急性次声波暴露后豚鼠位听功能及内耳超微结构的变化

目的观察次声波对豚鼠位听功能和内耳超微结构的影响。方法将豚鼠置于频率8Hz、声压级135dBSPL的次声声场中连续暴露90min。应用正弦摆动试验(sinusoidalpendulartest,SPT)、听性脑干反应（auditorybrainstemresponse,ABR）和畸变产物耳声发射(distortionproductionotoacousticemission,DPOAE)评价次声波暴露前后豚鼠前庭功能和听功能的变化,扫描电镜观察豚鼠内耳各结构表面超微形态的变化。结果次声波暴露后不同时间正弦摆动诱发的豚鼠前庭性眼震的最大慢相速度(slow-phasevelocity,SPV)和频率较次声暴露前轻微降低,但无显著性意义(P>0.05)。次声波暴露后各组动物ABR阈值较正常时略有升高,亦无统计学差异(P>0.05),各组动物ABR各波潜伏期和波间期与次声暴露前比较差异均无显著性(P>0.05);DPOAE的幅度值在各个频率段均有明显的降低(P<0.01)。扫描电镜下见各实验组动物内耳半规管壶腹嵴两囊斑及Corti器感觉毛细胞纤毛缺失、散乱、倒伏及融合,表皮板等结构均有不同程度的损伤。结论次声波对豚鼠前庭末梢感受器兴奋性可能有一过性的轻微抑制作用,但SPT无有意义改变。次声波可引起豚鼠内耳毛细胞超微结构的损伤,可导致豚鼠耳蜗外毛细胞功能明显减退,这种功能减退尚不足以引起听力的明显改变。     

电钻噪声对豚鼠听功能的影响

目的 观察耳科电钻噪声对豚鼠听功能的影响。方法 将48只豚鼠耳后切口置于电钻噪声连续暴露30分钟和60分钟,应用听性脑干反应（ABR）记录技术评价电钻噪声暴露前后不同时间豚鼠听功能的变化。结果 电钻噪声暴露后各组动物ABR阈值、潜伏期和波间期较暴露前略有升高,但无明显差异（P＞0.05）。结论 耳科电钻就当前临床应用的强度、时间及范围内来看,其噪声强度尚不会影响豚鼠的听功能。     

次声波对豚鼠畸变产物耳声发射幅度的影响

目的观察强次声波暴露后豚鼠畸变产物耳声发射(DPOAE)的变化情况.方法将15只豚鼠置于频率8Hz、强度为135dB SPL的次声声场中连续暴露90分钟.分别于强次声波暴露前及暴露后即刻(2h内)、2天和5天做畸变产物耳声发射测试.结果强次声波暴露后豚鼠DPOAE的幅度值在各个频率段与暴露前相比均有明显的降低(p＜0.01),随着时间的推移,各个频率的幅度虽有一定的恢复,但仍明显低于暴露前水平(p＜0.01).结论强次声波可导致豚鼠耳蜗外毛细胞功能明显减退.     

自身免疫性听神经病动物模型的建立及听性脑干反应和畸变产物耳声发射的变化

目的建立自身免疫性听神经病动物模型，探讨其听性脑干反应（auditory brainstem response ABR）和畸变产物耳声发射（distortion product otoacoustic emission DPOAE）的变化特征。方法选取耳廓反射正常的白色豚鼠250只，分离、电泳与纯化豚鼠螺旋神经节及蜗轴内的耳蜗神经纤维抗原，然后与等量完全弗氏佐剂免疫同种豚鼠，其中正常组10只，对照组10只，试验组50只。观察ABR、DPOAE、血清IgG水平、螺旋神经节和耳蜗核团形态学的改变、听神经抗原蛋白在螺旋神经节和耳蜗神经的表达、听神经纤维超微结构的变化。结果免疫后16只动物（32／100耳）出现听性脑干反应阈提高10～25dB，Ⅰ、Ⅲ波潜伏期延长，到免疫后第3周最为明显，随后有逐渐恢复的趋势，其中Ⅲ波潜伏期到第6周恢复正常；该组豚鼠DPOAE没有变化，动物血清IgG显著性升高，与对照组相比差异有统计学意义（F=10．03，P〈0．05）；均有不同程度的螺旋神经节细胞变性、数目减少，螺旋神经节和小血管周围有淋巴细胞浸润；听神经纤维出现脱髓鞘、髓鞘断裂等现象。豚鼠耳蜗核各亚核团平均细胞密度和细胞平均面积各组差异比较没有统计学意义；听神经蛋白完全分布于耳蜗螺旋神经节和听神经纤维组织。免疫后34只动物（68／100耳）没有出现ABR反应阈升高，血清IgG没有升高，与对照组相比差异没有统计学意义，螺旋神经节、耳蜗核团、听神经纤维超微结构没有变化。结论建立了豚鼠自身免疫性听神经病动物模型，该动物模型的ABR反应阈轻中度提高，Ⅰ、Ⅲ波有自然恢复的趋势。DPOAE没有变化。     

