Arhinencephaly induced by fetal laser surgery exo utero in mice.

在目前的研究中，有人认为嗅神经不附着在端脑上阻止了遗传性始脑小鼠胚胎(PDN/PDN)从端脑诱导出嗅球。在小鼠脑的后期形态发生过程中，胚胎激光手术破坏嗅球原基后，可能是导致胼胝体发育不全和前连合不规则连接的触发因素。我们推测，嗅神经中黄体激素释放激素(LHRH)神经元的迁移可能是由于嗅神经没有附着到端脑上而受到干扰。LHRH神经元部分停滞，提示在PDN/PDN脑内，嗅球原始区的前体二尖瓣细胞的凋亡是由嗅觉神经元的非神经支配引起的，梨状皮质的前体神经元的凋亡是由二尖瓣细胞的死亡引起的非神经支配引起的。在激光胎儿手术破坏嗅球原始区的胚胎中也观察到梨状皮质前体神经元的凋亡，这可能是PDN/PDN脑中前体神经元的序贯凋亡和脑异常的序贯表现，也可见于胚胎激光手术体外诱导的鼻脑脑。

In the present study, it has been suggested that non-attachment of the olfactory nerve to the telencephalon blocked the induction of the olfactory bulbs from the telencephalon in genetic archinencephalic mouse embryos (Pdn/Pdn). And it was shown that the destruction of the olfactory bulb anlage using fetal laser surgery exo utero becomes a trigger of agenesis of the corpus callosum and irregular connection of the anterior commissure in later morphogenesis of the mouse brain.We speculated that the migration of luteinizing hormone-releasing hormone (LHRH) neurons might be disturbed in the olfactoy nerve because of the non-attachment of the olfactory nerve to the telencephalon. partial arrest of LHRH neurons was observed.It was suggested that apoptosis of the precursor mitral cells in the anlage of the olfactory bulb was induced by non-innervation of olfactory neurons, and apoptosis of the precurosor neurons in the pyriform cortex was induced by the non-innervation caused by the death of mitral cells in Pdn/Pdn brain. Apoptosis in the precursor neurons in the pyriform cortex was also observed in the embryos whose anlages of the olfactory bulbs were destructed by fetal laser surgery.Thus, sequential apoptosis of the precursor neurons and sequential manifestation of the brain abnormalities were proposed in Pdn/Pdn brain and also in the arhinencephalic brains induced experimentally by fetal laser surgery exo utero.