Powers Jocelyn M, Koning Elena, Ioachim Gabriela, Stroman Patrick W
Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada.
Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada.
Front Pain Res (Lausanne). 2024 Dec 10;5:1388460. doi: 10.3389/fpain.2024.1388460. eCollection 2024.
The sensory/discriminative domain of pain is often given more consideration than the cognitive and affective influences that ultimately make pain what it is: a highly subjective experience that is based on an individual's life history and experiences. While many investigations of the underlying mechanisms of pain have focused on solely noxious stimuli, few have compared somatosensory stimuli that cross the boundary from innocuous to noxious. Of those that have, there is little consensus on the similarities and differences in neural signaling across these sensory domains. The purpose of this study was to apply our established network connectivity analyses toward the goal of understanding the neural mechanisms behind sensory, cognitive, and affective responses to noxious and innocuous stimuli. Functional MRI data were collected from 19 healthy women and men that experienced warm and hot thermal stimuli across multiple trials. This is a within-subjects cross-sectional experimental study with repeated measures. Ratings of stimulus intensity and unpleasantness that were collected during each run confirmed significant perceptual differences between the two types of stimuli. Despite this finding, no group differences in network connectivity were found across conditions. When individual differences related to pain ratings were investigated, subtle differences were found in connectivity that could be attributed to sensory and association regions in the innocuous condition, and cognitive, affective, and autonomic regions in the pain condition. These results were reflected in the time-course data for each condition. Overall, signaling mechanisms for innocuous and noxious somatosensation are intricately linked, but pain-specific perception appears to be driven by our psychological and autonomic states.
疼痛的感觉/辨别性领域往往比认知和情感影响得到更多关注，而正是这些认知和情感影响最终造就了疼痛的本质：一种高度主观的体验，它基于个体的生活经历。虽然许多关于疼痛潜在机制的研究仅聚焦于有害刺激，但很少有研究比较从无害跨越到有害的躯体感觉刺激。在那些进行过此类比较的研究中，对于这些感觉领域神经信号的异同几乎没有达成共识。本研究的目的是应用我们已建立的网络连通性分析，以理解对有害和无害刺激的感觉、认知及情感反应背后的神经机制。从19名健康男女中收集了功能性磁共振成像数据，他们在多次试验中经历了温暖和热的温度刺激。这是一项采用重复测量的受试者内横断面实验研究。每次扫描过程中收集的刺激强度和不适感评分证实了两种刺激类型之间存在显著的感知差异。尽管有这一发现，但在不同条件下未发现网络连通性存在组间差异。当研究与疼痛评分相关的个体差异时，发现连通性存在细微差异，在无害条件下可归因于感觉和联合区域，在疼痛条件下可归因于认知、情感和自主区域。这些结果反映在每种条件下的时间进程数据中。总体而言，无害和有害躯体感觉的信号传导机制错综复杂地联系在一起，但疼痛特异性感知似乎由我们的心理和自主状态驱动。
