Müller T
Department of Anatomy, University of Mainz, Germany.
Ital J Anat Embryol. 1995 Jul-Sep;100(3):179-87.
The distribution pattern of methylene blue in the murine hippocampus after supravital dye application was studied light and electron microscopically. The characteristic, selective staining of nerve cell subpopulations occurred only in the presence of oxygen. Solitary or grouped polymorph neurons, i.e. non-pyramidal nerve cells, mainly located in the stratum pyramidale and stratum oriens of the cornu Ammonis were intensely stained. Ultrastructurally, the dye could easily be identified as an electron dense precipitate. MB had accumulated within the cytoplasm with no apparent association with cell organelles and was additionally also found within the nucleus. Precipitate was also detected within profiles of nerve cell processes. MB seemed to accumulate at the plasma membrane in the early phase of staining. The ultrastructure of the stained cells was significantly damaged by the intracellularly bound dye. This oxygen-dependent selective staining is probably followed by the generation of reactive oxygen species and subsequent oxidative stress for the neurons; this phenomenon suggests a strong affinity of a subpopulation of non-pyramidal cells in the cornu Ammonis to oxygen and therefore a high vulnerability to hypoxia.
在活体染色后，通过光学显微镜和电子显微镜研究了亚甲蓝在小鼠海马体中的分布模式。神经细胞亚群的特征性、选择性染色仅在有氧的情况下发生。主要位于海马角锥体层和原层的单个或成群的多形神经元，即非锥体神经细胞，被强烈染色。在超微结构上，该染料很容易被鉴定为电子致密沉淀物。亚甲蓝积聚在细胞质内，与细胞器无明显关联，并且在细胞核内也有发现。在神经细胞突起的轮廓内也检测到沉淀物。在染色早期，亚甲蓝似乎积聚在质膜处。细胞内结合的染料严重破坏了染色细胞的超微结构。这种氧依赖性选择性染色可能随后会产生活性氧并对神经元造成氧化应激；这种现象表明海马角中非锥体细胞亚群对氧具有很强的亲和力，因此对缺氧高度敏感。
