AUTORADIOGRAPHIC STUDIES OF COMMISSURAL AND IPSILATERAL ASSOCIATION CONNECTIONS OF HIPPOCAMPUS AND DENTATE GYRUS OF RAT .1. COMMISSURAL CONNECTIONS
AUTORADIOGRAPHIC STUDIES OF COMMISSURAL AND IPSILATERAL ASSOCIATION CONNECTIONS OF HIPPOCAMPUS AND DENTATE GYRUS OF RAT .1. COMMISSURAL CONNECTIONS
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DOI：
10.1002/cne.901490402
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发表时间：
1973-01-01
影响因子：
2.5
通讯作者：
COWAN, WM
中科院分区：
文献类型：
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作者：
GOTTLIEB, DI;COWAN, WM
海马两个主要细胞构筑区的连合联系用放射自显影方法研究了大鼠海马结构内注射~ 3 H-亮氨酸后，海马齿状回（CA_1和CA_3区）和齿状回的投射，结果表明，向齿状回的连合投射起源于对侧海马的门区（可能来自亚区CA 3c的锥体细胞），其大部分纤维终止于分子层内三分之一的颗粒细胞树突（约30 μ宽）。与同侧的连接通路一样，连合投射沿着隔颞回轴广泛分布。CA 3区的连合连接似乎是同伦组织的，在这个意义上，它的每个子域似乎主要（如果不是唯一的话）与相对侧的相应子域有关。然而，沿着海马结构的隔颞轴，连合投射似乎要广泛得多，因此在任何一个水平上向该区域注射同位素总是会在相对侧相当大的头尾部范围内产生运输标记。在CA 3区内，连合终末局限于定向层的基底树突和放射层的顶树突中部。CA 1野似乎对连合系统没有贡献：这对于投射到背穹窿而不是伞部的前部分肯定是正确的，并且也可能适用于后部分的野。大多数（如果不是全部）的连合纤维到领域CA 1有他们的起源在领域CA 3的对侧。在腹侧海马连合的中线交叉后，这些纤维遵循海马内的课程，似乎平行的Schaffer侧支系统。在CA 1区域内，交叉纤维终止于基底树突和近端四分之三的顶树突的层方向和辐射层。
The commissural connections of the two major cytoarchitectonic fields of the hippocampus (fields CA1and CA3) and of the dentate gyrus of the rat have been studied autoradiographically following injections of3H‐leucine into the contralateral hippocampal formation.The commissural projection to thedentate gyrushas its origin in the hilar region of the gyrus of the opposite side (probably from the pyramidal cells of subfield CA3c) and the majority of its fibers terminate upon a restricted segment of the granule cell dendrites (about 30 μ wide) in the inner one‐third of the molecular layer. Like the ipsilateral association pathway to this region, the commissural projection has an extensive distribution along the septo‐temporal axis of the gyrus. The commissural connections offield CA3appear to be organized homotopically in the sense that each of its subfields seems to be related principally (if not exclusively) to the corresponding subfield on the opposite side. However, along the septo‐temporal axis of the hippocampal formation the commissural projection seems to be much more widespread, so that isotope injections into this field at any one level always give rise to transported label over a considerable rostro‐caudal extent on the opposite side. Within field CA3the commissural terminals are confined to the region of the basal dendrites in thestratum oriens, and the middle portion of the apical dendrites in thestratum radiatum. Field CA1does not appear to contribute to the commissural system: this is certainly true of its anterior portion which projects into the dorsal fornix rather than the fimbria, and may also hold for the posterior part of the field. Most, if not all, of the commissural fibers to field CA1have their origin in field CA3of the opposite side. After crossing the midline in the ventral hippocampal commissure, these fibers follow an intrahippocampal course which appears to parallel that of the Schaffer collateral system. Within field CA1the crossed fibers terminate in relation to the basal dendrites and the proximal three‐fourths of the apical dendrites in thestratum oriensand thestratum radiatum.