胚胎小鼠耳蜗感觉上皮的形态发生

目的了解胚胎小鼠耳蜗感觉上皮发育的形态学特征及规律。方法利用光镜、扫描电镜、透射电镜观察从胚胎第8天到刚出生期间C57BL/6小鼠耳蜗感觉上皮发育过程中的形态变化。结果C57BL/6小鼠胚胎第10.5天耳蜗开始发育,感觉上皮由高柱状上皮细胞组成,到胚胎第14天才开始分化为原始的毛细胞;胚胎第16天耳蜗底转Corti器原基形成,毛细胞和支持细胞初具雏形;到出生时,耳蜗形态基本成熟,但底转Corti器仅趋向成熟,蜗尖才形成Corti器原基。结论小鼠耳蜗感觉上皮发育的形态变化在胚胎第13天到出生时最明显,感觉细胞都来源于一种高柱状上皮细胞,到胚胎第14天开始分化为毛细胞;而Corti器的分化成熟是从底转向顶转进行的,出生时尚未完全发育成熟。

Morphogenesis in the sensory epithelia of embryonic mouse cochlea

OBJECTIVE To observe the morpho- genesis and the principles of developing cochlear sen- sory epithelia in embryonic mice. METHODS The de- veloping cochlear sensory epithelia of C57BL/6 embry- onic mice,aged from eighth embryonic day (E8) to just natal mice (P0), were observed with light microscope, scanning and transmission electronic microscopes. RESULTS Primordial cochlea arose at E10.5. Cochlear sensory epithelia consisted of tall columnar epithelial cells and began to differentiate and form primordial hair cells at E14. Primordial organ of Corti arose at E16, and shapes of supporting and hair cells tended to mature. Cochlea was maturely shaped at P0, but organ of Corti in base of cochlea tended only to mature, meanwhile the primordial organ of Corti just arose in apex of cochlea. CONCLUSION Significant morphologic changes oc- curred from E13 to P0 in the developing cochlear sen- sory epithelium of the mouse. The origin of sensory cells was tall columnar epithelial cells that began to differentiate and form hair cells after E14. Developing of organ of Corti was from base to apex of the cochlea. However, it was still incompletely mature at birth.