PTSD in cells

Chronic pain from old accidents or sports injuries is common, but until now, scientists haven’t understood why pain should persist after the injury has healed. They knew that cells involved in the immune system helped perpetuate the pain, but didn’t know how.

To answer the question, researchers at King’s College London studied immune cells in mice. They found that damage to nerves caused by injury can leave a permanent impact on genes in the cells, altering them so their descendants make proteins and other products that signal pain.