Mori Fumiaki, Tanji Kunikazu, Yoshida Yasuji, Wakabayashi Koichi
Department of Neuropathology, Institute of Brain Science, Hirosaki University School of Medicine, Japan.
Neuropathology. 2002 Sep;22(3):186-93. doi: 10.1046/j.1440-1789.2002.00445.x.
Congenitally hydrocephalic HTX rats develop ventricular dilatation with extensive damage of the cerebral white matter. Recently, we have reported that neuronal cell death also occurs in the thalamus of HTX rats. To investigate the mechanism underlying this thalamic degeneration in these animals, we carried out a histopathological study of the brain at different phases of postnatal development. Eosinophilic neurons with condensed chromatin or fragmented nuclei were observed in the thalamus from postnatal day 17 onward. The incidence of cell death in the thalamus increased with the progression of hydrocephalus. Ultrastructurally, thalamic neurons occasionally had apoptotic features including nuclear chromatin condensation and marginalization. Immunohistochemically, single-stranded DNA-positive neuronal nuclei were found in the thalamus. They were also positively stained with the TUNEL method. Marked loss of myelin and axons with many TUNEL-positive oligodendrocytes were found in the cerebral white matter. These findings suggest that the neuronal cell death observed in the thalamus in hydrocephalic HTX rats is retrograde degeneration due to extensive damage of axons in the cerebral white matter and that the thalamic retrograde degeneration is attributable to apoptotic cell death.
先天性脑积水的HTX大鼠会出现脑室扩张，并伴有广泛的脑白质损伤。最近，我们报道了HTX大鼠的丘脑也会发生神经元细胞死亡。为了研究这些动物丘脑变性的潜在机制，我们对出生后不同发育阶段的大脑进行了组织病理学研究。从出生后第17天起，在丘脑中观察到嗜酸性神经元，其染色质浓缩或核碎片化。丘脑中细胞死亡的发生率随着脑积水的进展而增加。超微结构上，丘脑神经元偶尔具有凋亡特征，包括核染色质浓缩和边缘化。免疫组织化学显示，丘脑中发现单链DNA阳性的神经元核。它们也被TUNEL法阳性染色。在脑白质中发现明显的髓鞘和轴突丢失，有许多TUNEL阳性的少突胶质细胞。这些发现表明，在脑积水的HTX大鼠丘脑中观察到的神经元细胞死亡是由于脑白质中轴突的广泛损伤导致的逆行性变性，并且丘脑逆行性变性归因于凋亡性细胞死亡。
