This theory explains that acupuncture works through the nervous system and alleviates pain. The theory states that the nervous system is made of nerves that transmit and inhibit pain. These nerves join together in the substantia gelatinosa. The substantia gelatinosa receives direct input from fibers, especially those responsible for pain. Acupuncture could help pain relief by stimulating the nerve fibers responsible for pain, which lowers pain input and therefore relieves pain in the patient.