Palanca-Castan Nicolas, Laumen Geneviève, Reed Darrin, Köppl Christine
Cluster of Excellence "Hearing4all" and Research Center Neurosensory Science and Department of Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University of Oldenburg, Carl von Ossietzky Str. 9-11, 26129, Oldenburg, Germany.
Center for Computational Neuroscience and Neural Technology, Boston University, 677 Beacon St, Boston, MA, 02215, USA.
J Assoc Res Otolaryngol. 2016 Dec;17(6):577-589. doi: 10.1007/s10162-016-0583-7. Epub 2016 Aug 25.
The auditory brainstem response (ABR) is an evoked potential that reflects the responses to sound by brainstem neural centers. The binaural interaction component (BIC) is obtained by subtracting the sum of the monaural ABR responses from the binaural response. Its latency and amplitude change in response to variations in binaural cues. The BIC is thus thought to reflect the activity of binaural nuclei and is used to non-invasively test binaural processing. However, any conclusions are limited by a lack of knowledge of the relevant processes at the level of individual neurons. The aim of this study was to characterize the ABR and BIC in the barn owl, an animal where the ITD-processing neural circuits are known in great detail. We recorded ABR responses to chirps and to 1 and 4 kHz tones from anesthetized barn owls. General characteristics of the barn owl ABR were similar to those observed in other bird species. The most prominent peak of the BIC was associated with nucleus laminaris and is thus likely to reflect the known processes of ITD computation in this nucleus. However, the properties of the BIC were very similar to previously published mammalian data and did not reveal any specific diagnostic features. For example, the polarity of the BIC was negative, which indicates a smaller response to binaural stimulation than predicted by the sum of monaural responses. This is contrary to previous predictions for an excitatory-excitatory system such as nucleus laminaris. Similarly, the change in BIC latency with varying ITD was not distinguishable from mammalian data. Contrary to previous predictions, this behavior appears unrelated to the known underlying neural delay-line circuitry. In conclusion, the generation of the BIC is currently inadequately understood and common assumptions about the BIC need to be reconsidered when interpreting such measurements.
听性脑干反应(ABR)是一种诱发电位,反映脑干神经中枢对声音的反应。双耳相互作用成分(BIC)是通过从双耳反应中减去单耳ABR反应之和而获得的。其潜伏期和振幅会随着双耳线索的变化而改变。因此,BIC被认为反映了双耳核的活动,并被用于非侵入性地测试双耳处理能力。然而,由于对单个神经元水平的相关过程缺乏了解,任何结论都受到限制。本研究的目的是描述仓鸮的ABR和BIC特征,仓鸮是一种其ITD处理神经回路已被详细了解的动物。我们记录了麻醉状态下仓鸮对啁啾声以及1kHz和4kHz音调的ABR反应。仓鸮ABR的一般特征与在其他鸟类中观察到的相似。BIC最突出的峰值与层状核相关,因此可能反映了该核中已知的ITD计算过程。然而,BIC的特性与先前发表的哺乳动物数据非常相似,并未揭示任何特定的诊断特征。例如,BIC的极性为负,这表明对双耳刺激的反应小于单耳反应之和的预测值。这与之前对兴奋性 - 兴奋性系统(如层状核)的预测相反。同样,BIC潜伏期随ITD变化的情况与哺乳动物数据无法区分。与先前的预测相反,这种行为似乎与已知的潜在神经延迟线电路无关。总之,目前对BIC的产生理解不足,在解释此类测量结果时,需要重新考虑关于BIC的常见假设。