大鼠双侧耳蜗毁损后下丘核生长相关蛋白表达研究

目的研究大鼠双侧耳蜗毁损后下丘核（inferior colliculus,IC）生长相关蛋白-43（growth-associat-ed protein43,GAP-43）表达水平的变化。方法成年健康SD大鼠35只,随机分为假手术组（对照组）和耳蜗毁损后3、7、14、21、28、90天组,每组各5只动物。应用耳蜗毁损手术法制备大鼠双侧耳蜗毁损模型,采用免疫组织化学方法检测耳蜗毁损后大鼠下丘核GAP-43的表达。结果各组大鼠双侧耳蜗毁损后下丘核内GAP-43均有表达,耳蜗毁损各组表达均高于对照组,毁损后3、7、14天GAP-43表达持续上升,14天时达高峰,21、28天逐渐下降,到毁损后90天GAP-43水平略高于正常组;除90天组外,耳蜗毁损各组的GAP-43表达水平与对照组比较,差异均有统计学意义（P〈0.05）。各组两耳间差异均无统计学意义。结论双侧耳蜗去传入损伤后,下丘核内GAP-43表达14天时达高峰,90天时接近正常水平,可能反映了下丘核内神经元的轴突生长及突触重塑情况。     

脉冲噪声暴露后大鼠听皮层神经颗粒素的表达研究

目的揭示脉冲噪声暴露后不同时期大鼠听皮层神经颗粒素(neurogranin,Ng)表达的变化。方法将50只成年SD大鼠随机分为5组:正常对照组及脉冲噪声暴露后3、7、14、28天组,每组10只。脉冲噪声暴露条件为:平均压力峰值156dB SPL,脉宽为0.25ms,暴露50次,每次间隔6s。于噪声暴露前及噪声暴露后即刻、3、7、14、28天检测各组大鼠ABR反应阈,同时,应用Western blot方法检测各组大鼠听皮层中的Ng的含量。结果与对照组相比,各组大鼠噪声暴露后即刻、3、7、14、28天各频率ABR反应阈均明显提高(P<0.05),噪声暴露后第7天,各频率ABR阈值有所恢复,第14天时趋于稳定;与对照组(0.68±0.08)比较,噪声暴露后第3、7、14天组大鼠听皮层中Ng的含量分别为0.96±0.05、1.11±0.05、0.78±0.04,显著高于对照组,第28天组为0.36±0.03,显著低于对照组,差异均有统计学意义(P<0.05)。结论噪声暴露后,大鼠ABR反应阈明显升高,听皮层Ng的表达呈现一个先上升后降低的过程,提示脉冲噪声刺激对大鼠听觉系统产生了一定持续性的影响,听皮层出现突触可塑性变化。     

外周听觉改变致听皮质突触N-甲基D-天冬氨酸受体亚基表达变化

目的观察听觉剥夺后重塑模型中听皮质突触N-甲基D-天冬氨酸受体亚基(N-methyl-D-aspartate receptor subunit 2B,NR2B)表达变化。方法采用清洁级SD大鼠90只,分成听觉剥夺组、听觉剥夺后重塑组及对照组,Optiprep沉降梯度超速离心从初级听皮质提取高度纯化的突触体后,采用Western blotting蛋白质印迹检测技术对生后听觉剥夺14天组、28天组、42天组、听觉剥夺7天后再给予纯声暴露的各实验组听皮质突触体NR2B表达进行比较。结果听觉剥夺使生后14天组和28天组动物听皮层NR2B表达水平明显下降(P<0.05),听觉剥夺7天后再给予纯声暴露则又使NR2B表达水平明显提高(P<0.05),呈现双向调节趋势。听觉剥夺和纯声暴露对生后42天组成熟大鼠听皮层NR2B表达不再产生明显调节作用(P>0.05)。结论在大鼠生后发育关键期,听觉剥夺、可改变听皮层NMDA受体NR2B蛋白表达水平;为研究感觉功能发育可塑性机制提供了重要实验资料。     

