title: Enriched environment increases myelinated fiber volume and length in brain white matter of 18-month female rats.
abstract: Cognition and memory decline with normal aging, which could be partly attributed to the degeneration of brain white matter. Previous studies demonstrated that exposure to an enriched environment (EE) could protect cognition and memory from aging. However, if or how EE might affect the brain white matter has not been thoroughly investigated. In the current study, 24 middle-aged (14-month-old) female Sprague -Dawley (SD) rats were randomly assigned to EE or standard environment (SE) for 4 months. At the end of the environment intervention, the Morris water maze tests were performed. Then, 5 rats were randomly selected from each group for stereological assessment of the brain white matter and its myelinated fibers. The results revealed that middle-aged rats living in EE displayed better spatial learning than SE controls. The white matter volume was 124.6 ± 7.8mm(3) in EE rats, which was significantly enlarged compared with 84.8 ± 3.4mm(3) in SE rats. Likewise, the myelinated fiber volume was markedly increased from 56.6 ± 1.7 mm(3) in SE rats to 87.2 ± 9.0mm(3) in EE rats; so was the myelinated fiber length from 83.5 ± 6.6 km in SE rats to 119.0 ± 10.0 km in EE rats. Our data suggested that EE could protect brain white matter and its myelinated fibers of female rats at middle age.
authors: Department of Histology and Embryology, Capital Medical University, Beijing 100069, PR China.
authors: Shu
authors: S
authors: Yang
authors: Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Department of Pediatrics, Navy General Hospital, Beijing 100048, PR China.
authors: Wei
authors: W
authors: Lu
authors: Department of Histology and Embryology, Capital Medical University, Beijing 100069, PR China. Electronic address: zhoudeshan2008@163.com.
authors: De-shan
authors: DS
authors: Zhou
authors: Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China. Electronic address: ytang062@163.com.
authors: Yong
authors: Y
authors: Tang
mesh_terms: D000375:Aging; D000818:Animals; D004777:Environment; D005260:Female; D018782:Maze Learning; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*; D017207:Rats, Sprague-Dawley; D065853:Spatial Learning; D066127:White Matter / Q000648:ultrastructure*
keywords: Enriched environment; Middle age; Myelinated fiber; Stereology; White matter