Week 4

I thoroughly enjoyed reading papers on this week’s topic of discussion, as there was a clear connection between the two. Although both papers proposed that excited LA neurons (through increasing CREB activity) were preferentially recruited to become part of the memory trace of fear memory than their non-excited counterparts, I would say Yui et al. did a phenomenal job at highlighting this connection. Even though Han et al. were not lacking in their data, I found Yui’s paper easier to read as they provided explanations and background information for most of their experiments. Additionally, their approach was not only clever but also extremely thorough. Every experiment was linked back to the main hypothesis (neurons compete against one another for inclusion in a memory trace, and that neurons with relatively higher levels of excitability are more likely to win this competition), and not only did they provide supporting evidence, they also went above and beyond to pin down the time frame when this excitability was most crucial (during the time of memory encoding, rather than during consolidation). It was really interesting to learn about the specificity of these neurons in the fear memory trace, as the same effect was not seen in anxiety-like behavior. I also found the result - artificially reactivating a key component of the fear memory trace (those neurons with increased excitability at the time of training) is sufficient to induce memory recall – to be quite striking. Overall, after reading both papers, I found it difficult to find any errors as both groups of researchers have done a convincing job by conducting enough tests as well as control experiments to validate their proposed theories and have provided a great window of opportunity for additional research and clinical implications.