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1.
有关猫听觉脑干电反应(ABR)两耳干涉作用的研究   总被引:4,自引:1,他引:3  
用不同声强稳态白噪声和短声同时分别刺激两耳,观察白噪声负荷侧耳蜗破坏前后另一侧ABR的改变,探讨两耳干涉作用及其可能的机制。结果显示,对侧耳蜗破坏前,40dB和75dB白噪声对0dB、45dB、70dB和75dBSPL的短声诱发的ABR各波振幅均有明显影响(P<0.050.01)。耳蜗破坏后,同样条件下记录的ABR振幅基本无明显变化(P>0.05)。提示白噪声对短声有一定的干涉作用。短声为70dBSPL时ABRP1波振幅的减小可能与中枢离中控制相关。  相似文献   

2.
有关猫交叉听力及其对检测耳影响的初步研究   总被引:3,自引:0,他引:3  
目的研究猫的交叉听力现象及其产生机理,初步探讨交叉听力对检测耳ABR振幅的影响。方法用彻底破坏一侧耳蜗的方法,观察16只听力正常家猫的交叉听力现象及其对检测耳的影响。结果①当短声强度≥75dB(SPL)时,开始出现交叉听力波形,声强增至95dB时,交叉听力波形最典型。②95dB短声产生的交叉听力波形可被40或45dB(SPL)的稳态白噪声(SWN)完全屏蔽掉。③在同一时间轴中比较95dB短声诱发的ABR和交叉听力波形,发现交叉听力之波谷恰与ABR之pⅢ、pⅣ波峰相对应。④两耳均正常时对侧耳负荷的40dBSWN可使95dB短声诱发的ABR之pⅢ、pⅣ波振幅增大,且具统计学意义(P<0.01)。结论交叉听力对ABR振幅的影响取决于两者的波峰与波谷在同一时间轴上的对应情况,声强较大时记录到的ABR,实质上是交叉听力与刺激侧产生的ABR在同一时间轴上的综合电位。  相似文献   

3.
采用具有不同间隔(0~32ms)的65dB nHL(正常听力水平)的成对短声刺激,记录20名正常人的单侧耳和两耳交替刺激的听觉脑干反应(ABR)。用计算机从成对短声反应中减去单一短声反应以提取衍生ABR。结果表明,单、双耳的衍生ABR V波振幅在成对短声间隔为0.2~1.5ms时,受到明显影响。单耳的减小54%~65%(P<0.01),两耳的减少46%~53%(P<0.01),但单、双耳的衍生ABR I波振幅未显示显著差异(P>0.05)。该结果说明,高位脑干通路在成对短声间隔为0.2~1.5ms时,不但对同侧耳的第2个短声反应能力降低,而且对来自对侧耳的第2个短声也如此。从而推断,在两耳交替刺激的耳间短声间隔小于2ms范围时,在下丘部位可能存在两耳交互作用。结果还提示,临床检查ABR时,采用的短声刺激间隔至少不应小于30ms。  相似文献   

4.
为研究噪声作用后听觉中枢诱发反应振幅变化,用豚鼠记录了器材怕作用前后皮层诱发反应(ACER)和脑干诱发反应(ABR)的振幅和潜伏期,比较了暴露噪声前后短声刺激系列强度中ACER和ABR最大振幅和潜伏期,110dBA宽带噪声作用30分钟后,听阈提高53dB,ACER最大振幅增大24%,1小时后仍为24%,2小时后增大28%,峰间潜伏期(P1-P2)比暴露前缩短,噪声作用后ABRV波最大振幅增大15%,1小时后为21%,2小时后为28%,潜伏期比暴露前缩短,AP、ABP、Ⅰ、Ⅲ。Ⅳ波最大振幅均经暴露前减小。结果表明,强噪声作用后ACER存在振幅增大,同时ABRV波也有振幅增大现象。  相似文献   