强次声波对豚鼠Corti器超微结构的损伤

目的 观察强次声波对豚鼠Corti器超微结构的损伤情况。方法 将豚鼠置于频率8Hz、强度为135dBSPL的次声声场中连续暴露90min。应用扫描电镜分别观测强次声波暴露后即刻（2h内）、2天和7天时动物Corti器超微结构的变化，计算各组耳蜗的受损率，与对照组进行比较。结果 扫描电镜下见各实验组动物Corti器感觉毛细胞纤毛缺失、散乱、倒伏，表皮板等结构均有不同程度的损伤。在存活较长时期后，还可见到纤毛融合．部分细胞的表皮板破裂，以及支持细胞分离，细胞溶解，形成空洞。耳蜗受损率分别为70％～80％。结论 强次声波可引起豚鼠Corti器超微结构不同程度的损伤。     

Effects of exposure of the ear to GSM microwaves: in vivo and in vitro experimental studies

The effects of mobile phone (GSM) microwaves on the ears of guinea pigs were investigated in two in vivo experiments and one in vitro experiment. In the first experiment, three groups of eight guinea pigs had their left ear exposed for 1 h/day, 5 days/week, for 2 months, to GSM microwaves (900 MHz. GSM modulated) at specific absorption rates (SARs) of 1, 2 and 4 W/kg respectively, and a fourth group was sham-exposed. Distortion-product otoacoustic emissions (DPOAEs) were measured for each ear before exposure, at the end of the 2-month exposure period, and 2 months later. In the second experiment, the same protocol was applied to eight sham-exposed and 16 exposed guinea pigs at 4W/kg, but the auditory brainstem response (ABR) thresholds were monitored. Repeated-measures ANOVA showed no difference in DPOAE amplitudes or in ABR thresholds between the exposed and non-exposed ears and between the sham-exposed and exposed groups In the course of the second experiment, acute effects were also investigated by measuring once, in all animals, ABR thresholds just before and just after the 1-h exposure: no statistically significant difference was observed. In vitro, the two organs of Corti (OCs) of newborn rats (n=15) were isolated and placed in culture. For each animal, one OC was exposed for 24-48 h to 1 W/kg GSM microwaves, and the other was sham-exposed. After 2-3 days of culture, all OCs were observed under light microscopy. They all appeared normal to naive observers at this stage of development. These results provided no evidence that microwave radiation, at the levels produced by mobile phones, caused damage to the inner ear or the auditory pathways in our experimental animals.     

Effects of exposure of the ear to GSM microwaves: in vivo and in vitro experimental studies

The effects of mobile phone (GSM) microwaves on the ears of guinea pigs were investigated in two in vivo experiments and one in vitro experiment. In the first experiment, three groups of eight guinea pigs had their left ear exposed for 1 h/day, 5 days/week, for 2 months, to GSM microwaves (900 MHz, GSM modulated) at specific absorption rates (SARs) of 1, 2 and 4 W/kg respectively, and a fourth group was sham-exposed. Distortion-product otoacoustic emissions (DPOAEs) were measured for each ear before exposure, at the end of the 2-month exposure period, and 2 months later. In the second experiment, the same protocol was applied to eight sham-exposed and 16 exposed guinea pigs at 4 W/kg, but the auditory brainstem response (ABR) thresholds were monitored. Repeated-measures ANOVA showed no difference in DPOAE amplitudes or in ABR thresholds between the exposed and non-exposed ears and between the sham-exposed and exposed groups. In the course of the second experiment, acute effects were also investigated by measuring once, in all animals, ABR thresholds just before and just after the 1-h exposure: no statistically significant difference was observed. In vitro, the two organs of Corti (OCs) of newborn rats (n = 15) were isolated and placed in culture. For each animal, one OC was exposed for 24–48 h to 1 W/kg GSM microwaves, and the other was sham-exposed. After 2–3 days of culture, all OCs were observed under light microscopy. They all appeared normal to naive observers at this stage of development. These results provided no evidence that microwave radiation, at the levels produced by mobile phones, caused damage to the inner ear or the auditory pathways in our experimental animals.     

