中文摘要：

目的通过设计的一系列前庭功能检测实验对同窝成组的软骨组织Smad4条件基因敲除野生型、杂合子、纯合子小鼠的前庭功能进行评估。方法前庭功能检测方法：一般行为观察;空间姿势反射;游泳实验;前庭眼反射（VOR）,使用前庭功能检查系统记录眼震电图;短声刺激前庭诱发肌源性电位（VEMP）记录麻醉下椎前颈长肌表面第3颈椎水平的声刺激诱发电位。结果虽然软骨组织Smad4条件基因敲除小鼠的耳蜗感受声音能力下降,但没有发现软骨组织Smad4条件基因敲除小鼠出现行为、步态、空间姿势反射和游泳实验等前庭综合功能障碍;3个基因型小鼠均能诱出眼震且相互之间没有差别（P〉0.05）;VEMP的潜伏期在3个基因型组间无差异（P〉0.05）,与野生型和杂合子相比,纯合子小鼠VEMP的反应阈值明显增加（P〈0.01）。结论只有Smad4条件基因敲除纯合子小鼠的部分球囊功能受到一定程度的影响,其他前庭功能不受影响。

英文摘要：

Objective To evaluate the vestibular functions in Smad4 conditional knockout mice.Methods Vestibular functions were evaluated through general behavioral observation,air righting reflex,and swimming test in 3 genotypes of mice,Smad4＋/＋.Smad4＋/-,and Smad4-/-.Vestibular ocular reflex（VOR） was recorded using vestibular function examination system.Vestibular evoked myogenic potential（VEMP） were recorded by loud clicks evoking on the pre-vertebral muscle at the level of the third cervical vertebral bone using silver ball electrodes under general anesthesia.Results Though cochlear perceiving sound was reduced in Smad4-/-mice,their behaviors,gaits,air righting reflex and swimming test were normal.The 3 genotypes of mice were induced identical nystagmus through rotation,but no difference was found among them（P0.05）.Latency of VEMP had no difference among the 3 genotypes of mice（P0.05）,but the response threshold of VEMP in Smad4-/-mice were obviously elevated（P0.01）.Conclusion Only partial functions of saccule are damaged to some extent in Smad4 conditional knockout mice,and other vestibular endorgans have normal functions.