According to the gate control theory, pain perception is a balance between information traveling into the spinal cord through two types of nonciceptive nerves:
i. Large nerve fibers (C-Delta nerve fibers), transmit chronic pain.
ii. Small nerve fibers( A-Delta nerve fibers), transmit intense pain.
A third type “nonnociceptive” (A-beta nerve fibers) are Inhibitory Neurons, they do not transmit pain.