Müller F, O'Rahilly R
Teratology. 1984 Oct;30(2):167-77. doi: 10.1002/tera.1420300203.
Cerebral dysraphia was studied histologically and by graphic reconstruction in a twin at stage 13, and comparisons were made with the normal (discordant) twin. The normal, bidirectional closure of the rostral neuropore was investigated in several embryos, from which it was concluded that the situs neuroporicus is represented by the future commissural plate rather than by the (adult) lamina terminalis. In the abnormal twin the neural tube was open over part of the midbrain and forebrain, although the situs neuroporicus was closed. The experimental production of anencephaly by Giroud and co-workers was reviewed, and comparisons between embryonic staging systems in the rat, mouse, and human were made. Three corresponding phases are found in the human: 1) cerebral dysraphia, occurring before or during Carnegie stage 11 (approximately 23-25 days); 2) exposure of a highly developing and well-differentiated brain during the remainder of the embryonic period; and 3) degeneration of the exposed brain throughout the fetal period, resulting in anencephaly. Hence the abnormal twin described here is believed to represent a precursor of typical anencephaly, and is the earliest example of purely cerebral dysraphia so far recorded.
对一名处于13期的双胞胎中的一个进行了脑发育不全的组织学研究和图形重建，并与正常（不一致）的双胞胎进行了比较。在几个胚胎中研究了头侧神经孔的正常双向闭合，由此得出结论，神经孔位置由未来的连合板而非（成人的）终板代表。在异常的双胞胎中，尽管神经孔位置已闭合，但神经管在中脑和前脑的部分区域是开放的。回顾了吉鲁德及其同事通过实验制造无脑儿的过程，并对大鼠、小鼠和人类的胚胎分期系统进行了比较。在人类中发现了三个相应阶段：1）脑发育不全，发生在卡内基11期之前或期间（约23 - 25天）；2）在胚胎期剩余时间内，高度发育且分化良好的大脑暴露在外；3）在整个胎儿期，暴露的大脑发生退化，导致无脑儿。因此，这里描述的异常双胞胎被认为是典型无脑儿的先兆，是迄今为止记录的最早的单纯脑发育不全的例子。
