Storing long term emotional memories.

A Journal of Neuroscience precis of an article by Cambiaghi et al., slightly edited:

When we remember events, we often also remember what we were feeling at the time. Cambiaghi et al. asked where in the brain we store such connections. To answer this, they conditioned rats to associate a tone with an unpleasant experience. They then simultaneously recorded from two brain regions, the higher-order auditory cortex and the amygdala, 1 day and 1 month after the conditioning. Animals displayed fearful behavior at both time points, and both areas showed learning-evoked changes. However, the two brain regions only interacted significantly after 1 month had passed (The cue increased the synchrony of their firing.) The degree of interaction predicted the animals' ability to recognize the tone as unpleasant.