三个半规管阻塞动物模型的建立

目的 旨在建立豚鼠单侧三个半规管阻塞的动物模型。方法 利用２０只豚鼠行单侧三个半规管阻塞,观察手术前后眼震电图、听性脑干反应（ａｕｄｉｔｏｒｙ ｂｒａｉｎｓｔｅｍ ｒｅｓｐｏｎｓｅｓ,ＡＢＲ）、畸变产物耳声发射（ｄｉｓｔｏｒｔｉｏｎ ｐｒｏｄｕｃｔ ｏｔｏａｃｏｕｓｔｉｃ ｅｍｉｓｓｉｏｎ,ＤＰＯＡＥ）及形态学的变化,非手术耳作对照。结果 豚鼠术后１ｄ出现自发性眼震,正弦摆动刺激单侧眼震反应消失,     

泊洛沙姆407局部灌注对豚鼠中耳及内耳的影响

目的观察泊洛沙姆407在豚鼠体内的生物降解与排出过程，以及对听泡结构及功能的影响。方法10只健康豚鼠右侧圆窗龛灌注100μl 20％泊洛沙姆407原位凝胶作为实验组，左侧灌注生理盐水作为对照组，另取2只豚鼠不予处理作为阴性对照。灌注前及灌注后第3、7、14、28及49天行听性脑干反应（auditory brainstem response，ABR）检测，每次检测后处死2只动物，取出听泡，固定，石蜡包埋连续切片，观察凝胶在中耳腔内的生物降解情况以及对中耳腔黏膜、圆窗膜、耳蜗和前庭终器结构的影响。结果圆窗龛灌注泊洛沙姆407凝胶后ABR阈值较灌注前有所提高，但在第49天恢复至灌注前水平。第49天时凝胶基本完全降解或排出，光镜下残留少量絮状物，内含少量炎性细胞。凝胶灌注对中耳腔黏膜、圆窗膜、耳蜗及前庭终器结构均无明显影响。结论泊洛沙姆407凝胶在听泡内通过生物降解和经咽鼓管排出两种形式清除，对听泡组织无明显致炎作用，对ABR阈值有暂时性影响，但未见耳蜗及前庭终器功能和结构有不可逆性损伤。     

周围神经脱髓鞘豚鼠模型听神经病变及听功能研究

目的:通过建立实验性变态反应性神经炎这一周围神经脱髓鞘动物模型,观察其听神经病变,初步探讨其听性脑干反应(ABR)和听神经复合动作电位(CAP)的改变。方法:以粗提的牛外周神经髓鞘碱性蛋白(MBP)作为抗原,免疫实验组豚鼠;对照组以生理盐水代替MBP。检测动物血清抗MBPIgG水平、坐骨神经传导速度,观察坐骨神经、听神经病理改变;检测ABR、CAP阈值及潜伏期;观察内耳病理损伤。结果:实验组血清抗MBPIgG水平升高,与对照组相比P<0.01;实验组坐骨神经传导速度减慢,与对照组相比P<0.05;透射电镜发现坐骨神经、听神经脱髓鞘改变;免疫前后实验组14只(26耳)出现ABR反应阈升高,伴Ⅰ、Ⅲ、Ⅴ波潜伏期明显延长,与对照组比较P<0.01,而Ⅰ～Ⅲ、Ⅲ～Ⅴ波间期与对照组比较P>0.05;CAPN1、N1波潜伏期延长,与对照组比较P<0.01;另有4只(8耳)仅出现潜伏期延长而无阈值升高;免疫组织化学显示内耳免疫损伤部位主要在蜗神经、内耳神经纤维、螺旋神经节;扫描电镜显示内毛细胞纤毛紊乱、胞质溢出。结论:实验性变态反应性神经炎动物模型作为一种可靠的周围神经脱髓鞘动物模型,其病变可累及听神经出现听神经脱髓鞘改变,ABR和CAP阈值升高、潜伏期明显延长,该模型可望成为探讨听神经脱髓鞘的听力学表现的一种有用的动物模型。     

