Memory and depression - John Lambert

These articles, Ramirez et al. (2013) and Ramirez et al. (2015) are closely related, in that they both use the same optogenetic methods to alter memories in mice. It is pretty amazing that one lab at MIT has found all of this in just 2 years. This was done by targeting memory engram cells in the hippocampus. The 2013 article focused on creating a false memory in mice, by modulating the activation of certain memory cells after being exposed to a fear- and neutral- experience. The 2015 paper took things a step further by reactivating a positive memory in animals that had been exposed to chronic immobilization stress. This was found to actually suppress the depressive-like behavior that the mice were exhibiting, though it did not affect anxiety behavior (measured by the OFT and EPMT). 
I was a bit surprised while reading these papers, because I did not know that this research had been conducted and had achieved these levels of results. I agree with the bulk of Dana's post, that while this is interesting and warrants further study, it does not really translate easily to clinical treatment. Additionally there are serious medical, ethical, moral, and technological challenges that come in to play when altering memories in higher-level organisms, such as monkeys and humans. I am interested in seeing where this research continues to go, but I honestly do not think that we, as a society, are ready to alter memories purposefully with this type of technology. It can be argued that we create false memories all of the time, interrogations of innocent people that result in them 'remembering' committing the crime comes to mind, but that is a different issue entirely. 
One of the reasons why I am so fascinated by neuroscience is memory. They make is who we are, change our behavior, literally enable us to learn and grow. Damage to the hippocampus or pathways related to memory can be devastating, and is often not revisable. Altering memories occurs often to some memories, but others are seemingly solid. It is all just so fascinating, so I really enjoyed reading these two papers. 

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