“患者H.M.”(该患者的病例在有关大脑功能与记忆的理论的发展中扮演过一个重要角色)大脑的尸检分析,揭示了可能会影响我们对海马体在记忆中所起作用之认识的新细节。
Henry Molaison(“患者H.M.”)是涉及记忆的最著名的人类神经科学研究病例。由于未知的原因,他在10岁时开始出现轻度癫痫,到15岁时发展成严重癫痫。当时的抗惊厥药物不是非常有效,所以在1953年他27岁时,“患者H.M.”做了一个神经外科手术,以将其大脑中海马体的一些部分去掉。这次手术之后,尽管发作的频率降低了,但“患者H.M.”无法在长期记忆中巩固和存储信息。上个世纪90年代的脑成像研究证实,他的海马体(大脑中与处理学习和记忆有很大关系的一个区域)大部分已被去掉。然而,这些方法不具备确定病变的精确边界所需的分辨率。
在他于2008年死后,Jacopo Annese及同事对“患者H.M.”的大脑做了切片,创建了关于病变区域的一个三维模型。与早先“患者H.M.”还活着时所做成像研究形成对比的是,他们发现该患者海马体相当大一部分实际上还保留着。这意味着,海马体的某些区域在记忆中所起作用可能需要予以重新评估。
Nature Communications doi:10.1038/ncomms4122
Postmortem examination of patient H.M.’s brain based on histological sectioning and digital 3D reconstruction
Jacopo Annese, Natalie M. Schenker-Ahmed, Hauke Bartsch, Paul Maechler, Colleen Sheh, Natasha Thomas, Junya Kayano, Alexander Ghatan, Noah Bresler, Matthew P. Frosch, Ruth Klaming & Suzanne Corkin
Modern scientific knowledge of how memory functions are organized in the human brain originated from the case of Henry G. Molaison (H.M.), an epileptic patient whose amnesia ensued unexpectedly following a bilateral surgical ablation of medial temporal lobe structures, including the hippocampus. The neuroanatomical extent of the 1953 operation could not be assessed definitively during H.M.’s life. Here we describe the results of a procedure designed to reconstruct a microscopic anatomical model of the whole brain and conduct detailed 3D measurements in the medial temporal lobe region. This approach, combined with cellular-level imaging of stained histological slices, demonstrates a significant amount of residual hippocampal tissue with distinctive cytoarchitecture. Our study also reveals diffuse pathology in the deep white matter and a small, circumscribed lesion in the left orbitofrontal cortex. The findings constitute new evidence that may help elucidate the consequences of H.M.’s operation in the context of the brain’s overall pathology.
转自生物谷