后半规管阻塞前后豚鼠前庭及耳蜗功能的动态变化

目的 探讨机械性后半规管阻塞前后豚鼠前庭和耳蜗功能的动态变化。方法 采用２０只豚鼠建立单侧后半规管阻塞的动物模型,观察手术前后眼震电图,听性脑干反应,耳声发射等变化。结果 术后第１天,第３天豚鼠正弦摆动刺激术侧眼震反应,明显减术,术后第５天起双侧眼震恢复正常。术后早期ＡＢＲ阈值一度升高,第５天达高峰,ＡＢＲ阈值平均升高４．５ｄＢ。ＤＰＯＡＥ反应幅度无明显改变。结论 后半规管阻塞能选择性地消除后半规     

Effect of high-dose cisplatin on auditory brainstem responses and otoacoustic emissions in laboratory animals

OBJECTIVE: The role of transient evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) as early indicators of cisplatin-induced ototoxicity in three different rodent species--the guinea pig. the albino rat, and the fat sand rat (Psammomys obesus)--was investigated. In addition, an attempt was made to determine which of the three rodent species is most susceptible to cisplatin-induced ototoxicity as measured by auditory brainstem responses (ABR), BACKGROUND: There have been numerous clinical and experimental reports on cisplatin-induced ototoxicity, but to the authors' best knowledge, there has been no comparative report on the short-term effects of cisplatin on OAE measured with commercially available equipment between different rodent species. METHODS: Cisplatin was systemically administered as a single high dose (12 mg/kg intraperitoneally) to all three species, and the ototoxic effects were measured before and 3 days after the injection of cisplatin in the same animals, using ABR, TEOAE, and DPOAE. RESULTS: The ABR thresholds were significantly elevated in the guinea pigs and the albino rats but not in the sand rats. Significant depression of TEOAE energy and DPOAE amplitude occurred only in the guinea pigs. The depression of the DPOAE was greater than that of the TEOAE. The guinea pigs showed the greatest degree of ototoxicity (depression of ABR and OAE). CONCLUSIONS: Among the three rodent species, the guinea pig has the potential to be used as a sensitive animal model in studies of cisplatin ototoxicity. The study also showed that the recordings of TEOAE and DPOAE, in addition to ABR, are sensitive techniques for the assessment of cisplatin-induced ototoxicity.     

Differing effects on the inner ear of three gentamicin compounds: GM-C1, -C2 and -C1a

OBJECTIVE: Gentamicin (GM) has been used to ablate the vestibular system function as a form of treatment for Ménière's disease. Generally, clinicians have not recognized that commercial GM comprises three major compounds--GM-C1, -C2 and -C1a--and the effects of the individual compounds on the inner ear have not been elucidated. In this study we investigated differences in cochleo- and vestibulotoxicity between the three compounds MATERIAL AND METHODS: Hartley guinea pigs were treated for 2 weeks with daily subcutaneous injections (100 mg/kg) of the GM complex or the GM-C1, -C2 or -C1a compounds. After a further 2 weeks, we assessed the inner ear by measuring the auditory brainstem response (ABR) and performing a sinusoidal rotation test (SRT) and morphological analyses. RESULTS: The ABR thresholds in the C2 group were found to be more impaired than those in the other groups In the SRT, the nystagmus counts in the C2 group were lower than those in the controls and in the C1 group. The counts in the C1a group were lower than those in the C1 group. Morphological analyses revealed that the proportion of remaining outer hair cells was less in the C2 group than in the other groups. CONCLUSION: Our results suggest that characterization of differences in ototoxicity may be useful for treatment of Ménière's disease with GM.     

Inner ear changes with intracochlear gentamicin administration in Guinea pigs

OBJECTIVES/HYPOTHESIS: Transtympanic administration of gentamicin is reported to be a useful treatment for vertigo in such conditions as Meniere's disease, and determining appropriate clinical dosage of gentamicin is difficult. The authors examined the relation between gentamicin dosages and inner ear function in guinea pigs. STUDY DESIGN: This study is a basic science project designed to examine cochlear and vestibular function in animal models. METHODS: Various concentrations of gentamicin solution were infused into the right inner ear of guinea pigs by osmotic pumps. Caloric nystagmus as a marker of vestibular function and the change in auditory brainstem response (ABR) threshold as a marker of cochlear function were observed. RESULTS: After 14 days of treatment, high gentamicin concentrations of 40 mg/mL caused canal paralysis and a rapid shift in ABR threshold. Animals exposed to low gentamicin concentrations of 4 mg/mL showed no obvious change in either vestibular or cochlear function. Animals exposed to moderate gentamicin concentrations of 12 mg/mL showed a moderate shift in ABR threshold and caloric malfunction. Histopathological examination revealed that after 14 days of treatment with 40 mg/mL gentamicin, severe cytoplasmic damage occurred in both vestibular and cochlear end organs. In animals treated with 12 mg/mL gentamicin, hair cells remained in the cochlear third turn and ampulla of the lateral semicircular canal. CONCLUSION: The authors established an animal model that showed the moderate damage of inner ear with moderate-dose gentamicin. The study results indicated that the appropriate administration of gentamicin could establish a stable effect on the inner ear. It may be important to select the protocol that delivers a stable dosage of gentamicin to treat patients with Meniere's disease safely and effectively.     

