PAIN, DRAWING. PAIN, DRAWING Pain activation and inhibition. Illustration of the circuit of pain activation (left) and inhibition (right). - Activation: through the effects of a nociceptive stimulus (wound, burn, inflammation, etc.), a nerve impulse is slowly transmitted by the nerve fibers to the spinal wide dynamic range neurons, then to the brain stem, through the hypothalamus, thalamus and cortex, for cognitive factors, or directly to the brain stem, for sensory factors. - Inhibiti