Age‐related changes in neural gap detection thresholds in the rat auditory cortex
Age‐related changes in neural gap detection thresholds in the rat auditory cortex
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DOI：
10.1111/ejn.12791
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发表时间：
2015-02
影响因子：
3.4
通讯作者：
Yin Zhao;Xiaoxiao Xu;Juan He;Jinghong Xu;Jiping Zhang
中科院分区：
文献类型：
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作者：
Yin Zhao;Xiaoxiao Xu;Juan He;Jinghong Xu;Jiping Zhang
听觉系统分辨声音时间信息的能力对于理解人类语言和其他物种特有的交流至关重要。间隙检测阈值，即检测声音中沉默间隔的最短持续时间的能力，通常用于研究听觉时间分辨率。对人类和大鼠的行为研究表明，正常发育的婴儿比成年人有更高的缝隙检测阈值；然而，其潜在的神经机制并不完全清楚。在本研究中，我们测定并比较了幼年组(出生后20-30天)、成年组I组(8-10周)和成年组II组(28-30周)三个年龄组大鼠初级听觉皮质的神经间隙检测阈值。我们发现在听皮层的听觉时间敏锐度随年龄的变化，即在恒定的声级下，青少年组具有短神经间隙检测阈值的皮质单位的比例比两个成年组低得多，而两个成年组之间的神经间隙检测阈值没有显著差异。此外，每组听觉皮质中的单位在较高的声级下通常比在较低的声级下表现出更好的间隙检测阈值，表现出依赖于声级的时间敏锐度。这些结果为出生后听力发育过程中与年龄相关的行为间隙检测能力变化的神经相关性提供了证据。
The ability of the auditory system to resolve sound temporal information is crucial for the understanding of human speech and other species‐specific communications. Gap detection threshold, i.e. the ability to detect the shortest duration of a silent interval in a sound, is commonly used to study the auditory temporal resolution. Behavioral studies in humans and rats have shown that normal developing infants have higher gap detection thresholds than adults; however, the underlying neural mechanism is not fully understood. In the present study, we determined and compared the neural gap detection thresholds in the primary auditory cortex of three age groups of rats: the juvenile group (postnatal day 20–30), adult group I (8–10 weeks), and adult group II (28–30 weeks). We found age‐related changes in auditory temporal acuity in the auditory cortex, i.e. the proportion of cortical units with short neural gap detection thresholds (< 5 ms) was much lower in juvenile groups compared with that in both adult groups at a constant sound level, and no significant differences in neural gap detection thresholds were found between the two adult groups. In addition, units in the auditory cortex of each group generally showed better gap detection thresholds at higher sound levels than at lower sound levels, exhibiting a level‐dependent temporal acuity. These results provided evidence for neural correlates of age‐related changes in behavioral gap detection ability during postnatal hearing development.