Scientists coaxed brain membrane cells from a human into stem cells, which grew into brain organoids. After incubation, they transplanted an organoid into a cavity in a mouse’s brain. Two weeks later the organoid was alive, and had grown capillaries that penetrated all the way to its inner layers.

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Scientists coaxed brain membrane cells from a human into stem cells, which grew into brain organoids. After incubation, they transplanted an organoid into a cavity in a mouse’s brain. Two weeks later the organoid was alive, and had grown capillaries that penetrated all the way to its inner layers.