Researchers who study how people see color grow human retinas in the lab

The researchers used stem cells to grow a human retina in a lab to find out how molecular switching takes place. The study hopes one day to be able to treat facial disorders. ( John Hopkins University )

Researchers at Johns Hopkins University in Maryland have successfully grown human retinas in a laboratory to find out how people see colors.

The goal is to better understand human biology, especially how cells transform into specific types that are responsible for certain functions. This study focuses on the three-cone photoreceptors or the specialized cells that enable people to see red, blue and green.

The study was published in the journal Science.

Lab-Grown Eyes

The study was quite special because in previous studies on vision both mice and fish were used. However, neither animal has the same color dynamics as people. So researchers at Johns Hopkins University have taken a step forward and made a human retina using stem cells.

The first to grow, according to the study, were the blue-detecting cells, followed by red and then green. The stem cells took months to develop into a full human retina in their laboratory.

During the research, they discovered that the molecular change that took place was based on the level of the thyroid hormone, which is independent or not controlled by the thyroid gland. Instead, the thyroid hormone was completely controlled by the eye cultured in the laboratory.

This discovery allowed researchers to manipulate the development of the retinas, creating those who could only see blue, red or green. How the level of thyroid hormones affects the development of cone-photoreceptors also explains why some babies have more problems seeing vision in the first term.

"Our research really tries to figure out which paths these cells take to give us that special color vision," said Robert Johnston, a development biologist at Johns Hopkins University.

Leads to better treatment of vision disorders

The researchers hope that the research will pave the way for correcting eye-related disorders. The next step is the use of organoids or organ-specific tissues grown from stem cells to learn more about the mechanisms involved in color vision and other parts of the retina. In particular, they also want to grow a new macula in a lab that could lead to the treatment of macular degeneration in the future.

"If we can answer what leads a cell to its ultimate destiny, we are closer to being able to restore color vision for people who have damaged photoreceptors," lead author Kiara Eldred added.

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