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Post 5: the cellular and circuit basis of fear and extinction

When the Sial et al. (2015) mentioned PTSD in individuals who witness a traumatic or fearful event, I thought of a scenario in which a child watches his or her parent suffer from domestic abuse which is a realistic situation that could cause PTSD and other cognitive/mental problems in children. The vicarious social defeat wouldn’t accurately model this specific type of PTSD since in the scenario I describe, there may be a strong emotional connection between the witness and the subject of the trauma and this could influence how seeing and being present for the traumatic event affects the witness. I wonder how they could change the vicarious social defeat to model a scenario/PTSD like the one I described. I’m not sure how mice bond emotionally, whether they bond most with littermates, siblings, parents/offspring, etc. but using two mice with a strong emotional connection for the physical stress and emotional stress mouse could help model this. I wonder how this would change the reaction in the emotional stress mouse. Could this elicit defensive and/or aggressive responses from the emotional stress mouse during the chronic defeat or during the social interaction? There are studies that show mice willing to help each other and prevent each other from getting hurt when possible so it would be interesting to see if mice will get protective if a emotionally close mice is being attacked or if it will worsen the social withdrawal because the attack feels even more personal and close.

The observational learning in the Allsop et al. paper reminds me of the experiment where a group of animals were housed together and if one animal attempted to obtain a reward, the rest of the animals would get shocked so the animals would stop any animal from trying to get the reward. When one of the animals gets replaced by a naive animal, all the animals try to stop the new animal from getting the reward. When another animal gets replaced, all the animals including the previously naive animal stops the new animal from getting the reward. Eventually all of the animals get replaced and all stop new animals from getting the reward even though none of them have been shocked. I know it’s not the same as the observation learning from the paper because these animals are being hurt/attacked whereas the observational learning animals only watched other animals getting hurt but it reminded me of it because in both, the animals are learning to associate punishment from other animals and not from experiencing it on their own. I wonder what commonalities these types of learning share in the ACC->BLA circuit or if there are any commonalities at all.

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