Department of Otolaryngology-Head and Neck Surgery, Anhui Medical University Affiliated Anhui Provincial Hospital, Hefei 230001, China.
Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of University of Science and Technology of China, Hefei 230001, China.
Neural Plast. 2018 Feb 8;2018:9828070. doi: 10.1155/2018/9828070. eCollection 2018.
Acoustic trauma is being reported to damage the auditory periphery and central system, and the compromised cortical inhibition is involved in auditory disorders, such as hyperacusis and tinnitus. Parvalbumin-containing neurons (PV neurons), a subset of GABAergic neurons, greatly shape and synchronize neural network activities. However, the change of PV neurons following acoustic trauma remains to be elucidated. The present study investigated how auditory cortical PV neurons change following unilateral 1 hour noise exposure (left ear, one octave band noise centered at 16 kHz, 116 dB SPL). Noise exposure elevated the auditory brainstem response threshold of the exposed ear when examined 7 days later. More detectable PV neurons were observed in both sides of the auditory cortex of noise-exposed rats when compared to control. The detectable PV neurons of the left auditory cortex (ipsilateral to the exposed ear) to noise exposure outnumbered those of the right auditory cortex (contralateral to the exposed ear). Quantification of Western blotted bands revealed higher expression level of PV protein in the left cortex. These findings of more active PV neurons in noise-exposed rats suggested that a compensatory mechanism might be initiated to maintain a stable state of the brain.
声创伤被报道会损害听觉外围和中枢系统，而皮质抑制的损伤与听觉障碍有关，如听觉过敏和耳鸣。含脑啡肽的神经元（PV 神经元）是 GABA 能神经元的一个子集，它们极大地塑造和同步神经网络的活动。然而，声创伤后 PV 神经元的变化仍有待阐明。本研究探讨了单侧 1 小时噪声暴露（左耳，一个倍频程噪声中心在 16 kHz，116 dB SPL）后听觉皮层 PV 神经元如何变化。噪声暴露后 7 天检查时，暴露耳的听觉脑干反应阈值升高。与对照组相比，噪声暴露大鼠双侧听觉皮层中可检测到更多的 PV 神经元。左侧听觉皮层（暴露耳同侧）对噪声暴露的可检测 PV 神经元数量多于右侧听觉皮层（暴露耳对侧）。Western 印迹带的定量分析显示左皮层中 PV 蛋白的表达水平更高。这些在噪声暴露大鼠中发现更多活跃的 PV 神经元的结果表明，可能启动了一种补偿机制来维持大脑的稳定状态。
