Biopsych seminar 2020

The first paper, Venniro et al (2018), explores the relationship between volitional social interaction and drug usage/addiction in rats. I thought their methodology and results quite thoroughly proved that, interestingly enough, volitional subject-controlled social interaction decreases drug self-administration in rats. The authors use the introduction to not only ground the research but to emphasis the human/clinical relevance of the findings, explaining the known relationship between social interaction and drug use in rodents, monkeys, and humans. Although I appreciate the thorough methodology used in this study and agree with the findings, I do not necessarily see the direct link to human treatment. Both addiction and social interaction are extremely sensitive and complicated processes in humans that are influenced by many other factors besides just each other. For example, genetic disposition, environment, mental health, impulsivity, introversion/extroversion, observational learni...

Venniro et al. (2018) & de Guglielmo et al. (2019) take two complementary approaches to furthering the study and discussion of drug addiction and dependence in rodent models and potential clinical translations. Overall, I found Venniro et al. particularly intriguing for their discussion of clinical applications but also appreciated the extensive consideration of controls used to verify de Guglielmo et al.’s methodology.   One critique I had for de Guglielmo et al. actually relates to their use of controls and how they originally induced alcohol dependence. The alcohol-dependent rats were exposed to cycling chronic intermittent alcohol vapors in operant chambers. For both dependent and non-dependent animals, they describe unaffected levels of water and saccharin intake in control and and NpHR-expressing rats. However, I think it would have been relevant for the researchers to also expose all groups to saccharin vapor and water vapor. If they are attempting to rule out the a...

Venniro (2018) When I was reading Experiment 1, I noticed that the authors only mentioned males for the methamphetamine experiments and mentioned both males and females for the heroin experiments which was interesting. It was positive that both sexes were being used in this experiment but not clear why only for the heroin experiment. I referred to the methods and there were 318 male rats and only 39 female rats used in this study, about 11%. Why wouldn’t the researchers use a ratio closer to 50/50 of male and female rats? I don’t know much about laboratory rat breeding but I would assume it’s not due to a shortage of females since most studies use only males. Why were all the females in the heroin group and none in the methamphetamine group? It says rats were randomly assigned to drug user and drug naive groups but it doesn’t say that they were randomly assigned to drug type groups. And if they were randomly assigned, it’s unlikely that all of the females were assigned to the heroin g...

Venniro et al. (2018) is my favorite paper of any we have read thus far in class. In part because of how blunt it is in calling out neuroscientific research’s deficits in studying the social aspect of addiction (I for some reason found this very humorous), but mainly because I could see just exactly how translational this research is. It is pretty amazing that they were able to show that rats prefer social interaction over self-administration of meth or heroin; I found it especially interesting in the context of animal receiving a punishment. It made me think about how if a support structure in humans is not rewarding enough, then someone might self-administer. Some ideas this gave me about additional experiments that might provide even more information about the social aspect of addiction were to have the ‘social partner’ instead be an aggressor to see if making the relationship even less rewarding would make the rat want to self-administer or if it is just the social interaction in ...

This week’s papers, Venniro et al. 2018 and deGuglielmo et al. 2019, dive deeply into secondary neural systems involved in perpetuating addiction. Most common knowledge implicates reward pathways and decision-making in driving an animal do pursue chronic drug use as a salient reward. But, these papers implicate social interaction dependent pathways as well as CRF reception in the amygdala respectively as other effectors in which can modulate rats’ addictive response to drug self-administration. In proving so, these papers back up the fact that addiction truly isn’t a homogeneous condition, therefore many other realms should be studied in order to understand the true complexity.              Venniro et al. 2018 presents an interesting look at how the choice of social interaction can overwhelm the choice of drug intake in rats regardless of certain predispositions in forming addiction. In the discussion of this paper, the...

The organization of the Venniro paper was extremely frustrating. At first read, the experiments seem to be laid out nicely with the subheadings, but the procedures and results were all over the place. It was so difficult to figure out the details of the methods, even with the supplementary note. I felt like some of the tests, or lack thereof, were random. Why, for instance, did they calculate addiction scores in two different ways? Why were females only used in two of the experiments that they performed? I felt like the researchers were trying to put a lot into this paper so that their conclusions could be significant, but it all felt a little bit messy to me. That being said, they did a good job at establishing a voluntary model that is more indicative of human behavior than previous forced abstinence models. As mentioned at the end of the paper, there are still several differences between this model and addiction in humans, but incorporating a social aspect is important. In addition...

The paper by Venniro et al. aimed to examine the protective ability of social interaction on susceptibility to drug addiction in rats, specifically in the context of methamphetamine and heroin. One aspect of this paper that I found particularly interesting was that devaluing the social reward resulted in a sharp increase in drug self-administration across all rats, regardless of drug type or addiction score. Based on previous literature, I anticipated that rats with higher addiction scores would not exhibit the same preference for social interaction as rats with lower addiction scores – it was fascinating to see that this was not the case. As the authors acknowledge, when an individual is working to overcome addiction, their social environment tends to be very polarizing, with the potential to be a very positive protective factor or the very opposite. Therefore, I think it would have been interesting to see how the valence of the social interaction correlated with the rat’s preference...