Cheng Liang, Wang Shao-Hui, Peng Kang, Liao Xiao-Mei
School of Life Sciences and Hubei Key Lab of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, China.
School of Psychology and Key Laboratory of Adolescent Cyberpsychology and Behavior, Ministry of Education, Central China Normal University, Wuhan 430079, China.
Neural Plast. 2017;2017:3026749. doi: 10.1155/2017/3026749. Epub 2017 May 14.
Most citizen people are exposed daily to environmental noise at moderate levels with a short duration. The aim of the present study was to determine the effects of daily short-term exposure to moderate noise on sound level processing in the auditory midbrain. Sound processing properties of auditory midbrain neurons were recorded in anesthetized mice exposed to moderate noise (80 dB SPL, 2 h/d for 6 weeks) and were compared with those from age-matched controls. Neurons in exposed mice had a higher minimum threshold and maximum response intensity, a longer first spike latency, and a higher slope and narrower dynamic range for rate level function. However, these observed changes were greater in neurons with the best frequency within the noise exposure frequency range compared with those outside the frequency range. These sound processing properties also remained abnormal after a 12-week period of recovery in a quiet laboratory environment after completion of noise exposure. In conclusion, even daily short-term exposure to moderate noise can cause long-term impairment of sound level processing in a frequency-specific manner in auditory midbrain neurons.
大多数普通民众每天都会短时间暴露在中等强度的环境噪声中。本研究的目的是确定每天短期暴露于中等强度噪声对听觉中脑声音水平处理的影响。在暴露于中等强度噪声（80 dB SPL，每天2小时，持续6周）的麻醉小鼠中记录听觉中脑神经元的声音处理特性，并与年龄匹配的对照组进行比较。暴露组小鼠的神经元具有更高的最小阈值和最大反应强度、更长的首次放电潜伏期，以及更高的斜率和更窄的速率水平函数动态范围。然而，与频率范围外的神经元相比，噪声暴露频率范围内最佳频率的神经元所观察到的这些变化更大。在噪声暴露完成后，在安静的实验室环境中经过12周的恢复，这些声音处理特性仍然异常。总之，即使是每天短期暴露于中等强度噪声也会以频率特异性方式导致听觉中脑神经元的声音水平处理长期受损。
