I have some mixed feelings about this, scientifically it's very interesting, but it also raises some ethical concerns...
What would Stewart Little make of it? Mice have been created whose brains are half human. As a result, the animals are smarter than their siblings.
The idea is not to mimic fiction, but to advance our understanding of human brain diseases by studying them in whole mouse brains rather than in dishes.
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.
"It's still a mouse brain, not a human brain," says Steve Goldman of the University of Rochester Medical Center in New York. "But all the non-neuronal cells are human."
