Although human females appear be at a higher risk of concussion and suffer worse outcomes than males, underlying mechanisms remain unclear. With increasing recognition that damage to white matter axons is a key pathologic substrate of concussion, we used a clinically relevant swine model of concussion to explore potential sex differences in the extent of axonal pathologies. At 24 h post-injury, female swine displayed a greater number of swollen axonal profiles and more widespread loss of axonal sodium channels than males. Axon degeneration for both sexes appeared to be related to individual axon architecture, reflected by a selective loss of small caliber axons after concussion. However, female brains had a higher percentage of small caliber axons, leading to more extensive axon loss after injury compared to males. Accordingly, sexual dimorphism in axonal size is associated with more extensive axonal pathology in females after concussion, which may contribute to worse outcomes.

尽管人类女性患脑震荡的风险似乎比男性更高，而且后果更糟，但其潜在机制仍不清楚。随着人们越来越认识到白质轴突损伤是脑震荡的关键病理基础，我们使用临床相关的猪脑震荡模型来探索轴突病理范围的潜在性别差异。受伤后 24 小时，雌性猪比雄性猪表现出更多的轴突肿胀和更广泛的轴突钠通道损失。两性的轴突变性似乎与个体轴突结构有关，这反映在脑震荡后小口径轴突的选择性丧失。然而，与男性相比，女性大脑中小口径轴突的比例更高，导致受伤后轴突损失更广泛。因此，轴突大小的性别二态性与女性脑震荡后更广泛的轴突病理有关，这可能导致更糟糕的结果。