5.
目的:探讨人工耳蜗电极的插入对耳蜗功能的影响,为研究人工耳蜗植入建立相应的动物模型。方法:取听力正常的豚鼠8只,4只注射卡那霉素联合呋塞米致聋,为致聋组;4只仅注射生理盐水,为对照组。对两组动物行听性脑干反应(ABR)及耳声发射(DPOAE)检查后,将耳蜗电极植入左侧耳蜗。结果:致聋组术侧4个频率段ABR阈移随着时间的推移逐渐减小,术后24 h、48 h、72 h时间段比较无显著性差异(P0.05);对照组术侧ABR阈移随着时间的推移逐渐减小,32 kHz频率的三个时间段比较有显著性差异(P0.05),其余3个频率无显著性差异。此外,致聋组与对照组术侧耳ABR阈移比较均无显著性差异(P0.05)。致聋组术前5个频率的DPOAE无法引出,术后DPOAE仍无法引出;对照组术前DPOAE均可引出,术后术侧的DPOAE均无法引出。术后72 h可见电极周围有组织包绕,固定良好,局部未见明显炎症反应。结论:本实验成功建立了卡那霉素致聋的豚鼠耳蜗电极植入模型,可为人工耳蜗植入术后颞骨病理改变的研究提供实验基础。  相似文献   

6.
采用耳蜗外淋巴液灌流催产素(OXT),记录由鼓阶电极引导的听神经复合动作电位(CAP)及耳蜗微音电位(CM)的输入—输出(I/O)函数。发现OXT可在90dB(SPL)以下各声强提高短纯音诱发的CM振幅以及短声诱发的CAP振幅,而当声强高于90dB时CM变化不明显。但在用含氯化筒箭毒(dTC)的外淋巴液灌流以阻断橄榄耳蜗束胆碱能传出控制后,OXT不再引起CM改变,而对CAP的作用在低声强段(<60dB)依然存在。这些结果提示OXT可能调节传出神经对内耳的控制,并可能对外毛细胞(OHC)的运动能力有直接影响。  相似文献   

7.
康健  魏保龄 《生理学报》1986,38(3):259-265
在33例猫将普鲁卡因或海人酸微量注入耳蜗核(CN)和上橄榄复合体(SOC)内,观察ABR的相应改变,以分析P_(2a)和P_(2b)波的来源。猫P_(2a)波的出现率与电极导联有关,颅顶-颈后为90%,颅顶-乳突仅为18%。普普卡因注入CN后,同侧耳短声诱发的ABR仅保留P_1波,对侧耳的则无改变。海人酸注入CN后,P_1和P_(2a)存留,P_(2a)不减小反而增大。普鲁卡因注入双侧SOC,可使P_3、P_4和P_5消失。这些结果提示,P_(2a)波主要起源于CN区域内的第一级听觉传入神经元轴突并受第二级神经元负电位的影响,P_(2b)波主要起源于SOC以下的第二级听觉传入神经元,猫的P_(2a)和P_(2a)波与对侧脑干结构无关。  相似文献   

8.
目的:研究丹参注射液(SM)对庆大霉素(GM)耳中毒豚鼠耳蜗氧自由基生成的影响,探讨SM对GM耳毒性损伤的保护作用及其机制.方法:检测豚鼠耳蜗组织中超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量,结合听性脑干反应(ABR)测试及透射电镜技术.结果:经GM处理的耳蜗组织中SOD活力明显下降,MDA含量则明显增加(P<0.01),且与ABR阈值升高高度相关(|r|>0.8,P<0.05).同时接受SM的动物,其耳蜗组织中SOD活力明显升高(P<0.01),MDA含量则明显减少(P<0.05),且听功能显著改善.电镜观察显示耳蜗形态学改变与听力变化相一致.结论:氧自由基及其引发的脂质过氧化参与了GM耳中毒过程,SM可通过提高耳蜗组织中SOD活力,防止脂质过氧化,减轻GM的耳蜗毒性,改善听功能.  相似文献   

9.
34例听觉正常受试者(共48耳)进行疏波短声诱发性耳声发射(EOAE)掩蔽实验,项目包括同侧同时掩蔽、同侧后掩蔽和对倒后掩蔽。同时掩蔽的掩蔽声是稳态白噪声,后掩蔽的掩蔽声是宽带噪声。同侧同时掩蔽强度达30dBSL时,未观察到对EOAE的掩蔽效应,但对主观听觉感受有掩蔽作用,表明EOAE的客观属性反映听觉行为有其局限性、同侧及对侧后掩蔽出现掩蔽效应时的掩蔽强度分别为30和50dBSL,掩蔽阈约分别为59和68dBSL。耳蜗的机械特性-非线性或耳蜗内存在的某种功能性的反馈调节系统可能是同侧后掩蔽的作用机理。下行的对侧橄榄耳蜗内侧束对外毛细胞主动收缩的抑制性作用,可有效解释对倒后掩蔽的EOAE变化。  相似文献   

