Stem cells are largely centred in heated debates over right to life, but the body contains stem cells all over the body – in the brain, bone marrow, skin and liver. These cells have the ability to divide indefinitely, allowing them to accomplish amazing things under the correct circumstances, like regenerating an entire original organ.
Limited in Production?
Stem cells in the brain, however, are a bit different. It is has been widely recognised that as we age these neural stem cells change as we develop, creating different neural cells as time goes on. Thousands of different types of nerve cells make up the brain and stem cells are responsible for regenerating whichever ones we need at certain periods in our life. Throughout this process, the neural stem cells slowly lose the ability to generate as big a number of cells and become limited in their production.
The regulating factor in this process has not been thoroughly understood until now. Researchers in Sweden at Karolinska Institute have shown that a brain molecule called TGF-beta readily influences the stem cells in the brain. It functions as a “time signal.”
Cellular Diversity of the Brain
TGF-beta tells stem cells when they should stop producing one type of cell and start producing another. Meanwhile, overtime it begins to limit the stem cell’s ability to develop new cells. From this, researchers can quantify the cellular diversity of a brain.
According to Johan Ericson, Professor of Developmental Biology, “this is the first known signalling molecule that regulates the potential of neuronal stem cells.” Implications of this reach far and wide. There is great potential for the development of pharmaceutical drugs based on stem cells to use time signals as a way to target things, like serotonin release in the brain, which is already a target for treatment of depression.
“With a better understanding of how potential is regulated, it could be possible to broaden the development spectrum of ageing stem cells…which in the long-term perspective could be relevant to future treatment methods for neurodegenerative disease,” Ericson says.