Russell H. Morgan Dept. of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
Russell H. Morgan Dept. of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
J Neurosci Methods. 2018 Oct 1;308:142-150. doi: 10.1016/j.jneumeth.2018.07.014. Epub 2018 Jul 26.
Intrasciatic nerve injection of the Ricinus communis agglutinin (RCA or ricin) causes degeneration of motor neurons (MNs) with functional deficits, such as those that occur in amyotrophic lateral sclerosis (ALS). The objective of this study was to develop a new comprehensive platform for quantitative evaluation of MN loss, muscular atrophy and behavioral deficits using different ricin injection regimens.
Fluorogold (FG)-guided stereological quantification of MNs, in vivo magnetic resonance imaging (MRI) of muscular atrophy, and CatWalk behavioral testing were used to evaluate the outcome of rats treated with different ricin regimens (RCA60 0.5 μg, RCA60 3 μg, and RCA120 6 μg) as animal models of MN degeneration.
FG-guided stereological counting of MNs enabled identification, dissection and robust quantification of ricin-induced MN loss. The RCA60 0.5 μg and RCA120 6 μg regimens were found to be best suited as preclinical MN depletion models, with a low mortality and a reproducible MN loss, accompanied by muscle atrophy and functional deficits evaluated by MRI and the CatWalk method, respectively.
Intrasciatic injection of RCA60 or RCA120 induces nerve injury and muscle atrophy, which can be properly evaluated by a comprehensive platform using FG-guided quantitative 3D topographic histological analysis, MRI and the CatWalk behavioral test.
蓖麻毒素（RCA 或 ricin）经坐骨神经注射会导致运动神经元（MNs）变性，出现功能缺陷，类似于肌萎缩侧索硬化症（ALS）。本研究的目的是开发一种新的综合平台，使用不同的蓖麻毒素注射方案定量评估 MN 丢失、肌肉萎缩和行为缺陷。
使用荧光金（FG）引导的 MN 立体学定量、肌肉萎缩的体内磁共振成像（MRI）和 CatWalk 行为测试来评估不同蓖麻毒素方案（RCA60 0.5μg、RCA60 3μg 和 RCA120 6μg）治疗大鼠的结果，这些大鼠作为 MN 变性的动物模型。
FG 引导的 MN 立体学计数能够识别、解剖和稳健地定量蓖麻毒素诱导的 MN 丢失。发现 RCA60 0.5μg 和 RCA120 6μg 方案最适合作为临床前 MN 耗竭模型，死亡率低，MN 丢失具有可重复性，伴有肌肉萎缩和功能缺陷，分别通过 MRI 和 CatWalk 方法评估。
1）荧光金神经元示踪提供了一种稳健且直接的方法来定量脊髓中的 MN 丢失；2）MRI 非常适合非侵入性地评估肌肉萎缩；3）CatWalk 方法比转棒测试更灵活，可用于研究运动缺陷。
坐骨神经内注射 RCA60 或 RCA120 会引起神经损伤和肌肉萎缩，可以使用 FG 引导的定量 3D 地形组织学分析、MRI 和 CatWalk 行为测试的综合平台进行适当评估。
