Using “optogenetics, a technique that allows scientists to stimulate or silence neurons with light,” on test mice, researchers found “a brain circuit that can trigger small regions of the brain to fall asleep or become less alert, while the rest of the brain remains awake.” So really, it’s not your fault that you’re just not with it today — it’s your pesky brain.
According to other recent research, the thalamic reticular nucleus (TRN) is responsible for sending signals to the thalamus and the brain’s cortex that slow some brain waves way, way down, leading to a sort of sleep state in parts of the brain even while the rest of the organ is fully functional. Whereas it was previously thought that your brain is either completely asleep or completely awake, the MIT team found that if they weakly stimulated the TRN, they could produce slower brain waves in just a portion of the brain’s cortex.
“We … found that when you induce these slow waves across the cortex, animals start to behaviorally act like they’re drowsy. They’ll stop moving around, their muscle tone will go down,” lead author Laura Lewis of MIT noted. And if you find that you become spacey when you’re exhausted, sleep-deprived, or just generally out of it, Lewis believes that this may be “because the brain begins to transition into sleep, and some local brain regions become drowsy even if you force yourself to stay awake.”
Ultimately, this research may be key in developing sleep drugs and anesthetics that work with the TRN to induce these slow wave patterns, thereby reducing the potential for harmful side effects. While the same results have not yet been reproduced in humans, here’s hoping that at least in this case, we behave like mice.
