Brain areas known to be involved in emotions and learning are more coordinated with each other during learning, suggests a paper published on line this week in Nature Neuroscience. This increased coupling could strengthen the neuronal connections underlying memory.
Denis Pare and colleagues measured the signals from a number of brain areas known to be active while learning about rewards. They focused on the amygdala, a brain structure that mediates emotions, and the striatum, a brain region that is involved in learning. They found that when a tone and a reward were presented independently, rhythmic neural activity in the two brain regions at the time of the tone was uncoordinated. However, as the animals learned that the offset of the tone predicted an upcoming reward, the timing of activity in the amygdala and the striatum became more correlated. The increase in coordination was unique to these two areas, and was not found for any of the other brain areas where the scientists were recording.
Previous work suggests that connections are strengthened between neurons that fire at the same time, so this increased coordination could be a mechanism for enhancing memory.