ORGANIZATION OF CEREBRAL CORTICAL AFFERENT SYSTEMS IN THE RAT .2. MAGNOCELLULAR BASAL NUCLEUS
ORGANIZATION OF CEREBRAL CORTICAL AFFERENT SYSTEMS IN THE RAT .2. MAGNOCELLULAR BASAL NUCLEUS
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DOI：
10.1002/cne.902220302
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发表时间：
1984-01-01
影响因子：
2.5
通讯作者：
SAPER, CB
中科院分区：
文献类型：
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作者：
SAPER, CB
用细胞构筑、免疫组织化学和顺、逆行运输方法研究了大鼠基底核（MBN）向大脑皮质投射的组织结构。皮质注射麦胚凝集素-辣根过氧化物酶结合物后，逆行标记的基底前脑神经元的分布基本上是相同的神经元染色胆碱乙酰转移酶。发现这些大的（20-30 μ m核周直径）多极神经元分散在许多基底前脑细胞群中：内侧隔核、Broca斜角带核、大细胞视前核、无名质和苍白球。这种特殊的分布模仿了下行皮质纤维进入间脑的路径的位置。每个皮质区由MBN神经元的特征子集支配，总是位于与下行皮质纤维密切相关。顺行放射自显影运输研究后，注射到MBN的3 H-氨基酸显示，MBN轴突到达大脑皮层主要通过2个途径。内侧通路起源于内侧隔核、斜角带核、内侧无名质和苍白球MBN神经元，向背侧弯曲至斜角带核，直至胼胝体属。外侧通路部分来自内侧隔、斜角带和大细胞视前神经元，其轴突横向扫过无名质，主要支配梨状、嗅周和内嗅皮质。这些纤维中的一些也可以通过腹侧下托从内嗅皮层进入海马结构。到目前为止，外侧通路的最大部分来自无名质和苍白球。MBN轴突在新皮层中被发现在最高浓度的第V层，并在最深的部分的第VI层，并在更温和的密度在第I和III层，只有很小的区域变化。在大脑下托、内嗅和梨状皮质中，浅层分子和深层细胞层的神经支配最为密集。在海马中，dennious神经支配被认为是相邻的肺泡和在浅层腔隙-moleculare;的上和颗粒下层最密集的神经支配在齿状回。在整个海马体中，MBN轴突似乎避开了更密集的细胞层：CA区域的神经层和齿状回的颗粒层（尽管齿状回门受到中度密集的神经支配）。与MBN的高度拓扑有序关系是大脑皮层每一部分组织的基本特征。MBN不仅为大脑皮层的每个区域提供类似分布的神经支配，而且MBN神经元可能从它们支配的相同皮层区域接收输入。尽管它的空间分散，MBN的每个部分与下行轴突从其皮质终末场的关系似乎是相对constnat。MBN，在细胞结构，生化和连接的基础上，是一个单一的核，其空间分散的分布可以解释的基础上，其皮质关系。
The organization of the magnocellular basal nucleus (MBN) projection to cerebral cortex in the rat was studied using cytoarchitectonic, immunohistochemical and retrograde and anterograde transport methods. The distribution of retrogradely labeled basal forebrain neurons after cortical injections of wheat germ agglutinin-horseradish peroxidase conjugate was essentially identical to that of neurons staining immunohistochemically for choline acetyltransferase. These large (20-30 .mu.m perikaryon diameter) multipolar neurons were found scattered through a number of basal forebrain cell groups: medial septal nucleus, nucleus of the diagonal band of Broca, magnocellular preoptic nucleus, substantia innominata and globus pallidus. This peculiar distribution mimics the locations of pathways by which descending cortical fibers enter the diencephalon. Each cortical area was innervated by a characteristic subset of MBN neurons, always located in close association with descending cortical fibers. Anterograde autoradiographic transport studies after injections of 3H-amino acids into MBN revealed that MBN axons reach cerebral cortex primarily via 2 pathways. The medial pathway, arising from the medial septal nucleus, nucleus of the diagonal band and medial substantia innominata and globus pallidus MBN neurons, curves dorsally rostral to the diagonal band nucleus, up to the genus of the corpus callosum. The lateral pathway arises in part from medial septal, diagonal band and magnocellular preoptic neurons whose axons sweep laterally through the substantia innominata to innervate primarily piriform, perirhinal and entorhinal cortex. Some of these fibers may also enter the hippocampal formation from the entorhinal cortex via the ventral subiculum. By far the largest part of the lateral pathway arises in the substantia innominata and globus pallidus. MBN axons in neocortex are found in highest concentration in layer V, and in the deepest part of layer VI, and in more moderate density in layers I and III, with only minor regional variation. In the subicular, entorhinal, and piriform cortex, the superficial molecular and deep cellular layers are most densely innervated. In the hippocampus, densest innervation was seen just adjacent to the alveus and in the superficial stratum lacunosum-moleculare; the supra- and infragranular layers were most densely innervated in the dentate gyrus. Throughout the hippocampus, MBN axons seemed to avoid the more densely cellular layers: stratum pyramidale in the CA fields and granular layer in the dentate gyrus (though the dentate hilus was moderately densely innervated). A highly topographically ordered relationship with MBN is a basic feature of the organization of every portion of the cerebral cortex. Not only does MBN provide a similarly distributed innervation to each area of cerebral cortex, but MBN neurons probably receive inputs from the same cortical areas which they innervate. Despite its spatial dispersion, the relationship of each portion of MBN with descending axons from its cortical terminal field appears to be relatively constnat. MBN, on cytoarchitectural, biochemical and connectional grounds, is a single nucleus, and its spatially dispersed distribution can be explained on the basis of its cortical relations.