Researchers Find New Pathway in Retina Allowing Photoreceptor Cells to Adapt Following Changes in Light Exposure

March 1, 2009

Researchers at Washington University School of Medicine in St. Louis and Boston University School of Medicine reported online in the journal Nature Neuroscience (and to appear as the cover story in the journal’s March print edition), have uncovered a new pathway in the retina that allows photoreceptor cells to adapt following changes in light exposure. The discovery could help scientists better understand human diseases that affect the retina, including age-related macular degeneration, because the process of adapting to darkness involves the same cells that are affected in macular degeneration and other blinding retinal diseases.

Scientists have long known that visual pigments are destroyed when they absorb light, and must therefore be recycled for cone cells to continue sensing light. The recycling process involves chromophores leaving the retina and traveling to the retinal pigment epithelium where they are restored and returned to the retina.

But the process of traveling to and from the pigment epithelium takes too long to explain how cones quickly adapt to darkness following exposure to bright light.  Searching for a second, supplementary pathway, the research team was able to identify cells in the retina called Müller cells, which support and interact with photoreceptors.

Read more about this research on the Washington University School of Medicine website.




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