Anesthesia works by changing the brain’s rhythms says new research

Simultaneous measurement of neural rhythms and spikes across five brain areas in animals reveals how propofol induces unconsciousness. 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. “There’s a folk psychology or tacit assumption that what anesthesia does is simply ‘turn off’ the brain,” said Earl Miller, Picower Professor of Neuroscience and co-senior author of the study in eLife. “What we show is that propofol dramatically changes and controls the dynamics of the brain’s rhythms.”…