Regenerating the Connection between the Eye and the Brain
To grow new vision cells and restore sight to an eye damaged by glaucoma, age-related macular degeneration, or other serious retinal disease, it will be necessary to re-establish the nerve cell connections between the eye and the brain.
During our development as embryos, nerve cells make millions of connections, growing projections called axons to connect to other nerve cells. However, as adults this process stops, likely to prevent abnormal growths. Evidence suggests that the ability to make new axons and new nerve connections is actively inhibited within the eyes and brain of adult mammals.
Courtesy of S. Thomas Carmichael, M.D., Ph.D., David Geffen
School of Medicine at the University of California Los Angeles
Philippe Monnier is studying this process, and how it is prevented in adults. His work focuses on a signalling molecule called repulsive guidance molecule a (RGMa) – a cellular communication signal that also has a role in programmed cell death. This signal appears to inhibit the formation of new nerve connections. His work has shown that If the actions of RGMa can be blocked, then new nerve axons can be grown and new nerve connections can form.
In the laboratory, Dr. Monnier’s team have prompted adult cells to grow new axons and make connections to each other. His work is now focused on controlling and targeting this process and the growth of axons within the layers of the eye. By harnessing the process of axon growth, Dr. Monnier hopes to create new treatments for glaucoma, retinal disease and for other neurological conditions such as multiple sclerosis and stroke.
Dr. Monnier’s research in this area is support by grants from the Canadian Institutes of Health Research, the Foundation Fighting Blindness, Brain Canada, and the Heart and Stroke Foundation.