Mice Get Smarter After Scientists Inject Them With Human Brain Cells

Researchers show how glial cells can give mice a boost.

When you think of a brain, you might imagine a flashing chain of neurons beaming messages to one another. But a new paper suggests that’s not the whole story, and they found this out by PUTTING HUMAN BRAIN CELLS IN MICE AND MAKING THEM SMARTER.

The non-neural brain cells they used are known as “glia“–like the “glue” of the system, although they’re also neural protectors and janitors–and they’ve been seen for awhile as supporting actors in the brain game. But the scientists involved in the experiment wanted to test for their importance to information processing. So, the team of researchers led by Steven Goldman and neurobiologist Maiken Nedergaard got to work.

Human Astrocytes In A Mouse

The yellow-green areas are human astrocytes and the blue spots are mouse cell nuclei.

The researchers first implanted glial progenitor cells into newborn mice. Those cells make different types of glia, including astrocytes, which in humans are much larger and more complex than in other animals (neurons, by contrast, are pretty much the same between species). That might mean astrocytes are what separates human brain-power from, say, mouse brain-power.

The results suggest that theory could be right. After about 6 months, the human progenitor cells mostly replaced the mouse’s progenitor cells and the human astrocytes mostly took over, too. The mice that got the blast of brain cells formed stronger synapses and performed better on tasks like learning maze routes than a control group of mice that got a shot of mouse progenitor cells (proving it wasn’t just more brain cells that did the trick but more human brain cells).

Hopefully the mice don’t become so smart that they figure out what’s making them smarter.