Environmental enrichment reverses proulcerogenic action of social isolation on the gastric mucosa and increases resilience to pain stimuli and working capacity in a treadmill
Authors: Filaretova Ludmila , Komkova Olga , Morozova Olga , Punina Polina , Yarushkina Natalia 
Published: May 2023

Social isolation (SI) negatively influences on a wide range of physiological function and behavior. Environmental enrichment (EE) that provides high sensory, motor, cognitive, and social stimulation can be one of approaches to modify or even reverse the negative consequences of SI. The aim of the study was to investigate the effect of housing keeping of rats – standard conditions (SC), social isolation (SI), environmental enrichment (EE) - and the subsequent reversion of these conditions on the vulnerability of the gastric mucosa to the action of ulcerogenic stimuli, somatic pain sensitivity and working capacity. The rats aged 30 days were divided into groups and placed in standard cages 6 rats per cage (standard conditions) or 1 rats per cage (isolation) or in enriched cages 6 rats per cage (environment enrichment) for 4 weeks. Then, housing conditions were reversed for half of the rats in each group following manner: isolated rats were placed in EE, rats kept in EE were moved to SI and rats kept in SC were moved to SI. The second half of the rats (control) were kept under initial conditions for all time of experiment. Two weeks after reversion the vulnerability of the gastric mucosa to action of ulcerogenic stimuli (indomethacin) as well as somatic pain sensitivity (hot plate test) and working capacity (the running distance in a treadmill, 9 m/min, 0 decline, for 30 min) were evaluated in control and reversed groups. Indomethacin (IM, 35 mg/kg, sc) administration caused the gastric erosion 2 h after injection in preliminary fasting (24 h) rats. In control rats (without reversion of housing conditions) SI resulted in an increase of mean area of gastric erosions (proulcerogenic effect) compared to that of SC and EE groups. Moving rats from SI to EE reverses the proulcerogenic action induced by SI. On the contrary, transfer rats from EE to SI exacerbated ulcerogenic action of IM. Control rats kept in EE as well as SI showed an increase in paw licking latency (PLL) in hot plate test compared to that of rats in SC, but PLLs in EE group were higher than that in SI group. Reversion of housing keeping eliminated the differences between PLL in rat placed in EE and SI. Rats kept in EE had the longest running distance in a treadmill compared to that in other groups. Reversion of housing keeping decreased running distance and eliminated the differences between the groups. Effects of housing keeping and following reversion of the conditions were dependent on the environmental conditions (temperature). The data obtained suggest that EE can reverse the proulcerogenic action of SI, increase the resistance to thermic pain stimuli and working capacity in a treadmill. The study was supported by the Ministry of Education and Science of the Russian Federation (agreement No. 075-15-2020-921 for the creation and development of the world-class scientific center “Pavlov Center “Integrative Physiology - to medicine, high-tech healthcare and technologies of stress resistance ”). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.