I found the basis of the Vassoler et al. paper very interesting - as they mentioned not many studies approach heritable traits from the paternal side, though epigenetic studies show there are distinct differences in how methylation and acetylation are inherited from each parent. I found the results perplexing, given that I would have thought that offspring of a CocSire male would demonstrate increased preference for cocaine administration. The authors did address this in the discussion with a broad statement about many environmental factors, drug availability and other possible explanations. I was still left wanting more information about the methylation, the role of BDNF in terms of addiction and wondering whether it would be possible to trace back some of these results to possible sex-linked genes.
My concern with Holly et al. starts with the paradigm; there are many forms of stress, including social and emotional stress like what is demonstrated with the social defeat paradigm. Females and males have been shown to respond to social stress differently, thought I'm not entirely sure whether this is consistent with rodents. I would have liked this paper better if they had used a different model of stress, though I'm not entirely sure if there is one that wouldn't receive this same argument. I also would have liked to see more about the results from different phases of the estrous cycle. Even day-to-day fluctuations of the cycle and any influence on the cocaine intake would be of interest to me, though I'm not sure how important it might seem in terms of a grant proposal. Overall I was left unconvinced by multiple aspects of this paper just in terms of how the data was presented and the paradigm of choice.