Associative memories can be extremely helpful. Touch the metal handle of a pot boiling water on the stove, for example, and chances are you won't do it again. But in other cases, associative memories can dramatically affect our development, such as in the case of a war veteran who associates all loud noises with the battlefield. A new technique tested in mice shows promise in turning off associative memories by preventing a gene from expressing itself.

Researchers at KU Leuven in Belgium and the Leibniz Institute for Neurobiology in Germany found that by turning of the gene known as neuroplastin, they could make mice forget an associative behavior they had learned. In this case, that behavior consisted of knowing to move to the other side of maze when a light went on in order to avoid a shock to the foot.

When the researchers turned off the neuroplastin gene, which is a gene that produces a protein, the mice couldn't complete the task properly. In other words, their associatively learned behaviors were erased.

When the mouse brains were examined using a gamma-ray technique called single-photon emission computed tomography imaging, it was found that they contained "substantial electrophysiologic deficits" according to the abstract for a research paper published in the journal Biological Psychiatry.

These defects interfered with cellular communication.

"We were amazed to find that deactivating one single gene is enough to erase associative memories formed before or during the learning trials," said Professor Detlef Balschun from the KU Leuven Laboratory for Biological Psychology, who was involved in the study. "Switching off the neuroplastin gene has an impact on the behavior of the mice, because it interferes with the communication between their brain cells."

Previous research shows that neuroplastin is an important component in maintaining the brain's plasticity, or its ability to modify its own structure in response to stimuli. Alterations to the gene have also been linked to schizophrenia.

While the work sheds even more light on neuroplastin's role in the brain, the researchers caution that the time when we can head into the doctor's office to have unpleasant memories erased is still quite a time away.

"This is still basic research," Balschun says. "We still need further research to show whether neuroplastin also plays a role in other forms of learning."

Source: KU Leuven