Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany.
Institute of Zoology and Neurobiology, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany.
Sci Rep. 2021 Mar 4;11(1):5139. doi: 10.1038/s41598-021-84230-9.
To counterbalance long-term environmental changes, neuronal circuits adapt the processing of sensory information. In the auditory system, ongoing background noise drives long-lasting adaptive mechanism in binaural coincidence detector neurons in the superior olive. However, the compensatory cellular mechanisms of the binaural neurons in the medial superior olive (MSO) to long-term background changes are unexplored. Here we investigated the cellular properties of MSO neurons during long-lasting adaptations induced by moderate omnidirectional noise exposure. After noise exposure, the input resistance of MSO neurons of mature Mongolian gerbils was reduced, likely due to an upregulation of hyperpolarisation-activated cation and low voltage-activated potassium currents. Functionally, the long-lasting adaptations increased the action potential current threshold and facilitated high frequency output generation. Noise exposure accelerated the occurrence of spontaneous postsynaptic currents. Together, our data suggest that cellular adaptations in coincidence detector neurons of the MSO to continuous noise exposure likely increase the sensitivity to differences in sound pressure levels.
为了平衡长期的环境变化，神经元回路会调整对感觉信息的处理。在听觉系统中，持续的背景噪声会驱动上橄榄中双耳吻合检测器神经元的长期适应机制。然而，中脑上橄榄核（MSO）中双耳神经元对长期背景变化的补偿性细胞机制尚不清楚。在这里，我们研究了成熟蒙古沙鼠 MSO 神经元在中度全向噪声暴露诱导的长期适应过程中的细胞特性。噪声暴露后，MSO 神经元的输入电阻降低，这可能是由于超极化激活阳离子和低电压激活钾电流的上调。功能上，长期适应增加了动作电位电流阈值，并促进了高频输出的产生。噪声暴露加速了自发性突触后电流的发生。总的来说，我们的数据表明，MSO 中的吻合检测器神经元对持续噪声暴露的细胞适应可能会增加对声压水平差异的敏感性。
