Researchers uncover how the brain maintains useful memories

17th Feb 2017

New research from the University of Toronto has discovered a reason why we struggle to remember the smaller details of past events/experiences.

The research team looked at the medial prefrontal cortex (mPFC) area of rats brains because this region has been previously shown to be associated with long term memory. They found specific groups of neurons that develop codes to help store relevant information from multiple experiences while, over time, losing the irrelevant details of each experience.

In the study, the researchers tested how two different memories with overlapping associative features are coded by neuron groups in the mPFC of rats brains, and how these codes change over time. The rats were given two experiences with an interval between each one. One experienced involved a light and tone stimulus and the other a physical stimulus. 

The neuronal activity was tracked in the rats' brains throughout the whole four week learning process. The researchers found initially the neurons encoded both the unique and shared features of the stimulus. However, over the month, the coding becomes more sensitive to the shared features and less to the unique ones, which eventually become lost. 

Further experiments revealed that the brain can adapt the general knowledge gained from multiple experiences immediately to a new situation. 

These findings provide insight into how the brain collects and stores useful knowledge about the world that can be adapted and applied to new experiences.

To read the full article, please visit eLife website.