Kuokkanen Paula T, Kraemer Ira, Köppl Christine, Carr Catherine E, Kempter Richard
Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin 10115, Germany
Department of Biology, University of Maryland College Park, College Park, MD 20742.
J Neurosci. 2025 May 28;45(22):e1139242025. doi: 10.1523/JNEUROSCI.1139-24.2025.
The auditory brainstem response (ABR) is an acoustically evoked EEG potential that is an important diagnostic tool for hearing loss, especially in newborns. The ABR originates from the response sequence of auditory nerve and brainstem nuclei, and a click-evoked ABR typically shows three positive peaks ("waves") within the first six milliseconds. However, an assignment of the waves of the ABR to specific sources is difficult, and a quantification of contributions to the ABR waves is not available. Here, we exploit the large size and physical separation of the barn owl first-order cochlear nucleus magnocellularis (NM) to estimate single-cell contributions to the ABR. We simultaneously recorded NM neurons' spikes and the EEG in owls of both sexes, and found that [Formula: see text] spontaneous single-cell spikes are necessary to isolate a significant spike-triggered average (STA) response at the EEG electrode. An average single-neuron contribution to the ABR was predicted by convolving the STA with the cell's peri-stimulus time histogram. Amplitudes of predicted contributions of single NM cells typically reached 32.9 ± 1.1 nV (mean ± SE, range: 2.5-162.7 nV), or [Formula: see text] (median ± SE; range from 0.01% to 1%) of the ABR amplitude. The time of the predicted peak coincided best with the peak of the ABR wave II, independent of the click sound level. Our results suggest that individual neurons' contributions to an EEG can vary widely, and that wave II of the ABR is shaped by NM units.
听觉脑干反应（ABR）是一种由声音诱发的脑电图电位，是诊断听力损失的重要工具，尤其适用于新生儿。ABR起源于听神经和脑干核的反应序列，典型的短声诱发ABR在前6毫秒内通常显示出三个正向波峰（“波”）。然而，将ABR的波峰与特定来源进行对应很困难，并且无法对ABR波峰的贡献进行量化。在此，我们利用仓鸮的一级耳蜗大细胞神经核（NM）体积大且物理分离的特点来估计单细胞对ABR的贡献。我们同时记录了雌雄仓鸮NM神经元的尖峰信号和脑电图，发现[公式：见正文]自发单细胞尖峰信号对于在脑电图电极处分离出显著的尖峰触发平均（STA）反应是必要的。通过将STA与细胞的刺激后时间直方图进行卷积，预测了单个神经元对ABR的平均贡献。单个NM细胞预测贡献的幅度通常达到32.9±1.1 nV（平均值±标准误，范围：2.5 - 162.
