This is how the brain restarts after deep sleep from anesthesia
You might have spent hours wondering what your laptop could take so long to boot up, and now scientists have asked the human brain the same question: how exactly does it restart after being anesthetized. , in a coma, or in a deep sleep?
Using a group of 30 healthy adults who were anesthetized for three hours and a group of 30 healthy adults who weren’t as a control measure, a new study reveals information about how the brain is doing. brings back to consciousness.
As it turns out, the brain comes back one section at a time, rather than just once – and abstract problem-solving abilities, as handled by the prefrontal cortex, are the functions that come back online. faster. Other areas of the brain, including those that manage reaction time and attention, take longer.
“Although initially surprising, it makes sense in evolutionary terms that higher cognition needs to recover early.” says the anesthesiologist Max Kelz, University of Pennsylvania.
“If, for example, someone woke up to a threat, structures like the prefrontal cortex would be important in categorizing the situation and generating a plan of action.”
Various methods have been used to measure what is going on in the brain, including electroencephalography (EEG) scans and cognitive tests before and after the fall. These tests measured reaction speed, memory recall, and other skills.
By analyzing the EEG readings, the researchers noted that the frontal regions of the brain – where functions such as problem-solving, memory, and motor control are located – became particularly active as the brain began to get well.
A comparison with the control group showed that it took about three hours for those who had been anesthetized to fully recover.
The team also tracked their sleep schedules with group participants in the days following the experience. The experience did not appear to adversely affect the sleep patterns of those who had been anesthetized.
“This suggests that the healthy human brain is resilient, even with prolonged exposure to deep anesthesia,” says the anesthesiologist Michael Avidan, from the University of Washington.
“Clinically, this implies that some of the impaired cognition that we often see for days or even weeks during recovery from anesthesia and surgery – like delirium – could be attributable to factors other than the lingering effects of the anesthetic drugs. on the brain.
Many surgeries simply wouldn’t be possible without anesthesia, an effective and controlled way to turn off consciousness in the brain – which can happen unintentionally in a coma.
Despite their widespread use, we don’t really understand how anesthetics work precisely, although we do understand how to use them safely. There are many ideas about how the brain processes these drugs, but no concrete evidence yet.
The latest findings may not only help in the treatment and care of patients – after major operations involving anesthesia, for example – but also give scientists a better understanding of the brain and its response to disturbances.
“How the brain recovers from states of unconsciousness is clinically important, but also gives us insight into the neural basis of consciousness itself.” says the anesthesiologist George Mashour, from the University of Michigan.
The research was published in eLife.