REDUCED GRAVITY--EFFECTS IN THE DEVELOPING NERVOUS SYST

描述：申请者提议研究太空的影响 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，3)神经元分化， 包括树突/轴突的定向和获得适当的 神经回路。细胞增殖的两个标记物 (溴脱氧尿苷和氚胸苷)将用于 孕鼠在大脑发育过程中选定的几天 大脑皮层。短期分析(注射后2.5小时后处死胎儿) 将研究细胞增殖对太空飞行的反应 检查增殖细胞的数量或长度的变化 细胞周期。将通过以下方式评估中期影响 注射后1~3d处死胎鼠。迁徙的 我们将研究发育中的大脑皮层内细胞的命运。 长期的影响将通过牺牲那些 在出生后30天内视为不同年龄的胎儿。这个 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.