EFFECTS OF PRENATAL EXPOSURE TO ETHANOL ON THE NUMBER OF AXONS IN THE PYRAMIDAL TRACT OF THE RAT
EFFECTS OF PRENATAL EXPOSURE TO ETHANOL ON THE NUMBER OF AXONS IN THE PYRAMIDAL TRACT OF THE RAT
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DOI：
10.1111/j.1530-0277.1994.tb00024.x
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发表时间：
1994-04-01
影响因子：
3.2
通讯作者：
ALRABIAI, S
中科院分区：
文献类型：
--
作者：
MILLER, MW;ALRABIAI, S
我们研究了妊娠期酒精暴露对尾锥体束轴突数量的影响。在妊娠第6天（G）和G21天（含）之间，给妊娠大鼠喂食含乙醇的液体饮食（Et）、等热量液体对照饮食（Ct）或饲料和水饮食（Ch）。在出生后第30天，这些大鼠的后代被杀死，其尾部髓质进行电子显微镜检查。在ET-治疗组大鼠中，锥体束和轴突所占据的空间的总体尺寸小于CT-治疗组大鼠。有髓轴突较小，髓鞘是在ET治疗的大鼠比CT治疗的大鼠薄。这些减少产生了乙醇诱导的锥体束中轴突密度的增加。特别是，有髓轴突（但不是无髓轴突）的密度在ET治疗的大鼠更大。净结果是，估计数的轴突在锥体束的ET-治疗的大鼠是没有显着不同的Ch-和CT-治疗的大鼠的数量。目前的数据表明，乙醇不影响锥体束中轴突的绝对数量。然而，由于乙醇诱导的小脑畸形，这些数据转化为锥体束轴突数量的相对增加。这种相对增加与乙醇诱导的皮质脊髓投射神经元密度增加相匹配，这可能是由于保留了发育旺盛的投射。
We examined the effect of gestational ethanol exposure on the number of axons in the caudal pyramidal tract. Between gestational day (G) 6 and G21, inclusive, pregnant rats were fed a liquid ethanol-containing diet (Et), an isocaloric liquid control diet (Ct), or a diet of chow and water (Ch). On postnatal day 30, the offspring of these rats were killed and their caudal medullas were processed for electron microscopy. The overall sire of the pyramidal tract and the space occupied by the axons was smaller in the Et-treated rats than in the Ct-treated rats. The myelinated axons were smaller and the myelin was thinner in the Et-treated rats than in the Ct-treated rats. These decreases produced an ethanol-induced increase in the density of axons in the pyramidal tract. In particular, the density of myelinated axons (but not nonmyelinated axons) was greater in Et-treated rats. The net result was that the estimated number of axons in the pyramidal tracts of the Et-treated rats was not significantly different than the number in the Ch- and Ct-treated rats. The present data demonstrate that ethanol does not affect the absolute number of axons in the pyramidal tract. As a result of the ethanol-induced microencephaly, however, the data translate into a relative increase in the number of pyramidal tract axons. This relative increase matches the ethanol-induced increase in the density of corticospinal projection neurons that may result from the retention of a developmentally exuberant projection.