A Franco-Belgian team has repaired the cerebral cortex of an adult mouse through a transplant of neurons derived from embryonic stem cells. A major step in the field of cellular therapies (which aim to restore the functions of a tissue when they are altered by an accident or a pathology) since it is the first time that the use of stem cells makes it possible to restore the cortical circuits damaged in adult mice. Eventually, the experience represents a hope to cure brain diseases.
Repairing the brain through the transplantation of neurons, a feasible reality? This is what we can hope in the long run, after the scientific prowess of Professor Afsnaeh Gaillard, a researcher at the University of Poitiers, in collaboration with the Institute for Interdisciplinary Research in Human and Molecular Biology of Brussels. . For the first time ever, a living being has received neurons grafted directly into its brain through cell therapy. The results of the experiment that lasted more than twelve months are reported in the scientific journal Neuron.
Restoring neurological connections
The researchers first had to collect the appropriate neurons from embryonic stem cells, grown in vitro. A delicate operation since the cortex is composed of a hundred types of neurons, distributed over six layers and distinct brain areas. And that these different neurons are not interchangeable.
They then grafted the resulting cells into the injured visual cortex of adult mice in a mouse and observed their behavior for one year. “The system was in place after a month and a half and connections were formed,” explains Professor Gaillard, quoted by Le Figaro. We transplanted progenitors of visual neurons, immature cells that after the transplant have further developed, and then established the right connections with the right neurons. By stimulating the eye of the mice, we have seen the graft neurons activate. At the end of the 12 months, the transplant had “taken” in 61% of the animals.
Limits and promises
A small flat comes to mitigate the enthusiasm of the operation. At the end of the observation, Le Figaro reports that “six grafts out of 47 contained a large proportion of non-neuronal cells, which could indicate the formation of a teratoma, a type of tumor formed by cells not correctly differentiated. Afsaneh Gaillard hopes, however, “to be able to obtain other types of neurons, especially motor neurons (…) and test these transplants in monkeys, which are closer to humans”.
The experiment remains unpublished in the field of cellular research. Futura Science gives the floor to researchers: “The success of our cellular engineering experiments to generate nerve cells in a controlled and unlimited way and to transplant them is a world first. This work opens up new approaches to repair the damaged brain, especially after stroke or brain trauma.