La mémoire de la douleur : de la LTP à la douleur du membre fantôme

Long term potentiation (LTP) at synapses of nociceptive primary afferents in nociceptive pathways is closely related with hyperalgesia. LTP constitutes a cellular model for pain amplification and central sensitization contributing to the development of chronic pain. We describe neurochemical pathways for the induction and for the maintenance of LTP as well as the role of glial cells for LTP. Pain experienced by young babies in the neonatal period may have long-lasting effects on their future adult pain behavior, a pain memory. Injury and tissue damage sustained in neonatal period can cause important changes in central nervous system which persist long after the injured tissues have healed and generate a neuronal environment more permissive for LTP development in adult spinal nociceptive circuitry which influence behavioral responses to painful events years later. Another dramatic example of a learnt memory for pain is phantom limb pain.