Xue Jing-Hui, Yanamoto Hiroji, Nakajo Yukako, Tohnai Norimitsu, Nakano Yoshikazu, Hori Takuya, Iihara Koji, Miyamoto Susumu
Lab for Cerebrovascular Disorders, Research Institute of National Cardio-Vascular Center, Suita, Osaka, Japan.
Stroke. 2009 Nov;40(11):e606-13. doi: 10.1161/STROKEAHA.109.560334. Epub 2009 Sep 24.
New immature neurons appear out of the germinative zone, in cortical Layers V to VI, after induced spreading depression in the adult rat brain. Because neural progenitors have been isolated in the cortex, we set out to determine whether a subgroup of mature cells in the adult cortex has the potential to divide and generate neural precursors.
We examined the expression of endogenous markers of mitotic activity, proliferating cell nuclear antigen, and vimentin as a marker for neuronal progenitor cells, if any, in the adult rat cortex after spreading depression stimulation. Immunohistochemical analysis was also performed using antibodies for proliferating cell nuclear antigen, for vimentin, and for nestin. Nestin is a marker for activity dividing neural precursors.
At the end of spreading depression (Day 0), glial fibrillary acidic protein-positive cells in the subpial zone and cortical Layer I demonstrated increased mitotic activity, expressing vimentin and nestin. On Day 1, nestin(+) cells were found spreading in deeper cortical layers. On Day 3, vimentin(-)/nestin(+), neural precursor-like cells appeared in cortical Layers V to VI. On Day 6, new immature neurons appeared in cortical Layers V to VI. Induced spreading depression evokes cell division of astrocytes residing in the subpial zone, generating neural precursor-like cells.
Although neural precursor-like cells found in cortical Layers V to VI might have been transferred from the germinative zone rather than the cortical subpial zone, astrocytic cells in the subpial zone may be potent neural progenitors that can help to reconstruct impaired central nervous system tissue. Special caution is required when observing or treating spreading depression waves accompanying pathological conditions in the brain.
在成年大鼠脑内诱发扩散性抑制后，新的未成熟神经元会从生发区出现，位于皮质的V层至VI层。由于已在皮质中分离出神经祖细胞，我们着手确定成年皮质中的一个成熟细胞亚群是否具有分裂并产生神经前体细胞的潜力。
我们检测了成年大鼠皮质在扩散性抑制刺激后有丝分裂活性的内源性标志物增殖细胞核抗原（PCNA）以及波形蛋白（作为神经元祖细胞的标志物，如果存在的话）的表达。还使用了针对PCNA、波形蛋白和巢蛋白的抗体进行免疫组织化学分析。巢蛋白是活跃分裂的神经前体细胞的标志物。
在扩散性抑制结束时（第0天），软脑膜下区和皮质I层中胶质纤维酸性蛋白阳性细胞的有丝分裂活性增加，表达波形蛋白和巢蛋白。在第1天，发现巢蛋白阳性细胞在皮质更深层扩散。在第3天，波形蛋白阴性/巢蛋白阳性的神经前体细胞样细胞出现在皮质V层至VI层。在第6天，新的未成熟神经元出现在皮质V层至VI层。诱发扩散性抑制可引发软脑膜下区星形胶质细胞的细胞分裂，产生神经前体细胞样细胞。
虽然在皮质V层至VI层发现的神经前体细胞样细胞可能是从生发区而非皮质软脑膜下区转移而来，但软脑膜下区的星形胶质细胞可能是强大的神经祖细胞，有助于重建受损的中枢神经系统组织。在观察或治疗伴随脑部病理状况的扩散性抑制波时需要格外谨慎。
