Scientists have used lab-grown human nerve cells to repair the breathing circuits damaged by spinal cord injury — at least in rats — an early proof-of-concept for a hard-to-treat problem.
Researchers at the Gladstone Institutes engineered human V2a interneurons (nerve cells that relay signals within the spinal cord) from induced pluripotent stem cells and transplanted them into rats with neck-level spinal cord injuries. The cells were designed to be activated by light and to be freezable for eventual clinical use — a process that took roughly 18 months to optimize. The study was published in Science Translational Medicine.
What happened
Transplanted a week after injury, the human cells survived the hostile injury environment, wired into the rats’ own neural circuits, and switched on in response to signals from the brainstem. When the animals were challenged with low-oxygen, high-CO₂ air, most treated rats kept breathing normally while untreated ones went into respiratory failure. “The cells not only survive, but form new pathways to repair damaged networks,” said lead researcher Lana Zholudeva.
The caveats
This is early work in rats during the acute phase of injury; it will need testing in larger animals and in chronic injuries, plus more consistency, before any human use. Still, with an estimated 15–20 million people worldwide living with spinal cord injuries, a way to rebuild specific damaged circuits is a meaningful direction.