Mengler Luam, Khmelinskii Artem, Diedenhofen Michael, Po Chrystelle, Staring Marius, Lelieveldt Boudewijn P F, Hoehn Mathias
In-vivo-NMR Laboratory, Max Planck Institute for Neurological Research, Cologne, Germany.
Neuroimage. 2014 Jan 1;84:35-44. doi: 10.1016/j.neuroimage.2013.08.034. Epub 2013 Aug 27.
Longitudinal studies on brain pathology and assessment of therapeutic strategies rely on a fully mature adult brain to exclude confounds of cerebral developmental changes. Thus, knowledge about onset of adulthood is indispensable for discrimination of developmental phase and adulthood. We have performed a high-resolution longitudinal MRI study at 11.7T of male Wistar rats between 21days and six months of age, characterizing cerebral volume changes and tissue-specific myelination as a function of age. Cortical thickness reaches final value at 1month, while volume increases of cortex, striatum and whole brain end only after two months. Myelin accretion is pronounced until the end of the third postnatal month. After this time, continuing myelination increases in cortex are still seen on histological analysis but are no longer reliably detectable with diffusion-weighted MRI due to parallel tissue restructuring processes. In conclusion, cerebral development continues over the first three months of age. This is of relevance for future studies on brain disease models which should not start before the end of month 3 to exclude serious confounds of continuing tissue development.
关于脑病理学的纵向研究以及治疗策略的评估依赖于完全成熟的成年大脑，以排除大脑发育变化带来的干扰因素。因此，对于区分发育阶段和成年期而言，了解成年期的起始时间是必不可少的。我们对21日龄至6月龄的雄性Wistar大鼠进行了一项11.7T的高分辨率纵向MRI研究，将脑容量变化和组织特异性髓鞘形成作为年龄的函数进行表征。皮质厚度在1个月时达到最终值，而皮质、纹状体和全脑的体积增加在两个月后才结束。髓鞘增生在出生后第三个月末之前都很明显。在此之后，组织学分析仍可观察到皮质中持续的髓鞘形成增加，但由于平行的组织重构过程，扩散加权MRI不再能可靠地检测到这种增加。总之，大脑发育在出生后的前三个月持续进行。这对于未来关于脑疾病模型的研究具有重要意义，这些研究不应在第三个月末之前开始，以排除持续组织发育带来的严重干扰因素。
