Kleiman R, Banker G, Steward O
Department of Neuroscience, University of Virginia, Charlottesville 22908.
Brain Res Mol Brain Res. 1992 Mar;13(1-2):103-9. doi: 10.1016/0169-328x(92)90049-h.
This study evaluates the temperature sensitivity of transport of recently synthesized RNA from the nucleus to the cytoplasm (nucleocytoplasmic transport) in CNS neurons. Rat hippocampal slices were incubated with [3H]uridine for 1 h to label recently synthesized RNA. Slices were then fixed immediately or maintained at 27 degrees C or 37 degrees C for chase intervals of 3, 4.5, and 6 h to allow for nucleocytoplasmic transport of recently synthesized RNA. The time-dependent translocation of recently synthesized RNA was evaluated autoradiographically. At the end of the 1 h pulse at either 27 degrees C or 37 degrees C, the label was localized exclusively over nuclei. In slices maintained at 37 degrees C, labeling expanded to cover the cell body and proximal dendrites. However, in slices that were labeled and maintained at room temperature, labeling remained confined to the nucleus. In slices that were pulse-labeled at room temperature, and then transferred to 37 degrees C medium, cytoplasmic labeling increased as a function of time. Nucleocytoplasmic transport of RNA in cultured rat hippocampal neurons showed a comparable temperature sensitivity. The inhibition of nucleocytoplasmic transport of RNA at room temperature provides an opportunity to evaluate neuronal function when no new RNA molecules can reach the cytoplasm.
本研究评估了中枢神经系统（CNS）神经元中最近合成的RNA从细胞核向细胞质转运（核质转运）的温度敏感性。将大鼠海马切片与[3H]尿苷孵育1小时以标记最近合成的RNA。然后立即固定切片，或将其在27℃或37℃下维持3、4.5和6小时的追踪间隔，以允许最近合成的RNA进行核质转运。通过放射自显影评估最近合成的RNA的时间依赖性易位。在27℃或37℃下1小时脉冲结束时，标记仅位于细胞核上。在维持在37℃的切片中，标记扩展至覆盖细胞体和近端树突。然而，在标记并维持在室温的切片中，标记仍局限于细胞核。在室温下脉冲标记然后转移至37℃培养基的切片中，细胞质标记随时间增加。培养的大鼠海马神经元中RNA的核质转运表现出类似的温度敏感性。在室温下RNA核质转运的抑制提供了一个在没有新的RNA分子能够到达细胞质时评估神经元功能的机会。
