PERIPHERAL ORGANS CONTROL CENTRAL NEUROGENESIS IN THE LEECH
PERIPHERAL ORGANS CONTROL CENTRAL NEUROGENESIS IN THE LEECH
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DOI：
10.1038/346855a0
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发表时间：
1990-08-30
期刊：
影响因子：
64.8
通讯作者：
MACAGNO, ER
中科院分区：
文献类型：
--
作者：
BAPTISTA, CA;GERSHON, TR;MACAGNO, ER
已知发育中的神经中枢和外周靶点之间的相互作用会影响神经元的存活，从而调节许多系统中神经元的成年数量1，2。在这里，我们提供的证据表明，外周组织也可以通过刺激神经元的产生来影响细胞数量。在水蛭medicularis，有一个人口的几百个神经元，只发现在两个节段神经节支配生殖器3，似乎是逐渐增加在胚胎后成熟4，5。通过化学方法监测5-溴-2 ′-脱氧尿苷掺入，我们现在已经确定这些神经元实际上是在胚胎发生的晚期出生的，在所有其他中枢神经元出生之后，以及在这些神经节和外周之间建立传出和传入投射之后。在胚胎发育早期切除雄性生殖器，或将生殖器与神经节连接的神经拔出，会阻止这些神经元的诞生。然而，他们未能出现异位时，男性生殖器移植到其他部分，尽管神经支配的地方神经节。我们的结论是，晚出现的神经元的产生依赖于一个高度本地化的信号产生的男性生殖器，只有神经节，通常支配这些器官有能力作出反应。
INTERACTIONS between developing nerve centres and peripheral targets are known to affect neuronal survival and thus regulate the adult number of neurons in many systems1,2. Here we provide evidence that peripheral tissues can also influence cell numbers by stimulating the production of neurons. In the leechHirudo medicinalis, there is a population of several hundred neurons that is found only in the two segmental ganglia that innervate the genitalia3and which seem to be added gradually during post-embryonic maturation4,5. By monitoring 5-bromo-2′-deoxyuridine incorporation immunohistochemically, we have now determined that these neurons are actually born late in embryogenesis, well after all other central neurons are born and after efferent and afferent projections are established between these ganglia and the periphery. Ablation of the male genitalia early in embryogenesis, or evulsion of the nerves that connect them to the ganglia, prevent the birth of these neurons. However, they fail to appear ectopically when male genitalia are transplanted to other segments, despite innervation by local ganglia. We conclude that the generation of the late-appearing neurons depends on a highly localized signal produced by the male genitalia, to which only the ganglia that normally innervate these organs have the capacity to respond.