Ramirez Papers

This week’s papers were significantly more interesting to me compared to the past 2 weeks. For starters, I don’t think I truly understood optogenetics until having to read these articles in depth since I am presenting on them. Optogenetics is truly such an amazing innovation that I believe can change the way mental diseases are treated. Secondly, these papers were more relatable to humans. I don’t know if its Ramirez’s lab style of writing or the Science journal requiring more detail, but these papers put everything into context. They clearly explained what they were interested in investigating, why they wanted to investigate said thing, and how their results could be applied to different models. Ramirez’s first paper, Creating a False Memory in the Hippocampus, was so full of detail I had to map out all of the experimental designs on a whiteboard in order to keep it all straight. I was amazed they were able to create a true false memory in DG neurons! They used optogenetics to reactivate cells that were labeled during a contextual memory and use that retrieved memory pairing it with a foot shock in order to make a new false memory so that when the animal was placed in a context without shock they still froze. What I thought was a very interesting point that they brought up was how different conditioned stimuli compete, which leads to a decrease in memory recall. They saw this happen when encoding context A the fear memory in context B wasn’t remembered as clearly when re-exposed. Another point made that I found peculiar was the inability to create false memories in CA1 cells. If there was greater overlap of cells activated in the CA1 compared to in the DG (Figure2 E & L), then wouldn’t we expect to see a false memory formed there as well or perhaps an even stronger memory formed? They hypothesized that they could create false memories in the CA1 because maybe it had to do more with temporal code opposed to population code, so I wonder how they would be able to test for that to see if that is a valid theory. Also, since the dentate gyrus is known for being the site of neurogenesis in the brain, would creating false memory in this region produce the given long lasting effects if the new cells created had the memory as a result? I might be thinking of neurogenesis and formation of false memories in the wrong way but I wonder if that could be something to look at in the future.