Testing to see if glial progenitor cells — the early form of neurons and glia in the brain — can be integrated into human brains that are missing these vital building blocks, scientists have injected human progenitor cells into mouse brains.

The human progenitor cells went to the correct locations and performed the correct function in the mouse brains…but then this happened:

The human progenitor cells are larger, more complex, and have more staying power than mouse progenitor cells in the brains of mice. Which means that over time, the brains of mice injected with these cells are becoming more…human. Goldman’s collaborator (and spouse) Maiken Nedergaard and her team at the Center for Translational Neuromedicine, also at U Rochester, has tested these mice to see if their humanised brains make them smarter. The hu-mice do seem to condition more quickly, and show signs at the molecular level of differences in synaptic connections that suggest they might be cognitively different.

Anyone else shuddering at the concept of “hu-mice?”

Courtesy of In The Field, at Nature.com