Environmental enrichment modulates inflammation during development in long‐evans rats (Rattus norvegicus)

Abstract

It is unknown whether increased production of pro‐inflammatory mediators during the life span is caused by aging per se or via the combination of a cumulative allostatic load due to life challenges. This study aimed to investigate the long‐term effects of stress and environmental enrichment on the inflammatory status associated with aging in rats. Animals were assigned to the following five treatment groups: chronic stress with and without environmental enrichment; acute stress with and without environmental enrichment; control animals. Enrichment was provided as an open field containing novel objects (30 min three times per week). Animals assigned to chronic stress groups were exposed to predator sound stressors (e.g., hawk sound) for 30 min daily, while animals assigned to acute stress groups were exposed once a week for 30 min. The interaction between the hypothalamic–pituitary–adrenal axis and the immune system was investigated by measuring metabolized dehydroepiandrosterone (DHEA) levels and peripheral levels of the cytokines IL‐6 and IL‐10. Results suggested that inflamm‐aging was more pronounced in animals with low DHEA levels, which in turn were affected by exposure to environmental enrichment and acute stress. This study showed that environmental enrichment and acute stress can significantly attenuate disruptions in DHEA production, consequently contributing to improved neuroimmune function of aging animals.

The Impact of Hormesis, Neuronal Stress Response, and Reproduction, upon Clinical Aging: A Narrative Review

“…For instance, some authors have argued that an enriched environment improves vision [ 62 , 63 ], while others reported the benefits of a cognitively enriched environment on: Immunity [ 64 ]; Wound healing [ 65 , 66 ]; The retina [ 67 ]; Muscle strength, without the need to physically exercise (!) [ 68 ]; Inflammatory response [ 69 , 70 ] and other physical parameters [ 71 ], such as vitality, physical functioning and bodily pain, as well as social and emotional functioning [ 72 ]. Many of these effects may persist for several years, in some cases even after a 10 year period [ 73 ].…”

“…Inflammatory response [ 69 , 70 ] and other physical parameters [ 71 ], such as vitality, physical functioning and bodily pain, as well as social and emotional functioning [ 72 ]. Many of these effects may persist for several years, in some cases even after a 10 year period [ 73 ].…”

“…Inflammatory response [69,70] and other physical parameters [71], such as vitality, physical functioning and bodily pain, as well as social and emotional functioning [72].…”

Introduction to the SEED Science special issue

“…Our one paper concerning processes of adulthood and aging by Scarola and Bardi (2022) examined the interaction of environmental stress (hawk sound) and environmental enrichment (open field with novel objects) during aging utilizing HPA axis (DHEA) and immune markers (IL‐6, IL‐10) in rats. Interactions were observed, suggesting that inflammation was more pronounced during aging in animals with low DHEA levels and DHEA levels were influenced by both environmental enrichment and acute stress.…”