Skip to main content

Buffington and Reber

By
Buffington et al. explore a mechanism by which maternal obesity can induce neuronal and subsequent behavioral disorders. Using a model of high-fat diet (MHFD)-induced obesity, the authors showcase the strong connection between the brain and the gut, and its impact on behavior. The findings are provocative; by exposing these offspring to the microbiome of control offspring, there was evidence of a rescued observed behavioral phenotype. Furthermore, a phylogenetic profiling of the gut microbiome revealed a decrease in L. reuteri within MHFD offspring, and introduction of live L. reuteri into the drinking water shows successful rescue of the behavioral issues in the MHFD offspring. L. reuteri-induced expression of oxytocin within the paraventricular nuclei of the hypothalamus provides a potential mechanistic explanation for the behavioral changes. I thought this paper provided robust support for the hypothesized interaction between the gut biome and the developing CNS, with tremendous potential for clinical applications. I especially enjoyed the idea that from the human perspective, the gut microbiota transmitted to our children can influence their social behavior and could affect the frequency of autism spectrum disorder (!!), and how these results raise possibilities in terms of probiotic treatments for relief of behavioral abnormalities associated with neurodevelopmental disorders. My only concern regarding this research is of the population that it affects; I did further research and found out that the prevalence of maternal obesity is highest among deprived and minority ethnic populations. Of course more research is necessary to carry out research in human subjects, but I hope that future experiments would yield a widely accessible treatment to meet the needs of these populations.

Reber et al. found that immunization with a heat-killed preparation of M. vaccae promotes stress resilience in animal models, including a number of negative outcomes of chronic psychosocial stress and stress-induced exaggeration of anxiety in mice. Again, super provocative study with immense clinical applications once further research is conducted. This got me thinking about more applications of heat-killed preparations of other immunoregulatory bacteria beyond M. vaccae. Furthermore, I was surprised (and disappointed) to find that the study did not utilize female rats, which are more prone to stress. I’m curious to see what a study with female rats (including pregnant females) would look like.

Both studies also got me thinking about OpenBiome, an organization that I heard about recently in Boston and its work with making Fecal Microbiota Transplantation (FMT) more widely available to patients with C. difficile infections. Would it be possible to have a similar transplantation for people with IBS/IBD with possible behavioral rescue implications? I’m excited to see what sort of direction this research continues to move in for sure.

Comments

Post a Comment

Popular posts from this blog

Week 2- Dopamine Modulation of Depressive-like Behaviors

By
The Chaudhury et al paper explored the neural circuit mechanisms involved in the dopamine modulation of certain symptoms of depression. In this study, the researchers looked at social interaction and sucrose preference as part of their social-defeat paradigm, which has been shown in the past to be indicative of depressive-like behaviors. Although I initially did not completely see the connection between the social-defeat stress model of depression and the tonic vs phasic firing of dopamine neurons, it seemed that susceptibility and resilience to stress played a role in the functional/behavioral effects of dopamine firing. It was interesting to see how chronic mild stress with phasic firing of VTA dopamine neurons converted even resilient mice into susceptible mice.  The Tye et al paper similarly looked at the dopamine modulation of depressive-like behaviors, focusing on motivation with the forced swim tests and open field tests, followed by measurement of anhedonia by quantifyi...
Post a Comment
Read more

Sial & Allsop

By
Sial et al. derived a novel approach for studying what they deem vicarious defeat stress (VSDS) as a model for MDD, PTSD, and other mood-related disorders as an alternative to the classical CSDS paradigm. Using adult male mice, they demonstrate that their model induces a robust and measurable social avoidant phenotype as well as other stress and anxiety related behavioral outputs. Their subsequent rescue study with chronic fluoxetine treatment shows reversal of the behavioral phenotypes and emphasizes the predictive validity of the model. Allsop et al. found that BLA-projecting ACC neurons preferentially encode socially derived aversive cue information by encoding the demonstrator’s distress response during observational learning, hence enabling acquisition of negative valence of cue by BLA neurons and behavioral output. In order to test their hypothesis, Allsop et al. used an observational fear conditional paradigm to create association between a conditioned stimulu...
Post a Comment
Read more