Automated Impactor for Contusive Spinal Cord Injury Model in Mice

Summary

Presented here is a novel automated spinal cord injury contusion device for mice, which can accurately produce spinal cord injury contusion models with varying degrees.

Abstract

Spinal cord injury (SCI) due to traumatic injuries such as car accidents and falls is associated with permanent spinal cord dysfunction. Creation of contusion models of spinal cord injury by impacting the spinal cord results in similar pathologies to most spinal cord injuries in clinical practice. Accurate, reproducible, and convenient animal models of spinal cord injury are essential for studying spinal cord injury. We present a novel automated spinal cord injury contusion device for mice, the Guangzhou Jinan University smart spinal cord injury system, that can produce spinal cord injury contusion models with accuracy, reproducibility, and convenience. The system accurately produces models of varying degrees of spinal cord injury via laser distance sensors combined with an automated mobile platform and advanced software. We used this system to create three levels of spinal cord injury mice models, determined their Basso mouse scale (BMS) scores, and performed behavioral as well as staining assays to demonstrate its accuracy and reproducibility. We show each step of the development of the injury models using this device, forming a standardized procedure. This method produces reproducible spinal cord injury contusion mice models and reduces human manipulation factors via convenient handling procedures. The developed animal model is reliable for studying spinal cord injury mechanisms and associated treatment approaches.

Introduction

Spinal cord injury usually results in permanent spinal cord dysfunction below the injured segment. It is mostly caused by objects striking the spine and hyperextension of the spine, such as traffic accidents and falls¹. Due to the limited availability of effective treatment options for spinal cord injury, elucidation of the pathogenesis of spinal cord injuries using animal models will be informative for the development of appropriate treatment approaches. The contusion model of spinal cord injury caused by impact on the spinal cord results in the development of animal models with similar pathologies to most clinical spinal cord injury cases

Protocol

The studies involving animals were reviewed and approved by the Ethics Committee of Jinan University.

1. Anesthetization of animals and T10 spinal laminectomy

1. Use 8 weeks-old female young adult C57/6J mice for this study. Anesthetize the mice by intraperitoneal injection of ketamine (100 mg/kg) and diazepam (5 mg/kg). Check for successful anesthetization indicated by loss of pain reflex. Apply vet ointment on eyes to prevent dryness under anesthesia.
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Discussion

Spinal cord injury can lead to sensory and motor deficits, which can result in severe physical and mental impairments. In China, incidences of spinal cord injuries in different provinces vary from 14.6 to 60.6 per million¹⁸. The increase in the prevalence of SCI will put more pressure on the healthcare system. Currently, there are limited effective treatment option for spinal cord injury, injuries because its pathomechanisms and repair processes are yet to be fully understood¹⁹

Materials

Name	Company	Catalog Number	Comments
0.01M PBS (powder, pH7.2-7.4)	Solarbio Life Sciences	P1010
2,2,2-Tribromoethanol	Macklin	75-80-9
4% paraformaldehyde tissue fixative	Biosharp life science	BL539A
Biomicroscope	Leica	LCC50 HD
CatWalk	Noldus Information Technology	CatWalk XT 9.1
Cover glass	CITOTEST Scientific	10212432C
Embedding machine	Changzhou Zhongwei Electronic Instrument	BMJ-A
Ethanol absolute	DAMAO	64-17-5
FootFaultScan	Clever Sys Inc.	-
Glass slide	CITOTEST Scientific	80302-2104
Hematoxylin and Eosin Staining Kit	Beyotime Biotechnology	C0105S
micro-grinding drill	FEIYUBIO	19-7010
Mouse spinal fixator	RWD Life Science	68094
Paraffin microtome	Thermo	shandon finesse 325
RotaRod for Mice	Ugo Basile	47600
Stereomicroscope	KUY NICE	SZM-7045
Tert-Amyl alcohol	Macklin	75-85-4
Xylene	China National Pharmaceutical	#10023418