Yang Shu, Lu Wei, Zhou De-shan, Tang Yong
Department of Histology and Embryology, Capital Medical University, Beijing 100069, PR China.
Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Department of Pediatrics, Navy General Hospital, Beijing 100048, PR China.
Neurosci Lett. 2015 Apr 23;593:66-71. doi: 10.1016/j.neulet.2015.03.025. Epub 2015 Mar 18.
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.
认知和记忆会随着正常衰老而衰退，这可能部分归因于脑白质的退化。先前的研究表明，置身于丰富环境（EE）中可以保护认知和记忆免受衰老影响。然而，EE是否以及如何影响脑白质尚未得到充分研究。在当前研究中，将24只中年（14个月大）雌性斯普拉格-道利（SD）大鼠随机分配到EE组或标准环境（SE）组，为期4个月。在环境干预结束时，进行莫里斯水迷宫测试。然后，从每组中随机选取5只大鼠，对脑白质及其有髓纤维进行体视学评估。结果显示，生活在EE环境中的中年大鼠比SE对照组表现出更好的空间学习能力。EE组大鼠的白质体积为124.6±7.8mm³，与SE组大鼠的84.8±3.4mm³相比显著增大。同样，有髓纤维体积从SE组大鼠的56.6±1.7mm³显著增加到EE组大鼠的87.2±9.0mm³；有髓纤维长度也从SE组大鼠的83.5±6.6km增加到EE组大鼠的119.0±10.0km。我们的数据表明，EE可以保护中年雌性大鼠的脑白质及其有髓纤维。
