Previous postmortem and animal studies have shown decreases in the prefrontal cortex (PFC) volume and the number of glial cells in the PFC of depression. Running exercise has been shown to alleviate depressive symptoms. However, the effects of running exercise on the medial prefrontal cortex (mPFC) volume and oligodendrocytes in the mPFC of depressed patients and animals have not been investigated. To address these issues, adult male rats were subjected to chronic unpredictable stress (CUS) for 5 weeks, followed by treadmill running for 6 weeks. Then, the mPFC volume and the mPFC oligodendrocytes were investigated using stereology, immunohistochemistry, immunofluorescence and western blotting. Using a CUS paradigm that allowed for the analysis of anhedonia, we found that running exercise alleviated the deficits in sucrose preference, as well as the decrease in the mPFC volume. Meanwhile, we found that running exercise significantly increased the number of CNPase+ oligodendrocytes and Olig2+ oligodendrocytes, reduced the ratio between Olig2+/NG2+ oligodendrocytes and Olig2+ oligodendrocytes and increased myelin basic protein (MBP), CNPase and Olig2 protein expression in the mPFC of the CUS rat model. However, running exercise did not change NG2+ oligodendrocyte number in the mPFC in these rats. These results indicated that running exercise promoted the differentiation of oligodendrocytes and myelin-forming ability in the mPFC in the context of depression. These findings suggest that the beneficial effects of running exercise on mPFC volume and oligodendrocytes in mPFC might be an important structural basis for the antidepressant effects of running exercise.

中文翻译：

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在慢性不可预测的应激大鼠模型中，跑步运动可以保护内侧前额叶皮质中的少突胶质细胞。

先前的验尸和动物研究表明，抑郁症的前额叶皮质 (PFC) 体积和 PFC 中神经胶质细胞数量减少。跑步锻炼已被证明可以减轻抑郁症状。然而，跑步运动对抑郁症患者和动物的内侧前额叶皮层 (mPFC) 体积和 mPFC 中少突胶质细胞的影响尚未得到研究。为了解决这些问题，成年雄性大鼠接受了 5 周的慢性不可预知压力 (CUS)，然后在跑步机上跑步 6 周。然后，使用体视学、免疫组织化学、免疫荧光和蛋白质印迹法研究 mPFC 体积和 mPFC 少突胶质细胞。使用允许分析快感缺乏的 CUS 范例，我们发现跑步锻炼减轻了蔗糖偏好的缺陷，以及 mPFC 体积的减少。同时，我们发现跑步运动显着增加了 CUS 大鼠 mPFC 中 CNPase+ 少突胶质细胞和 Olig2+ 少突胶质细胞的数量，降低了 Olig2+/NG2+ 少突胶质细胞与 Olig2+ 少突胶质细胞的比例，增加了髓鞘碱性蛋白（MBP）、CNPase 和 Olig2 蛋白的表达模型。然而，跑步运动并没有改变这些大鼠 mPFC 中 NG2+ 少突胶质细胞的数量。这些结果表明，在抑郁症的背景下，跑步运动促进了 mPFC 中少突胶质细胞的分化和髓鞘形成能力。这些发现表明，跑步运动对 mPFC 体积和 mPFC 中少突胶质细胞的有益影响可能是跑步运动抗抑郁作用的重要结构基础。