INSERM: A team led by Afsaneh Gaillard (Inserm Unit 1084,
Experimental and Clinical Neurosciences Laboratory, University of
Poitiers), in collaboration with the Institute of Interdisciplinary
Research in Human and Molecular Biology (IRIBHM) in Brussels, has just
taken an important step in the area of cell therapy: repairing the
cerebral cortex of the adult mouse using a graft of cortical neurons
derived from embryonic stem cells. These results have just been
published in Neuron.
The
cerebral cortex is one of the most complex structures in our brain. It
is composed of about a hundred types of neurons organised into 6 layers
and numerous distinct neuroanatomical and functional areas.
Brain injuries, whether caused by trauma or neurodegeneration, lead
to cell death accompanied by considerable functional impairment. In
order to overcome the limited ability of the neurons of the adult
nervous system to regenerate spontaneously, cell replacement strategies
employing embryonic tissue transplantation show attractive potential.
A major challenge in repairing the brain is obtaining cortical
neurons from the appropriate layer and area in order to restore the
damaged cortical pathways in a specific manner.
The results obtained by Afsaneh Gaillard’s team and that Pierre
Vanderhaeghen at the Institute of Interdisciplinary Research in Human
and Molecular Biology show, for the first time, using mice, that
pluripotent stem cells differentiated into cortical neurons make it
possible to reestablish damaged adult cortical circuits, both
neuroanatomically and functionally.
These results also suggest that damaged circuits can be restored only by using neurons of the same type as the damaged area.
This study constitutes an important step in the development of cell therapy as applied to the cerebral cortex.
This approach is still at the experimental stage (laboratory mice
only). Much research will be needed before there is any clinical
application in humans. Nonetheless, for the researchers, “The
success of our cell engineering experiments, which make it possible to
produce nerve cells in a controlled and unlimited manner, and to
transplant them, is a world first. These studies open up new approaches
for repairing the damaged brain, particularly following stroke or brain
trauma,” they explain.