Background

Sholl analysis is used to quantify the dendritic complexity of neurons. Differences between two-dimensional (2D) and three-dimensional (3D) Sholl analysis can exist in neurons with extensive axial stratification of dendrites, however, in retinal ganglion cells (RGCs), only 2D analysis is typically reported despite varying degrees of stratification within the retinal inner plexiform layer. We determined the impact of this stratification by comparing 2D and 3D analysis of the same RGCs.

New Method

Twelve retinas of mice expressing yellow fluorescent protein in RGCs under the control of the Thy1 promotor were whole-mounted. The entire dendritic arbor of 120 RGCs was traced, after which 2D and 3 Sholl analysis was performed. Two parameters describing dendritic complexity; area under the curve (AUC) and peak number of intersections (PNI) were then derived and analyzed.

Results and Comparison with Existing Methods

The AUC and PNI were significantly higher with 3D analysis compared to 2D analysis with medians of 2805 and 2508 units, and 31 and 27, respectively (P < 0.01). Both 2D and 3D AUC increased with arbor thickness. The discrepancy in AUC between the two methods depended on mean AUC (with every 1 unit increase in mean AUC resulting in a discrepancy of 0.1 unit), but not arbor thickness.

Conclusion

In RGCs imaged in vitro, there is a difference in AUC and PNI derived with 2D and 3D Sholl analysis. Where possible, 3D Sholl analysis of RGCs should be performed for more accurate quantitative analysis of dendritic structure.

中文翻译：

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肖氏分析中视网膜神经节细胞3D分层的影响。

背景

肖尔分析用于量化神经元的树突复杂性。在具有广泛的树突轴向分层的神经元中，可以存在二维（2D）和三维（3D）Sholl分析的差异，但是，在视网膜神经节细胞（RGC）中，尽管内部分层程度不同，但通常仅报告了2D分析。视网膜内丛状层。通过比较同一RGC的2D和3D分析，我们确定了这种分层的影响。

新方法

在Thy1启动子的控制下，在RGC中表达黄色荧光蛋白的小鼠的十二个视网膜是完整安装的。追踪了120个RGC的整个树状乔木，之后进行了2D和3 Sholl分析。描述树突复杂性的两个参数；然后导出并分析曲线下的面积（AUC）和交叉点的峰数（PNI）。

结果与现有方法的比较

3D分析的AUC和PNI显着高于2D分析的中位数，分别为2805和2508个单位，中位数分别为31和27（P  <0.01）。2D和3D AUC均随心轴厚度的增加而增加。两种方法之间的AUC差异取决于平均AUC（平均AUC每增加1个单位就会导致0.1个单位的差异），而不取决于心轴厚度。

结论

在体外成像的RGC中，通过2D和3D Sholl分析得出的AUC和PNI存在差异。在可能的情况下，应进行RGC的3D Sholl分析，以对树状结构进行更准确的定量分析。