Target influences on the morphology of trigeminal axons.
Target influences on the morphology of trigeminal axons.
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目标对三叉神经轴突形态的影响。
DOI：
10.1006/exnr.1995.1061
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Jhaveri,S
中科院分区：
文献类型：
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作者：
Erzurumlu,RS;Jhaveri,S
轴突的生长分为两个阶段：首先，它们表现出快速的、靶向的延伸;然后它们开始在其靶点中抵押和精心制作终端乔木。为了研究轴突生长的这些阶段可能的调控影响，我们使用了一种体外范例，在该范例中，我们共培养胚胎或出生后的大鼠三叉神经节外植体与等时，异时，和/或异型目标。5天后固定培养物，用DiI标记神经节细胞突起。三叉神经过程能够再生成几个周边目标，以及从三叉神经或非三叉神经区域的大脑中枢神经系统外植体。在外周组织中，突起显示出靶特异性生长模式。在中枢神经系统组织中，生长的类型（无分支的扩展与侧支化/乔木形成）显着不同的外植体年龄：如果三叉神经节收获的时间（E15）时，他们的轴突将在胚胎中伸长，并与等时组织共培养，他们的过程有一个简单的形态，松散的捆绑，并重建一个独特的纤维束，模仿他们在体内的生长模式。如果受到更成熟的组织的挑战，E15神经节细胞的轴突形成离散的乔木。最后，如果在年龄（E20，PND 5）时收获三叉神经节，此时它们的轴突已经在大脑中形成了乔木，并被诱导神经支配年轻（E15）的目标，它们的轴突恢复到伸长阶段。这些结果表明，目标环境设置特定的，发育调控的初级感觉轴突表现出的增长模式的限制。
Axons grow in two stages: First, they exhibit rapid, target-directed extension; then they begin to collateralize and elaborate terminal arbors in their targets. To investigate possible regulatory influences on these phases of axon growth, we have used an in vitro paradigm in which we cocultured embryonic or postnatal rat trigeminal ganglion explants with isochronic, heterochronic, and/or heterotypic targets. Cultures were fixed after 5 days and ganglion cell processes were labeled with DiI. Trigeminal processes were able to regenerate into several peripheral targets as well as into CNS explants from trigeminal or nontrigeminal regions of the brain. In peripheral tissues, the processes showed target-specific growth patterns. In CNS tissue, the type of growth (unbranched extension versus collateralization/arbor formation) varied markedly with the explant age: If trigeminal ganglia were harvested at a time (E15) when their axons would be elongating in the embryo and cocultured with isochronic tissues, their processes had a simple morphology, were loosely bundled, and reconstituted a distinct fiber tract, mimicking their in vivo growth pattern. If, challenged by more mature tissue, axons of E15 ganglion cells formed discrete arbors. Finally, if trigeminal ganglia were harvested at an age (E20, PND 5) when their axons had already formed arbors in the brain and induced to innervate younger (E15) targets, their axons reverted back to the elongation stage. These results demonstrate that the target environment sets specific, developmentally regulated constraints on the patterns of growth manifested by primary sensory axons.