University of Zurich - ScholarPeer

The image on the left shows a brain lesion (diameter: just under 0.5 mm). Around the perimeter of the lesion, the newly discovered “regenerative” astrocytes begin to seal the defect by forming long cellular extensions (shown in red). Newly formed cell nuclei (shown in blue) migrate along the cellular extensions toward the damaged area. Unaltered astrocytes (shown in green) surround the lesion area. The image on the right shows an enlargement of the marked area in the left image. (Image: Institute of Pharmacology and Toxicology, UZH)

Astrocytes Refill Brain Lesions by Moving New Nuclei Through Their Own Branches

In living mice, astrocytes around small brain lesions divided and sent new nuclei through their own branches to refill the emptied tissue. The nuclei moved in stop-and-go bursts, stretching as they squeezed through narrow processes. In comparable stroke lesions, the same refilling response was almost absent.