By: Nour Hany

Have you ever wondered what happens to your brain while you are unconscious? How does your brain reboot after a coma or the deep sleep of anesthesia? Well, a lot of these questions have come into the scientists’ minds and a study was conducted to investigate and track the process of regaining consciousness after being anesthetized.

The brilliant invention of anesthesia allowed for millions of pain-free surgeries over decades, but what makes our brain fall in deep sleep and what happens during the process of waking up again? To answer that, the experiment involved 30 healthy humans who were anesthetized for three hours. During this period of time, scientists measured their brain activity with electroencephalography (EEG) and their sleep-wake activity was measured before and after the experiment.

The study showed that the brain sections switch back one by one and not at the same time. Abstract problem-solving capabilities, which are handled by the prefrontal cortex, are the first to switch back. However, other areas of the brain take longer to come back, such as managing reaction, time, and attention. "Although initially surprising, it makes sense in evolutionary terms that higher cognition needs to recover early," says anesthesiologist Max Kelz, from the University of Pennsylvania. If someone, for example, was unconscious and suddenly woke up to a threat, the prefrontal cortex will help them create an action plan.

During the time of the experiment and while the group of 30 people was asleep, another group of 30 healthy human beings was awake during the entire time. After being anesthetized for hours, the sleeping group woke up, and both groups were examined to measure their brain activity. Amazingly, participants recovered their cognitive function to almost the same level of those who stayed awake during the entire experiment. Moreover, their sleeping patterns on the days following the experiment were not affected.

“This suggests that the healthy human brain is resilient, even with a prolonged exposure to deep anesthesia. Clinically, this implies that some of the disorders of cognition that we often see for days or even weeks during recovery from anesthesia and surgery—such as delirium—might be attributable to factors other than lingering effects of anesthetic drugs on the brain,” says Michael Avidan, MBBCh of the Washington University School of Medicine.

It is truly amazing how the human brain always surprises us with its endless capabilities. There are many other brain-related studies that need to be conducted, as there are endless questions out that need to be answered. It is our own curiosity that drives us to seek answers, probably about questions we never thought existed.

References

https://labblog.uofmhealth.org/lab-report/escape-from-oblivion-how-brain-reboots-after-deep-anesthesia

https://www.sciencealert.com/here-s-how-the-brain-reboots-itself-after-the-deep-sleep-of-anesthesia

https://www.sciencedaily.com/releases/2021/05/210527112419.htm