The amygdala, the hippocampus, and emotional modulation of memory.

There are two views regarding the role of the amygdala in emotional memory formation. According to one view, the amygdala modulates memory-related processes in other brain regions, such as the hippocampus. According to the other, the amygdala is a site for some aspects of emotional memory. Here the authors adduce behavioral, electrophysiological, and biochemical evidence in support of an integrative view, assuming both roles for the amygdala. This integrative view, however, suggests a level of complexity not referred to before: the assumption that emotional conditions induce long-term neural plasticity in the amygdala suggests that the interrelations between the amygdala and brain regions, such as the hippocampus, may not be static but dynamic. The way the amygdala will affect memory-related processes in the hippocampus may thus largely depend on the previous history of the individual.