Scientists identify key mechanism for nerve cell growth critical for three-dimensional vision

nerve cells—called retinal ganglion cells—send projections to the brain via the optic nerve, they either remain on the same side or cross over to the other half of the brain. It is the balance of these projections that allows us to see the world in 3D, but until now how exactly this is controlled has remained poorly understood.

The work of Cayouette and his colleagues marks an important advance toward solving this mystery.

A new gene is discovered

In their study, the scientists identified a gene called Pou3f1.

It acts as a major regulator controlling the expression of dozens of other genes, which together generate the full instructions to ensure retinal ganglion cells send projections that cross to the opposite hemisphere of the brain.

The researchers showed that expression of Pou3f1 in retinal stem cells is sufficient to force them to become retinal ganglion cells sending projections to the optic nerve.

“Our work identifies Pou3f1 as a critical regulator of processes underlying binocular vision in mammals and as a potential candidate for the regeneration and repair of the visual system,” said Thomas Brown, a doctoral student in Cayouette’s lab and the study’s co-first author with former student Michel Fries.

“Nerves are roads for information, and if they cannot send information to the appropriate area in the brain, then it leads to serious problems, as observed in blinding eye diseases like glaucoma,” added Christine Jolicoeur, a senior research assistant in the team and co-author of the study.

“Our work helps understand how the roadmap of visual information is constructed and sheds light on how nerves reach the right area of the brain, which is essential information to help develop regenerative approaches for various neurodegenerative diseases,” Cayouette concluded.