THE COMMISSURAL CONNECTIONS OF THE MONKEY HIPPOCAMPAL-FORMATION
THE COMMISSURAL CONNECTIONS OF THE MONKEY HIPPOCAMPAL-FORMATION
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DOI：
10.1002/cne.902240302
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发表时间：
1984-01-01
影响因子：
2.5
通讯作者：
COWAN, WM
中科院分区：
文献类型：
--
作者：
AMARAL, DG;INSAUSTI, R;COWAN, WM
用顺行和逆行标记技术分析了猕猴的海马区结构的连合联系。我们观察到猴子的连合投射的组织与啮齿动物大脑的连合投射的组织有许多显著的差异。具体地说，只有阿蒙角的喙(或钩)部分(或海马体本身)和齿状回的相关部分被发现由连合纤维连接。这与啮齿动物大脑的交叉连接的组织形成了鲜明的对比，在啮齿动物的大脑中，海马体的两个主要区域(即上区和下区)在其整个吻尾范围内从对侧的下区接收到一个强大的、按地形组织的投射，而整个齿状回分子层的内侧三分之一从对侧齿状回的门区接收到一个按地形组织的输入。猴子的这种半球状复杂结构导致了大量的连合定向纤维的产生。下丘脑本身投射到对侧内侧嗅觉皮质的后部，并接受来自同一区域的较不明显的相互投射；下丘脑似乎不是同伦相互连接的。下丘下层形成猴海马体结构的主要连合投射。从丘脑前丘的所有吻尾水平向对侧内侧内嗅觉皮质发出强有力的投射。这种投射似乎在地形上是有组织的，终止最多的是内嗅皮层的第三层和第四层。这种交叉的前丘-内嗅觉投射在其组织上是平行的，从前丘前到同侧内嗅皮层的联合投射是平行的，但有趣的是，前丘似乎并不投射到对侧的前丘前。副下丘既不投射到对侧内嗅皮层，也不投射到对侧副下丘。然而，作为一个整体，下丘复合体似乎接受了来自对侧海马旁回(Bonin和Bailey的Tf区和Th区)的少量输入。主要位于内侧内嗅皮质第三层(28a区)的细胞同位投射到对侧内嗅皮质，终止于第三层。内侧内嗅皮质也有一个小的投射，投射到对侧副小结和对侧海马区的上方以及齿状回外分子层的尾部几乎部分。这种交叉的颞氨投射似乎只出现在内侧内嗅觉皮质的尾部。外侧内嗅皮层(28b区)与对侧对应野没有连合投射，但它接受对侧嗅周皮质(35区)的少量投射。内嗅皮层的两个部分都接受来自对侧海马旁回的光投射。
The commissural connections of the hippocampal formation have been analyzed in the monkey (Macaca fascicularis) using both anterograde and retrograde labeling techniques. We have observed a number of striking differences between the organization of the commissural projections in the monkey and that observed in the rodent brain. In particular, only the rostral (or uncal) part ofAmmon's horn(or hippocampus proper) and the associated part of thedentate gyrushave been found to be connected by commissural fibers. This is in marked contrast to the organization of the crossed connections in the rodent brain where both major fields of the hippocampus (i.e., the regio superior and the region inferior) receive a strong, topographically organized, projection throughout their rostrocaudal extent from theregio inferiorof the opposite side, while the inner third of the molecular layer of the entire dentate gyrus receives a topographically organized input from calls in the hilar region of the contralateral dentate gyrus.Thesubicular complexof the monkey gives rise to a substantially greater number of commissurally directed fibers. Thesubiculumitself projects to the postserior portion of the contralateral medial entorhinal cortex and receives a less substantial reciprocal projection from this same area; the subiculum does not appear to be homotopically interconnected. Thepresubiculumgives rise to the major commissural projection of the monkey hippocampal formation. From all rostrocaudal levels of the presubiculum there is a robust projection to the contralateral medial entorhinal cortex. This projection seems to be topographically organized and terminates most heavily in layers III and IV of the entorhinal cortex. This crossed presubiculo‐entorhinal projection is paralleled in its organization by an associational projection from the presubiculum to the ipsilateral entorhinal cortex, but, interestingly, the presubiculum does not seem to project to the presubiculum of the opposite side. Theparasubiculumprojects to neither the contralateral entorhinal cortex nor the contralateral parasubiculum. However, the subicular complex as a whole appears to be in receipt of a minor input from the contralateral parahippocampal gyrus (fields TF of and TH of Bonin and Bailey). Cells primarily in layer III of themedial entorhinal cortex(area 28a) project homotopically to the contralateral entorhinal cortex where they terminate in layer III. The medial entorhinal cortex also gives rise to a minor projection the contralateral parasubiculum and to theregion superiorof the contralateral hippocampus and the caudalmost part of the outer molecular layer of the dentate gyrus. This crossed temporo‐ammonic projection appears to arise only from the caudal part of the medial entorhinal cortex. The lateral entorhinal cortex (area 28b) has no commissural projection to the corresponding field on the opposite side, but it does receive a minor projection from the contralateralperirhinal cortex(area 35). Both divisions of the entorhinal cortex receive a light projection from the contralateral parahippocampal gyrus.