Analysis of the mechanism underlying the pathway formation using mutant animals.

我们主要用形态学技术研究了正常和突变动物的脑发育。最近获得的发现如下：1）钙结合蛋白D-28 k，一种钙结合蛋白，定位于大鼠中从新生犁鼻器迁移到脑的神经元中（Toba等人，2001年）。N-多配体聚糖，一种硫酸乙酰肝素蛋白聚糖，在从大鼠嗅觉基板的迁移途径中表达（Toba等人，2002）。2）在缺乏转录因子Brn-2、Nkx 2.1和Pax-6的动物中发现了下丘脑神经分泌神经元的发育和通路形成的缺陷（Kawano等人，3）在缺乏Brn-1和Brn-2的双敲除小鼠中观察到大脑新皮层的异常发育（Sugitani等人，4）InPax-6突变大鼠，延髓的小脑前神经元表现出延迟的迁移和异常的迁移路线（Horie等人，5）在缺乏Nkx2.1的knochout小鼠中，中脑的多巴胺能轴突上行异常地穿过中线（Kawano等人，6）缺乏细胞识别分子NB 3的小鼠的运动功能是异常的（Takeda等人，2003年）。

We have examined the brain development in both normal and mutant animals by chiefly using the morphological technique. Recent findings obtained are as follows.1) Calbindin D-28k, a calsium-binding protein, is localized in neurons migrating from the nascent vomeronasal organ to the brain in rats (Toba et al., 2001). N-syndecan, a heparansulfate proteoglycan, is expressed in the migratory route from the rat olfactory placode (Toba et al., 2002).2) Defects of the development and pathway formation of hypothalamic neurosecretory neurons were found in animals lacking transcription factors Brn-2, Nkx2.1 and Pax-6 (Kawano et al., 2002).3) The abnormal development of cerebral neocortex is observed in double-knockout mice lacking both Brn-1 and Brn-2 (Sugitani et al., 2002).4) InPax-6 mutant rats, precerebellar neurons of the medulla oblongata exhibit a delayed migration and aberrant migratory route (Horie et al., 2003).5) Ascending dopaminergic axons of the mesencephalon abnormally cross the midline in knochout mice lacking Nkx2.1 (Kawano et al., 2003).6) The motor function of mice lackingNB3, a cell recognition molecule, is abnormal (Takeda et al., 2003).