Anxiety-like Behavior in Female Sprague Dawley Rats Associated with Cecal Clostridiales

Abstract

The relationship between the microbiota profile and exposure to stress is not well understood. Therefore, we used a rat model of unpredictable chronic mild stress (UCMS) to investigate this relationship. Depressive-like behaviors were measured in Female Sprague Dawley rats using the sucrose preference test and the Porsolt swim test. Anxiety-like behaviors were measured with the light–dark box test. Fecal corticosterone, cecal microbiota (composition and organic acids), plasma gut permeability (lipopolysaccharide-binding protein, LBP) and plasma inflammation (12 cytokines) markers were measured. Atypical behaviors were observed in female rats following UCMS, but no depressive-like behaviors were observed. Circulating concentrations of cytokines granulocyte-macrophage colony-stimulating factor and cytokine-induced neutrophil chemoattractant 1 were higher in UCMS-exposed female rats; plasma LBP and cecal organic acid levels remained unchanged. Our results reflect a resilient and adaptive phenotype for female SD rats. The relative abundance of taxa from the Clostridiales order and Desulfovibrionaceae family did, however, correlate both positively and negatively with anxiety-like behaviors and plasma cytokine concentrations, regardless of UCMS exposure, supporting the brain-to-gut influence of mild anxiety with a microbiota profile that may involve inflammatory pathways.

Dose-Dependent Beneficial Effect of Ketone Supplement-Evoked Ketosis on Anxiety Level in Female WAG/Rij Rats: Sometimes Less Is More

“…However, the current study aimed to further validate and extend our previous studies on the effects of ketone supplementation on anxiety levels in similarly aged male WAG/Rij rats [9,14]. While the LDB test is a commonly used method for the investigation of anxiety levels in rats [22,63,64], and the LDB test is frequently used alone to investigate anxiety-like behavior [25,28,65], additional studies using other age groups and methods will be needed to further evaluate the current results. It also needs to be considered that the results of the behavioral testing may be affected by the strain and estrous cycle of animals, as well as the drug delivery method [21], and these potential influencing factors were not considered in this study.…”