The discovery of how zebra fish recover from eye damage that would permanently blind other species has sparked hope that one day catastrophic blinding in humans could be healed.
Scientists have known for a long time that the retina of fish species (Danio rerio) possessed a remarkable ability to self-repair, but the mechanism has been poorly understood.
Research led by James Patton at Vanderbilt University in Nashville, Tennessee, has identified a crucial role played by a neurotransmitter called gamma-aminobutyric acid (GABA).
In the normal course of events the neurotransmitter is kept busy facilitating communication between adjacent neurons. Following damage to the retina, however, its level rapidly drops.
This prompts a type of retinal cell called Muller glia to spring into action, transforming into stem cells, proliferating and differentiating to quickly repair the damage.
Patton and his colleague Mahesh Rao gathered evidence for the role of GABA by injecting it into undamaged zebra fish eyes and noting a regenerative response. Conversely, inhibiting it in injured eyes resulted in the absence of repair.
The research was funded by the National Eye Institute (NEI) and is published in Stem Cell Reports.
“This work opens up new ideas for therapies for blinding diseases and has implications for the broader field of regenerative medicine,” says NEI program officer Tom Greenwell.
