Validation of a psychosocial chronic stress model in the pig using a multidisciplinary approach at the gut-brain and behavior levels

Abstract : Psychological chronic stress is an important risk factor for major depressive disorder, of which consequences have been widely studied in rodent models. This work aimed at describing a pig model of chronic stress based on social isolation, environmental impoverishment and unpredictability. Three groups of animals of both sexes were constituted. Two were exposed to the psychosocial stressors while receiving (SF, n = 12) or not (SC, n = 22) the antidepressant fluoxetine, and a third group (NSC, n = 22) remained unstressed. Animals were observed in home pens and during dedicated tests to assess resignation and anxiety-like behaviors. Brain structure and function were evaluated via proton MRS and fMRI. Hippocampal molecular biology and immunodetection of cellular proliferation (Ki67+) and neuron maturation (DCX+) in the dentate gyrus were also performed. Salivary cortisol, fecal short-chain fatty acids (SCFAs), and various plasmatic and intestinal biomarkers were analyzed. Compared to NSC, SC animals showed more resignation (p = 0.019) and had a higher level of salivary cortisol (p = 0.020). SC brain responses to stimulation by a novel odor were lower, similarly to their hippocampal neuronal density (p = 0.015), cellular proliferation (p = 0.030), and hippocampal levels of BDNF and 5-HT1AR (p = 0.056 and p = 0.007, respectively). However, the number of DCX+ cells was higher in the ventral dentate gyrus in this group (p = 0.025). In addition, HOMA-IR was also higher (p < 0.001) and microbiota fermentation activity was lower (SCFAs, SC/NSC: p < 0.01) in SC animals. Fluoxetine partially or totally reversed several of these effects. Exposure to psychosocial stressors in the pig model induced effects consistent with the human and rodent literature, including resignation behavior and alterations of the HPA axis and hippocampus. This model opens the way to innovative translational research exploring the mechanisms of chronic stress and testing intervention strategies with good face validity related to human.
Document type :
Journal articles
Complete list of metadatas

Cited literature [103 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-02263855
Contributor : Archive Ouverte Prodinra <>
Submitted on : Monday, August 5, 2019 - 8:07:11 PM
Last modification on : Thursday, August 8, 2019 - 1:12:34 AM

File

fnbeh-13-00161.pdf
Explicit agreement for this submission

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Citation

Sophie Menneson, Samuel Ménicot, Stéphanie Ferret-Bernard, Sylvie Guerin, Véronique Rome, et al.. Validation of a psychosocial chronic stress model in the pig using a multidisciplinary approach at the gut-brain and behavior levels. Frontiers in Behavioral Neuroscience, Frontiers, 2019, 13, ⟨10.3389/fnbeh.2019.00161⟩. ⟨hal-02263855⟩

Share

Metrics

Record views

14

Files downloads

16