Scientists Successfully Used Lasers to Control Dreaming Brains

By Alyse Borkan  |  Oct 17, 2015
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When we’re lost in deep sleep, brain activity slows to the dullest of roars. The dreaming brain is anything but dormant. EEG recordings reveal nearly as much activity during REM sleep as in wakefulness. Our dreaming bodies, on the other hand, lie still; muscle paralysis sets in so we don’t physically act out the adventures transpiring inside our heads.

Sleep is a complex act, and multiple brain regions and networks team up to run REM operations. But neuroscientists from the University of California Berkeley pinpointed a group of neurons in the brain’s medulla oblongata that do some serious multi-tasking. Though previously thought only to be involved with the muscle paralysis aspect of dreaming, the cluster of neurons actually seems involved in regulating all aspects of REM sleep. In the study, published in Nature, scientists used lasers to switch these neurons on and off in the brains of mice, effectively propelling them in and out of a dream-state.

The method, called optogenetics, involves insertion of a “light-sensitive ion channel” into specific groups of neurons. In this case, the researchers targeted GABAergenic neurons, which release GABA, the feel-good neurotransmitter that floods the brain when people down such anti-anxiety meds as Xanax or take part in calming, pleasurable activities like eating.

Once the ion channel reached the neurons, scientists stimulated neuronal activity through a laser light. Ninety-four percent of the time, the dozing mice entered REM sleep within seconds of neuronal activation. Using the same basic method, researchers turned off neuronal activity, and the mice exited dreamland in a similarly hasty manner.

“People used to think that this region of the medulla was only involved in the paralysis of skeletal muscles during REM sleep,” said lead study author Yang Dan in a press release. “What we showed is that these neurons triggered all aspects of REM sleep, including muscle paralysis and the typical cortical activation that makes the brain look more awake than in non-REM sleep.”

via Van Winkle’s

Image credit: Alex // Creative Commons

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