P.A.I.N. Group, McLean Hospital, Belmont, MA, USA Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA Department of Psychiatry, Massachusetts General Hospital, Charlestown, MA, USA.
Pain. 2012 Feb;153(2):444-454. doi: 10.1016/j.pain.2011.11.006. Epub 2011 Dec 6.
This study investigated sex similarities and differences in pain-related functional connectivity in 60 healthy subjects. We used functional magnetic resonance imaging and psychophysiological interaction analysis to investigate how exposure to low vs high experimental pain modulates the functional connectivity of the periaqueductal gray (PAG). We found no sex differences in pain thresholds, and in both men and women, the PAG was more functionally connected with the somatosensory cortex, the supplemental motor area, cerebellum, and thalamus during high pain, consistent with anatomic predictions. Twenty-six men displayed a pain-induced increase in PAG functional connectivity with the amygdala caudate and putamen that was not observed in women. In an extensive literature search, we found that female animals have been largely overlooked when the connections between the PAG and the amygdala have been described, and that women are systematically understudied with regard to endogenous pain inhibition. Our results emphasize the importance of including both male and female subjects when studying basic mechanisms of pain processing, and point toward a possible sex difference in endogenous pain inhibition.
这项研究调查了 60 名健康受试者在与疼痛相关的功能连接上的性别相似性和差异。我们使用功能磁共振成像和心理生理交互分析来研究在暴露于低强度和高强度实验性疼痛下，如何调节导水管周围灰质（periaqueductal gray，PAG）的功能连接。我们没有发现性别在疼痛阈值上的差异，而且在男性和女性中，PAG 在高强度疼痛下与躯体感觉皮层、补充运动区、小脑和丘脑的功能连接更为紧密，这与解剖学预测一致。26 名男性表现出 PAG 与杏仁核尾状核和壳核之间的功能连接增加，而女性则没有观察到这种情况。在广泛的文献检索中，我们发现当描述 PAG 和杏仁核之间的连接时，雌性动物在很大程度上被忽视了，而且在研究内源性疼痛抑制时，女性被系统地研究不足。我们的结果强调了在研究疼痛处理的基本机制时纳入男性和女性受试者的重要性，并指出内源性疼痛抑制可能存在性别差异。