豚鼠自身免疫性梅尼埃病模型的主要内耳抗原分析

目的 探寻导致豚鼠自身免疫性梅尼埃病(autoimmune Meniere's disease,AIMD)的主要内耳组织抗原成分.方法 采用同种粗制内耳抗原免疫豚鼠,观察听觉功能、前庭功能及内耳组织形态学方面的变化,判断AIMD模型与非模型动物.采用免疫印迹法(Western blotting)对比分析模型动物与非模型动物血清内针对内耳组织抗原不同成分特异性免疫反应的差异,寻找只针对AIMD模型动物的特异性成分.结果 内耳组织所含抗原成分较多,免疫后酶联免疫吸附试验(ELISA)结果显示,AIMD模型与非AIMD模型动物均不同程度地存在针对内耳组织抗原的血清抗体水平升高.听功能检测,非AIMD模型动物听力损失不明显.Western bohting结果显示,AIMD模型动物出现针对相对分子质量为68 000、58 000、42 000及28 000蛋白质成分的反应条带,而非AIMD模型动物则未显示这些条带的特异性抗原抗体反应.结论 可能只有出现针对导致内耳自身免疫性疾病的主要抗原成分的特异性免疫反应,才会造成明显的内耳免疫病理损伤和功能障碍.相对分子质量为68 000、58 000、42 000及28 000的内耳组织抗原可能是导致豚鼠自身免疫性膜迷路积水的主要抗原成分.     

Effects of selective cochlear toxicity and vestibular deafferentation on vestibular evoked myogenic potentials in guinea pigs

CONCLUSION: The findings suggest that sound-evoked myogenic potentials on the guinea pig sternocleidomastoid muscle (SM) originate from the vestibular end organ and not from the cochlea of the inner ear. OBJECTIVE: Studies in animals of the sound evoked vestibular myogenic potentials on the SM should aid in elucidating the pathway of the vestibular-evoked myogenic potential (VEMP). However, details of the pathway of the VEMP remain to be elucidated. This study aimed to clarify aspects of this pathway. MATERIALS AND METHODS: In the present study, short latency biphasic myogenic potentials on the SM in guinea pigs were induced by an intense brief sound. RESULTS: The thresholds of the potentials were 67 dB SPL above those of the auditory brainstem response (ABR). The potentials were eliminated by a vestibular deafferentation, but were observed after selective cochlea toxicity using an amikacin injection.     

透明质酸圆窗灌注对豚鼠内耳功能和形态学的影响

为探索透明质酸中耳应用对内耳的影响，以２６只健康豚鼠于左耳用２％透明质酸圆窗灌注前和灌注后５、１４、２８天检测前庭和听觉功能，并行基底膜铺片及颞骨火棉胶包埋连续切片，发现２％透明质酸圆窗灌注后５天，滤波短声０．２５￣１０ｋＨｚ诱发的听神经动作电位阈值的提高（Ｐ〈０．０５），术后１４天在１、２、４ｋＨｚＡＰ阈值明显改善（Ｐ〈０．０５），术后２８天均恢复至术前水平（Ｐ〉０．０５），灌注前后ＥＮＧ眼震时     

