Ingestion of probiotic (Lactobacillus helveticus and Bifidobacterium longum) alters intestinal microbial structure and behavioral expression following social defeat stress

AbstractSocial stress exacerbates anxious and depressive behaviors in humans. Similarly, anxiety- and depressive-like behaviors are triggered by social stress in a variety of non-human animals. Here, we tested whether oral administration of the putative anxiolytic probiotic strains Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 reduces the striking increase in anxiety-like behavior and changes in gut microbiota observed following social defeat stress in Syrian hamsters. We administered the probiotic at two different doses for 21 days, and 16S rRNA gene amplicon sequencing revealed a shift in microbial structure following probiotic administration at both doses, independently of stress. Probiotic administration at either dose increased anti-inflammatory cytokines IL-4, IL-5, and IL-10 compared to placebo. Surprisingly, probiotic administration at the low dose, equivalent to the one used in humans, significantly increased social avoidance and decreased social interaction. This behavioral change was associated with a reduction in microbial richness in this group. Together, these results demonstrate that probiotic administration alters gut microbial composition and may promote an anti-inflammatory profile but that these changes may not promote reductions in behavioral responses to social stress.

Download Full-text

Stress-induced sleep-like inactivity modulates stress susceptibility in mice

Scientific Reports ◽

10.1038/s41598-020-76717-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Midori Nagai ◽

Hirotaka Nagai ◽

Chisato Numa ◽

Tomoyuki Furuyashiki

Keyword(s):

Sleep Deprivation ◽

Social Stress ◽

Social Interest ◽

Social Behaviors ◽

Social Defeat ◽

Brain Regions ◽

Social Characteristics ◽

Social Avoidance ◽

Social Defeat Stress ◽

Positive Valence

AbstractSevere environmental and social stress induces dysregulation of sleep along with mood and cognitive disturbances. However, the role and mechanism of this sleep dysregulation remain elusive. Here we evaluated sleep-like inactivity measured by voluntary movements and its relationship to social behaviors in mice without or with social defeat stress as well as the stressed mice with subsequent sleep deprivation. Social defeat stress immediately induced sleep-like inactivity with decreased body temperature. In the social interaction test, the control mice showed high social interest and its correlation with social sniffing intensity, the latter of which indicates positive valence of social sniffing. After the stress, these social characteristics were maintained in stress-resilient mice, but disrupted in stress-susceptible mice, leading to social avoidance. Sleep deprivation after the stress decreased social sniffing intensity along with reduced social interest, but enhanced the exploratory activity with the positive valence of social sniffing. We also found by c-Fos immunohistochemistry that the stress activated sleep-related brain regions, the dorsomedial hypothalamus and ventrolateral periaqueductal gray. Collectively, these findings show that stress activates sleep-related brain regions and induces sleep-like inactivity, contributing to multiple roles of stress-induced sleep for social behaviors.

Download Full-text

Hop Bitter Acids Increase Hippocampal Dopaminergic Activity in a Mouse Model of Social Defeat Stress

International Journal of Molecular Sciences ◽

10.3390/ijms21249612 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9612

Author(s):

Yasuhisa Ano ◽

Shiho Kitaoka ◽

Rena Ohya ◽

Keiji Kondo ◽

Tomoyuki Furuyashiki

Keyword(s):

Mouse Model ◽

Chronic Administration ◽

Social Defeat ◽

Underlying Mechanism ◽

Mental Illnesses ◽

Social Avoidance ◽

Social Defeat Stress ◽

Dopaminergic Activity ◽

Healthy Older Adults ◽

Bitter Acids

As daily lifestyle is closely associated with mental illnesses, diet-based preventive approaches are receiving attention. Supplementation with hop bitter acids such as iso-α-acids (IAA) and mature hop bitter acids (MHBA) improves mood states in healthy older adults. However, the underlying mechanism remains unknown. Since acute oral consumption with IAA increases dopamine levels in hippocampus and improves memory impairment via vagal nerve activation, here we investigated the effects of chronic administration of hop bitter acids on the dopaminergic activity associated with emotional disturbance in a mouse model of repeated social defeat stress (R-SDS). Chronic administration of IAA and MHBA significantly increased dopaminergic activity based on the dopamine metabolite to dopamine ratio in the hippocampus and medial prefrontal cortex following R-SDS. Hippocampal dopaminergic activity was inversely correlated with the level of R-SDS-induced social avoidance with or without IAA administration. Therefore, chronic treatment with hop bitter acids enhances stress resilience-related hippocampal dopaminergic activity.

Download Full-text

Knockdown of ventral tegmental area mu-opioid receptors in rats prevents effects of social defeat stress: Implications for amphetamine cross-sensitization, social avoidance, weight regulation and expression of brain-derived neurotrophic factor

Neuropharmacology ◽

10.1016/j.neuropharm.2014.10.010 ◽

2015 ◽

Vol 89 ◽

pp. 325-334 ◽

Cited By ~ 13

Author(s):

Caitlin E. Johnston ◽

Daniel J. Herschel ◽

Amy W. Lasek ◽

Ronald P. Hammer ◽

Ella M. Nikulina

Keyword(s):

Ventral Tegmental Area ◽

Opioid Receptors ◽

Neurotrophic Factor ◽

Social Defeat ◽

Brain Derived Neurotrophic Factor ◽

Weight Regulation ◽

Social Avoidance ◽

Mu Opioid Receptors ◽

Social Defeat Stress ◽

Mu Opioid

Download Full-text

Unique effects of social defeat stress in adolescent male mice on the Netrin-1/DCC pathway, prefrontal cortex dopamine and cognition (Social stress in adolescent vs. adult male mice)

eNeuro ◽

10.1523/eneuro.0045-21.2021 ◽

2021 ◽

pp. ENEURO.0045-21.2021

Author(s):

Philip Vassilev ◽

Andrea Haree Pantoja-Urban ◽

Michel Giroux ◽

Dominique Nouel ◽

Giovanni Hernandez ◽

...

Keyword(s):

Prefrontal Cortex ◽

Adult Male ◽

Social Stress ◽

Social Defeat ◽

Adolescent Male ◽

Male Mice ◽

Social Defeat Stress

Download Full-text

Dysfunction in Ribosomal Gene Expression in the Hypothalamus and Hippocampus following Chronic Social Defeat Stress in Male Mice as Revealed by RNA-Seq

Neural Plasticity ◽

10.1155/2016/3289187 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 22

Author(s):

Dmitry A. Smagin ◽

Irina L. Kovalenko ◽

Anna G. Galyamina ◽

Anatoly O. Bragin ◽

Yuriy L. Orlov ◽

...

Keyword(s):

Gene Expression ◽

Social Stress ◽

Ribosome Biogenesis ◽

Social Defeat ◽

Brain Regions ◽

Ribosomal Gene ◽

Rna Seq ◽

Male Mice ◽

Social Defeat Stress ◽

Chronic Social Defeat Stress

Chronic social defeat stress leads to the development of anxiety- and depression-like states in male mice and is accompanied by numerous molecular changes in brain. The influence of 21-day period of social stress on ribosomal gene expression in five brain regions was studied using the RNA-Seq database. MostRps, Rpl, Mprs, andMprlgenes were upregulated in the hypothalamus and downregulated in the hippocampus, which may indicate ribosomal dysfunction following chronic social defeat stress. There were no differentially expressed ribosomal genes in the ventral tegmental area, midbrain raphe nuclei, or striatum. This approach may be used to identify a pharmacological treatment of ribosome biogenesis abnormalities in the brain of patients with “ribosomopathies.”

Download Full-text