CORTICOSPINAL NEURONS WITH BRANCHING AXONS TO THE DORSAL COLUMN NUCLEI IN THE MONKEY
CORTICOSPINAL NEURONS WITH BRANCHING AXONS TO THE DORSAL COLUMN NUCLEI IN THE MONKEY
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DOI：
10.1002/cne.902530212
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发表时间：
1986-11-08
影响因子：
2.5
通讯作者：
RUSTIONI, A
中科院分区：
文献类型：
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作者：
BENTIVOGLIO, M;RUSTIONI, A
以前在猫身上的研究表明，皮质脊髓束的起源细胞产生背柱核（DCN）的侧支。本实验在猴（Macaca fascicularis）中进行，其中2%坚牢蓝和2%二脒基黄被递送以渗透在C2和C6之间的水平的背外侧索和同侧的楔状核。皮质中的逆行标记允许同时可视化三类神经元：皮质脊髓束（CST）神经元、皮质丘索束（CCT）神经元和双标记神经元。CST和CCT神经元的形态特征和分布与以前主要基于辣根过氧化物酶（HRP）逆行运输的研究报道的相似。CST神经元出现在V层中的前和后中央回，除了外侧部分（面部代表），在补充运动和感觉皮层，并在SII。CCT神经元主要存在于中央后回和SII中的第V层中。双标记神经元存在于CST和CCT神经元被发现的任何地方。来自中央周围皮质的重建和定量数据显示，高达60%的CCT神经元是双标记的，主要在1区和2区发现，并且它们的胞体位于较大CCT神经元的相同范围内。将这些结果与先前通过使用HRP和氚化的、酶失活的HRP在猫中获得的结果进行比较（3 H-apo-HRP，Rustioni和Hayes：Exp. Brain Res.43：237-245，1981）表明，具有到DCN的分支轴突的CST神经元在猴中比在猫中多得多。以确定这种差异是否是由两个物种中使用的不同示踪剂引起的。将2%固蓝和2%二脒基黄分别注入猫C2-C3背外侧索和同侧楔状核。这些猫的结果与先前使用HRP和3 H-apo-HRP的研究中获得的结果非常相似：双标记神经元主要出现在3a区，占十字周围区CCT神经元的14-16%。这些结果与背柱内侧丘系系统的下行控制和性能调整机制有关，例如，离散时空线索的辨别。种属差异可能与猴相对于猫在DCN和脊髓的触觉分辨率和感觉流入的同步控制程度更高有关。
Previous work in cats has shown that cells of origin of the corticospinal tract give rise to collateral branches to the dorsal coloumn nuclei (DCN). The present experiments were performed in monkeys (Macaca fascicularis) in which 2% fast blue and 2% diamidino yellow were delivered to infiltrate the dorsolateral funiculus at levels between C2 and C6 and the cuneate nucleus on the same side. Retrograde labelling in the cortex allows simultaneous visualization of three classes of neurons: corticospinal tract (CST) neurons, corticocuneate tract (CCT) neurons, and double-labelled neurons. The morphological feature and distribution of CST and CCT neurons are similar to those previously reported from investigations based mainly upon the retrograde transport of horseradish peroxidase (HRP). CST neurons occur in layer V in the pre- and postcentral gyri, except for the lateral part (face representation), in the supplementary motor and sensory cortex, and in SII. CCT neurons are present in layer V largely in the postcentral gyrus and in SII. Double-labelled neurons are present wherever CST and CCT neurons are found. Recontruction and quantitative data from the pericentral cortex show that up to 60% of CCT neurons are double-labelled and are found predominantly in areas 1 and 2, and that their perikarya are in the same range of the larger CCT neurons. Comparison of these results with those obtained previously in cats by using HRP and tritiated, enzymatically inactive HRP (3H-apo-HRP, Rustioni and Hayes: Exp. Brain Res. 43:237-245, 1981) suggest that CST neurons with branching axons to the DCN are considerably more numerous in monkeys than in cats. To determine whether this difference is caused by the different tracers used in the two species. 2% fast blue and 2% diamidino yellow were delivered in cats to infiltrate the dorsolateral funiculus at C2-C3 and the cuneate nucleus on the same side. The results in these cats are remarkably similar to those obtained in the previous study, which used HRP and 3H-apo-HRP: double-labelled neurons occur predominantly in area 3a and constitute 14-16% of the CCT neurons in the pericruciate area. The results bear upon mechanism of descending control and tuning of performances that characterize the dorsal column-medial lemniscal system, e.g., discrimination of discrete spatiotemporal cues. The species differences may be related to the higher degree of tactile resolution and synchronous control of sensory inflow at the DCN and spinal cord in monkeys relative to cats.