A New and Simple Method for Spinal Cord Injury Induction in Mice

INTRODUCTION: Spinal Cord Injury (SCI) is a devastating disease with poor clinical outcomes. Animal models provide great opportunities to expand our horizons in identifying SCI pathophysiological mechanisms and introducing effective treatment strategies. The present study introduces a new murine contusion model. METHODS: A simple, cheap, and reproducible novel instrument was designed, which consisted of a body part, an immobilization piece, and a bar-shaped weight. The injury was inflicted to the spinal cord using an 8-g weight for 5, 10, or 15 minutes after laminectomy at the T9 level in male C57BL/6 mice. Motor function, cavity formation, cell injury, and macrophage infiltration were evaluated 28 days after injury. RESULTS: The newly designed instrument minimized adverse spinal movement during injury induction. Moreover, no additional devices, such as a stereotaxic apparatus, were required to stabilize the animals during the surgical procedure. Locomotor activity was deteriorated after injury. Furthermore, tissue damage and cell injury were exacerbated by increasing the duration of weight exertion. In addition, macrophage infiltration around the injured tissue was observed 28 days after injury. CONCLUSION: This novel apparatus could induce a controllable SCI with a clear cavity formation in mice. No accessory elements are needed, which can be used in future SCI studies. HIGHLIGHTS: A simple and precise method has been introduced for creating Spinal Cord Injury (SCI) in mice by a novel device. The device consists of a body part, an immobilization piece, and a bar-shaped weight. Assessment of locomotor activity, tissue damage, and macrophage infiltration confirmed the capability of the new SCI method. Reduction of adverse spinal movements and working without any accessory elements are the key points of this new animal model of SCI. PLAIN LANGUAGE SUMMARY: Spinal Cord Injury (SCI) is a medical problem that can cause the permanent motor and sensory dysfunction. Traffic accidents, falls, and violence are the most frequent causes of SCI, often affecting young people. Patients and even their families may encounter other problems, including reducing life quality, psychological burden, and enormous medical costs. Despite scientific and technological advances, no effective treatment has been found for SCI. Therefore, animal models help study damage mechanisms and evaluate novel treatment strategies. All SCI research centers require an economical and reproducible device without using complex surgical procedures by experienced surgeons to minimize variations in damage to the spinal cord. In this study, a simple, cheap, and reproducible novel instrument for SCI induction is introduced. The instrument consists of various parts, including a body part, an immobilization piece, and a bar-shaped weight. An 8-g weight was used for 5, 10, or 15 minutes to inflict injury to the spinal cord. Behavioral and tissue studies indicated that SCI could be induced in rodents in different severity without other elements. This instrument can be used in future investigations for SCI studies, including tissue engineering, stem cell therapy, and drugs delivery to access effective treatment.