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Six of the sheep were given a single higher dose of ketamine, 24mg/kg. This is at the high end of the anesthetic range. Initially, the same response was seen as with a lower dose. But within two minutes of administering the drug, the brain activity of five of these six sheep stopped completely, one of them for several minutes – a phenomenon that has never been seen before.

“This wasn’t just reduced brain activity. After the high dose of ketamine the brains of these sheep completely stopped. We’ve never seen that before,” said Morton. Although the anesthetized sheep looked as though they were asleep, their brains had switched off. “A few minutes later their brains were functioning normally again – it was as though they had just been switched off and on.”

0: https://www.technologynetworks.com/neuroscience/news/sedated...