Frozen mouse brains revived from cryosleep in a scientific first

Put “Alien” on standby — because science may be inching a tiny step closer to real-life cryosleep.In a breakthrough that sounds ripped straight from a Ridley Scott flick, researchers in Germany have managed to freeze brain tissue to ultra-cold temperatures and bring it back with key signs of life still flickering — including electrical activity linked to learning and memory.The feat, detailed in a new study published in the journal “Proceedings of the National Academy of Sciences,” suggests that one day scientists may be able to place brain tissue — or even entire organs — into a deep freeze and revive them later without wrecking the delicate circuitry that makes them tick, originally reported on by Nature.com.That’s long been the sticking point.When biological tissue freezes the old-fashioned way, water inside cells crystallizes into jagged ice shards that shred membranes and sever the microscopic connections between neurons. In the brain, those connections are everything — the infrastructure behind thought, memory and consciousness.To dodge that icy death spiral, neurologists at the University of Erlangen–Nuremberg turned to a technique known as vitrification — a rapid-cooling method that transforms liquid into a glass-like state before ice crystals can form.Instead of freezing into rigid ice, the tissue becomes something closer to molecular glass.Chemical activity essentially pauses in place.For their test run, the researchers flash-froze thin slices of mouse brain tissue containing the hippocampus — the region crucial for learning and memory — plunging them into liquid nitrogen at a bone-chilling −196°C.The samples then sat suspended in this glassy deep freeze, anywhere from 10 minutes to a week.The real moment of truth came during the thaw.Scientists carefully reheated the tissue at lightning speed while flushing out the chemical “antifreeze” solution used during freezing — a delicate balancing act designed to prevent the ...