🧬 Cambridge Scientists Reverse "Irreversible" Nerve Damage in Lab-Grown Human Brain-Spinal Cord Model

Researchers at the University of Cambridge have built a miniature human brain-spinal cord system in the lab and used it to overturn a long-held assumption: that nerve damage in the central nervous system is permanent.

The team, led by Dr. András Lakatos, grew pea-sized brain and spinal cord organoids from human stem cells and kept them physically separate. Axons from the brain tissue grew across the gap and connected with the spinal cord tissue, forming a functional neural circuit that could even trigger muscle contractions.

Key findings:

— Neurons could regrow damaged axons until roughly day 150 of development (mid-pregnancy equivalent). After that, a sharp decline in regenerative ability sets in — a biological switch hardwired into maturing human neurons.

— The team identified the gene network responsible for this switch. When they blocked its key regulators, neurons regained the ability to grow axons again.

— An existing drug, lynestrenol (a hormone currently approved for menstrual disorders), significantly improved axon regrowth when tested on the damaged neurons.

— While lynestrenol itself is unlikely to be the clinical answer, it proves the principle: human neurons can be directly targeted to regenerate.

Quote from Dr. Lakatos: "When the brain and spinal cord are damaged, the nerve fibers that carry movement signals rarely grow back. That's why paralysis is usually permanent. But our model shows this block can be reversed."

This matters because most nerve regeneration research has relied on rodents, whose neurons behave differently from human ones. Human organoid models bridge that gap and may accelerate the path to treating conditions like spinal cord injury, motor neurone disease, and multiple sclerosis.

Original paper (Cell Reports): https://www.cell.com/cell-reports/fulltext/S2211-1247(26)00477-8

ScienceDaily summary: https://www.sciencedaily.com/releases/2026/05/260528082459.htm

#neuroscience #organoids #regeneration #spinalcordinjury #cambridge