Buchholz Sarah, Schnupp Jan W H, Arndt Susan, Rosskothen-Kuhl Nicole
Neurobiological Research Laboratory, Section for Experimental and Clinical Otology, Department of Otorhinolaryngology, Head and Neck Surgery, Faculty of Medicine, Medical Center - University of Freiburg, Killianst. 5, 79106, Freiburg im Breisgau, Germany.
Department of Neuroscience, City University of Hong Kong, Kowloon Tong, Hong Kong SAR.
Sci Rep. 2024 Dec 16;14(1):30515. doi: 10.1038/s41598-024-82978-4.
Bilateral cochlear implant (CI) patients exhibit significant limitations in spatial hearing. Their ability to process interaural time differences (ITDs) is often impaired, while their ability to process interaural level differences (ILDs) remains comparatively good. Clinical studies aiming to identify the causes of these limitations are often plagued by confounds and ethical limitations. Recent behavioral work suggests that rats may be a good animal model for studying binaural hearing under neuroprosthetic stimulation, as rats develop excellent ITD sensitivity when provided with suitable CI stimulation. However, their ability to use ILDs has not yet been characterized. Objective of this study is to address this knowledge gap. Neontally deafened rats were bilaterally fitted with CIs, and trained to lateralize binaural stimuli according to ILD. Their behavioral ILD thresholds were measured at pulse rates from 50 to 2400 pps. CI rats exhibited high sensitivity to ILDs with thresholds of a few dB at all tested pulse rates. We conclude that early deafened rats develop good sensitivity, not only to ITDs but also to ILDs, if provided with appropriate CI stimulation. Their generally good performance, in line with expectations from other mammalian species, validates rats as an excellent model for research on binaural auditory prostheses.
双侧人工耳蜗（CI）植入患者在空间听觉方面存在显著局限。他们处理双耳时间差（ITD）的能力常常受损，而处理双耳声级差（ILD）的能力相对较好。旨在确定这些局限原因的临床研究常常受到混淆因素和伦理限制的困扰。近期的行为学研究表明，大鼠可能是研究神经假体刺激下双耳听觉的良好动物模型，因为在给予合适的CI刺激时，大鼠会发展出出色的ITD敏感性。然而，它们利用ILD的能力尚未得到表征。本研究的目的是填补这一知识空白。对新生致聋大鼠双侧植入CI，并训练它们根据ILD对双耳刺激进行定位。在50至2400次/秒的脉冲率下测量它们的行为ILD阈值。CI大鼠对ILD表现出高敏感性，在所有测试脉冲率下阈值为几分贝。我们得出结论，如果给予适当的CI刺激，早期致聋大鼠不仅对ITD，而且对ILD都会发展出良好的敏感性。它们总体良好的表现，与其他哺乳动物物种的预期一致，证实大鼠是双耳听觉假体研究的优秀模型。
