Call on one and word quickly goes out to the larger network of cells, each apparently adding some detail, sight, sound, smell. The brain appears to retain a memory by growing thicker, or more efficient, communication lines between these cells.
By manipulating PKMzeta, it may be possible to edit memories, which “raises huge ethical issues,” according to Dr. Steven E. Hyman, a neurobiologist at Harvard. While you might be able to remove traumatic memories, the drug could be misused to eliminate memories that support moral conscience. [Link]