REDUCED GRAVITY--EFFECTS IN THE DEVELOPING NERVOUS SYST

描述：申请人建议检查空间的影响 飞行和微重力对发育中的大脑皮层细胞的影响。 这些研究将检查三个细胞过程：1）细胞 增殖，2）神经元迁移，和3）神经元分化， 包括树突/轴突定向和获得适当的 神经回路细胞增殖的两个标志物 （溴脱氧尿苷和氚化胸苷）将给予 在大脑发育期间的选定日期， 皮层短期分析（注射后2.5小时处死胎仔） 将研究细胞增殖对太空飞行的反应， 检查增殖细胞数量或细胞长度的变化， 细胞周期中期效应将通过以下方式进行评估： 注射后1 - 3天处死胎仔动物。迁徙 将检查发育中的大脑皮层内的细胞的命运。 将通过处死以下动物来评估长期影响： 在出生后30天内，将不同年龄的胎儿作为治疗对象。的 将分析在特定年龄出生的细胞的最终位置。

DESCRIPTION: The applicant proposes to examine the effects of space flight and microgravity on the cells of the developing cerebral cortex. These studies will examine three cellular processes: 1) cell proliferation, 2) neuronal migration, and 3) neuronal differentiation, including dendrite/axon orientation and acquisition of appropriate neuronal circuitry. Two markers of cell proliferation (bromodeoxyuridine and tritiated thymidine) will be administered to pregnant rats on selected days during the development of the cerebral cortex. Short term analyses (sacrifice fetuses 2.5 hrs post-injection) will examine the responses of cell proliferation to space flight by examining changes in the number of proliferating cells or the length of the cell cycle. Intermediate-term effects will be assessed by sacrificing the fetal animals 1-3 days post-injection. The migratory fates of cells within the developing cerebral cortex will be examined. Long-term effects will be assessed by sacrificing animals that were treated as fetuses at different ages through 30 days after birth. The final position of cells born at particular ages will analyzed.