Rihn L L, Claiborne B J
Division of Life Sciences, University of Texas, San Antonio 78285.
Brain Res Dev Brain Res. 1990 Jun 1;54(1):115-24. doi: 10.1016/0165-3806(90)90071-6.
The goal of this study was to determine whether dendritic regression occurs in granule neurons of the rat dentate gyrus during late postnatal development. In vitro hippocampal slices were prepared from rats between the ages of 14 and 60 days, and granule neurons in one portion of the suprapyramidal blade were labeled by intracellular injection of horseradish peroxidase. The dendrites of filled neurons were analyzed in both two and three dimensions directly from 400 microns thick whole-mounts. Results showed that the molecular layer expanded by approximately 50% between days 14 and 60. At every age examined, granule cell dendrites reached the top of the molecular layer, suggesting that dendrites continued to grow during this time period. In contrast, the number of dendritic segments per neuron decreased from an average of 36 to 28. Three-dimensional measurements showed that total dendritic length and surface area per granule cell did not change, suggesting that the overall dendritic tree size of granule neurons may be regulated during late postnatal development in the rodent.
本研究的目的是确定在出生后晚期发育过程中，大鼠齿状回颗粒神经元是否会发生树突退缩。从14至60日龄的大鼠制备体外海马切片，通过细胞内注射辣根过氧化物酶标记上锥体叶片一部分中的颗粒神经元。直接从400微米厚的整装标本在二维和三维上分析填充神经元的树突。结果显示，在14至60日龄之间分子层扩展了约50%。在每个检测的年龄，颗粒细胞树突都到达分子层顶部，表明在此时间段内树突持续生长。相比之下，每个神经元的树突节段数量从平均36个减少到28个。三维测量显示，每个颗粒细胞的总树突长度和表面积没有变化，表明在啮齿动物出生后晚期发育过程中，颗粒神经元的整体树突树大小可能受到调控。
