Fish Species Spinal Cord Injury Models Utility for Research: A Systematic Review of Methodologies and Outcomes

Context: Spinal cord injury (SCI) is a devastating condition that results in severe disability and significant comorbidities. The complex pathophysiology of SCI repair and difficulties understanding neural regeneration are treatment challenges. Objectives: The aim of this study is to systematically review the diverse applications of various fish species as models for SCI research. Evidence Acquisition: PRISMA guidelines were used to review observational and interventional studies that utilized fish species as SCI models, published from inception to July 2023. Two independent reviewers screened and performed the data extraction. One independent reviewer assessed the risk of bias for the included studies. Results: Five thousand six hundred and thirty-three records were reviewed, and 144 met the inclusion criteria and were categorized by fish species. The majority of studies employed complete transection injuries, with the remainder being crush injuries, laser injuries, electro-ablations, and demyelination with substances. Zebrafish (Danio rerio) were most commonly utilized 102/144 (71%), primarily with larval models. Other models included Lamprey (Petromyzon marinus and Lethenteron reissneri); Goldfish (Carassius auratus); European eel (Anguilla Anguilla); Knifefish (Apteronotus leptorhynchus and Apteronotus albifrons); Sailfin Molly (Poecilia latipinna); and African turquoise killifish (Nothobranchius furzeri). Conclusions: This systematic review highlights that fish models, particularly zebrafish, goldfish, and European eels, are important models for further defining SCI pathophysiology and regenerative processes. These models provide a less complex model to gain insights into apoptosis and glial networks.