Every signal between the brain and the body passes through the medulla oblongata, the piece of the brain stem connected to the spinal cord. It’s also the home of many of our automatic functions: breathing, heart rate, vomiting, elimination, etc. In other words, the medulla oblongata takes care of our creature needs, on top of which a couple hundred million years of evolution have built the capacity for thought, language, and culture, making possible things like Socrates and the movie Beverly Hills Chihuahua.
The medulla oblongata may also be a counterintuitive component of the placebo effect—counterintuitive because the placebo effect has traditionally been attributed to higher areas of the brain capable of prediction, expectation, and evaluation (thought overrides pain). But researchers in Germany watched with high-tech gadgetry as placebos induced opioid release in the medulla oblongata. And rather than bouncing around the brain, these opioids traveled straight to the spinal cord, where they tamped down pain signals coming from the body before they even reached the brain.