Taguchi Daisuke, Ehara Ayuka, Seo Yoshiteru, Ueda Shuichi
Department of Judo Therapy, Faculty of Medical Technology, Teikyo University, Utsunomiya, Tochigi 320-8551, Japan.
Department Histology and Neurobiology, Dokkyo Medical University, School of Medicine, Shimotsuga, Tochigi 321-0293, Japan.
Acta Histochem Cytochem. 2020 Aug 26;53(4):83-91. doi: 10.1267/ahc.20007. Epub 2020 Aug 6.
Previous studies have shown that neonatal shaking brain injury (SBI) causes transient microhemorrhages (MHs) in the gray matter of the cerebral cortex and hippocampus. Iron deposits and iron-uptake cells are observed surrounding MHs in this SBI model, suggesting local hypoxic-ischemic conditions. However, whether the shaken pups suffered systemic hypoxic-ischemic conditions has remained uncertain. Further, histopathological correlations of MHs on magnetic resonance imaging (MRI) are still unclear. The present study examined MHs after neonatal SBI using a combination of histochemical and susceptibility-weighted imaging (SWI) analyses. Systemic oxygen saturation analyses indicated no significant difference between shaken and non-shaken pups. MHs on postnatal day 4 (P4) pups showed decreased signal intensity on SWI. Iron histochemistry revealed that these hypointense areas almost completely comprised red blood cells (RBCs). MHs that appeared on P4 gradually disappeared by P7-12 on SWI. These resolved areas contained small numbers of RBCs, numerous iron-positive cells, and punctate regions with iron reaction products. Perivascular iron products were evident after P12. These changes progressed faster in the hippocampus than in cortical areas. These changes in MHs following neonatal SBI may provide new insights into microvascular pathologies and impacts on brain functions as adults.
先前的研究表明，新生儿摇晃脑损伤（SBI）会在大脑皮层和海马体的灰质中引起短暂性微出血（MHs）。在该SBI模型中，在微出血周围观察到铁沉积和铁摄取细胞，提示局部存在缺氧缺血状态。然而，遭受摇晃的幼崽是否存在全身性缺氧缺血状态仍不确定。此外，微出血在磁共振成像（MRI）上的组织病理学相关性仍不明确。本研究结合组织化学和磁敏感加权成像（SWI）分析，对新生儿SBI后的微出血进行了研究。全身血氧饱和度分析表明，摇晃组和未摇晃组幼崽之间无显著差异。出生后第4天（P4）幼崽的微出血在SWI上显示信号强度降低。铁组织化学显示，这些低信号区域几乎完全由红细胞（RBCs）组成。P4时出现的微出血在SWI上到P7 - 12时逐渐消失。这些消退区域含有少量红细胞、大量铁阳性细胞以及有铁反应产物的点状区域。P12后血管周围铁产物明显。这些变化在海马体中比在皮质区域进展更快。新生儿SBI后微出血的这些变化可能为微血管病变以及对成年后脑功能的影响提供新的见解。