GluR4在单侧聋大鼠耳蜗核不同发育时间的表达△

目的 观察单侧耳蜗毁损后1、2、3、4周谷氨酸受体4(glutmate receptor 4,GluR4)在大鼠耳蜗核的表达变化，为探讨单侧聋听觉中枢重组的分子机制提供参考。方法 新生SD大鼠饲养至出生后12 d(P12),随机分为实验组(左侧耳蜗毁损32只)、伪手术组(进行伪操作32只)及对照组24只，术后1、2、3、4周取三组大鼠双侧耳蜗核，切片后采用免疫组化方法观察耳蜗核GluR4的表达变化。结果 伪手术组及对照组大鼠术后1、2、3、4周，双侧耳蜗核之间比较GluR4表达无统计学差异(P>0.05);伪手术组及对照组双侧耳蜗核GluR4的表达在不同发育时间比较，术后1周与2周相比，2周与3周相比差异均有显著统计学意义(P<0.01)。实验组大鼠耳蜗核两侧之间对比，术后1、2、3周双侧表达差异均有统计学意义(P<0.05);在不同发育时间对比，实验组术侧耳蜗核中GluR4的表达在术后2周与3周相比表达差异有显著统计学意义(P<0.01),而术后1周与2周、3周与4周相比无统计学差异(P>0.05)。实验组健侧术后2周与3周相比表达差异有统计学意义(P&...     

大鼠听皮层发育关键期胶质纤维酸性蛋白表达及听功能变化

目的：观察大鼠听觉发育关键期听功能的变化及听皮层星形胶质细胞标记物胶质纤维酸性蛋白（glial fibrillary acidic protein ,GFAP）的表达。方法清洁级 SD 大鼠幼鼠50只随机分成出生后第14、21、28、35和42天组,每组10只,分别检测各组大鼠 ABR 反应阈后,采用免疫组化染色方法及 Western blot 检测各组大鼠听皮层 GFAP 的表达。结果大鼠出生后第14、21、28、35、42天组 ABR 平均反应阈分别为84．5±4．97、70．5±3．69、58．5±5．80、37．0±4．83和35．5±3．69 dB SPL,除第35天组与第42天组之外,其余各组两两之间比较差异均有统计学意义（P＜0．05或 P＜0．01）;第14、21、28、35、42天组大鼠听皮层 GFAP 平均累积光密度值（IOD）分别为474．36±234．56、1465．93±474．96、2163．06±353．36、6572．01±808．88和7244．37±932．90,各组间两两相比差异均有显著统计学意义（P＜0．05或 P＜0．01）。第14、21、28、35和42天组大鼠听皮层 GFAP 蛋白表达水平分别为1．00±0．06、3．07±0．07、4．92±0．05、6．88±0．03和8．92±0．04,各组间两两相比差异有统计学意义（P＜0．05）。结论大鼠出生后第14～42天其 ABR 反应阈逐渐下降,GFAP 表达逐渐增强,提示星形胶质细胞可能有促进听皮层及听觉中枢的发育与成熟的作用。     

单侧耳蜗毁损后大鼠下丘核γ-氨基丁酸能神经元的分布及调控

目的研究单侧耳蜗毁损后大鼠下丘核（inferior colliculus，IC）内γ-氨基丁酸（γaminobutyric acid，GABA）能神经元数量及分布的变化与谷氨酸脱羧酶（glutamic acid decarboxylase，GAD65）表达水平的关系。方法采用免疫组织化学方法，通过计算机图象分析系统分别检测大鼠单侧耳蜗毁损后3、7、30天双侧下丘核内GABA能神经元的数量及GAD65表达水平的变化。结果大鼠下丘核内GABA能阳性神经元主要分布于下丘中央核，单侧耳蜗毁损后3天手术对侧下丘中央核GABA能阳性神经元数目明显减少，术后7天进一步下降，至术后30天，下丘中央核中GABA能神经元数量回升，但仍显著低于手术同侧及正常对照组。术后3天手术同侧及对侧下丘中央核GAD65表达水平较正常对照组分别下降23％（P〈0．05）和41％（P〈0．01）。术后7天，双侧下丘GAD65水平均出现回升，但手术对侧仍显著低于正常对照组。手术后30天，下丘核内GAD65表达基本恢复到正常水平。结论耳蜗去传人损伤后，下丘核内GABA能神经元的数量变化与GAD65的水平有关，提示脑干听觉中枢可能通过GABA合成的减少而产生去抑制，从而发生功能重组。但GAD65主要参与对短时程GABA需求变化的调控。     

