Researchers are gaining a better understanding of how the brain transitions from a state of unconsciousness to wakefulness. A barrier to awareness, called "neural inertia," is similar in a way, they say, to the everyday phenomenon of "sleep inertia" -- that groggy feeling we have when we're abruptly woken from sleep.
To study the concept of neural inertia, scientists modified genes known to play a role in sleep in fruit flies anesthetized with isoflourine, in order to see how they impacted the brain's transition from sleep to wakefulness, and vice versa. Researchers found that four of them -- Sh (Shaker), sss (sleepless), na, and unc79 -- were able to control the transition, therefore controlling the "neural inertia."
Even though the study, published in PLOS Genetics, was in flies, this method of studying the transition in the brain could lead to findings that are applicable to humans as well.
"One of the interesting consequences of the study was that the forward process of entering and exiting [from the stages of sleep and wakefulness] are dissociable," study researcher Dr. Max Kelz, M.D., Ph.D., an assistant professor of anesthesiology and critical care at the University of Penn's Perelman School of Medicine, explained to HuffPost.
In other words, the idea that the same brain processes that occur when a person is going under anesthesia are the same, just reversed, when a person is coming out of anesthesia, is an incorrect one.
An analogy: It's not like watching a video and then rewinding it. "You'd need two different movies to watch what's happening in the brain," Kelz says.
Kelz said the findings could also be applied to better understanding sleep disorders, as well as those rare instances when patients go under anesthesia and yet make memories and can recall what has happened in the operating room.
"Some findings imply that perhaps the inertia barrier is impaired somehow in these individuals," he said. Further research could also yield strategies for bringing coma patients back to consciousness or therapies for people with insomnia.