Mechanisms of Long-Latency Paired Pulse Suppression: MEG Study
Mechanisms of Long-Latency Paired Pulse Suppression: MEG Study
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DOI：
10.1007/s10548-021-00878-6
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发表时间：
2021-11-08
期刊：
影响因子：
2.7
通讯作者：
Inui，Koji
中科院分区：
文献类型：
--
作者：
Takeuchi，Nobuyuki;Fujita，Kohei;Inui，Koji
成对脉冲抑制是一种用于评估感觉抑制的电生理方法，通常用于精神疾病患者。然而，目前尚不清楚这种抑制是否来自特定的抑制机制，难治性或疲劳。本研究应用脑磁图技术，对19名健康受试者进行听觉成对脉冲诱发抑制的机制研究。控制刺激是一串25-ms的65 dB SPL的纯音，持续2500 ms。为了引起测试反应，将对照声音中2200 ms处的两个连续音调的声压增加到80 dB（测试刺激）。在1000（CS2）和1600（CS 1）ms作为条件刺激也插入类似的声压变化。使用四种刺激条件：（1）单独测试，（2）测试+CS 1，（3）测试+CS 1 + CS2，和（4）测试+ CS2，随机提供四种声音刺激，每种条件的皮质反应平均至少100次。在四种条件下比较了测试响应的P50 m、N100 m和P200 m分量的基线-峰值和峰-峰值振幅。此外，在条件（2）和（3）之间比较对CS 1的响应。结果显示CS 1对测试反应有显著的抑制作用。虽然当CS2存在时，对CS 1的反应被显著抑制，但它不影响CS 1对测试反应的抑制。因此，这表明，对条件刺激的反应幅度不是决定测试反应抑制作用的因素，表明抑制是由于兴奋性通路的外部影响。
Paired pulse suppression is an electrophysiological method used to evaluate sensory suppression and often applied to patients with psychiatric disorders. However, it remains unclear whether the suppression comes from specific inhibitory mechanisms, refractoriness, or fatigue. In the present study, to investigate mechanisms of suppression induced by an auditory paired pulse paradigm in 19 healthy subjects, magnetoencephalography was employed. The control stimulus was a train of 25-ms pure tones of 65 dB SPL for 2500 ms. In order to evoke a test response, the sound pressure of two consecutive tones at 2200 ms in the control sound was increased to 80 dB (Test stimulus). Similar sound pressure changes were also inserted at 1000 (CS2) and 1600 (CS1) ms as conditioning stimuli. Four stimulus conditions were used; (1) Test alone, (2) Test + CS1, (3) Test + CS1 + CS2, and (4) Test + CS2, with the four sound stimuli randomly presented and cortical responses averaged at least 100 times for each condition. The baseline-to-peak and peak-to-peak amplitudes of the P50m, N100m, and P200m components of the test response were compared among the four conditions. In addition, the response to CS1 was compared between conditions (2) and (3). The results showed significant test response suppression by CS1. While the response to CS1 was significantly suppressed when CS2 was present, it did not affect suppression of the test response by CS1. It was thus suggested that the amplitude of the response to a conditioning stimulus is not a factor to determine the inhibitory effects of the test response, indicating that suppression is due to an external influence on the excitatory pathway.