Researchers from the UMH-CSIC Institute of Neurosciences, in Alicante, have discovered an essential genetic process for the formation of bilateral circuits, such as the one that makes 3D vision possible or the coordination of movements on both sides of the body.
As reported by the research center on Friday, the finding, carried out in mice, has been published this Friday in Science Advances. This new study not only clarifies how the transmission of images from the retina to the brain takes place in order to see in 3D, but it will also help to understand how laterality is established in other neural circuits, such as the one that makes motor coordination between both possible. sides of the body.
The work also revealed the important role of the Zic2 protein in the regulation of a signaling pathway called Wnt, which is essential for the proper development of the embryo and is highly conserved between species, from fruit flies to humans, including mice. in which this study has been carried out.
This pathway is usually altered in pathological scenarios such as spina bifida or other disorders associated with incomplete closure of the neural tube, as well as in various types of cancer. The new details described in this work on the regulation of this pathway through Zic2 will help to understand the origin of this type of pathology to try to prevent its appearance.
The 3D vision
The ability to perceive the world in 3D and respond appropriately to external stimuli depends to a large extent on a type of neuronal circuits called bilateral that communicate the two cerebral hemispheres and are essential for many of the tasks we perform daily.
In this regard, the director of the research group, Dr. Eloísa Herrera, explained that these bilateral circuits require both the crossing of a part of the nerve fibers to the contralateral cerebral hemisphere from which they originate and the permanence of the other half in its hemisphere of origin.
“The genetic program that we have identified ensures that a part of the neurons located in the retina carry visual information to the opposite cerebral hemisphere and the action of a protein called Zic2 turns off this program in another group of retinal neurons to achieve that the visual signal reaches also to the same hemisphere ”.
On “embryonic development”
Years ago, Dr. Herrera’s group discovered that the Zic2 protein makes bilaterality possible by ensuring that part of the neuron extensions (axons) remain in the same hemisphere from which they come. And in this new work they describe that in order to get the axons to stay in the same hemisphere, Zic2 turns off the genetic program that makes them cross to the opposite hemisphere.
“This finding has allowed us to identify the contralateral program and observe that it shares common elements with a well-known signaling pathway, called Wnt, involved in various processes of embryonic development.”