It's not just deep sleep: Anesthesia drives brain into a strange state doctors are only beginning to map (opens in new tab)

People often describe anesthesia as something that puts a patient in a "deep sleep." An anesthesiologist enters the operating room, and part of their mission is to ensure that the patient is completely unaware of what is happening around them until they wake up, often several hours later. Scientists and doctors have long debated what happens to the brain under anesthetic drugs during a surgical procedure.