Schwartz Sophie, Ponz Aurélie, Poryazova Rositsa, Werth Esther, Boesiger Peter, Khatami Ramin, Bassetti Claudio L
Laboratory for Neurology and Imaging of Cognition, Department of Clinical Neurology, University Medical Center, Michel-Servet 1, 1211 Geneva, Switzerland.
Brain. 2008 Feb;131(Pt 2):514-22. doi: 10.1093/brain/awm292. Epub 2007 Dec 19.
Narcolepsy with cataplexy (NC) is a complex sleep-wake disorder, which was recently found to be associated with a reduction or loss of hypocretin (HCRT, also called orexin). HCRT is a hypothalamic peptide implicated in the regulation of sleep/wake, motor and feeding functions. Cataplexy refers to episodes of sudden and transient loss of muscle tone triggered by strong, mostly positive emotions, such as hearing or telling jokes. Cataplexy is thought to reflect the recruitment of ponto-medullary mechanisms that normally underlie muscle atonia during REM-sleep. In contrast, the suprapontine brain mechanisms associated with the cataplectic effects of emotions in human narcolepsy with cataplexy remain essentially unknown. Here, we used event-related functional MRI to assess brain activity in 12 NC patients and 12 controls while they watched sequences of humourous pictures. Patients and controls were similar in humour appreciation and activated regions known to contribute to humour processing, including limbic and striatal regions. A direct statistical comparison between patients and controls revealed that humourous pictures elicited reduced hypothalamic response together with enhanced amygdala response in the patients. These results suggest (i) that hypothalamic HCRT activity physiologically modulates the processing of emotional inputs within the amygdala, and (ii) that suprapontine mechanisms of cataplexy involve a dysfunction of hypothalamic-amygdala interactions triggered by positive emotions.
发作性睡病伴猝倒（NC）是一种复杂的睡眠-觉醒障碍，最近发现它与下丘脑分泌素（HCRT，也称为食欲素）减少或缺失有关。HCRT是一种下丘脑肽，参与调节睡眠/觉醒、运动和进食功能。猝倒指的是由强烈的、大多为积极情绪（如听到或讲笑话）引发的突然和短暂的肌张力丧失发作。猝倒被认为反映了在快速眼动睡眠期间通常作为肌肉张力缺失基础的脑桥-延髓机制的激活。相比之下，在伴有猝倒的发作性睡病患者中，与情绪的猝倒效应相关的脑桥上机制基本上仍不清楚。在此，我们使用事件相关功能磁共振成像来评估12名NC患者和12名对照在观看幽默图片序列时的大脑活动。患者和对照在幽默欣赏方面以及在已知对幽默处理有贡献的激活区域（包括边缘和纹状体区域）方面相似。患者与对照之间的直接统计学比较显示，幽默图片在患者中引发下丘脑反应减弱以及杏仁核反应增强。这些结果表明：（i）下丘脑HCRT活动在生理上调节杏仁核内情绪输入的处理；（ii）猝倒的脑桥上机制涉及由积极情绪触发的下丘脑-杏仁核相互作用功能障碍。
