Quantification of motor neuron loss and muscular atrophy in ricin-induced focal nerve injury

Yajie Liang; Jiangyang Zhang; Piotr Walczak; Jeff W M Bulte

doi:10.1016/j.jneumeth.2018.07.014

Quantification of motor neuron loss and muscular atrophy in ricin-induced focal nerve injury

J Neurosci Methods. 2018 Oct 1:308:142-150. doi: 10.1016/j.jneumeth.2018.07.014. Epub 2018 Jul 26.

Authors

Yajie Liang¹, Jiangyang Zhang², Piotr Walczak³, Jeff W M Bulte⁴

Affiliations

¹ 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.
² Russell H. Morgan Dept. of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
³ 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; Department of Neurology and Neurosurgery, Faculty of Medical Sciences, University of Warmia and Mazury, Olsztyn, Poland.
⁴ 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; Dept. of Chemical & Biomolecular Engineering, The Johns Hopkins University Whiting School of Engineering, Baltimore, MD, 21205, USA; Dept. of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Dept of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. Electronic address: jwmbulte@mri.jhu.edu.

Abstract

Background: 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.

New method: 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.

Results: 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.

Comparison with existing methods: 1) Fluorogold neuronal tracing provides a robust and straightforward means for quantifying MN loss in the spinal cord; 2) MRI is well-suited to non-invasively assess muscle atrophy; and 3) The CatWalk method is more flexible than rotarod test for studying motor deficits.

Conclusion: 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.

Keywords: Magnetic resonance imaging; Motor neuron; Muscle atrophy; Neuronal tracing; Ricin; Sciatic nerve.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Amyotrophic Lateral Sclerosis / pathology*
Animals
Cell Count / methods*
Disease Models, Animal*
Female
Imaging, Three-Dimensional
Locomotion
Magnetic Resonance Imaging
Motor Neurons / drug effects
Motor Neurons / pathology*
Muscular Atrophy / chemically induced*
Muscular Atrophy / diagnostic imaging
Muscular Atrophy / pathology
Peripheral Nerve Injuries / chemically induced*
Peripheral Nerve Injuries / diagnostic imaging
Peripheral Nerve Injuries / pathology
Rats, Sprague-Dawley
Ricin / administration & dosage*
Sciatic Nerve / diagnostic imaging
Sciatic Nerve / drug effects
Sciatic Nerve / pathology
Stilbamidines / administration & dosage

Substances

2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt
Stilbamidines
Ricin

Abstract

Publication types

MeSH terms

Substances

Grants and funding