MEDIODORSAL NUCLEUS - AREAL, LAMINAR, AND TANGENTIAL DISTRIBUTION OF AFFERENTS AND EFFERENTS IN THE FRONTAL-LOBE OF RHESUS-MONKEYS
MEDIODORSAL NUCLEUS - AREAL, LAMINAR, AND TANGENTIAL DISTRIBUTION OF AFFERENTS AND EFFERENTS IN THE FRONTAL-LOBE OF RHESUS-MONKEYS
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DOI：
10.1002/cne.902770204
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发表时间：
1988-11-08
影响因子：
2.5
通讯作者：
GOLDMANRAKIC, PS
中科院分区：
文献类型：
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作者：
GIGUERE, M;GOLDMANRAKIC, PS
丘脑传入神经在灵长类前额叶皮层的末梢分布从未被详细研究过。在本研究中，将WGA-HRP注射到恒河猴内侧背核（MD）的主要亚部，以确定（1）MD投射的区域分布，（2）MD传入终止的层，（3）MD轴突终末的切线模式，（4）皮质丘脑相互通路的起源细胞，（5）前额叶皮质不同区域皮质丘脑和丘脑皮质通路之间的相互作用程度，正如逆行变性和转运研究所预期的那样，注射集中在腹侧和内侧前额叶皮质MD标记细胞和终末的大细胞亚核（MDmc）。涉及腹侧MDmc的注射标记了这些区域的更外侧（步行者区域11和12）;背侧MDmc的注射标记了腹内侧区域（区域13和14）。相反，主要涉及外侧小细胞（MDpc）部分的注射标记了背外侧和背内侧区域的细胞和终末（步行者46、9和8 B）。当注射包括MD的多形部分（MDmf）时，区域8A标记最显著，区域10与MD的前部连接。MDpc的背腹侧地形存在背侧MDpc标记背侧和背内侧前额叶区域，腹侧MDpc标记背外侧前额叶皮质。我们对MD的研究结果与其丘脑皮质投射系统的核-场组织结构相一致，在传统的前额叶皮质边界之外，外侧MD投射延伸到补充运动区（SMA）和前扣带回（AC）的背侧部分，而内侧MD投射针对腹内侧扣带回皮质，保留SMA。此外，少数标记细胞和稀疏的终端被发现在顶下小叶，上级颞沟，和前部分的注射后，涉及MD的内侧部分标记终末总是局限于IV层和邻近的深层III。在注射局限于MD的任何部分后，在大脑皮层的任何部分的I、II、浅表III、V或VI层中均未观察到终末标记。从MD到PFC的投影形成了一个范围为0.3至1.3 mm的分离性条带图案，当注射量相对较小时尤其明显;当注射涉及较大的丘脑体积时，末端标记图案在整个第III层和第IV层中更加弥散和切线广泛。这些数据可以指示源自丘脑细胞的相邻簇的终末场的交错（Goldman-Rakic和Porrino：J. Comp. Neurol. 242：535-560，'85）。PFC、SMA和AC中的逆行转运的分析揭示了皮质丘脑细胞的层状起源中的意外的区域差异。在所有的前额叶区，标记的皮质丘脑神经元主要分布在第VI层的浅部，少数标记细胞也分布在第V层的浅部。在辅助运动区，标记细胞的分布基本上是双层的，浅V层的标记细胞数量比PFC层多得多。标记细胞分布于第VI层，并分层分布于第VI层，其浅层和深层的标记细胞密度大致相等，逆行标记细胞与顺行标记终末野的关系也存在明显的地区差异。在前额区域，标记细胞密度的波动...
The terminal distribution of thalamic afferents in primate prefrontal cortex has never been examined in any detail. In the present study, WGA‐HRP was injected into major subdivisions of the mediodorsal nucleus (MD) in the rhesus monkey in order to determine (1) The areal distribution of MD projections, (2) the layer (s) in which MD afferents terminate, (3) the tangential pattern of the MD axonal terminals, (4) the cells of origin of the reciprocal corticothalamic pathway, and (5) the degree of reciprocity between the corticothalamic and thalamocortical pathways in the different regions of the prefrontal cortex.As expected on the basis of retrograde degeneration and transport studies, injections centered in the magnocellular (MDmc) subnucleus of MD labeled cells and terminals in the ventral and medial prefrontal cortex. Injections involving ventral MDmc labeled the more lateral of these areas (Walker's areas 11 and 12); injections of the dorsal MDmc labeled the ventromedial regions (areas 13 and 14). In contrast, injections involving mainly the lateral, parvicellular (MDpc) moiety labeled cells and terminals in dorsolateral and dorsomedial areas (Walker's 46, 9, and 8B). Area 8A was labeled most prominently when injections included the multiform portion of MD (MDmf) and area 10 had connections with anterior portions of MD. A dorsal‐ventral topography for MDpc exists with dorsal MDpc labeling dorsal and dorsomedial prefrontal areas and ventral MDpc labeling dorsolateral prefrontal cortex. Our findings with respect to MD are consistent with a nucleus‐to‐field organization of its thalamocortical projection system.Outside of the traditional boundaries of prefrontal cortex, lateral MD projections extended to the supplementary motor area (SMA) and the dorsal part of the anterior cingulate (AC) whereas the medial MD projection targeted the ventromedial cingulate cortex and spared SMA. In addition, a few labeled cells and sparse terminals were found in the inferior parietal lobule, the superior temporal sulcus, and the anterior part of the insula after injections that involved the medial part of MD.Labeled terminals were invariably confined to layer IV and adjacent deep layer III. No terminal label was ever observed in layers I, II, superficial III, V, or VI in any part of the cerebral cortex following injections confined to any part of MD. The projection from MD to the PFC formed a disjunctive pattern of bands ranging from 0.3 to 1.3 mm, which were especially evident when injections were relatively small; when the injection involved a larger thalamic volume, the pattern of terminal labeling was somewhat more diffuse and tangentially extensive throughout layers III and IV. These data may indicate an interdigitation of the terminal fields originating from adjacent clusters of thalamic cells (Goldman‐Rakic and Porrino:J. Comp. Neurol. 242:535–560, '85).Analysis of retrograde transport in the PFC, SMA and AC revealed unexpected regional differences in the laminar origin of corticothalamic cells. In all prefrontal areas, labeled corticothalamic neurons were found mainly in the superficial part of layer VI with a few labeled cells situated also in the superficial part of layer V. In the supplementary motor area the distribution of cells was essentially bilaminar with the number of labeled cells in superficial V much more substantial than in PFC. Finally, in the anterior cingulate cortex, the labeled cells were confined to and stratified in layer VI with about equal density in its superficial and deep strata.Regional differences were also apparent in relationships of retrogradely labeled cells and anterogradely labeled terminal fields. In prefrontal areas, fluctuations in the density of labeled cells …