OFF responses in the auditory thalamus of the guinea pig
OFF responses in the auditory thalamus of the guinea pig
复制标题
DOI：
10.1152/jn.00083.2002
复制
发表时间：
2002-11-01
影响因子：
2.5
通讯作者：
He, JF
中科院分区：
文献类型：
--
作者：
He, JF
在豚鼠的内侧膝状体（MGB）中检查了开和关听觉反应。对 12 只麻醉动物进行单单元和多单元录音，并对录音半球对侧的耳朵施加突发噪声或纯音刺激。研究了 135 个 OFF 或 ON-OFF 神经元和 160 个 ON 神经元，并检查了来自 MGB 不同核的 21 个 ON-OFF 或 OFF 神经元的调谐曲线。 OFF 响应的平均最小阈值（40.8 +/- 20.0 dB SPL，平均值 +/- SD；范围：0-80 dB SPL）显着高于 ON 响应的平均最小阈值（28.5 +/- 17.6 dB SPL，范围：0-60 dB SPL；n = 17，P < 0.001）。在 10 个显示 ON 和 OFF 响应的可识别调谐频率的 ON-OFF 神经元中，7 个显示 OFF 高于 ON 最佳频率 (BF)，2 个显示 ON 和 OFF 相同的 BF，只有 1 个显示 OFF 略低于 ON BF。从 MGB 的腹侧 (MGv) 和喙内侧 (MGrm) 核边缘采样的大多数 OFF 响应显示出单峰调谐曲线，与 MGv 中的 ON 响应相似。位于 MGB 的壳核 (MGs) 和背核 (MGd) 的神经元表现出复杂的多峰或宽调谐曲线。所有 OFF 反应均显示出对声刺激的长持续时间选择性：平均半最大持续时间为 116.5 +/- 114.8 ms（n = 19，范围：27-411 ms）。 MGB 的各个部门对 135 个 OFF 反应的潜伏期进行了研究。 MGv 的腹侧边缘区域表现出最短的潜伏期，其次是 MGv 的背侧边缘区域、MGrm 和 MGB 的尾内侧核 (MGcm)。丘脑后核 (Po)、MGd 和 MGs 显示出更长的平均潜伏期，>30 ms（与 MGv 边缘区域相比，P < 0.05，方差分析），Po 显示最大平均潜伏期为 60.3 ms，最大偏差为 25.5 ms）。 OFF 响应的潜伏期（29.0 +/- 14.0 ms，n = 135）显着大于 ON 响应的潜伏期（15.6 +/- 9.6 ms，n = 160，P < 0.001）。目前的结果提供了有关听觉丘脑中关闭神经元的阈值、频率调谐特性、最小响应延迟和持续时间选择性的有价值的信息。
ON and OFF auditory responses were examined in the medial geniculate body (MGB) of the guinea pig. Single- and multiunit recordings were carried out on 12 anesthetized animals, and noise-burst or pure-tone stimuli were applied to the ear contralateral to the recording hemisphere. One hundred and thirty-five OFF or ON-OFF neurons and 160 ON neurons were studied, and the tuning curves of 21 ON-OFF or OFF neurons were examined from various nuclei of the MGB. The mean minimum threshold of the OFF responses (40.8 +/- 20.0 dB SPL, mean +/- SD; range: 0-80 dB SPL) was significantly higher than that of the ON responses (28.5 +/- 17.6 dB SPL, range: 0-60 dB SPL; n = 17, P < 0.001). Of 10 ON-OFF neurons that showed identifiable tuning frequencies for both ON and OFF responses, 7 showed a higher OFF than ON best frequency (BF), 2 showed the same BF for both ON and OFF, and only 1 showed a slightly lower OFF than ON BF. Most OFF responses sampled from the borders of the ventral (MGv) and the rostromedial (MGrm) nuclei of the MGB showed single-peaked tuning curves, similar to those of the ON responses in the MGv. The neurons located in the shell (MGs) and dorsal (MGd) nuclei of the MGB showed complicated-either multi-peaked or broad-tuning curves. All OFF responses showed long-duration-selectivity for acoustic stimuli: the mean half-maximum duration was 116.5 +/- 114.8 ms (n = 19, range: 27-411 ms). The latencies of 135 OFF responses were studied in various divisions of the MGB. The ventral border region of MGv showed the shortest latency, followed by the dorsal border region of the MGv, the MGrm, and the caudomedial nucleus (MGcm) of the MGB. The posterior nucleus of the thalamus (Po), the MGd, and the MGs showed much longer mean latencies of >30 ms (P < 0.05 compared with the border regions of the MGv, ANOVA), with Po showing the greatest mean latency of 60.3 ms and the greatest deviation of 25.5 ms). The latency of the OFF response (29.0 +/- 14.0 ms, n = 135) was significantly greater than that of the ON response (15.6 +/- 9.6 ms, n = 160, P < 0.001). The present results provide valuable information about the threshold, frequency tuning characteristics, minimal response latency, and duration selectivity of OFF neurons in the auditory thalamus.