Acupuncture increases connections between different areas of the brain, according to Dhond and other Korean researchers who published their findings in the journal Pain.  They compared the effect of true and sham acupuncture in healthy volunteers using functional MRI of the brain.  They discovered that true acupuncture (insertion of one needle into the forearm) enhanced the “spacial extent of resting brain networks to include anti-nociceptive (pain-relieving), memory, and affective (responsible for emotions) brain regions”.   The researchers felt that this enhancement of connections between various parts of the brain is probably responsible for the pain relief induced by acupuncture.   After the recent German study of acupuncture for headaches which involved over 15,000 patients there is little doubt that acupuncture works for headaches (and many other pain conditions), but this study helps provide stronger scientific evidence that the relief is not due to placebo.