Out-of-body experiences are all about rhythm, a team reported Wednesday in the journal Nature.
In mice and one person, scientists were able to reproduce the altered state often associated with ketamine by inducing certain brain cells to fire together in a slow-rhythmic fashion.
"There was a rhythm that appeared and it was an oscillation that appeared only when the patient was dissociating," says Dr. Karl Deisseroth, a psychiatrist and neuroscientist at Stanford University.
Dissociation is a brain state in which a person feels separated from their own thoughts, feelings and body. It is common in people with some mental illnesses, or who have experienced a traumatic event. It can also be induced by certain drugs, including ketamine and PCP (angel dust).
The study linking dissociation to brain rhythms represents "a big leap forward in understanding how these drugs produce this unique state," says Dr. Ken Solt, an anesthesiologist at Harvard Medical School and Massachusetts General Hospital. Solt is the co-author of an article that accompanied the study, but was not involved in the research.
The finding also could be a step toward finding non-drug methods to control states of consciousness, Solt says.
Deisseroth's lab made the discovery while studying the brains of mice that had been given ketamine or other drugs that cause dissociation. The team was using technology that allowed them to monitor the activity of cells throughout the brain
"It was like pointing a telescope at a new part of the sky," Deisseroth says. "And something really unexpected jumped out at us."
What jumped out was a very distinct rhythm produced by cells in an area involved in learning and navigation. Those cells were firing three times each second.
To learn more, the team used a tool called optogenetics, which Deisseroth helped invent. It uses light to control the firing of specific cells in the brain.
As a result, the team was able to artificially generate this rhythm in the brains of mice.
The mice then behaved as if they had been given ketamine. And once the slow rhythm began, the scientists could see that brain areas that had previously been working together were now out of synch.
We could see, right before our eyes, dissociation happening," Deisseroth says.
But that was in mice. Deisseroth wanted to know about people.
And he got an opportunity, thanks to some good luck and sandwiches. The sandwiches, provided by Deisseroth, were part of a regular but informal gathering of scientists in his lab.
"One day they were talking about their work and one of the neurosurgeons said, 'Hey, you know, we have a patient,'" Deisseroth says.
The patient had a form of epilepsy that sometimes caused dissociation. And as part of the treatment, doctors had temporarily implanted electrodes in the patient's brain.
That gave Deisseroth's team a way to monitor brain cells in the same area they'd been studying in mice. And once again, they found something important.
"There was a rhythm that appeared and it appeared only when the patient was dissociating," Deisseroth says.
To confirm their finding, the team delivered pulses of electricity to the areas where they'd seen the rhythm. The patient immediately reported having an out-of-body experience.
The research appears to explain how mammal brains are able to temporarily decouple mind and body – though it's still not clear why they have this ability.
The research also could lead to ways to control dissociation without using drugs. That could eventually help a wide range of patients, Solt says.
"In the operating room we'd love to have a drug like ketamine that just produces the pain-killing properties without having these other psychological manifestations," he says.
Preventing dissociation might also help patients who have certain mental illnesses, or who are recovering from a traumatic experience.
But dissociation can be beneficial, Solt says.
For example, ketamine appears to help people with severe depression in part because it temporarily decouples certain areas of the brain.
"There seems to be this link between dissociation and the anti-depressive effect of ketamine," he says, noting that doses too low to produce even a mildly altered state appear to offer less benefit to people with depression.
AILSA CHANG, HOST:
The Trump Administration released a plan today for distributing a future coronavirus vaccine, but officials have been offering conflicting information on the timeline of that rollout. Earlier in the day, CDC Director Robert Redfield testified that the vaccine would be widely available late next year, though he did say first responders may get it sooner. Then this afternoon, President Trump said the government could begin distributing a vaccine as early as next month.
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PRESIDENT DONALD TRUMP: Under no circumstance will it be as late as the doctor said.
CHANG: All right. NPR national political correspondent Mara Liasson joins us now with more.
MARA LIASSON, BYLINE: Hey there, Ailsa.
CHANG: So just walk us through this. What exactly did President Trump say about the vaccine rollout this afternoon?
LIASSON: Well, the problem was is that what he said didn't jibe with what his own CDC director said.
LIASSON: The president said they're ready to go. He said the vaccine is going to be extremely strong, extremely powerful and extremely successful. It could come in the next couple of weeks, could be before the election. And, of course, he was asked a lot of questions about why did he not seem to be on the same page than his own CDC director. And he had an answer for that. And here's what he said.
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TRUMP: I think he made a mistake when he said that. It's just incorrect information. And I called him, and he didn't tell me that. And I think he got the message maybe confused. Maybe it was stated incorrectly. No, we're ready to go immediately.
LIASSON: So the CDC director is wrong and confused. Once again, the president is at odds with his own scientists. That seems to be a feature not a bug of the Trump administration's pandemic response.
CHANG: OK. And I understand that the president's own health adviser, Dr. Scott Atlas, also spoke this afternoon. What timeline did he give?
LIASSON: Well, he gave a timeline that was much more consistent with what Dr. Redfield of the CDC had said. He said there will be 700 million doses by the end of Q1. He kept on talking Q1. And the reporters would say, you mean March because that's the end of quarter one.
LIASSON: And he agreed with that, but he kept on using the term Q1. Maybe that sounded better than saying that the vaccine would not be available to the broad general public until spring of next year. But that's what he said, which is not inconsistent with what Dr. Redfield said. Although, he did say that elderly minority communities will be prioritized and maybe could get the vaccine sooner.
CHANG: OK. I understand that the president also spoke today about masks. What exactly did he say on that front?
LIASSON: That was another place that he differed from Dr. Redfield, who testified before Congress that masks were more important than a vaccine. He said that was - the president totally disagrees with that. He says a mask is going to - vaccines are more important than masks. Masks, he said, were a mixed bag. Some people don't like masks. Last night, at a town hall meeting with voters on ABC, he was asked, what people don't like masks? He said, waiters and restaurants don't like masks. So again, you know, he said Dr. Redfield was confused when he gave that answer about masks, even though what Dr. Redfield said comports with what the vast majority of scientists say; that masks are very important to stop the spread of COVID. So once again, Dr. Redfield is wrong, and he's confused. But when asked if he still had confidence in him, the president said yes.
CHANG: That is NPR national political correspondent Mara Liasson.
Thank you, Mara.
LIASSON: Thank you. Transcript provided by NPR, Copyright NPR.