Department of Neuroscience, Central Clinical School, Monash University, Level 6, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia.
Alfred Health, Prahran, VIC, Australia.
Sci Rep. 2022 Sep 1;12(1):14175. doi: 10.1038/s41598-022-18643-5.
While it is well-established that bone responds dynamically to mechanical loading, the effects of mild traumatic brain injury (mTBI) on cranial bone composition are unclear. We hypothesized that repeated mTBI (rmTBI) would change the microstructure of cranial bones, without gross skull fractures. To address this, young adult female Piebald Viral Glaxo rats received sham, 1×, 2× or 3× closed-head mTBIs delivered at 24 h intervals, using a weight-drop device custom-built for reproducible impact. Skull bones were collected at 2 or 10 weeks after the final injury/sham procedure, imaged by micro computed tomography and analyzed at predetermined regions of interest. In the interparietal bone, proximal to the injury site, modest increases in bone thickness were observed at 2 weeks, particularly following 2× and 3× mTBI. By 10 weeks, 2× mTBI induced a robust increase in the volume and thickness of the interparietal bone, alongside a corresponding decrease in the volume of marrow cavities in the diploë region. In contrast, neither parietal nor frontal skull samples were affected by rmTBI. Our findings demonstrate time- and location-dependent effects of rmTBI on cranial bone structure, highlighting a need to consider microstructural alterations to cranial bone when assessing the consequences of rmTBI.
虽然已经明确骨骼会对机械负荷做出动态响应，但轻度创伤性脑损伤（mTBI）对颅骨成分的影响尚不清楚。我们假设，反复 mTBI（rmTBI）会改变颅骨的微观结构，而不会导致明显的颅骨骨折。为了验证这一点，年轻成年雌性 Piebald 病毒性 Glaxo 大鼠接受了假手术、1×、2×或 3×间隔 24 小时的闭合性头部 mTBI，使用专门为可重复冲击而定制的重物坠落装置。在末次损伤/假手术程序后的 2 或 10 周，收集颅骨，通过微计算机断层扫描成像，并在预定的感兴趣区域进行分析。在损伤部位近端的顶骨中，在 2 周时观察到骨厚度的适度增加，特别是在 2×和 3×mTBI 后。到 10 周时，2×mTBI 导致顶骨体积和厚度显著增加，同时骨松质区域的骨髓腔体积相应减少。相比之下，rmTBI 既不会影响顶骨也不会影响额骨。我们的研究结果表明，rmTBI 对颅骨结构具有时间和位置依赖性影响，这强调了在评估 rmTBI 的后果时需要考虑颅骨微观结构的改变。
