【摘要】 目的研究我国现存蝙蝠的耳蜗形态和客观听力图与体型参数的相关性,为现存蝙蝠的听觉器官形态和功能进化状态提供数据资料,给蝙蝠听觉器官与发声频率的匹配关系提供依据,建立和完善客观评估蝙蝠听力图的理论和方法,通过本研究拟为蝙蝠的进化理论、生态适应对策和回声定位生理机制提供依据。方法应用美国TDT系统Ⅲ(Tucker-Davis Technologies TDT SystemⅢ)对大蹄蝠、黄大蹄蝠、中蹄蝠和小蹄蝠四种蹄蝠的听性脑干反应(auditory brainstem response,ABR)听力图进行测量和对比分析,测量四种蹄蝠的体型参数和耳蜗形态参数,采用统计学方法分析体型参数前臂长与耳蜗基底宽、耳蜗高和基部头盖骨宽,以及体型与蹄蝠叫声主频率的相关关系。结果本研究结果证明,蝙蝠体型与其叫声主频率呈负相关关系,体型与蝙蝠的社会交流叫声频率亦呈负相关关系。ABR听力图与行为听力图基本相似,蹄蝠听力图具有两到三个听阈敏感区,与蝙蝠的社会交流叫声频率和回声定位声纳频率相对应,而蝙蝠的社会交流叫声频率的ABR听力图在不同种蝙蝠间具有间断跳跃的趋势。从耳蜗基底宽与基部头盖骨宽的关系看,小翼手亚目较大翼手亚目的耳蜗形态要大得多,基本呈现负相关趋势。发现在同科蝙蝠间耳蜗形态与体型呈正向相关关系,比较四种蝙蝠的听力图形状,大蹄蝠均较体型小的蹄蝠听阈值要低及听觉频率范围要宽广。结论本研究结果说明目前体型大的蝙蝠拥有较大的耳蜗形态,与其发声器官相匹配的是耳蜗既要接收高频叫声的回声定位声纳信号,又要进行较低频率叫声的社会信息交流,支持蝙蝠叫声频率与听觉器官及听觉功能协同进化的结论。更多还原

【Abstract】 Objective To study evolution of bat auditory organs and functions and the relationship between bat auditory organs and call frequencies through examining the auditory brainstem response (ABR) audiogram,cochlear morphology and body parameters in four bat species in China. The study is intended to establish a methodology of reliable evaluation of bat audiogram and to provide guidance in understanding bat evolution and policy-making for eco-protection. Methods ABR audiograms were obtained using a TDT Ⅲ system in Hipposideridae:Hipposideros armiger,Hipposideros pratti,Hipposideros larvatus and Hipposideros cineraceus. Cochlear and body parameters were also measured in these species. The relationships among the forearm length,cochlear base width,cochlear height,skull base width and call frequencies were analyzed. Results The body size was negatively correlated to the primary call frequency and social call frequencies in these bats. The ABR audiogram correlated well with behavioral audiogram. Two or three high sensitivity threshold areas were identified on the audiogram,which corresponded to the bats’ social call and echolocation sonar frequencies. Discrete social call frequency intervals were noticed on the audiogram when compared among different species. Judging from the ratio between cochlear base width and skull base width,the cochlea in small size species is relatively large compared to large size species,demonstrating a trend of negative correlation. Within the same species,however,the size of the cochlea is positively correlated to the body size. On audiogram,larger size bats showed lower auditory thresholds and wider auditory frequency range than smaller size bats. Conclusion Large size bats appear to have relatively large size cochleae which are used to receive high echolocation frequencies as well as low social call frequencies. The data support the notion that bat auditory organs and functions are synchronized to evolution of their call frequencies.更多还原