10.
Ni YQ  Tang H  Fu WS 《生理学报》2005,57(3):328-332
为探讨热休克蛋白(heatshockprotein,HSP)70mRNA在庆大霉素(gentamicin,GM)耳中毒中的意义,本实验选用耳廓反射灵敏的健康白色红目豚鼠(200~250g)20只,雌雄不拘,随机分成两组,每组10只。实验组动物每日腹腔注射GM100mg/kg;对照组动物每日腹腔注射与GM等量的生理盐水2.5ml/kg。两组动物混合饲养,均连续用药10d。在用药前1天和停药后第1天进行听脑干反应(auditorybrainstemresponse,ABR)测试。各组豚鼠在行第二次ABR检测后,应用原位杂交及图像分析技术观察GM耳中毒后HSP70mRNA在豚鼠耳蜗中表达。结果显示:实验组耳蜗ABR阈值明显高于对照组,有显著性差异(P<0.01);实验组豚鼠耳蜗血管纹、螺旋韧带、螺旋神经节细胞HSP70mRNA表达呈强阳性,其平均灰度值较正常对照组明显减小(P<0.001),即GM能显著增强耳蜗HSP70mRNA的表达。结果提示,GM中毒后,动物可能通过增加HSP70mRNA在耳蜗的表达,起保护听力的作用。  相似文献   

11.
Summary Auditory brain stem responses (ABR) were recorded from the head surface of non-anesthetized and non-relaxed bottle-nosed dolphins, Tursiops truncatus. The region of best ABR recording was shown to be located 6–9 cm caudal to the blowhole. The threshold values were about 1 mPa for noise bursts and –3 dB re 1 mPa for tone bursts of the optimal frequency (80 kHz). The maximum frequency at which ABR could be evoked was 140 kHz. The duration of temporal summation reached 0.5 ms at intensities near the threshold and decreased with an increase in intensity. When the stimuli were paired clicks of the same intensity, the time to complete recovery from the second response was about 5 ms, while that to its 50% recovery was 0.7 ms. When the conditioning click exceeded the testing one in intensity, prolongation of the recovery period was observed. A 40-dB intensity difference led to an approximately 10-fold prolongation of this period.Abbreviations ABR auditory brain stem response - EP evoked potential  相似文献   

12.
Zhang YM  Ma B  Gao WY  Wen W  Liu HY 《生理学报》2007,59(1):103-110
本文旨在研究谷氨酸及其受体在噪声致豚鼠螺旋神经节细胞损伤中的作用。实验分为在体和离体两部分。(1)在体实验:豚鼠分为生理盐水(NS,10μL)组,NS(10μL)+噪声组和犬尿喹啉酸(kynurenic acid,KYNA,5mmol/L,10μL)+噪声组,每组15只。用微量注射器经完整圆窗膜表面给予NS或KYNA:暴露于白噪声110dBSPL,1h。在圆窗给药前及噪声暴露后测试听觉脑干诱发电位(auditory brainstem response,ABR)阈值及Ⅲ波幅值,听神经复合动作电位(compound action potential,CAP)阈值及N1波幅值和潜伏期,测试后取基底膜进行透射电镜观察。(2)离体实验:观察高浓度谷氨酸对急性分离的豚鼠螺旋神经节细胞的影响。结果显示,NS+噪声组豚鼠ABR及CAP阈移显著高于KYNA+噪声组,且Ⅲ波和NI波幅值明显降低,潜伏期明显延长。NS+噪声组豚鼠毛细胞及传入神经末梢急性水肿和线粒体结构破坏:KYNA+噪声组豚鼠的毛细胞和传入神经末梢无明显变化。离体胞外施加谷氨酸可引起螺旋神经节细胞逐渐出现水肿、变性,最后死亡。本实验提示,噪声暴露可引起豚鼠听功能损伤,毛细胞/传入神经突触的结构破坏和螺旋神经节细胞变性、死亡:这种损伤可能与噪声暴露引起谷氨酸的过度释放有关;谷氨酸通过其受体介导致使螺旋神经节细胞损伤,谷氨酸受体的广谱拮抗剂KYNA可减轻噪声对螺旋神经节细胞的损伤。  相似文献   

