Witter M P, Amaral D G
Department of Anatomy and Embryology, Vrije Universiteit, Amsterdam, The Netherlands.
J Comp Neurol. 1991 May 15;307(3):437-59. doi: 10.1002/cne.903070308.
The topographic and laminar organization of entorhinal projections to the dentate gyrus, hippocampus, and subicular complex was investigated in the Macaca fascicularis monkey. Injections of 3H-amino acids were placed at various positions within the entorhinal cortex and the distribution of anterogradely labeled fibers and terminals within the other fields of the hippocampal formation was determined. Injections of the retrograde tracers Fast blue, Diamidino yellow, and wheat germ agglutinin-horseradish peroxidase (WGA-HRP) were also placed into the dentate gyrus, hippocampus, and subicular complex, and the distribution of retrogradely labeled cells in the entorhinal cortex was plotted using a computer-aided digitizing system. The entorhinal cortex gave rise to projections that terminated in the subiculum, in the CA1, CA2, and CA3 fields of the hippocampus, and in the dentate gyrus. Projections to the dentate gyrus, and fields CA3 and CA2 of the hippocampus, originated preferentially in layers II and VI of the entorhinal cortex whereas projections to CA1 and to the subiculum originated mainly in layers III and V. Anterograde tracing experiments demonstrated that all regions of the entorhinal cortex project to the outer two-thirds of the molecular layer of the dentate gyrus and to much of the radial extent of the stratum lacunosum-moleculare of CA3 and CA2. While the terminal distributions of entorhinal projections to the dentate gyrus, CA3, and CA2 were not as clearly laminated as in the rat, projections from rostral levels of the entorhinal cortex preferentially innervated the outer portion of the molecular layer and stratum lacunosum-moleculare, whereas more caudal levels of the entorhinal cortex projected relatively more heavily to the deeper portions of the entorhinal terminal zones. The entorhinal projection to the CA1 field of the hippocampus and to the subiculum followed a transverse rather than radial gradient of distribution. Rostral levels of the entorhinal cortex terminated most heavily at the border of CA1 and the subiculum. More caudal levels of the entorhinal cortex projected to progressively more distal portions of the subiculum (towards the presubiculum) and more proximal portions of CA1 (towards CA2). Lateral portions of the entorhinal cortex projected to caudal levels of the recipient fields and more medial parts of the entorhinal cortex projected to progressively more rostral portions of the fields.
在食蟹猴中研究了内嗅皮层投射至齿状回、海马及下托复合体的局部定位和分层组织。将³H-氨基酸注射到内嗅皮层的不同位置，并确定海马结构其他区域内顺行标记纤维和终末的分布。还将逆行示踪剂快蓝、双脒基黄和小麦胚芽凝集素-辣根过氧化物酶（WGA-HRP）注射到齿状回、海马及下托复合体中，并使用计算机辅助数字化系统绘制内嗅皮层中逆行标记细胞的分布图。内嗅皮层发出的投射终止于下托、海马的CA1、CA2和CA3区以及齿状回。投射至齿状回以及海马的CA3和CA2区的纤维，优先起源于内嗅皮层的第II层和第VI层，而投射至CA1和下托的纤维主要起源于第III层和第V层。顺行追踪实验表明，内嗅皮层的所有区域均投射至齿状回分子层的外三分之二以及CA3和CA2的腔隙-分子层的大部分径向范围。虽然内嗅皮层投射至齿状回、CA3和CA2的终末分布不像在大鼠中那样明显分层，但内嗅皮层嘴侧水平的投射优先支配分子层和腔隙-分子层的外侧部分，而内嗅皮层更尾侧水平的投射相对更重地投射至内嗅终末区的较深部分。内嗅皮层至海马CA1区和下托的投射遵循横向而非径向的分布梯度。内嗅皮层嘴侧水平的投射主要终止于CA1和下托的边界处。内嗅皮层更尾侧水平的投射至下托逐渐更靠远端的部分（朝向副下托）和CA1逐渐更靠近近端的部分（朝向CA2）。内嗅皮层的外侧部分投射至接受区的尾侧水平，而内嗅皮层更内侧的部分投射至接受区逐渐更靠嘴侧的部分。
