择性激活皮肤伤害感受器，并引起硬膜下电位（LEPs）。这些LEPs位于人类前扣带回（ACC），躯体感觉（SI）和侧裂旁（PS）皮质。在我们的初步数据，病变的影响，和灵长类动物的电生理学研究的LEPs的分布表明，可能有这些皮质区内的每个功能元件。 我们建议通过LEPs和附近的源分析来定义这些结构中的每一个内的元素，这些结构的源分析是由振动或听觉刺激以及电神经刺激的发生器表征的。将采用双模态、同时呈现范式来评估定向注意和由新颖刺激引起的注意对LEPs、硬膜下EEG激活和结构之间的同步性的影响。我们对同步性的初步分析表明，在刺激之前，SI和PS之间存在显著的功能连接，因为患者在注意力任务中预期刺激。刺激发生后，病人计数它和同步发展之间的SI-ACC和PS-ACC. We现在提出的特征，这种快速切换，任务依赖性的功能连接疼痛相关的皮层区域之间。这些研究中的许多是通过在手术外癫痫监测期间直接从人脑表面记录来进行的，这种技术具有巨大的清晰度和分辨率。因此，这一建议代表了一个独特的机会，研究前脑疼痛相关结构的功能解剖和连接。

DESCRIPTION (provided by applicant): The long-term goal of these studies is to understand human cortical mechanisms of the sensory and affective dimensions of acute pain. Little is known about the specific functions of the human cortical structures receiving nociceptive input, their relationship to various dimensions of pain, the modulation of these inputs by attention, or the interactions which may connect these structures. In preliminary studies, we have used a cutaneous laser stimulus to produce a pure pain sensation by selective activation of cutaneous nociceptors, and to evoke subdural potentials (LEPs). These LEPs were localized over human anterior cingulate (ACC), somatosensory (SI) and parasylvian (PS) cortices. The distribution of LEPs in our preliminary data, the effect of lesions, and primate electrophysiological studies suggest that there may be functional elements within each of these cortical areas. We propose to define the elements within each of these structures by source analysis of LEPs and of nearby, well-characterized, generators for vibratory, or auditory stimuli and for electric nerve stimuli. A two-modality, simultaneous presentation paradigm will be employed to assess the effect of directed attention and attention evoked by novel stimuli on LEPs, subdural EEG activation and synchrony between structures. Our preliminary analysis of synchrony demonstrates significant functional connectivity between SI and PS prior to the stimulus, as the patient anticipates the stimulus in an attention task. After the stimulus occurs, the patient counts it and synchrony develops between both SI-ACC and PS-ACC. We now propose to characterize this rapidly switching, task-dependent functional connectivity between pain-related cortical areas. Many of these studies are performed by recording directly from the surface of the human brain during extra-operative seizure monitoring, a technique which has tremendous clarity and resolution. Therefore, this proposal represents a unique opportunity to study the functional anatomy and connectivity of forebrain pain-related structures.