Linking age-related cochlear dysfunction to the perception of temporal fine structure

尽管听力阈值正常，但老年人在嘈杂的环境中往往难以沟通。有人认为这是由于听觉神经纤维中听觉信号的表征受损而导致听觉信号的时间精细结构（TFS）的感知受损。这种损害可能是由于耳蜗神经病变影响特别是低自发率纤维或耳蜗内电位的恶化。通过相关的听觉歧视的刺激，依赖于TFS在不同年龄的蒙古沙鼠的代表性，这种刺激的听觉神经纤维和传入突触的解剖量化在同一个人的耳蜗，我们将提供相关的证据，提出病因的知觉缺陷有关TFS。通过对幼沙鼠耳蜗神经病变的反复操作，并评估操作前后的TFS感知，我们将进一步提供证据，证明神经病变与基于TFS的辨别刺激的能力之间存在因果关系。这种结合的方法将提供一个前所未有的水平的理解的过程中连接年龄相关的耳蜗功能障碍的感知TFS。

Despite normal hearing thresholds, elderly people often have difficulties communicating in noisy situations. It has been suggested that this is due to a compromised perception of the temporal fine structure (TFS) of acoustic signals caused by its impaired representation in auditory nerve fibers. Such impairment may result from cochlear neuropathy affecting especially low spontaneous rate fibers or from deterioration of the endocochlear potential. By relating auditory discrimination of stimuli that relies on TFS in Mongolian gerbils of different ages to the representation of such stimuli by auditory-nerve fibers and the anatomical quantification of afferent synapses in the cochleae of the same individuals, we will provide correlational evidence for the proposed etiology of the perceptual deficits regarding TFS. By pharmacologically manipulating the cochlear neuropathy in young gerbils and evaluating TFS perception before and after the manipulation, we will further provide evidence for a causal link between the neuropathy and the ability to discriminate stimuli based on TFS. This combined approach will provide for an unprecedented level of understanding of the processes linking age-related cochlear dysfunction to the perception of TFS.