Šuta Daniel, Rybalko Natalia, Shen Da-Wei, Popelář Jiří, Poon Paul W F, Syka Josef
Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic; Department of Medical Biophysics and Informatics, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
Physiol Behav. 2015 May 15;144:60-5. doi: 10.1016/j.physbeh.2015.03.005. Epub 2015 Mar 4.
Sound exposure during the early postnatal period can significantly influence the function of the auditory system in rats during adulthood. In the present study, rat pups (strain Long-Evans) were exposed to broad-band noise at 125dB SPL for 8, 12 or 25min on postnatal day 14 and then at the age of 3-5months their frequency discrimination at 4 and 16kHz was assessed using a modified method of the prepulse inhibition of the acoustic startle reflex. In all groups of exposed rats, an altered frequency discrimination of the tonal stimuli was observed, in comparison with controls, at 70dB SPL. A worsening of frequency discrimination was observed even in animals exposed for 8min, the auditory thresholds of which were almost identical to that of control animals. The individual auditory thresholds did not correlate with frequency discrimination. The difference in frequency discrimination between the exposed and control animals disappeared at 85-90dB SPL. Our data suggests that brief noise exposure during the critical period of development results in the altered frequency discrimination at moderate sound intensities in adult rats, which may appear even in individuals with normal hearing thresholds.
出生后早期的声音暴露可显著影响成年大鼠听觉系统的功能。在本研究中，将幼鼠（Long-Evans品系）在出生后第14天暴露于125dB SPL的宽带噪声中8、12或25分钟，然后在3至5个月龄时，使用改良的惊吓反射前脉冲抑制方法评估它们在4kHz和16kHz的频率辨别能力。与对照组相比，在所有暴露组大鼠中，在70dB SPL时观察到音调刺激的频率辨别发生改变。即使在暴露8分钟的动物中也观察到频率辨别能力变差，其听觉阈值与对照动物几乎相同。个体听觉阈值与频率辨别无关。在85 - 90dB SPL时，暴露组和对照组动物之间的频率辨别差异消失。我们的数据表明，发育关键期的短暂噪声暴露会导致成年大鼠在中等声音强度下频率辨别发生改变，即使是听力阈值正常的个体也可能出现这种情况。
