本研究旨在探讨庆大霉素对前庭水平半规管壶腹嵴毛细胞的频率选择性感受功能损伤特点及其形态学基础。以豚鼠为研究对象,给予实验组1、2、3连续每天皮下注射庆大霉素(50mg/kg)1周、2周、3周,对照组皮下注射等量生理盐水。停药后用冰水试验和高频旋转实验诱发并记录视频眼震图(videonystagmography,VNG),用低频和高频旋转实验诱发并记录前庭诱发电位(vestibular evoked potential,VsEP)。视频眼震检查记录眼震持续时间和频率,VsEP检查记录P1、P2波潜伏期和波幅(P1、P2分别起源于前庭神经和前庭神经核)。另将实验组豚鼠分批处死,取水平半规管壶腹嵴标本,扫描、透射电镜观察。结果显示:(1)视频眼震检查:冰水刺激后实验组1、2眼震持续时间和频率与对照组差别无统计学意义(P>0.05),实验组3未引出明显眼震。高频旋转刺激后,与对照组相比,实验组1眼震持续时间和频率无显著差异(P>0.05),而实验组2眼震持续时间缩短和频率下降,差别具有统计学意义(P<0.01);实验组3亦未引出明显眼震。(2)VsEP检查:低频旋转后实验组1、2诱发电位参数与对照组无明显差别(P>0.05),实验组3未见典型波形。高频旋转刺激后,与对照组相比,实验组1的P1,P2无显著差异(P>0.05),而实验组2P1,P2潜伏期延长,两波的波幅均缩短,差异具有统计学意义(P<0.01);实验组3未见典型波形。(3)电镜观察:对照组壶腹嵴毛细胞形态未见异常;实验组1壶腹嵴顶毛细胞纤毛略稀疏,毛细胞水肿;实验组2壶腹嵴毛细胞损伤以中央部分坏死为主,外周细胞形态结构基本完整;实验组3毛细胞纤毛完全消失,未见形态完整毛细胞。以上结果提示,庆大霉素主要影响水平半规管壶腹嵴的高频旋转感受功能,对壶腹嵴毛细胞的损伤先以中央顶部为主,逐渐累及嵴顶外周,直至完全损伤壶腹嵴毛细胞,位于前庭感受器壶腹嵴顶部的毛细胞的损伤和丢失可能是高频旋转感受功能损害和缺失的形态学基础。 The aim of this study was to investigate the characteristics and morphological features of gentamicin on the frequency-selective functional impairment of the ampulla of hair cells in the vestibular semicircular canal. Taking guinea pigs as experimental subjects, rats in experimental group 1, 2, and 3 were injected subcutaneously with gentamicin (50 mg / kg) once daily for 1 week, 2 weeks and 3 weeks respectively, and the control group was injected subcutaneously with normal saline. After stopping the drug, videonystagmography (VNG) was induced and recorded by ice water test and high-frequency rotation test. The vestibular evoked potential (VsEP) was induced and recorded by low-frequency and high-frequency rotation experiments. Nystagmus recorded the duration and frequency of nystagmus. VsEP recorded the latency and amplitude of P1 and P2 waves (P1 and P2 originated from the vestibular and vestibular nuclei, respectively). In addition, guinea pigs in experimental group were sacrificed in batches. The specimens of ampulla of horizontal semicircular canal were screened and examined by transmission electron microscopy. The results showed that: (1) Nystagmus test: The duration and frequency of nystagmus in experimental group 1 and 2 were not significantly different from those in control group (P> 0.05). Experimental group 3 did not induce obvious nystagmus. Compared with the control group, the duration and frequency of nystagmus in experimental group 1 were not significantly different (P> 0.05), but the duration and frequency of nystagmus in experimental group 2 were shortened (P <0.01). Experimental group 3 also did not induce obvious nystagmus. (2) VsEP examination: After the low-frequency rotation, the evoked potential parameters of experimental group 1 and 2 were not significantly different from those of the control group (P> 0.05). No typical waveform was observed in experimental group 3. Compared with the control group, P1 and P2 in experimental group 1 had no significant difference (P> 0.05) after high-frequency rotation stimulation, while the latency of 2P1 and P2 in experimental group was prolonged and the amplitude of both waves were shortened, the difference was statistically significant P <0.01). Experimental group 3 showed no typical waveform. (3) Electron microscope observation: the control group, ampulla ridge hair cell morphology was not abnormal; experimental group 1 ampulla crest hair cell cilia slightly sparse, hair cell edema; experimental group 2 Ampulla of hair cell damage to the central part of the main necrosis , The shape and structure of the peripheral cells were basically intact; in the experimental group, 3 cilia of the hair cells disappeared completely, and no hair cells of the shape were found completely. The above results suggest that gentamicin mainly affect the level of semi-regulatory ampulla ridges of the high-frequency rotational sensory function of the ampulla of hair cells in the central top of the damage first, gradually involving the crest of the periphery, until completely damaged ampulla of ridge hair Damage to and loss of hair cells from cells, located at the apical vestibule of vestibular receptors, may be the morphological basis of dysfunction and loss of high frequency rotational sensation.