Washington: Scientists, including one of Indian-origin, have identified a chemical signal in the zebrafish brain that helps it regenerate retina, a finding that may help cure blindness in humans.

The discovery raises the possibility that human retinas can be induced to regenerate, naturally repairing damage caused by degenerative retinal diseases and injury, including age-related macular degeneration and retinitis pigmentosa, researchers said.

"The prevailing belief has been that the regeneration process in fish retinas is triggered by secreted growth factors, but our results indicate that the eurotransmitter GABA might initiate the process instead," said James Patton, Professor at Vanderbilt University in the

Graduate student Mahesh Rao got the idea that GABA — normally a fast-acting neurotransmitter best known for its role of calming nervous activity by inhibiting nerve transmission in the brain — might be the trigger for retinal regeneration.