P.a.i.n. Group, Children's Hospital Boston, Waltham, MA 02453, USA.
J Neurophysiol. 2012 May;107(10):2633-48. doi: 10.1152/jn.00012.2012. Epub 2012 Feb 8.
The habenula, located in the posterior thalamus, is implicated in a wide array of functions. Animal anatomical studies have indicated that the structure receives inputs from a number of brain regions (e.g., frontal areas, hypothalamic, basal ganglia) and sends efferent connections predominantly to the brain stem (e.g., periaqueductal gray, raphe, interpeduncular nucleus). The role of the habenula in pain and its anatomical connectivity are well-documented in animals but not in humans. In this study, for the first time, we show how high-field magnetic resonance imaging can be used to detect habenula activation to noxious heat. Functional maps revealed significant, localized, and bilateral habenula responses. During pain processing, functional connectivity analysis demonstrated significant functional correlations between the habenula and the periaqueductal gray and putamen. Probabilistic tractography was used to assess connectivity of afferent (e.g., putamen) and efferent (e.g., periaqueductal gray) pathways previously reported in animals. We believe that this study is the first report of habenula activation by experimental pain in humans. Since the habenula connects forebrain structures with brain stem structures, we suggest that the findings have important implications for understanding sensory and emotional processing in the brain during both acute and chronic pain.
缰核位于丘脑后部，涉及多种功能。动物解剖学研究表明，该结构接收来自多个脑区（如额叶、下丘脑、基底神经节）的输入，并主要将传出连接发送到脑干（如导水管周围灰质、中缝核、脚间核）。缰核对疼痛的作用及其解剖连接在动物中已有充分的记录，但在人类中尚未有相关研究。在这项研究中，我们首次展示了如何使用高磁场磁共振成像来检测缰核对有害热的激活。功能图谱显示出缰核具有显著的、局部的和双侧的反应。在疼痛处理过程中，功能连接分析显示缰核与导水管周围灰质和壳核之间存在显著的功能相关性。概率追踪用于评估先前在动物中报道的传入（如壳核）和传出（如导水管周围灰质）通路的连接。我们认为，这是人类实验性疼痛激活缰核的首次报道。由于缰核将前脑结构与脑干结构连接起来，我们认为这些发现对理解急性和慢性疼痛期间大脑中的感觉和情绪处理具有重要意义。
