Mouse rudimentary diastema tooth primordia are devoid of peripheral nerve fibers
Mouse rudimentary diastema tooth primordia are devoid of peripheral nerve fibers
复制标题
小鼠未发育纵裂牙原基缺乏周围神经纤维
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
K. Luukko
中科院分区：
文献类型：
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作者：
Sigbjørn Løes;P. Kettunen;I. Kvinnsland;K. Luukko
牙齿是三叉神经纤维明确的外周靶器官。然而，只有有限的信息是可用的关于先锋轴突引导发展中的牙齿目标领域。在啮齿类动物中，门齿和磨牙之间有一个无牙的间隙区，在老鼠的上颌骨中包含三个初级牙原。当初级神经轴突向发育中的第一磨牙胚芽生长时，它们的发育停止在早期萌芽阶段。为了为研究先锋轴突引导牙胚发育的调控机制提供背景资料，我们通过外周蛋白和PGP9.5的免疫组化定位，研究了小鼠膈牙芽中神经纤维的分布情况，并将其与上颌和下颌第一磨牙胚轴突生长情况进行了比较。序列切片分析显示，三叉神经纤维从三叉上颌神经干和下颌神经干开始向发育中的磨牙胚生长，随后在牙间质凝聚处分化为颊支和舌支。在牙帽期，在牙毛囊区牙胚周围可见神经纤维。相比之下，在研究的任何阶段，没有神经纤维位于齿膈孔原基附近，也没有任何神经纤维向该区域生长。我们的研究结果表明，膈牙原基的发育和随后的消失是在没有周围三叉神经支配的情况下发生的。因此，牙间隙原基可能是未来研究先锋轴突对牙胚引导的分子调控机制的一个有用的模型系统，也可能是外周轴突引导机制的进化研究的一个有用的模型系统。
The tooth is a well-defined peripheral target organ for trigeminal nerve fibers. However, only limited information is available regarding pioneer axon guidance to the developing tooth target field. In rodents there is a toothless diastema region between incisors and molars that in the mouse maxilla contains three rudimentary tooth anlagen. Their development stop at the early bud stage when the primary nerve axons grow towards the developing first molar tooth germs. In order to provide background information for studies of regulatory mechanisms of pioneer axon guidance to the developing tooth germs, we investigated the distribution of nerve fibers in the mouse diastema tooth buds, and compared it to the axon growth to the maxillary and mandibular first molar tooth germs by immunohistochemical localization of peripherin and PGP9.5. Analysis of serial sections showed that trigeminal nerve fibers emerging from the trigeminal maxillary and mandibular nerve trunks started to grow towards the developing molar tooth germ at the early bud stage, and subsequently they diverged into buccal and lingual branches next to the condensed dental mesenchyme. During the cap stage, nerve fibers were observed around the tooth germ in the dental follicle region. In contrast, no nerve fibers were located in the vicinity of the diastema tooth primordia at any stage studied, nor did any nerve fibers appear to grow towards this region. Our results show that the development and subsequent disappearance of the diastema tooth primordia takes place without peripheral trigeminal innervation. The diastema tooth primordia may therefore be a useful model system for future studies on molecular regulatory mechanisms of pioneer axon guidance to the tooth germs, and possibly also for evolutionary studies of peripheral axon guidance mechanisms.
NGF、BDNF、NT3、NT4 和 GDNF 在牙齿发育中的作用。
影响因子：
1.9
作者：
Nosrat,CA;Fried,K;Ebendal,T;Olson,L
通讯作者：
Olson,L