正常小鸡耳蜗毛细胞神经支配的发育与听功能的关系

目的探讨正常小鸡耳蜗毛细胞神经支配的发育成熟与听功能的关系。方法将3、13、28、43d龄罗曼小鸡用4000Hz半周正弦波刺激进行ABR测试后，采用透射电镜观察其耳蜗近端0.4～0.8mm区域内的毛细胞神经支配。结果3、13、28、43d组小鸡的ABR阈值分别为83.0±7.15、73.5±12.84、72.0±2.99、70.5±2.84dBSpL。3d组与13、28、43d组之间的ABR阈值差异有统计学意义，出生2周后，听功能已发育完善。3d组小鸡耳蜗毛细胞上的神经终扣几乎均为传入性，至13d时，毛细胞上的传出神经终扣明显增加，28、43d组的小鸡耳蜗毛细胞神经支配同13d时相比无明显差异，同时接受传入和传出神经支配。结论耳蜗毛细胞神经支配模式的成熟是正常小鸡听功能发育完善的物质基础。

Relationship between the Development of Innervation on Cochlea Hair Cell and Hearing Function in Normal Chick

Purpose To study the relationship between the development of innervation on cochlea hair cells and hearing function in normal chick. Methods After the measurement of ABR,the innervation on cochlea hair cells in 3,13,28,43 days'old chickens was observed by using transmission electron microscope. Results The difference of ABR threshold between 3 days group and others was significant,and chick's hearing was developed to maturity in two weeks.Nearly all nerve terminals on hair cell in the cochlea of 3 days animals were afferent nerve terminals,while both afferent and efferent nerve terminals could be observed on hair cells in the cochlea of 13,28,43 days'old chicks. Conclusions The maturity of innervation pattern on hair cells in the chick cochlea may be the matetrial base in chick's hearing development.