水杨酸盐诱发大鼠听皮层中TNF-α和GluA1表达的改变

目的通过检测水杨酸盐诱导耳鸣大鼠听皮层中TNF-α和AMPA受体亚基(GluA1)蛋白的表达,研究耳鸣大鼠听皮层是否出现炎症因子和膜受体表达的改变,探讨TNF-α在耳鸣中的作用机制。方法 24只SD大鼠,随机等分成4组:对照组、慢性注射7天组、慢性注射14天组、停药后恢复14天组。前脉冲抑制实验评估动物是否发生耳鸣样行为。Western Blot检测听皮层中TNF-α和GluA1蛋白表达。结果⑴长期注射水杨酸盐后,大鼠的前脉冲抑制率增加,差异有统计学意义(P<0.05)。⑵在慢性注射7天组,TNF-α和GluA1蛋白表达水平较对照组升高,差异有统计学意义(P=0.036,P=0.019,P<0.05);在慢性注射14天组,TNF-α和GluA1蛋白表达水平较对照组、停药后恢复14天组升高,差异有统计学意义(P=0.003,P=0.002,P<0.01)。⑶TNF-α和GluA1蛋白表达具有显著正相关(P=0.000,P<0.001)。结论耳鸣模型大鼠听皮层中TNF-α和GluA1蛋白表达均上调且两者变化有显著正相关性,推测TNF-α可能通过调节GluA1的表达导致大鼠耳鸣。     

隔声后听觉重塑模型中听皮质突触NR2A表达的变化

目的：观察隔声后听觉重塑模型中听皮质突触N甲基-D-天冬氨酸（NMDA）受体亚基NR2A表达的变化。方法：采用清洁级SD大鼠45只,分成隔声组、隔声后听觉重塑组及对照组各15只,Optiprep沉降梯度超速离心从初级听皮质提取高度纯化的突触体后,采用Western blotting蛋白质印迹检测技术对生后隔声14d组、28d组、42d组、隔声7d后再给予纯音暴露的各实验组听皮质突触体NR2A表达进行比较。结果：隔声使生后14d组和28d组动物听皮层NR2A表达水平明显下降（P〈0．05）,隔声7d后再给予纯音暴露则又使NR2A表达水平明显提高（P〈0．05）,呈现双向调节趋势。隔声和纯音暴露对生后42d组成熟大鼠听皮层NR2A表达不再产生明显调节作用（P〉0．05）。结论：在大鼠生后发育关键期,听觉经验可改变听皮层NMDA受体NR2A蛋白表达水平。研究结果为研究感觉功能发育可塑性的机制提供了重要的实验资料。     

经完整圆窗膜途径EGFP基因在大鼠耳蜗中的表达

目的 研究经完整圆窗膜途径进行耳蜗基因转导的可行性及安全性，为内耳基因治疗提供实验基础和理论依据。方法 24只SD大鼠术前及术后分别行听性脑干反应(ABR)检查。实验组(18只)用阳离子脂质体携带的增强型绿色荧光蛋白(enhanced green fluoresent protein，EGFP)基因，对照组(6只)用生理盐水，注入置于圆窗龛处的明胶海绵内。分别于术后3、7、14天取双侧耳蜗标本做基底膜铺片观察。结果 于圆窗龛处放置明胶海绵的转导方法对听力无明显影响。转染耳蜗呈明显的绿色荧光。3天组表达产物最高，7天组逐渐降低，14天组更弱。对侧及对照组耳蜗均未见荧光表达。结论 于圆窗龛处放置明胶海绵进行基因转导的方法对听力没有影响，且能够成功转染耳蜗组织，是一种行之有效的方法。     

Effects of Early Auditory Deprivation and Stimulation on Auditory Brainstem Responses in the Rat

The purpose of this study was to investigate the effect of auditory sound deprivation or stimulation on auditory brainstem responses (ABRs) during the maturation period of the rat auditory system. At postnatal day (PND) 21, 40 newborn Norway Brown male rats were categorized into 3 groups: (i) an auditory deprivation group in which a bilateral average conductive hearing loss of 27 dB was induced; (ii) an auditory activation group exposed to 65-90 dB sound pressure level; and (iii) a control group. ABR recordings were made on PND 84. In order to compare group differences in interpeak latency (IPL), sensation level (SL), defined as stimulus intensity above threshold, was used. IPL measurements and analysis were restricted to the 20-60 dB SL range. No differences were observed in the IPLs of peaks I-IV between the three groups. Small, but not statistically significant, differences in mean estimated IPLs of peaks I-IV were shown in the ranges >50 dB SL and <25 dB SL. Possible confounding factors explaining the apparent discrepancy between these results and those of other animal studies are reviewed.     

