Institute of Neuroscience and Department of Biology, University of Oregon, Eugene, Oregon 97403.
Institute of Neuroscience and Department of Biology, University of Oregon, Eugene, Oregon 97403
eNeuro. 2022 Mar 3;9(2). doi: 10.1523/ENEURO.0264-21.2021. Print 2022 Mar-Apr.
The ability to separate background noise from relevant acoustic signals is essential for appropriate sound-driven behavior in natural environments. Examples of this separation are apparent in the auditory system, where neural responses to behaviorally relevant stimuli become increasingly noise invariant along the ascending auditory pathway. However, the mechanisms that underlie this reduction in responses to background noise are not well understood. To address this gap in knowledge, we first evaluated the effects of auditory cortical inactivation on mice of both sexes trained to perform a simple auditory signal-in-noise detection task and found that outputs from the auditory cortex are important for the detection of auditory stimuli in noisy environments. Next, we evaluated the contributions of the two most common cortical inhibitory cell types, parvalbumin-expressing (PV) and somatostatin-expressing (SOM) interneurons, to the perception of masked auditory stimuli. We found that inactivation of either PV or SOM cells resulted in a reduction in the ability of mice to determine the presence of auditory stimuli masked by noise. These results indicate that a disruption of auditory cortical network dynamics by either of these two types of inhibitory cells is sufficient to impair the ability to separate acoustic signals from noise.
从相关的声学信号中分离背景噪声的能力对于在自然环境中进行适当的声音驱动行为至关重要。这种分离的例子在听觉系统中很明显，在听觉系统中，对行为相关刺激的神经反应沿着听觉通路上行变得越来越不受噪声影响。然而，这种对背景噪声反应减少的机制尚不清楚。为了解决这一知识空白，我们首先评估了听觉皮层失活对接受过简单听觉信号-噪声检测任务训练的雌雄小鼠的影响，结果发现听觉皮层的输出对于在噪声环境中检测听觉刺激很重要。接下来，我们评估了两种最常见的皮层抑制性细胞类型，即表达 parvalbumin (PV) 和表达 somatostatin (SOM) 的中间神经元，对掩蔽听觉刺激感知的贡献。结果发现，失活 PV 或 SOM 细胞会降低小鼠确定被噪声掩蔽的听觉刺激存在的能力。这些结果表明，这两种抑制性细胞中的任何一种破坏听觉皮层网络动态都足以损害从噪声中分离声信号的能力。
