Scientists Discover New Mechanism that Repairs the Human Brain After a Stroke

Scientists have discovered a new mechanism that allows the brain to produce new nerves cells after a stroke. The findings could lead to future treatments in patients who have suffered from a stroke.

A stroke is caused by a blood clot blocking a blood vessel in the brain. This leads to an interruption of blood flow and a shortage of oxygen. Many nerve cells die, resulting in motor, sensory and cognitive issues.

In this case, the researchers found that mice that suffered from a stroke had help in the form of support cells called astrocytes. These astrocytes started to form nerve cells in the injured part of the brain right after a stroke. In fact, the scientists found that astrocytes formed immature nerve cells, which then developed into mature nerve cells.

That's not all, either. The scientists also identified the signaling mechanism that regulates the conversion of the astrocytes to nerve cells. In a healthy brain, this signaling is active and inhibits the conversion. Following a stroke, though, the signaling mechanism is suppressed and astrocytes form nerve cells.

"This is the first time that astrocytes have been shown to have the capacity to start a process that leads to the generation of new nerve cells after a stroke," said Zaal Kokaia, one of the researchers, in a news release. "Interestingly, even when we blocked the signaling mechanism in mice not subjected to a stroke, the astrocytes formed new nerve cells. This indicates that it is not only a stroke that can activate the latent process in astrocytes. Therefore, the mechanism is a potentially useful target for the production of new nerve cells, when replacing dead cells following other brain diseases or damage."

Now, the researchers plan to explore whether astrocytes are also converted to neurons in the human brain following damage or disease. This could lead to better techniques to promote self-repair in the human brain, which could help restore function in patients who have not only suffered from a stroke, but those who have disorders such as Parkinson's disease and Huntington's disease.

The findings are published in the journal Science.