Dementia, accidents, or traumatic events can make us lose the memories formed before the injury or the onset of the disease. Researchers from KU Leuven and the Leibniz Institute for Neurobiology have now shown that some memories can also be erased when one particular gene is switched off.

The team trained mice that had been genetically modified in one single gene: neuroplastin. This gene, which is investigated by only a few groups in the world, is very important for brain plasticity. In humans, changes in the regulation of the neuroplastin gene have recently been linked to decreased intellectual abilities and schizophrenia.

In the reported study, the mice were trained to move from one side of a box to the other as soon as a lamp lights up, thus avoiding a foot stimulus. This learning process is called associative learning. Its most famous example is Pavlov’s dog: conditioned to associate the sound of a bell with getting food, the dog starts salivating whenever it hears a bell.

When the scientists switched off the neuroplastin gene after conditioning, the mice were no longer able to perform the task properly. In other words, they showed learning and memory deficits that were specifically related to associative learning. The control mice with the neuroplastin gene switched on, by contrast, could still do the task perfectly.