Sophisticated mini-brains add to evidence of Zika's toll on fetal cortex

Studying a new type of pinhead-size, lab-grown brain made with technology first suggested by three high school students, Johns Hopkins researchers have confirmed a key way in which Zika virus causes microcephaly and other damage in fetal brains: by infecting specialized stem cells that build its outer layer, the cortex.

The lab-grown mini-brains, which researchers say are truer to life and more cost-effective than similar research models, came about thanks to the son of two Johns Hopkins scientists and two other high school students who were doing summer research internships. They had the idea to make the equipment for growing the mini-brains with a 3-D printer.

These so-called bioreactors, and the mini-brains they foster, should open other new and valuable windows into human brain development, brain disorders and drug testing -- and perhaps even produce neurons for treatment of Parkinson's disease and other disorders, the investigators say.

"We have been working for three years to develop a better research model of brain development, and it's fortunate we can now use this one to shed light on the major public health crisis posed by Zika infections," says Hongjun Song, Ph.D., professor of neurology and neuroscience at the Johns Hopkins University School of Medicine's Institute for Cell Engineering.

"This more realistic, 3-D model confirms what we suspected based on what we saw in a two-dimensional cell culture: that Zika causes microcephaly -- abnormally small brains and heads -- mainly by attacking the neural progenitor cells that build the brain and turning them into virus factories."