Uncovering the mechanism of our oldest anesthetic
Nitrous oxide, commonly known as “laughing gas,” has been used in anesthesiology practice since the 1800s, but the way it works to create altered states is not well understood. In a study published this week in Clinical Neurophysiology, MIT researchers reveal some key brainwave changes among patients receiving the drug. For a period of about three minutes after the administration of nitrous oxide at anesthetic doses, electroencephalogram (EEG) recordings show large-amplitude slow-delta waves, a powerful pattern of electrical firing that sweeps across the front of the brain as slowly as once every 10 seconds. This frequency is characteristic of our deepest sleep, but the waves induced by nitrous oxide are twice as large as — and seemingly more powerful than — the ones seen in slumber. “We literally watched it and marveled, because it was totally unexpected,” says Emery Brown, the Edward Hood Taplin Professor of Medical Engineering at MIT and an...