Analysis of p1 latency in normal hearing and profound sensorineural hearing loss

Objectives

P1 is a robust positivity at a latency of 50-150 msec in the auditory evoked potential of young children. It has been reported that over the first 2-3 years of life, there is a rapid decrease of the latency and the mean P1 latency in adults with normal hearing is approximately 60 msec. This study was designed to evaluate the change of the P1 latency in Koreans with normal hearing according to age and to compare this with the P1 latency of young patients with profound sensorineural hearing loss before and/or after cochlear implantation.

Methods

Among the patients who visited the Department of Otorhinolaryngology at Seoul National University Hospital from June 2007 to September 2009, the P1 response was recorded in 53 patients in the normal hearing group, in 13 patients in the pre-cochlear implantation (CI) group and in 10 patients in the post-CI group. A synthesized consonant-vowel syllable /ba/ was used to elicit the evoked responses. The evoked responses were collected using the center of the frontal head. For each subject, an individual grand average waveform was computed by averaging the ten recordings. The P1 latency was visually identified as a robust positivity in the waveform.

Results

For the normal hearing group, the P1 latency showed the pattern of shortening as the age increased (coefficient, -0.758; P<0.001). For the pre-CI group, 10 cases showed delayed latencies and 3 cases did not show the P1 wave. For the post-CI group, the P1 latencies showed a less delayed tendency than those of the pre-CI group, but this was not statistically different.

Conclusion

This report provides the standard value of the P1 latency at each age in Koreans for the first time and the findings support that the maturation of the central auditory pathways could be measured objectively using the P1 latency.     

听神经病患者人工耳蜗植入后听觉言语康复效果分析

目的评价重度或极重度听力损失听神经病(Auditory neuropathy,AN)患者人工耳蜗植入术后的听觉言语康复效果。方法用纯音听阈、听觉行为分级标准(Categorise of Auditory Performance,CAP)、言语可懂度分级标准(speech Intelligibility Rating,SIR)、有意义听觉整合量表(meaningful auditor integration scale,MAIS),对行人工耳蜗植入术的18例重度或极重度听力损失语前聋AN患者、4例重度或极重度听力损失语后聋AN患者进行术后效果调查,并与非综合症且无明显病因的重度或极重度感音神经性聋的人工耳蜗植入患者比较,用SPSS13.0进行统计学分析。结果 11例AN患者术后平均助听听阈(250Hz、500 Hz、1000 Hz、2000 Hz、4000 Hz)为(38.64±6.36)d B HL。AN组语前聋患者术后发声情况得分、对声音的自发性觉察能力得分与对照组语前聋患者术后得分相比,差异均无统计学意义(P>0.05),而对声音的理解能力得分、MAIS总得分与对照组语前聋患者术后得分相比,差异有统计学意义(P<0.05),AN组语前聋患者对声音的理解能力得分、MAIS总得分均低于对照组语前聋患者得分。AN组语后聋患者术后CAP评分、SIR评分与对照组语后聋患者术后评分相比,差异无统计学意义(P>0.05)。结论重度或极重度听力损失语前聋AN患者人工耳蜗植入术后的发声情况、对声音的自发性觉察能力与耳蜗形态正常且无任何已知综合症的重度或极重度感音神经性聋语前聋患者术后无明显差异,但是重度或极重度听力损失语前聋AN患者人工耳蜗植入术后对声音的理解能力明显低于耳蜗形态正常且无任何已知综合症的重度或极重度感音神经性聋语前聋患者术后对声音的理解能力。重度或极重度听力损失语后聋AN患者人工耳蜗植入术后听觉言语能力与耳蜗形态正常且无任何已知综合症的重度或极重度感音神经性聋语后聋患者术后无明显差异。     

