While females may be more inherently susceptible to an augmented reaction to cocaine (especially under stressed conditions), it seems from the Vassoler et al. paper that males are more susceptible to a dampened "desire", indicated by self-administration studies, for cocaine if sired from a cocaine addicted male. One thing I loved about this study was the inclusion of the sucrose FR1 and PR self-administration tests. While I had not thought about a general operant learning deficit until I read that part of the paper, especially in relating the results to humans, it seemed important to include based on the belief that offspring of drug-addicted parents are inherently "cognitively deficient".
Sunday, March 26, 2017
While both papers seemed well structured in their hypothesis and experimental design, I felt as though I didn't have much to say on either. The Holly et al. paper seemed to confirm what has long been considered in regards to stress and sex interactions on cocaine use. While not entirely unsurprising, given my own experience with stress and the desire to have a glass of wine, it was great to see how clean the data was in regards to the interaction between stress and behavioral sensitization. However, I did find it alarming that it appears as though females are more susceptible to stress induced behavioral sensitization. One interesting thing about the results were that it seemed as though, on the whole, females were more susceptible to cocaine and a stress X cocaine interaction, however males had a higher baseline DAergic tone in comparison to females. Especially when coupled with the data suggesting that stressed males have a higher DAergic tone than non stressed, but do not necessarily show the same stress X cocaine interaction as females, it seems as though perhaps a higher DAergic tone at baseline "protects" stressed males from an augmented reaction to cocaine. I did have one significant question about the methods of this paper: why would they have the rats on a reverse light-dark cycle? I thought that perhaps it was to counteract some of the effects of a circadian rhythm, but the more I think about that the more I'm convinced that there must be another reason. One thing I did not like about this paper was the "binge" results based on estrous cycle. While their explanation of finding no significance made sense, it seemed as though this was an inherent flaw in the experimental design that could have been easily rectified using their suggestion of OVX females + estradiol replacement. This would have added to their results and helped fill a missing gap that was present solely based on the short estrous cycles of rats (4 days I believe).