EARLY DEVELOPMENT OF SEROTONIN-CONTAINING NEURONS AND PATHWAYS AS SEEN IN WHOLEMOUNT PREPARATIONS OF THE FETAL-RAT BRAIN
EARLY DEVELOPMENT OF SEROTONIN-CONTAINING NEURONS AND PATHWAYS AS SEEN IN WHOLEMOUNT PREPARATIONS OF THE FETAL-RAT BRAIN
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DOI：
10.1002/cne.902740105
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发表时间：
1988-08-01
影响因子：
2.5
通讯作者：
TORK, I
中科院分区：
文献类型：
--
作者：
AITKEN, AR;TORK, I
在胎鼠全脑（E12-E18）中研究了含胡萝卜素神经元的早期发育。根据免疫过氧化物酶技术，对整个标本进行免疫细胞化学处理，以显示发育中的胆碱能神经元的全貌。5-羟色胺能神经元定位于脑干内的两个离散的组或簇。含5-羟色胺的神经元首先在E12被鉴定，形成中脑曲尾部的吻侧细胞簇。 更尾部的细胞群首先出现在E14的髓质。在E12至E18期间，免疫反应细胞数量增加，并获得更复杂的树突状树，同时迁移到它们的永久位置。在E16，吻侧组的细胞表现出非常均匀的中外侧方向。喙组的免疫反应阳性神经元产生了几乎所有的上升纤维，而尾组产生了大部分的下降纤维。生长中的肾上腺素能纤维顶端突出的生长锥，这是强烈的免疫反应。纤维表现出突出的取向选择性，几乎完全分离成上升和下降束。一些上升的免疫反应性纤维显示其生长方向的急剧变化，这表明，cardioninergic纤维的方向是由特定的cardioninergic纤维的特定群体的方向线索介导的。内侧前脑内的5-羟色胺能轴突可以很容易地跟踪。免疫反应性纤维进入端脑在E17两个门户网站，一个沿着下丘脑的外侧缘和一个rostrally，邻近嗅结节。在E18时的全峰中，从后一个位置产生的纤维可以在腭部内作为两个不同的带;位于腹外侧的基底带，邻近外侧嗅束，和位于端脑内侧边缘的背带。两个束都指向枕极，并含有不分支的纤维。在E18，从这两个松散的组织束产生的轴突覆盖了大部分的额端脑。本研究的结果表明，胚胎脑的整体可以提供新的时空数据的神经递质系统的发展，并可能在未来被证明是有用的实验准备在发育神经生物学。
The early development of serotonin-containing neurons was studied in wholemounts of the fetal rat brain (E12-E18). The wholemounts were treated immunocytochemically according to an immunoperoxidase technique to reveal a panorama of developing serotininergic neurons. Serotoninergic neurons were localized to two discrete groups or clusters within the brainstem. Serotonin-containing neurons were identified first at E12 forming a rostral cluster of cells just caudal to the mesencephalic flexure. The more caudal cluster of cells first appeared at E14 in the medulla. During the period from E12 to E18, the immunoreactive cells increased in number and acquired a more complex dendiritic tree while migrating to their permanent position. At E16, cells of the rostral group exhibited remarkably uniform mediolateral orientation. The rostral group of immunoreactive neurons gave rise to almost all ascending fibers, whereas the caudal group gave rise to the majority of descending fibers. Growing serotoninergic fibers were tipped by prominent growth cones, which were strongly immunoreactive. The fibers demonstrated prominent orientational selectivity with an almost total separation into ascending and descending bundles. Some of the ascending immunoreactive fibers displayed acute changes in their direction of growth, suggesting that the orientation of serotoninergic fibers is mediated by directional cues that are specific to particular populations of serotoninergic fibres. Serotoninergic axons within the medial forebrain could be easily followed. Immunoreactive fibers entered the telencephalon at E17 two portals, one along the lateral border of the hypothalamus and one rostrally, adjacent to the olfactory tubercle. In wholemounts at E18, fibers arising from this latter location could be followed as two distinct bands within the pallium; a basal band located ventrolaterally, adjacent to the lateral olfactory tract, and a dorsal band located at the medial edge of the telencephalon. Both fascicles were directed toward the occipital pole and contained unbranched fibers. At E18, serotonergic axons arising from these two loosely organized fascicles covered most of the frontal telencephaon. The results of the present study indicate that wholemounts of embryonic brain can provide novel spaciotemporal data on the development of neurotransmitter systems and may in the future prove to be useful experimental preparations in developmental neurobiology.