AFFERENT AND EFFERENT CONNECTIONS OF THE VENTROMEDIAL THALAMIC NUCLEUS IN THE RAT
AFFERENT AND EFFERENT CONNECTIONS OF THE VENTROMEDIAL THALAMIC NUCLEUS IN THE RAT
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DOI：
10.1002/cne.901830304
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发表时间：
1979-01-01
影响因子：
2.5
通讯作者：
HERKENHAM, M
中科院分区：
文献类型：
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作者：
HERKENHAM, M
用辣根过氧化物酶逆行细胞标记法和放射自显影顺行纤维示踪法对大鼠丘脑腹内侧核的传入和传出纤维联系进行了实验研究。3 H-氨基酸微电泳沉积到VM标记皮质投影，其分布到几乎整个同侧新皮质的I层的明确定义的浅表部分。标记是最密集的额叶皮质水平，其中纤维辐射通过更深的层终止在外部25%的层I在整个新皮质吻侧的胼胝体的胼胝体。标记的侧枝通过皮质层上升到第一层，在那里的表面部分的颗粒被发现在一个逐渐降低的密度梯度，达到尾极的半球。冠状面在大多数水平包含一个带的标签在第一层，不间断地延伸从中线的胼胝体沟的银行的鼻沟横向。在更深的层中的额外的终端分布的证据被发现，只有在背侧和侧部的皮质喙的稀疏标记的乐队出现在第三层和第五层的VM皮质传入层I的几乎排他性的分布进行比较和对比与多层分布的其他非特异性皮质传入纤维。HRP注入VM标记神经元在各种结构的水平，从额叶皮质到尾髓质。苍白球、上级丘深层、小脑核和黑质网状部的细胞标记表明VM是锥体外系运动系统几个组成部分的会聚点。在前额叶皮质，皮质沿着鼻沟，外侧缰核，被盖和延髓网状结构和臂旁核的细胞标记表明，VM也收到来自更多的异质性来源的预测。
The afferent and efferent connections of the ventromedial (VM) nucleus of the thalamus in the rat were studied by experiments using the methods of retrograde cell marking by horseradish peroxidase (HRP) and anterograde fiber tracing by autoradiography. 3H-Amino acids deposited microelectrophoretically into VM label a cortical projection that is distributed to a sharply defined superficial portion of layer I of almost the entire extent of the ipsilateral neocortex. The labeling is most dense at frontal cortical levels, where fibers radiate through the deeper layers to terminate in the outer 25% of layer I throughout all neocortex rostral to the genu of the corpus callosum. Labeled collaterals ascend through the cortical layers to reach layer I, where grains in the superficial portion are found in a gradually decreasing rostrocaudal gradient of density that reaches the caudal pole of the hemisphere. Coronal sections at most levels contain a band of labeling in layer I that extends uninterrupted from the callosal sulcus at the midline to the banks of the rhinal sulcus laterally. Evidence for additional terminal distribution in deeper layers is found only in the dorsal and lateral sectors of the cortex rostral to the genu where sparsely labeled bands appear in layers III and V. The nearly exclusive distribution of VM cortical afferents to layer I is compared and contrasted with multilaminar distributions of other unspecific cortical afferent fibers. HRP injected into VM labels neurons in a variety of structures at levels ranging from the frontal cortex to caudal medulla. Cell labeling in the globus pallidus, deep layers of the superior colliculus, cerebellar nuclei and the substantia nigra, pars reticulata suggest that VM is a point of convergence for several components of the extrapyramidal motor system. Cell labeling in the prefrontal cortex, the cortex along the rhinal sulcus, the lateral habenular nucleus, tegmental and medullary reticular formations and parabrachial nuclei indicates that VM also receives projections from more heterogeneous sources.