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Addiction Models in Rats: Venniro et al. and deGuglielmo et al.

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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 for social self-administration or drug self-administration. Also, I am curious as to what the effect of social interaction would be on drug-dependent rats who had been exposed to the social defeat model. I am tempted to hypothesize that these rats would be more likely to choose the drug over social interaction, in the case that social interaction was associated with a deeper level of anxiety. 
I really enjoyed the second paper, by deGuglielmo et al., which demonstrated that optogenetic inactivation of CRF-dependent neurons in the amygdala can reverse addiction in alcoholic rats. Part of the reason I liked this paper so much, I think, was because their alcohol-dependent phenotype was very much rooted in neurobiology, through an examination of CeA CRF neurons recruited during alcohol withdrawal. I have found that with many rodent models (specifically when it comes to behavior), I struggle to see the translational validity to humans. However, with a model such as this in which the basis of the experimental conclusion was rooted in an examination of neural pathways, I felt that it was more convincing. I also thought it would be interesting to see if there were any neuronal ensembles that contributed to alcohol addiction in the nucleus accumbens, which is greatly implicated in addiction. It would be interesting to see if the NAc, as well as the amygdala, could be targeted for treatment of alcohol use disorder. 

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