Working with fish, birds and mice, Johns Hopkins Medicine researchers report new evidence that some animals’ natural capacity to regrow neurons is not missing, but is instead inactivated in mammals. Specifically, the researchers found that some genetic pathways that allow many fish and other cold-blooded animals to repair specialized eye neurons after injury remain present in mammals as well, but are turned off, blocking regeneration and healing.
A description of the study, published online by the journal Science on Oct. 1, offers a better understanding of how genes that control regeneration are conserved across species, as well as how they function. This may help scientists develop ways to grow cells that are lost due to hereditary blindness and other neurodegenerative diseases.
“Our research overall indicates that the potential for regeneration is there in mammals, including humans, but some evolutionary pressure has turned it off,” says Seth Blackshaw, Ph.D., professor of