No pain, no gains. Pain and memory are two critical functions of animals and humans. Through painful experience humans and animals learn what is potentially harmful and then store this information in the brain in order to avoid future injury. It is the essential skill for animals and humans to survive through their lifespan. However, it is unclear if both processes may share common signal molecules or proteins in the brain. It is known that the NMDA receptor, a receptor for glutamate, in the higher structures of the brain is important for memory formation and storage. NMDA receptors in the spinal cord contribute to central sensitization of sensory information such as pain after injuries.