Inside each of our calcified teeth is a population of stem cells that can differentiate into many types of tissue. The origin of those cells has long been unknown, but scientists may have a completely surprising answer: cells of the nervous system can migrate into the middle of a tooth and turn back into stem cells.
If verified, this could be a possible new source for stem cells. Teeth are connected to nerves, as anyone who’s had the misfortune of a toothache would know. Igor Adameyko of the Karolinska Institute in Stockholm and his team were studying glial cells, which support and protect neurons, in mice. By fluorescently labelling these glial cells, they could track the fate of these cells over time.
What they found was entirely surprising. Glial cells from nerves in the gums actually migrated into teeth, where they turned into mesenchymal stem cells and eventually into tooth cells. Stem cells differentiating into specific cells is to be expected, but glial cells turning into stem cells is the exact opposite of what we thought we knew.