SEX AND ENVIRONMENTAL-INFLUENCES ON THE SIZE AND ULTRASTRUCTURE OF THE RAT CORPUS-CALLOSUM
SEX AND ENVIRONMENTAL-INFLUENCES ON THE SIZE AND ULTRASTRUCTURE OF THE RAT CORPUS-CALLOSUM
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DOI：
10.1016/0006-8993(88)91538-7
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发表时间：
1988-05-31
期刊：
影响因子：
2.9
通讯作者：
KOPCIK, JR
中科院分区：
文献类型：
--
作者：
JURASKA, JM;KOPCIK, JR
一份关于人类胼胝体脾大小的性别差异的有争议的报告促使了目前对大鼠胼胝体的研究。我们之前已经发现，性别差异会随着养育环境的不同而变化。因此，雄性和雌性大鼠从断奶饲养到55日龄，分别在一个复杂或孤立的环境中饲养。大鼠矢状面胼胝体大小无性别差异；然而，如果在复杂的环境中长大，雌雄老鼠的胼胝体后三分之一都更大。由于胼胝体的大小在55天后继续增长，我们在113天的时候检查了社会饲养的大鼠，再次发现没有性别差异。用电镜观察55日龄复杂饲养大鼠和离体饲养大鼠的脾脏。超微结构分析显示，从总尺寸测量不明显的差异。无论环境如何，雌性都有更多的无髓鞘轴突，而来自复杂环境的雌性比同等环境的雄性有更多的有髓鞘轴突。相比之下，复杂环境中的雄性比雌性具有更大的髓鞘轴突。来自复杂环境的雌雄大鼠比孤立的大鼠有更大的无髓鞘轴突。此外，在有髓鞘的轴突中，雌性的可塑性通过轴突数量的变化而发生，雄性的可塑性通过轴突大小的变化而发生。因此，两性在轴突数量和大小上存在差异，而环境影响了这些差异。
A contested report of sex differences in the size of the splenium of the corpus callosum in humans prompted the present examination of the corpus callosum in the rat. We have previously found that sex differences can vary with the rearing environment. Consequently, male and female rats were raised from weaning to 55 days of age in either a complex or an isolated environment. There were no sex differences in the size of the corpus callosum in sagittal cross section in these rats; however, rats of both sexes had a larger posterior third of the corpus callosum if they were raised in the complex environment. Because the corpus callosum continues to grow in size past 55 days of age, we examined socially housed rats at 113 days and again found no sex differences. The splenium was examined with electron microscopy in complex and isolated reared rats at 55 days of age. The ultrastructural analysis revealed differences that were not apparent from gross size measures. Females had more unmyelinated axons regardless of environment, and females from the complex environment had more myelinated axons than comparably housed males. In contrast, males in the complex environment had larger myelinated axons than females. Rats of both sexes from the complex environment had larger and more unmyelinated axons than isolated rats. In addition in myelinated axons, plasticity in the females occurred through changes in axon number and in males, through axon size. Thus sex differences exist in axonal number and size and the environment influences these differences.