Cyborg Embryos Offer New Insights into Brain Growth

Summary

Scientists have created cyborg embryos by implanting electrode arrays into the developing brains of frogs, mice, and salamanders. Although the researchers reject implants in human embryos as unethical, they suggest their technology might one day help study and treat neurodevelopmental conditions in children. The stretchable technology at the core of the electrode arrays could record brain activity while remaining soft enough to accommodate the children’s growth.Recording the activity of neurons during brain development can help scientists “understand how the brain transforms from a piece of tissue into a computing machine,” says Jia Liu, an assistant professor of bioengineering at Harvard University. “Virtually all neural technology was developed for the adult brain, but there are so many questions left unanswered about the developing brain.” However, until now, there has been no way for researchers to record neural activity throughout the entire brain on the cellular level on millisecond time scales throughout development. For instance, functional magnetic resonance imaging (fMRI) can scan the entire brain, but it has low resolution in space and time. Previous research using electrode arrays implanted in the brain yielded high resolution in space and time across the brain, but the way in which embryonic brains can rapidly change meant that such devices could not stay accurate over time.Flexible Brain Probes for EmbryosIn 2015, Liu and his colleagues developed flexible, minimally invasive brain probes. This led Liu to wonder if these pliant electronics might keep up with the mutable nature of embryonic brains. However, our brains and those of other vertebrates are complex, three-dimensional structures, and so embedding any electrodes into their interiors would inflict at least some damage during implantation.In the new study, Liu and his colleagues overcame this problem by implanting electrodes into developing brains when these were still two-dimensional layers of s...