The placebo effect is very real. This we've known for decades, as seen in real-life observations and the best double-blinded randomized clinical trials researchers have devised for many diseases and conditions, especially pain. And yet, how and why the placebo effect occurs has remained a mystery.
Now, neuroscientists have discovered a key piece of the placebo effect puzzle. Publishing in Nature , researchers at the University of North Carolina School of Medicine– with colleagues from Stanford, the Howard Hughes Medical Institute, and the Allen Institute for Brain Science – discovered a pain control pathway that links the cingulate cortex in the front of the brain, through the pons region of the brainstem, to cerebellum in the back of the brain. The researchers, led by Greg Scherrer, PharmD, PhD, associate professor in the UNC Department of Cell Biology and Physiology, the UNC Neuroscience Center, and the UNC Department of Pharmacology, then showed that certain neurons and synapses along this pathway are highly activated when mice expect pain relief and experience pain relief, even when there is no medication involved.
That neurons in our cerebral cortex communicate with the pons and cerebellum to adjust pain thresholds based on our expectations is both completely unexpected, given our previous understanding of the pain circuitry, and incredibly exciting. Our results do open the possibility of activating this pathway through other therapeutic means, such as drugs or neuro.