Newswise — Zebrafish are members of a rarefied group of vertebrates capable of fully healing a severed spinal cord. A clear understanding of how this regeneration takes place could provide clues toward strategies for healing spinal cord injuries in people. Such injuries can be devastating, causing permanent loss of sensation and movement.

A new study from Washington University School of Medicine in St. Louis maps out a detailed atlas of all the cells involved — and how they work together — in regenerating the zebrafish spinal cord. In an unexpected finding, the researchers showed that survival and adaptability of the severed neurons themselves is required for full spinal cord regeneration.

Surprisingly, the study showed that stem cells capable of forming new neurons — and typically thought of as central to regeneration — play a complementary role but don’t lead the process. The study is published Thursday, Aug. 15, in the journal Nature Communications.

Unlike humans’ and other mammals’ spinal cord injuries, in which damaged neurons always die, the damaged neurons of zebrafish dramatically alter their cellular functions in response to injury, first to survive and then to take on new and central roles in orchestrating the precise events that govern healing, the researchers found. Scientists knew that zebrafish neurons survive spinal cord injury, and this new study reveals how they do it. “We found that most, if not all, aspects of neural repair that we’re tr.