Nicotine Enhances Amplitude and Consistency of Timing of Responses to Acoustic Trains in A1.
Nicotine Enhances Amplitude and Consistency of Timing of Responses to Acoustic Trains in A1.
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尼古丁能增强 A1 对声音序列反应的振幅和时间一致性。
DOI：
10.3389/fncir.2021.597401
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发表时间：
2021
影响因子：
3.5
通讯作者：
Metherate R
中科院分区：
文献类型：
--
作者：
Intskirveli I;Metherate R
全身性尼古丁增强初级听觉皮层（A1）的神经处理，如使用音调诱发的电流源密度（CSD）测量所确定的。例如，尼古丁增强了A1第4层中的特征频率（CF）诱发电流汇，增加了振幅并降低了潜伏期。然而，由于在刺激流中呈现听觉刺激增加了响应动力学的复杂性，因此我们试图确定尼古丁对CF刺激序列（2-40 Hz的1秒序列;每个序列重复25次）的CSD响应的影响。CSD记录获得使用16通道多探针插入在A1的氨基甲酸乙酯/甲苯噻嗪麻醉小鼠，和分析集中在两个电流汇在中间（层4）和深层（层5/6）。CF序列产生了第4层反应的适应，在2 Hz时较弱，在5-10 Hz时较强，在20-40 Hz时完成。相反，5/6层电流汇在2-10 Hz时表现出较小的适应性，并且同时记录的听觉脑干反应（ABR）即使在40 Hz时也没有表现出适应性。全身性尼古丁（2.1 mg/kg）在≤10 Hz的1秒刺激序列中增强了第4层反应。尼古丁增强了每个列车内的反应幅度和25次试验中反应时间的一致性。尼古丁在一秒钟的试验中并没有改变适应的程度，但它增加振幅的效果揭示了一种新的、缓慢的适应形式，这种适应形式是在多次试验中发展起来的。尼古丁不影响完全适应的反应（20-40 Hz序列），尼古丁也不影响第5/6层电流汇或ABR的任何方面。尼古丁在第4层中的总体作用是增强每个队列中的所有反应，强调多个试验中的早期试验，并提高所有试验中时间的一致性。这些效果可以改善包含2-10 Hz范围内的信息的复杂声学流（包括语音）的处理。
Systemic nicotine enhances neural processing in primary auditory cortex (A1) as determined using tone-evoked, current-source density (CSD) measurements. For example, nicotine enhances the characteristic frequency (CF)-evoked current sink in layer 4 of A1, increasing amplitude and decreasing latency. However, since presenting auditory stimuli within a stream of stimuli increases the complexity of response dynamics, we sought to determine the effects of nicotine on CSD responses to trains of CF stimuli (one-second trains at 2–40 Hz; each train repeated 25 times). CSD recordings were obtained using a 16-channel multiprobe inserted in A1 of urethane/xylazine-anesthetized mice, and analysis focused on two current sinks in the middle (layer 4) and deep (layers 5/6) layers. CF trains produced adaptation of the layer 4 response that was weak at 2 Hz, stronger at 5–10 Hz and complete at 20–40 Hz. In contrast, the layer 5/6 current sink exhibited less adaptation at 2–10 Hz, and simultaneously recorded auditory brainstem responses (ABRs) showed no adaptation even at 40 Hz. Systemic nicotine (2.1 mg/kg) enhanced layer 4 responses throughout the one-second stimulus train at rates ≤10 Hz. Nicotine enhanced both response amplitude within each train and the consistency of response timing across 25 trials. Nicotine did not alter the degree of adaptation over one-second trials, but its effect to increase amplitudes revealed a novel, slower form of adaptation that developed over multiple trials. Nicotine did not affect responses that were fully adapted (20–40 Hz trains), nor did nicotine affect any aspect of the layer 5/6 current sink or ABRs. The overall effect of nicotine in layer 4 was to enhance all responses within each train, to emphasize earlier trials across multiple trials, and to improve the consistency of timing across all trials. These effects may improve processing of complex acoustic streams, including speech, that contain information in the 2–10 Hz range.
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影响因子：
3.4
作者：
Askew, Caitlin;Intskirveli, Irakli;Metherate, Raju
通讯作者：
Metherate, Raju
影响因子：
25
作者：
Kawai, Hideki;Lazar, Ronit;Metherate, Raju
通讯作者：
Metherate, Raju
影响因子：
2.3
作者：
Askew, Caitlin E.;Lopez, Alberto J.;Metherate, Raju
通讯作者：
Metherate, Raju
影响因子：
5.3
作者：
Fuglsang, Soren A.;Marcher-Rorsted, Jonatan;Hjortkjaer, Jens
通讯作者：
Hjortkjaer, Jens
影响因子：
3.4
作者：
Pham, Carol Q.;Kapolowicz, Michelle R.;Zeng, Fan-Gang
通讯作者：
Zeng, Fan-Gang