A recent article from the website neuroscience news gives some insight into the work of Dr. Glanzman at UCLA; Glanzman has been trying to figure out the molecular basis for long term memory. Many now believe that when a protein kinase phosphorylates certain proteins in the synapse (CAMKII), the catalytic region of the protein remains accessible, which will increase the probability of long term potentiation (LTP: neurons that fire together wire together). CAMKII usually requires a second messenger for it to remain open, but the protein kinase phosphorylates the “hinge-like” protein, essentially blocking its closure, which allows access to the catalytic region. Glanzman has identified Protein Kinase M as a crucial kinase in this process; and so if Kinase M is inhibited, the chances of LTP and memory formation are drastically reduced or diminished. (Holes in my memory plugged by Bear et al. 2007 – see recommended resources).
There seems a long way to go before the molecular mechanisms in human memory are properly understood and techniques applied to weaken or reduce traumatic memories, but Elizabeth Phelps, a neuroscientist from NYU, has a made some phenomenal steps in understanding how re-writing fear memories in humans could be accomplished, see the video below.
Elizabeth Phelps on re-writing fear memories (I also recommend watching the other videos on youtube where Dr. Phelps discusses her research)