13.
The present study aimed to observe the changes in the cochlea ribbon synapses after repeated exposure to moderate-to-high intensity noise. Guinea pigs received 95 dB SPL white noise exposure 4 h a day for consecutive 7 days (we regarded it a medium-term and moderate-intensity noise, or MTMI noise). Animals were divided into four groups: Control, 1DPN (1-day post noise), 1WPN (1-week post noise), and 1MPN (1-month post noise). Auditory function analysis by auditory brainstem response (ABR) and compound action potential (CAP) recordings, as well as ribbon synapse morphological analyses by immunohistochemistry (Ctbp2 and PSD95 staining) were performed 1 day, 1 week, and 1 month after noise exposure. After MTMI noise exposure, the amplitudes of ABR I and III waves were suppressed. The CAP threshold was elevated, and CAP amplitude was reduced in the 1DPN group. No apparent changes in hair cell shape, arrangement, or number were observed, but the number of ribbon synapse was reduced. The 1WPN and 1MPN groups showed that part of ABR and CAP changes recovered, as well as the synapse number. The defects in cochlea auditory function and synapse changes were observed mainly in the high-frequency region. Together, repeated exposure in MTMI noise can cause hidden hearing loss (HHL), which is partially reversible after leaving the noise environment; and MTMI noise-induced HHL is associated with inner hair cell ribbon synapses.  相似文献   

14.
本文对豚鼠噪声暴露后的耳蜗电图功率谱进行了分析,实验表明:噪声组豚鼠耳蜗电图功率谱150~300Hz频段能量较正常组有明显增长;500~850Hz和850~1400Hz频段能量不集中(表2).另外,噪声组耳蜗电图功率谱与标准型的相关度比正常组与标准型的相关度差(P<0.01).  相似文献   

15.
用慢性面神经管长期置入电极方法,测试了不同时间,不同强度的白噪声或2.83KHz,强纯音暴露下清醒豚鼠的AP(N1)潜伏期,结果发现,暴露后对短声及各频率短纯音反应的AP(N1)潜伏期均出现统计学意义的延长者,可作为预测永久性阈移(PTS)的一项较理想的指标。  相似文献   

16.
用慢性面神经管长期置入电极方法,测试了不同时间,不同强度的白噪声或2.83KHz强纯音暴露下清醒豚鼠的AP(N1)潜伏期。结果发现,暴露后对短声及各频率短纯音反应的AP(N1)潜伏期均出现统计学意义的延长者,可作为预测永久性阈移(PTS)的一项较理想的指标。  相似文献   

17.
Chronic tinnitus, or “ringing of the ears”, affects upwards of 15% of the adult population. Identifying a cost-effective and objective measure of tinnitus is needed due to legal concerns and disability issues, as well as for facilitating the effort to assess neural biomarkers. We developed a modified gap-in-noise (GIN) paradigm to assess tinnitus in mice using the auditory brainstem response (ABR). We then compared the commonly used acoustic startle reflex gap-prepulse inhibition (gap-PPI) and the ABR GIN paradigm in young adult CBA/CaJ mice before and after administrating sodium salicylate (SS), which is known to reliably induce a 16 kHz tinnitus percept in rodents. Post-SS, gap-PPI was significantly reduced at 12 and 16 kHz, consistent with previous studies demonstrating a tinnitus-induced gap-PPI reduction in this frequency range. ABR audiograms indicated thresholds were significantly elevated post-SS, also consistent with previous studies. There was a significant increase in the peak 2 (P2) to peak 1 (P1) and peak 4 (P4) to P1 amplitude ratios in the mid-frequency range, along with decreased latency of P4 at higher intensities. For the ABR GIN, peak amplitudes of the response to the second noise burst were calculated as a percentage of the first noise burst response amplitudes to quantify neural gap processing. A significant decrease in this ratio (i.e. recovery) was seen only at 16 kHz for P1, indicating the presence of tinnitus near this frequency. Thus, this study demonstrates that GIN ABRs can be used as an efficient, non-invasive, and objective method of identifying the approximate pitch and presence of tinnitus in a mouse model. This technique has the potential for application in human subjects and also indicates significant, albeit different, deficits in temporal processing in peripheral and brainstem circuits following drug induced tinnitus.  相似文献   

18.
猫耳蜗电图中N_2波起源的分析   总被引:4,自引:0,他引:4  
魏保龄  康健  曲非 《生理学报》1986,38(5):535-538
在35只猫进行了耳蜗电图、听觉脑干电反应及耳蜗核局部电位的同时描记,将普鲁卡因或海人酸微量注入耳蜗核内,观察电位的变化,以分析耳蜗电图中N_2 波的起源。实验结果表明:猫的 N_2 波来源于外周第一级神经元冲动的成分和耳蜗核电活动的成分。  相似文献   

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