Short-Term Environmental Enrichment is a Stronger Modulator of Brain Glial Cells and Cervical Lymph Node T Cell Subtypes than Exercise or Combined Exercise and Enrichment

• Published in: Cellular and molecular neurobiology Vol. 41; no. 3; pp. 469 - 486
• Main Authors: Singhal, Gaurav, Morgan, Julie, Corrigan, Frances, Toben, Catherine, Jawahar, Magdalene C., Jaehne, Emily J., Manavis, Jim, Hannan, Anthony J., Baune, Bernhard T.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2021; Springer Nature B.V
• Subjects: Aging; Animals; Antigens, CD - metabolism; Astrocytes; Astrocytes - cytology; Biomarkers - metabolism; Biomedical and Life Sciences; Biomedicine; Brain - cytology; Calcium-Binding Proteins - metabolism; CD4 antigen; CD8 antigen; Cell Biology; Cervical Vertebrae - cytology; Dentate gyrus; Dentate Gyrus - metabolism; Effector cells; Enrichment; Environment; Flow cytometry; Glial cells; Glial Fibrillary Acidic Protein - metabolism; Immunohistochemistry; Immunophenotyping; Lymph nodes; Lymph Nodes - cytology; Lymphocytes; Lymphocytes T; Memory cells; Mice; Mice, Inbred C57BL; Microfilament Proteins - metabolism; Microglia; Neurobiology; Neuroglia - cytology; Neurosciences; Original Research; Physical Conditioning, Animal; Physical training; T-Lymphocytes - immunology; Wheel running; Physical exercise; Aging; T cells; Astrocytes; Environmental enrichment; Microglia
• ISSN: 0272-4340; 1573-6830
• DOI: 10.1007/s10571-020-00862-x

Physical exercise (PE) and environmental enrichment (EE) can modulate immunity. However, the differential effects of short-term PE, EE, and PE + EE on neuroimmune mechanisms during normal aging has not been elucidated. Hence, a cohort of 3-, 8-, and 13-month-old immunologically unchallenged C57BL/6 wild-type mice were randomly assigned to either Control, PE, EE, or PE + EE groups and provided with either no treatment, a running wheel, a variety of plastic and wooden objects alone or in combination with a running wheel for seven weeks, respectively. Immunohistochemistry and 8-color flow cytometry were used to determine the numbers of dentate gyrus glial cells, and the proportions of CD4 + and CD8 + T cell numbers and their subsets from cervical lymph nodes, respectively. An increase in the number of IBA1 + microglia in the dentate gyrus at 5 and 10 months was observed after EE, while PE and PE + EE increased it only at 10 months. No change in astroglia number in comparison to controls were observed in any of the treatment groups. Also, all treatments induced significant differences in the proportion of specific T cell subsets, i.e., CD4 + and CD8 + T naïve (T N ), central memory (T CM ), and effector memory (T EM ) cells. Our results suggest that in the short-term, EE is a stronger modulator of microglial and peripheral T cell subset numbers than PE and PE + EE, and the combination of short-term PE and EE has no additive effects.