Skip to main content

Venniro et al. 2018 and de Guglielmo et al. 2019

The article by Venniro and colleagues examined the role of volitional social interaction as a means of preventing drug seeking in addicted rats. This paper used methamphetamine and heroin as their drugs. I found this paper incredibly difficult to follow, partially due to the Nature Neuroscience organization, but mostly because it seemed like this was a jumble of conclusions. It seemed like perhaps this paper was written when the authors looked at datasets from old experiments and saw a chance to pull patterns they observed into one publication instead of running a new experiment to test that observation. That aside, I found the findings of this study a little odd and unexpected. It was my understanding that most people first experiment with drug taking in social situations due to social pressures to participate. So, when the authors reported that receiving a social reward would attenuate choice to use drugs (both methamphetamine and heroin)—that rats would choose social rewards over drugs nearly 100% of the time—I was shocked. More shocking, though, was that any changes in behavior in response to social reward punishment or lack of reward were not at all related to addiction scores. That finding made me question the reliability of the criteria used to determine each rat's score, but then it made me think about the DSM criteria for diagnosing humans with addiction. Overall, my biggest concern for this paper was its ability to translate the findings to rats to any viable clinical outcome in humans. Why, if faced with the choice between continuing drug use and maintaining a relationship with family, for example, do so many drug addicts continue to use? Clearly social reward is not weighted equally between humans and rats, or even across all humans for that matter.

The article by de Guglielmo and colleagues focused more so on using optogenetics to manipulate pathways thought to underlie addiction as a means to prevent alcohol seeking and decrease withdrawal symptoms. Similar to the papers we read last week, de Guglielmo and colleagues point to CeA projections to the BNST as a key pathway in maintaining addiction. The authors took this one step further and determined that corticotropin-releasing factor neurons are a critical component of this pathway. The possibilities for translating these findings into clinical practice are far clearer in this study than they were in the Venniro et al. article. The CRF Cea-BNST pathway could potentially be a target for pharmaceutical intervention or maybe surgical intervention (Is deep brain inhibition a thing? If not, it should be.) to treat patients with severe alcohol addiction that is resistant to treatment with traditional methods, like CBT. In Clinical Neuroscience, we discussed a drug that is used to treat alcoholism (Antabuse) by creating a very unpleasant reaction to even the tiniest drop of alcohol, even in everyday items like mouthwash. That kind of treatment has strong, likely undesired, effects on a person's general daily life, so it would be awesome to be able to improve treatment to the point that an addict simply doesn't have the desire to consume a drug that they previously had a poor relationship with. However, this study was specifically investigating alcohol addiction, so it isn't necessarily true that this pathway would also be implicated in all types of addiction (or even substance use).

I still have one major question after now reading 4 papers about addiction. Drugs of abuse were used in all of the studies we examined, but I am curious how each of the results might differ with addiction non-pharmacological things. Many humans are addicted to gambling, pornography/sex, shopping, or plastic surgery (just to name a few). How are "behavioral" addictions different? Do they activate the same neuroanatomical pathways? Can they be reversed with the same mechanisms? I would imagine that isn't the case, but it would be very difficult to research considering rats and mice don't really get lip injections and butt implants, and rodents definitely don't have money to blow on designer bags. It doesn't seem too far fetched to train rodents to gamble for something like fruit loops, so maybe that could be a way to test behavioral addictions in the future.

Comments

Popular posts from this blog

Gut-Brain Interactions: Buffington et al, Reber et al 2016

April 13 Papers (Buffington et. al, Reber et. al) I found this week’s papers to be quite novel in that they both proposed potential treatments for neurodevelopmental or psychiatric disorders that target bacterial or microbial abnormalities and how these give rise to certain behavioral and physical symptoms associated with the disorders. I thought this was a very unusual yet interesting approach, and as I have not previously studied the gut-brain axis, these papers offered me a fresh perspective on researching psychiatric and neurodevelopmental disorders. They were also unconventional in their focus of the physical symptoms that often accompany mental disorders, as this is not something that I have seen many other papers touch upon very much. Particularly, I was surprised by the Reber et al paper’s focus on the link between psychiatric disorders and inflammation in organs other than the brain, such as the colon, and the Buffington et al paper’s description of a relationship between ...

Buffington et al. and Reber et al.: Gut-Brain Interactions

While I have not encountered a lot of gut-brain interaction literature yet. I found each paper unique and fascinating. Reber et al felt inaccessible for me. I felt like I didn’t understand what the goal of the paper really was and why they did the tests that they did. It seems like most of their relevant information got shoved into numerous supplementary figures and their behavior was quite difficult to follow. Multiple sections of their paper were supported with data found entirely in supplementary figures, which makes it difficult to follow the same conclusions. I have a few issues with the behavior they chose and because of this, I struggle to find driving conclusions from their work. I don’t understand why the CSC was not only the prior stressor but was also the acute stress condition both groups faced. To me, I feel like it would have made more sense to have the CSC be the prior stressor and then judge the effect on social behavior with maybe a three choice chamber test or te...

Buffington et al (2016) and Reber et al. (2016)

This week's articles were about the role of the gut-brain axis in neurodevelopment and stress. Reber and colleagues used a heat-killed version of the bacteria, M. vaccae, as a type of vaccine and found that administration to mouse models resulted in decreased response to chronic stress, prevented colitis related to stress, and reduced measures of anxiety. Reber et al. also used the inactivated M. vaccae in a mouse model of IBD and found that the bacteria prevented stress-induce flare-ups of colitis, but that this could be reversed by removing T cells. Buffington and colleagues instead examined the role of gut microbiota in maternal high-fat diets (MHFD) in the neurodevelopment and social behaviors of their offspring. Buffington et al. found that housing MHFD rats with the offspring of regular diet (MRD) rats prevented social deficits in their offspring. They also found that this co-housing arrangement prevented an imbalance in the gut bacteria Reber and colleagues' findings w...