A team of neuroscientists and bioengineers from MIT’s Department of Brain and Cognitive Sciences and Center for Biomedical Engineering have been able to partially restore the vision of rodents whose visual neural pathways had been severed by injecting them with a tiny, biodegradable substrate on which brain cells were able to regrow and reconnect. The research marks the first time that nanotechnology has been used to heal a damaged brain region and restore lost functionality. The results could lead to major advancements in the treatment of traumatic brain and spinal cord injuries and strokes.
During the study, co-authored by Rutledge G. Ellis-Behnke and Gerald E. Schneider, researchers injected the brains of hamsters whose visual neural pathways had been purposely damaged with a solution of self-assembling peptides. The peptides formed thin sheets that would interlock together to create a nanoscale scaffold through which the axons of the damaged neurons were able to regrow and reform synaptic connections with other neurons. Within a month and a half enough of the neural communication was restored that the hamsters were able to effectively see again.
The peptide mesh not only mimics structures that occur naturally in tissue, potentially allowing doctors to avoid the troublesome scar tissue that results from most brain injuries, but it also eventually breaks down into safe byproducts that are either expelled or used by tissue elsewhere.
While the total recovery from the neural damage is far less than complete, the results offer great hope nonetheless.
“If we can reconnect parts of the brain that were disconnected by a stroke, then we may be able to restore speech to an individual who is able to understand what is said but has lost the ability to speak,” said Ellis-Behnke. “This is not about restoring 100 percent of damaged brain cells, but 20 percent or even less may be enough to restore function, and that is our goal.”
“If you can return a certain quality of life, if you can get some critical functions back, you have accomplished a lot for a victim of brain injury,” said Schneider.
The study appears in this week’s online edition of the Proceedings of the National Academy of Sciences (PNAS).
Read the full MIT press release: “MIT researchers restore vision in rodents blinded by brain damage“