Nonuniform impacts of forward suppression on neural responses to preferred stimuli and nonpreferred stimuli in the rat auditory cortex
Nonuniform impacts of forward suppression on neural responses to preferred stimuli and nonpreferred stimuli in the rat auditory cortex
复制标题
前向抑制对大鼠听觉皮层偏好刺激和非偏好刺激的神经反应的非均匀影响
DOI：
10.1111/ejn.13943
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发表时间：
2018-06-01
影响因子：
3.4
通讯作者：
Zhang, Jiping
中科院分区：
文献类型：
--
作者：
Gao, Fei;Chen, Liang;Zhang, Jiping
在自然条件下，人类和动物需要从嘈杂的声学环境中提取目标声音信息，以进行通信和生存。然而，背景环境的声音如何影响中央听神经元的调谐，以在广泛的声级范围内瞄准声源方位，还没有完全了解。在这里，我们通过记录大鼠听皮层神经元在安静(单独探测)和前向掩蔽(前噪声+探测)条件下对探测音的反应随水平和声源方位的变化来确定它们的方位向反应区域(ALRA)。在安静状态下，皮层神经元对其偏好刺激的反应比对非偏好刺激的反应更强烈。在前向掩蔽条件下，有效的前置噪声通过降低反应强度和延长第一峰潜伏期，降低了ALRA的幅度，并抑制了跨越ALRA的神经反应。对神经反应强度的前向抑制作用随掩蔽剂水平的增加而增加，随掩蔽剂与探针之间时间间隔的延长而减弱。对于所研究的部分皮层神经元，前向抑制对偏好刺激的反应强度的影响弱于对非偏好刺激的反应强度，对偏好刺激的反应强度正向抑制的恢复早于对非偏好刺激的反应强度的恢复。我们认为，这种对首选刺激和非首选刺激的神经反应的非均匀正向抑制对于皮质神经元在噪声环境中保持对目标声源的方位和电平的相对稳定的偏好是重要的。
In natural conditions, human and animals need to extract target sound information from noisy acoustic environments for communication and survival. However, how the contextual environmental sounds impact the tuning of central auditory neurons to target sound source azimuth over a wide range of sound levels is not fully understood. Here, we determined the azimuth‐level response areas (ALRAs) of rat auditory cortex neurons by recording their responses to probe tones varying with levels and sound source azimuths under both quiet (probe alone) and forward masking conditions (preceding noise + probe). In quiet, cortical neurons responded stronger to their preferred stimuli than to their nonpreferred stimuli. In forward masking conditions, an effective preceding noise reduced the extents of the ALRAs and suppressed the neural responses across the ALRAs by decreasing the response strength and lengthening the first‐spike latency. The forward suppressive effect on neural response strength was increased with increasing masker level and decreased with prolonging the time interval between masker and probe. For a portion of cortical neurons studied, the effects of forward suppression on the response strength to preferred stimuli was weaker than those to nonpreferred stimuli, and the recovery from forward suppression of the response strength to preferred stimuli was earlier than that to nonpreferred stimuli. We suggest that this nonuniform forward suppression of neural responses to preferred stimuli and to nonpreferred stimuli is important for cortical neurons to maintain their relative stable preferences for target sound source azimuth and level in noisy acoustic environments.