Yamaguchi K, Goto N, Yamamoto T Y
Department of Anatomy, Tohoku University School of Medicine, Sendai, Japan.
Acta Anat (Basel). 1989;136(1):61-8. doi: 10.1159/000146799.
The morphometric development of the human cerebellar nuclei was examined in 9 fetuses (16-40 weeks of gestation; WG), an infant (2 months old) and 2 adults (16 and 63 years old). With the morphological observation of serial sections of the brain containing the cerebellar nuclei, the authors measured sections to get several morphometric parameters: the volume of nuclear column and number, packing density and cell body area of neurons. Each nucleus (dentate, emboliform, globose and fastigial nucleus) was recognized even at 16 WG. Nerve cells containing Nissl bodies were observed in all nuclei after 23 WG. Degenerative changes were detected in some neurons for every nucleus at 21 and 23 WG. Three stages were observed in the developmental course of nuclear volume and neuronal packing density: the primary or undifferentiated stage at 16 WG, the secondary stage with variability at 21-32 WG and the tertiary stage with monotonous increase (nuclear volume) or gradual decrease (neuronal packing density) after 35 WG. No significant correlation between neuronal number and gestational age was noticed for every nucleus. The analysis of cell body area (neuronal size) demonstrated that the dentate neurons developed after the intermediate or fastigial neurons. It is concluded that there is a critical period between slightly before 20 WG and slightly after 30 WG, matched with the secondary stage in the development of the cerebellar nuclei.
研究人员对9例胎儿（妊娠16 - 40周）、1例婴儿（2个月大）和2例成人（16岁和63岁）的小脑核形态计量学发育进行了检查。通过对包含小脑核的脑连续切片进行形态学观察，作者测量切片以获得多个形态计量学参数：核柱体积、神经元数量、堆积密度和细胞体面积。即使在妊娠16周时，每个核（齿状核、栓状核、球状核和顶核）也已可辨认。在妊娠23周后，在所有核中均观察到含有尼氏体的神经细胞。在妊娠21周和23周时，每个核的一些神经元中检测到退行性变化。在核体积和神经元堆积密度的发育过程中观察到三个阶段：妊娠16周时的初级或未分化阶段，妊娠21 - 32周时具有变异性的次级阶段，以及妊娠35周后核体积单调增加或神经元堆积密度逐渐降低的三级阶段。每个核的神经元数量与胎龄之间未发现显著相关性。细胞体面积（神经元大小）分析表明，齿状神经元的发育晚于中间神经元或顶核神经元。得出的结论是，在妊娠20周稍前至30周稍后之间存在一个关键时期，这与小脑核发育的次级阶段相匹配。
