Abstract：
CA2 is probably the most enigmatic of the hippocampal fields. It is small in size (in humans about 500 μm across the mediolateral axis), and yet, it is involved in important functions, such as in social memory and anxiety. This study offers a glimpse of several significant aspects of the anatomical organization of CA2. We present an overview of the anatomical structure of CA2, imbued in the general organization of the human hippocampal formation. The location and distinctiveness of CA2 is presented in relation with CA3 and CA1, based in a total of 23 human control cases serially sectioned throughout the whole longitudinal axis of the hippocampus, examined every 500 μm in Nissl-stained sections. The longitudinal extent of CA2 is close to 30 mm, starting in the hippocampal head, 2.5 mm caudal to the DG and 3.5 mm caudal to the start of CA3, approximately 10 mm from the hippocampus rostral end. The connectional information of human CA2 is very scarce, thereby we relied on nonhuman primate tract tracing studies of the hippocampal formation, given its resemblance to the human brain. Human CA2 is subject of neuropathological studies, and we chose to present Alzheimer\'s disease, schizophrenia, and Mesial Temporal Lobe Epilepsy with hippocampal sclerosis in those aspects that impinge directly into CA2.
摘要：
CA2可能是海马视野中最神秘的。它的尺寸很小（在人类中，横跨中外侧轴约500μm），然而，它涉及重要的功能，比如社交记忆和焦虑。这项研究提供了CA2解剖组织的几个重要方面的一瞥。我们概述了CA2的解剖结构，该结构浸透在人类海马结构的一般组织中。CA2的位置和独特性与CA3和CA1相关，基于在海马的整个纵轴上连续剖切的23例人类对照病例，在Nissl染色的切片中每500μm检查一次。CA2的纵向范围接近30mm,从海马头部开始,DG的尾部2.5mm，CA3的尾部3.5mm，距海马头端约10mm。人类CA2的连接信息非常稀缺，因此，我们依赖于海马形成的非人灵长类动物道追踪研究，考虑到它和人类大脑的相似之处.人类CA2是神经病理学研究的主题，我们选择介绍老年痴呆症,精神分裂症,内侧颞叶癫痫伴海马硬化在那些方面直接影响CA2。
