Replacing missing brain cells

Scientists at UCLA have been able to regrow working brain cells in empty spaces left in the brain after a stroke.

By itself, the brain doesn’t regenerate tissue after a stroke. The damaged cells are absorbed, leaving behind an empty space that never fills.

The UCLA researchers solved that problem by injecting a hydrogel material into the areas surrounding the cavity. The hydrogel was infused with compounds that stimulate blood vessel growth and suppress inflammation, which hampers vessel formation. The gel created a scaffold for the new vessels to grow on.

After 16 weeks, stroke-damaged brains in mice showed brain tissue growing in the void, making dynamic connections among new brain cells. The affected mice were able to move better than before the treatment.


This innovative procedure was designed to help humans, including six million Americans, living with the debilitating long-term effects of stroke. The mice were treated within an ideal window that, in humans, lasts for about two months after the event. The UCLA team is now testing whether new brain cells can be grown after that ideal period has passed. Nevertheless, human trials are likely to be years away.

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