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Post 5- Modeling PTSD- Fear Conditioning and Extinction

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Sial et al’s paper became accepted in 2015. At a first glance it became interesting to see that the paper explores the build-up of topics that we have discussed in class so far. Specifically, the researchers mention how physical stress exposure models can be applied to PTSD. The information expands from previous data in the attempt to deepen their findings relative to behavioural disorders. Although the researchers claim the validity and accuracy of the VSDS model, I am left with a few questions regarding this. Firstly, I believe that it would be helpful to read more in-depth about the differences between physical stress (PS) and emotional stress (ES), for a better comprehension about the two and their applicability to behavioural disorders. Additionally, the researchers do not specify any affected brain region nor touch upon the influence of physical versus emotional stress on memory areas. In the discussion section, they do briefly mention that the HPA axis becomes dysregulated in stress exposure. I would be curious in finding out more about the HPA axis and its relation to the models investigated in the experiment and with regards to the different stress stimuli. I also thought more clarification could be needed since the researchers mention PTSD and depression as if they are similar and parallel to each other, which certainly is not the case as they are two separate disorders. Sial et al also mention that they wish to expand the model to female mice, which I believe should be given more emphasis in their study. As discussed in class, female and male mice brains vary greatly in terms of response to stress and disorders as well as in their molecular components. This may thereby have a substantial effect on differential findings. 

Furthermore, the second paper by Allsop et al, answered some of the questions I had from the first paper. Published three years later, this study argues that the cortex and amygdala are important in social interaction and cognition. However, one may question the extent to which social information can be applied to PTSD specifically. The researchers mention that the ACC à BLA circuit involvement in observational fear conditioning is important for further investigation in specific psychiatric disorders. They also solely mention observational fear conditioning and not PTSD. Are these two behavioural outcomes the same? From my understanding fear conditioning differs in severity compared to PTSD. The paper discusses a lot of information in relation to ACC à BLA pathway but it would also be beneficial to include more findings that relate to other brain regions or pathways, again expanding on stress and the HPA axis. I also would be curious to know more about the pathway specifically for memory expression as well as additional cues and memories than only social cues. However, I believe that this information has been excluded from the paper due to funding issues and structure regulations. Although Allsop et al do go more in-depth when investigating fear in observational learning, I am still left with one unanswered question. To what extent are we able to know that observing behaviour will give us the same level of empathy as when we are actually experiencing the behaviour?

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