Caption: Researchers measured how strongly brain waves were synchronized before, during, and after anesthesia with propofol. Data from the research shows strong increases in synchrony only in very slow frequencies (deep red color along bottom) between the thalamus and four cortical regions while animals were unconscious. Credits: Image courtesy of the Miller/Brown labs, Picower Institute Previous image Next image In a uniquely deep and detailed look at how the commonly used anesthetic propofol causes unconsciousness, a collaboration of labs at the Picower Institute for Learning and Memory at MIT shows that as the drug takes hold in the brain, a wide swath of regions become coordinated by very slow rhythms that maintain a commensurately languid pace of neural activity. Electrically stimulating a deeper region, the thalamus, restores synchrony of the brain’s normal higher frequency rhythms and activity levels, waking the brain back up and restoring arousal.