Week 4

Both papers were well thought out and seemed to have a control for every possible condition that could affect their results. I like to write down notes and ideas I have while reading, and right after jotting down that it would be interesting if Yiu et al. used optogenetics as a method, I read on to find out they did. Both sets of authors thought of everything, eventually answering most questions I had and making it hard for me to further comment on their research.

My main question after reading was if it would be possible to erase a fear memory that was not enhanced. Han et al. puts forth a convincing argument that enhanced fear memories can be erased by ablating neurons that overexpress CREB, which I support. But would ablation of the neurons associated with a past fear memory be successful in erasure? I know memory enhancement was a result of showing the way increased CREB expression in neurons is linked to recruitment for the fear memory pathway, but could enhancing a memory potentially make it more a distinct event and easier to completely erase? I feel like I am reaching, but something about enhanced memories strikes me as having different properties than one formed under regular conditions. For clinical purposes, I would be interested to see if an already formed fear memory could be permanently erased, potentially as a treatment for those with PTSD.

For the Yiu et al. paper, I thought it was really interesting that the increased excitability from CREB overexpression was the reason for recruitment of the neurons for the memory pathway and led to memory enhancement. It opened a lot of doors for new research. Though I wish the parts of the experiment done ex vivo were recreated in vivo to see any potential downstream or lasting effects, I thought there were enough other tests performed to validate the data. I would be curious to see if increased excitability is cause for recruitment in different neurons in memory pathways involving other emotions, like reward, that are not as intertwined with the amygdala as fear is. Also, building off Yiu et al.’s findings, there is potential to manipulate memory pathways by pre-activating neurons before training.