Department of Neurology of the Second Affiliated Hospital of Zhejiang University School of Medicine, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, Zhejiang Province, China; Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, China.
Department of Neurology of the Second Affiliated Hospital of Zhejiang University School of Medicine, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, Zhejiang Province, China.
Neuroscience. 2021 Feb 10;455:79-88. doi: 10.1016/j.neuroscience.2020.11.042. Epub 2020 Dec 5.
The rat auditory cortex is divided anatomically into several areas, but little is known about the functional differences in information processing among these areas. Three tonotopically organized core fields, namely, the primary (A1), anterior (AAF), and ventral (VAF) auditory fields, as well as one non-tonotopically organized belt field, the dorsal belt (DB), were identified based on their response properties. Compared to neurons in A1, AAF and VAF, units in the DB exhibited little or no response to pure tones but strong responses to white noise. The few DB neurons responded to pure tones with thresholds greater than 60 dB SPL, which was significantly higher than the thresholds of neurons in the core regions. In response to white noise, units in DB showed significantly longer latency and lower peak response, as well as longer response duration, than those in the core regions. Responses to repeated white noise were also examined. In contrast to neurons in A1, AAF and VAF, DB neurons could not follow repeated stimulation at a 300 ms inter-stimulus interval (ISI) and showed a significant steeper ISI tuning curve slope when the ISI was increased from 300 ms to 4.8 s. These results indicate that the DB processes auditory information on broader spectral and longer temporal scales than the core regions, reflecting a distinct role in the hierarchical cortical pathway.
大鼠听觉皮层在解剖上可分为几个区域，但对于这些区域在信息处理方面的功能差异知之甚少。根据其反应特性，可将三个具有调谐组织的核心区域（初级（A1）、前（AAF）和腹侧（VAF）听觉区域）以及一个非调谐组织的带状区域（DB）确定为。与 A1、AAF 和 VAF 中的神经元相比，DB 中的单位对纯音几乎没有反应或反应很小，但对白噪声的反应很强。少数 DB 神经元对阈值大于 60dB SPL 的纯音有反应，这明显高于核心区域神经元的阈值。对白噪声的反应中，DB 中的单位潜伏期较长、峰值响应较低、响应持续时间较长，与核心区域的单位相比。还检查了对重复白噪声的反应。与 A1、AAF 和 VAF 中的神经元不同，DB 神经元不能在 300ms 刺激间隔（ISI）下跟随重复刺激，并且当 ISI 从 300ms 增加到 4.8s 时，ISI 调谐曲线斜率明显更陡。这些结果表明，DB 处理的听觉信息在更广泛的频谱和更长的时间尺度上比核心区域更为广泛，反映了在分层皮质通路中的独特作用。
