The influence of intestinal microbiota on cognitive abilities of laboratory Wistar rats

Purpose: to identify antibiotic-associated behavioral disorders in white laboratory rats using an elevated plus maze and an open field. The work is aimed at establishing a possible correlation between intestinal microflora disorders and anxious or exploratory reactions of animals.

Materials and methods. The object of the study were six-month-old male and female white laboratory rats of the Wistar line breed weighing 400–410 g. Four groups of animals were formed, with ten individuals in each group: group No. 1 (males) and group No. 3 (females) were the control part of the experiment; group No. 2 (males) and group No. 4 (females) were the experimental part of the study. The animals of the experimental groups were given an antibacterial drug of the semi-synthetic penicillin group — "Amoxiclav". At the end of antibiotic therapy, feces from the litter were cultured. To assess the correlation of intestinal dysbiotic changes on the cognitive functions of rats, the "open field" and "elevated plus maze" methods were used.

Results. The study demonstrated that long-term use of the antibiotic Amoxiclav (0,02 ml/individual for 10 days) in white laboratory rats led to significant structural and functional changes in the composition of the intestinal microflora, which, in turn, was accompanied by stable behavioral changes. Against the background of microbiological changes in the open field test, rats from the experimental group (males and females) demonstrated a noticeable decrease in overall motor and exploratory activity. In addition to decreased activity, antibiotic-dependent rats showed signs of anxiety: the number of grooming episodes increased (in males). In the elevated plus maze test, the behavioral profile of rats from the experimental groups also corresponded to increased anxiety.

Conclusion. The results of the work confirm the hypothesis about the influence of the state of the intestinal microflora on the brain and prove that even a short course of antibiotics can cause stable behavioral changes through the mechanism of dysbiosis.

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