A new study has found that the process of storing long-term memories in our brains is much more dynamic than suggested.

Prof. Yadin Dudai, Head of the Weizmann Institute's Neurobiology Department, and his colleagues discovered that the memory storing process involves a miniature molecular machine that runs constantly to keep memories going. The team, which also found that jamming the machine briefly can erase long-term memories, suggests that their findings may pave the way to future treatments for memory problems.

Prof. Dudai said that their study challenges the idea that long-term memories stabilize after maturing from short-term memories.

In the study, the U.S. and Israeli researchers fed the rats with saccharine, which made them sick and taught them to associate the taste with feeling unwell.

They then injected an enzyme inhibitor called ZIP into the rats' brains that blocked a protein, PKMzeta, which controls the flow of information involving memory between brain cells.

After the injection, the rats did not remember the association with saccharine, no matter how long the researchers had trained them to do so, said Dudai, a researcher at the Weizmann Institute of Science in Israel.

This suggests a key mechanism in the brain works like a piece of machinery to store long-term memory, Dudai said. Once the machinery stops, memory shuts down.

The technique worked as successfully a month after the memories were formed (in terms of life span, more or less analogous to years in humans) and all signs so far indicate that the affected unpleasant memories of the taste had indeed disappeared. This is the first time that memories in the brain were shown to be capable of erasure so long after their formation.