Myelination in the human hippocampal formation from midgestation to adulthood
Myelination in the human hippocampal formation from midgestation to adulthood
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DOI：
10.1016/j.ijdevneu.2010.03.004
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发表时间：
2010-08-01
影响因子：
1.8
通讯作者：
Seress, Laszlo
中科院分区：
文献类型：
--
作者：
Abraham, Hajnalka;Vincze, Andras;Seress, Laszlo
髓鞘形成是神经元发育的最后步骤之一，在人类胎儿和出生后的海马形成中使用免疫组织化学检测髓鞘的蛋白质成分，髓鞘是由少突胶质细胞合成的髓鞘碱性蛋白。髓鞘碱性蛋白免疫反应性少突胶质细胞在妊娠第20周首次出现在胎膜和肺泡中。在第21 ~ 35周时，巢状被膜也出现髓鞘轴突。孕39周时，海马毛毡、肺泡中出现了短而细的髓鞘纤维，海马定向层中较少出现髓鞘纤维，而在空隙层-分子层和海门中出现了第一批少突胶质细胞。出生后第2周，在阿蒙角的空隙层分子中出现髓鞘纤维。在第3个月时，肺泡有髓鞘形成较强，阿蒙角的定向层、腔隙分子和辐射体有中度髓鞘形成，而门部仅有少量髓鞘纤维形成。到第5个月时，在齿状回分子层检测到第一批少突胶质细胞。在接下来的几年里，髓鞘形成继续进行，特别是在齿状回，即使在11岁时，髓鞘纤维的密度也没有达到成人的水平。第一个有髓鞘的轴突似乎属于长突出的大海马锥体细胞和/或它们的皮层下和皮层传入神经。髓鞘形成的顺序遵循已知的海马传入和传出通路的发育模式，延长的髓鞘形成可能是海马回路功能成熟延长的一个因素。(c) 2010 isdn。Elsevier Ltd.出版。版权所有。
Myelination, one of the last steps of neuronal development, was examined in the human fetal and postnatal hippocampal formation using immunohistochemistry to detect a protein component of the myelin sheath, the myelin basic protein synthesized by oligodendroglial cells. Myelin basic protein-immunoreactive oligodendroglial cells were first seen at the 20th gestational week in the fimbria fornicis and in the alveus. Between the 21st and 35th weeks, myelinated axons also appeared in the fimbria fornicis. At the age of 39 gestational weeks, short and thin myelinated fibers were present in the fimbria, in the alveus, and less so in the stratum oriens of the hippocampus, while the first oligodendroglial cells appeared in the stratum lacunosum-moleculare and in the hilus. By the 2nd postnatal week myelinated fibers appeared in the stratum lacunosum-moleculare of Ammon's horn. At the 3rd month, myelination was strong in the alveus, moderate in the strata oriens, lacunosum-moleculare and radiatum of Ammon's horn, while only a small number of myelinated fibers were detected in the hilus. By the 5th month, the first oligodendroglial cells were detected in the molecular layer of the dentate gyrus. Myelination continued in the following years, particularly in the dentate gyrus, where even at the age of 11 years the density of myelinated fibers did not reach the adult level. It appears that the first myelinated axons belong to the long-projecting large hippocampal pyramidal cells and/or to their subcortical and cortical afferents. The sequence of myelination follows the known developmental pattern of hippocampal afferent and efferent pathways, and the prolonged myelination might be a factor in the prolonged functional maturation of hippocampal circuitry. (C) 2010 ISDN. Published by Elsevier Ltd. All rights reserved.