Yiu et al. and Ramirez et al.

Both Yiu et al. (2014) and Ramirez et al (2013) conducted research exploring the fascinating topic of memory formation. Yiu et al. focused on using the transcription factor CREB to increase excitation in neurons in the lateral amygdala, which resulted in enhanced memory formation of conditioned fear. I thought the experimenters were convincing in their evidence and provided very thorough research with extensive controls throughout. I found the investigation into the timing of when the increased neuronal excitability resulted in enhanced fear memory formation. They suggest that the time of memory encoding causes the strength of the memory, rather than during consolidation, as demonstrated by comparing the increase of excitation before and after training. Only the increase before training enhanced the fear memory formation, while after had no effect.

Similarly, Ramirez et al. investigated the possibility of artificially evoking fear memory and response through context-specific fear conditioning and optogenetics focusing on hippocampal neurons. I found this article conceptually fascinating, though the information was presented in a rather complex manner. I found their argument that artificially reactivating the memory-engram cells that had been activated during fear conditioning could produce a fear association memory response to be very interesting. I also found their mention of how multiple conditioned stimuli will cause competition that interferes with the strength of the memory formed for both artificial and genuine memories.

In terms of clinical application, I see both of these studies as incredibly useful for future investigation into PTSD therapies. If it is possible to artificially produce fear memories and responses, it seems likely that further manipulation would allow for artificially eradicating or replacing inappropriate fear memories or responses, such as those caused by severe trauma. While this research is very new and fear is probably the most useful type of memory to research at this time, I wonder if it would also be possible to control other types of memories as well. For example, if memories associated with anxiety, anhedonia, or sadness could be targeted, than perhaps these memory alterations could potentially be applied to depression in addition to PTSD.