出生前山羊颈段脊髓运动神经元的发育

应用HE染色和超薄切片技术研究第6周到出生前山羊脊髓腹角运动神经元胞体的发育变化。结果表明：1．出生前山羊脊髓腹角运动神经细胞发育包括未分化期、不成熟期、发育成熟期和成熟期4个阶段。2．发育过程中，山羊脊髓运动神经元细胞核的体积持续增长；常染色质增加，异染色质减少且趋边分布；核仁数量减少，中央核仁在第8周形成，以后逐渐发育成熟；核膜渐趋成熟。3．山羊脊髓运动神经元胞体内膜系统的发育变化的规律与神经元的发育阶段相适应。

The Development of Motor Neurons in the Ventral Horn of Cervical Spinal Cord in Prenatal Goat

The development of motor neurons in the ventral horn of spinal cord in prenatal goat were observed by light microscope and electron microscope. The results showed: (1)The form of motor neurons in the ventral horn of spinal cord underwent four developing phases: the undifferentiation neurons, the immature neurons, the youthful neurons and the ripe neurons; (2)With the development of the motor neurons the nucleus were enlarging,the heterochromatin was reducing and tending to distribute in the peripheral gradually. With the number of nucleolus decreasing, the central nucleolus occurred in eighth week, and it become to develop after that the karyotheca matured gradually; (3)The changes in the development of endomembrane system of the motor neurons accorded with that of motor neurons.