Rodent of the Week: Fearful memories are buried, temporarily, during adolescence

Fearful memories acquired early in life may be temporarily forgotten, researchers suggested this week. Although the study is in mice, it raises the question of whether humans may suppress or recall memories at different times of life.

The researchers, from Cornell, Brown and New York University, conducted a series of experiments in early-, mid- and late-adolescent mice. As the mice entered adolescence, previously formed fearful memories were suppressed. But the mice could recall the fearful memory -- after being exposed to the context of the situation as a reminder -- once they entered adulthood.

The study showed that the period in which the mice suppressed the memories was linked to a blunted response in the amygdala, a part of the brain that processes fear. Brain activity also changed in a part of the hippocampus that retrieves memories.

The research might help explain some of the behavior and symptoms of people who have post-traumatic stress disorder and phobias. Scientists are also working on techniques that might blunt or erase fearful memories shortly after they develop.

The study is published in Proceedings of the National Academy of Sciences.

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