听觉剥夺后大鼠听皮层神经元的形态学变化和SHP-2基因的表达

目的研究双侧耳蜗毁损后大鼠听皮层神经元细胞的形态学变化和蛋白酪氨酸磷酸酶2型（src-homology domain containing protein tygosine phosphatase type 2,SHP -2）基因的表达。方法选取SD大鼠48只,随机分为4个实验组（2周组、4周组、6周组、8周组）和4个相应的对照组,每组6只。实验组动物行双侧耳蜗损毁术,通过HE染色和Nissl染色观察听皮层神经元细胞的形态学变化,用RT -PCR技术检测各组听皮层神经元细胞的SHP-2基因的表达,行相对定量分析。结果 HE染色和Nissl染色可见各实验组大鼠听皮层神经元细胞的凋亡形态随时间延长而加重,呈多样化表现;各对照组大鼠听皮层细胞形态正常。实验2、4、6、8周组SHP-2基因的RT -PCR相对表达量分别为1．1±0．28、1．5±0．04、2．5±0．08、11．0±0．06,随时间延长呈上升趋势,各实验组之间差异均有统计学意义（P＜0．05）。结论听觉剥夺可导致听皮层神经元细胞凋亡,凋亡的程度随时间延长逐渐加重;SHP-2基因可促进听皮层神经元细胞的增生,增生的程度也随时间延长而加重;在这两个相互拮抗的因素中,凋亡是最终的结果。     

Onset and development of auditory brainstem responses in the Mongolian gerbil (Meriones unguiculatus)

The ontogeny of auditory function in the Mongolian gerbil (Meriones unguiculatus) was examined by measuring auditory brainstem response (ABR) thresholds for clicks and tone bursts at frequencies between 0.125 and 32 kHz. ABRs were elicited as early as 10 postnatal days (PND) in a small proportion of animals (28.6%). Three phases of development were identified based on the appearance of frequency-threshold curves: (a) an onset period (10–12 PND) during which ABRs could be elicited only by intense stimuli (95–110 dB SPL) within a restricted range of frequencies (0.25–8 kHz); (b) a transition period (13–14 PND) during which thresholds improved but frequency-threshold curves remained relatively flat; and (c) a refinement period (15–30 PND) during which frequency-threshold curves exhibited an adult-like (‘V’) shape and thresholds improved steadily to adult-like values. Opening of the external auditory meatus was associated with threshold improvements but not with changes in the frequency region of greatest sensitivity. Between the ages of 13 and 21 PND, low-frequency (0.125–1 kHz) and high-frequency (10–32 kHz) thresholds improved at statistically equivalent rates (4.9 and 5.6 dB/day, respectively), while thresholds for mid-frequency stimuli (2–8 kHz) improved at a significantly faster rate of 9.2 dB/day.     

特殊需要儿童听觉干预的理论与实践

听觉是信息输入的重要渠道,不仅需要对听障儿童进行听觉干预,其他类型的听知觉障碍者也需要相应的干预。本文建构了听觉干预的框架,理清了听觉干预的流程,阐述了听觉干预的内容,说明了听觉干预的原则,为听觉干预的实践提供了较为完整的理论体系和指导模式。     

脑性瘫痪患儿听性脑干反应及多频稳态听性反应分析

目的：通过听性脑干诱发反应（ABR）及听性稳态反应（ASSR）分析，探讨脑性瘫痪（脑瘫）患儿的听力障碍及脑干听通道功能变化。方法：采用美国GSIAudera听性脑干反应及听性稳态诱发电位测试仪，测试脑瘫患儿52例104耳。对照组为同龄健康儿童19例38耳。结果：脑瘫组患儿的ABR各波潜伏期及峰间潜伏期均较对照组明显延长；脑瘫组ASSR结果以轻度低频听力损失为著，并且各频率听力损失的平均值非常接近。结论：ABR和ASSR同时应用，为脑瘫患儿听力损失进行定性定量诊断提供了客观的测试方法。     

Auditory training program for Arabic-speaking children with auditory figure-ground deficits

ObjectiveListening to speech in noise makes up a great challenge for school children with auditory processing disorders mainly those with deficit in auditory figure ground (AFG) ability. These children are candidates for auditory training programs targeting AFG such as noise-desensitization programs. This work aimed to develop a new training material in Arabic language targeting this ability.MethodsA noise-desensitization semi-formal training program was developed and standardized on normal children in a pilot study preceding the main one. Seventeen school children with AFG deficit were submitted to the program for eight weeks then reevaluated.ResultsThe paired sample t-test revealed significant improvement of all trained children after training period in their psychophysical and electrophysiological results. The electrophysiological threshold of signal to noise ratio decreased from −5.3 dB to −11.3 dB after training.ConclusionThe newly developed training material revealed efficacy in managing children with AFG deficit. The other affected auditory abilities improved also because of the multi-ability tapping character of the program.