Vor ein paar Wochen erst hatten sie einer Maus menschliche Gene eingepflanzt, die daraufhin tatsächlich schlauer wurde. Jetzt haben sie gleich ein ganzes Maus-Gehirn mit menschlichen Hirnzellen angereichert, die sich vermehrten und mit den Maus-Neuronen ein prima Maus/Mensch-Hybrid-Hirn bildeten. „Gee, Brain, what do you want to do tonight?“ – „The same thing we do every night, Pinky – try to take over the world!“
The altered mice still have mouse neurons – the "thinking" cells that make up around half of all their brain cells. But practically all the glial cells in their brains, the ones that support the neurons, are human. […] Goldman's team extracted immature glial cells from donated human fetuses. They injected them into mouse pups where they developed into astrocytes, a star-shaped type of glial cell.
Within a year, the mouse glial cells had been completely usurped by the human interlopers. The 300,000 human cells each mouse received multiplied until they numbered 12 million, displacing the native cells. "We could see the human cells taking over the whole space," says Goldman. "It seemed like the mouse counterparts were fleeing to the margins." […] A battery of standard tests for mouse memory and cognition showed that the mice with human astrocytes are much smarter than their mousy peers.
New Scientist: The smart mouse with the half-human brain