Observational Stress Learning in Mice - John Lambert

            The articles this week both touched upon observational learning. Sial et al. (2015) was a neuroscience methods article that explored how the researchers developed a new model of stress, vicarious social defeat stress (VSDS), which seems to be a better version of chronic social defeat stress (CSDS) for certain cases. VSDS is used to induce ‘psychological’ stress in mice, as opposed to physical stress, by having a mouse observe another mouse being socially defeated. This model was developed so that there would be an ethologically valid model to induce ‘psychological’ behavioral deficits. The authors put a spotlight on its potential for post traumatic stress disorder (PTSD) related research, and also mention the potential use for anxiety and depression related research. I really like the VSDS model, as well as the paper itself. I think that the witness-driven stressor model may be more valid than the physical stressor models for all 3 of the research fields above, in large part because that is more similar to human experiences. I really liked that this paper deviated from many of the previous papers we have read, because it is a methods paper and was introducing a novel model; it detailed how and when to use VSDS.
            Tye et al. (2018) conducted research with some similarities to Sial et al.’s 3 years earlier, but approached with different research questions and came from a different direction. It focused primarily on the link between observational learning and the neurological connections involved. They specifically looked at the link between the anterior cingulate cortex (ACC) and the basolateral amygdala (BLA) and social information/observational learning. They did not use VSDS from Sial et al. but they did use a similar method to study observational learning. This included many different groups that experienced or observed shocks and tones (or some lack of or variation on). They utilized optogenetic methods to study modulation of BLA and ACC neurons and discovered some great results. Tye et al. explored a LOT and as a result has a lot of results to unpack. This paper was much more difficult to digest (and understand) than Sial et al. I found some of the sections in figures 2-4 to be confusing and overly complex (I won’t pretend to understand all of them, because I don’t), but perhaps that was just me. Interestingly, Tye et al. overwhelmingly focused on their research being used for different psychiatric conditions than the previous paper.  
            Overall I thought that both of these were interesting papers. I liked that both articles had graphical abstracts (is this common now?). I haven’t had time to look into it, but I’m interested in how/if VSDS (or at least similar models) have caught on in animal research. I don't really see any direct clinical applications from this research, but they could be foundational for a lot of cool research going forward.

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