One in four adults suffers a stroke during their lifetime, leaving approximately half with residual damage such as paralysis or speech impairment. This occurs because internal bleeding or lack of oxygen supply causes irreversible death of brain cells.
New research from the University of Zurich (UZH) Institute for Regenerative Medicine demonstrates that neural stem cell therapy can reverse stroke damage in mice, regenerating neurons and restoring movement capabilities.
Christian Tackenberg, Scientific Head of Division in the Neurodegeneration Group at UZH, states: “That’s why it is essential to pursue new therapeutic approaches to potential brain regeneration after diseases or accidents.”
The findings come from two studies conducted by a team led by Tackenberg and postdoctoral researcher Rebecca Weber. The research was carried out in collaboration with a group headed by Ruslan Rust from the University of Southern California.
Using human neural stem cells derived from induced pluripotent stem cells—manufactured from normal human somatic cells—the researchers induced a permanent stroke in mice whose characteristics closely resemble those seen in humans. The animals were genetically modified to prevent rejection of the human stem cells.
One week after stroke induction, the team transplanted neural stem cells into the injured brain region and monitored recovery through imaging and biochemical methods. Tackenberg reports: “We found that the stem cells survived for five weeks and transformed into neurons that communicated with existing brain cells.”
The research also revealed additional markers of regeneration: new blood vessel formation, reduced inflammatory responses, and improved blood-brain barrier integrity. Tackenberg notes that their analysis goes far beyond previous studies which focused on immediate effects after transplantation. Additionally, stem cell transplantation reversed motor impairments in mice, as confirmed by AI-assisted gait analysis.
These results bring scientists closer to developing human treatments that could transform recovery from brain injuries.
