Damage to the retina is one of the main causes of blindness in humans, and unfortunately, this process is irreversible. However, unlike us, some creatures, in particular, the zebrafish, are doing much better with this.
Scientists have found that in these fish with humans, the genes coincide by almost 2/3. Among them, genes that are responsible for the ability to regenerate the retina of the eye are of particular interest. Its main function is to “read” light images with the help of special photoreceptors (rods and cones), as well as neurons and synapses, converting them into nerve impulses.
The phenomenon of retinal regeneration inherent in zebrafish is far from the only one. Some other species of fish and reptiles also have the ability to repair damaged retinas. In their eyes there are so-called Müller cells, which are capable of transforming into retinal neurons, including photoreceptors - cones and rods.
Neuroscientists from Hopkins University (USA) Thanh Hoang and Seth Blackshaw analyzed the response to retinal trauma in zebrafish, mice and chickens. Scientists have established the involvement of activated genes in blocking injury. The reaction of the immune cells was that they began to cleanse damaged tissues and protect them from potential threats. However, then the reaction that suppressed these genes "worked" only in mice, blocking the ability of Müller cells to transform into other types of retinal cells. By manipulating these processes, scientists were able to trigger the regeneration of visual neurons in mice.
Seth Blackshaw, summing up the research results, noted that the results obtained indicate a hidden potential for regeneration in mammals, which include humans. It is still a long way to get a working technology, but research in this area will continue.