Scientists implant bioengineered human brain cells into the brains of rats

Neuroscientists at Stanford University report that they have found a new way to analyze human neurons by transplanting human brain-like tissue into rats.

In a new study published in Nature, neuroscientists at Stanford University led by Sergiu Pasca say they transplanted blobs of bioengineered neural tissue known as “organoids” into the brains of newborn rat pups two to three days old, a stage when their brains connections are still forming. The researchers said that over a period of eight months, the organoids grew to occupy roughly one-third of the hemisphere of the rat’s brain where they were implanted and that neurons from the organoids formed working connections with circuits in the brain.

In addition to reporting organoid growth, the researchers’ study showed the survival rate of animals 12 months after transplantation to be 74%, with “no discernible locomotor or memory deficits, gliosis or electroencephalogram (EEG) abnormalities” detected in the rats.