A study on the effect of infrasound

In order to examine the influence of infrasound that is becoming topical in society, human beings and guinea pigs were exposed to infrasound. After exposure, the hearing level, vestibular functions and autonomic nervous functions of human beings were examined, and endocochlear potential (EP) and cochlear microphonics (CM) of guinea pigs were examined. Next, after guinea pigs were exposed to intense audible low frequency sound that was born secondarily from infrasound and/or vibration of whole body concerning about air pressure change of infrasound, their EP and CM were examined. The results obtained were as follows: 1) By exposure of infrasound 10-15Ha 130-135dB LSPL for 30min. to human beings, their hearing level, vestibular functions and autonomic nervous functions were not changed. 2) After exposure of infrasound 15Hz 135-140dB LSPL for 24hrs.-72hrs. to guinea pigs, their EP and CM remained normal. 3) After each exposure of audible low frequency sound 90Hz 120dB SPL for 72hrs., 150Hz 110dB SPL for 72hrs. and 200Hz 100dB SPL for 72hrs. to guinea pigs, their EP became abnormal though their CM remained normal. 4) After exposure of 15Hz 500 mu +/- 30 mu vibration for 72hrs. to guinea pigs, both EP and CM remained normal. 5) After exposure of both audible low frequency sound 150Hz 100dB SPL and vibration 15Hz 500 mu +/- 30 mu for 72hrs. to guinea pigs, their EP became abnormal though their CM remained normal.     

Effects of alcohol and noise on temporary threshold shift in Guinea pigs

The purpose of this study was to investigate the effects of concomitant exposure to noise and alcohol on the auditory thresholds. Twenty-four guinea pigs were equally divided into three groups: the acute intoxication group, the chronic intoxication group and the control group. Animals in the acute group received single intraperitoneal injections of ethanol (2 g/kg). In the chronic group, alcohol was administered via drinking water (10%, v/v) over a 60-day period. All animals were exposed to a white noise at the intensity of 105 dB A for 30 min. Auditory brainstem response (ABR) thresholds and distortion product otoacoustic emission (DPOAE) levels were measured before, immediately after noise exposure and also 1, 2, and 7 days following exposure. The results showed: first, acute alcohol injection caused a significant, temporary elevation of ABR threshold (4.8 dB in average), while chronic alcohol treatment did not change auditory threshold significantly. Second, noise exposure induced a mean threshold shift of 15.4- 19.7 dB. ABR threshold returned to normal 2 days after exposure. Both acute and chronic alcohol treatment did not alter the magnitude and time course of recovery of the temporary threshold shift (TTS). Third, the mean DPOAE amplitudes decreased at most frequencies following acute injection of alcohol. However, the differences did not reach statistical significance. Fourth, the mean DPOAE levels dropped 3.4-9.6 dB in all groups after noise exposure and returned to normal 1 day to 2 days after noise. There were no significant differences in the amount of DPOAE suppression after noise between the three groups. In summary, we have found that acute and chronic treatment of alcohol in combination with noise did not significantly exacerbate TTS or decrease DPOAE amplitudes relative to noise exposure alone.     

豚鼠耳颞部60Coγ射线照射对耳蜗核影响的实验研究

目的探讨60 Coγ射线照射对豚鼠耳蜗核神经元的影响。方法 48只豚鼠随机分为对照组(8只)和实验组(40只),实验组豚鼠于右耳颞部做一次性40Gy 60 Coγ射线照射后的1、4、7、14、30d行听性脑干反应(audi-tory brainstem response,ABR)测试,然后处死,行耳蜗核石蜡切片HE染色及免疫组织化学染色,观察细胞形态及半胱氨酸天冬氨酸蛋白酶3(Caspase 3)。对照组不予60 Coγ射线照射,行ABR测试后行耳蜗核HE染色,方法同实验组。结果对照组ABR反应阈为29.17±1.95dB SPL,实验组在接受60 Coγ射线照射后1、4、7、14、30dABR阈值升高,分别为31.88±2.59、35.00±3.17、35.83±2.04、39.17±2.05、41.67±2.58dB SPL,照射后4、7、14、30d ABR反应阈与对照组比较差异有统计学意义(P<0.05);实验组各时间点ABR波I、II、III潜伏期及I-II、II-III、I-III波间期延长,与对照组比较差异有统计学意义(P<0.05)。HE染色显示实验组在照射后不同时间点均出现耳蜗核神经细胞肿胀、胞核皱缩或碎裂、尼氏体减少,以14、30天时改变明显。对照组耳蜗核Caspase3免疫组化染色的灰度值为172.33±17.81,实验组60 Coγ射线照射后1、4、7、14、30d耳蜗核Caspase3免疫组化灰度值分别为136.37±24.42、94.67±15.33、91.40±11.71、110.80±4.23、123.56±32.56,两组比较差异有统计学意义(P<0.05)。结论 60 Coγ射线照射可导致耳蜗核损伤;Caspase3表达上调可能与耳蜗核神经元射线损伤有关。