Freezing a brain and bringing it back online is no longer just the stuff of fiction—at least for mice. German researchers report they've chilled slices of brain tissue from the rodents to about minus 196 degrees Celsius, thawed them days later, and found the neurons still firing and talking to each other, reports the Wall Street Journal. The work, published in the Proceedings of the National Academy of Sciences, suggests brain tissue can be cryopreserved without losing its ability to function, not just its structure.
"As a proof of principle, it genuinely shifts the boundary of what seems biologically possible," neuroscientist Kirill Volynski of University College London, who was not involved in the research, tells the Journal. The team used a carefully tuned mix of cryoprotective chemicals and ultra-fast cooling to "vitrify" the tissue—locking water into a glasslike state that avoids destructive ice crystals, explains Nature. Potential uses include better lab models for testing drugs and studying brain diseases. But don't expect full-body freezing anytime soon: Scaling up from thin slices to an intact human brain or organ remains a major hurdle, and the researchers emphasize that such applications are a long way off.