Pineda J A, Westerfield M
Department of Cognitive Science, University of California, San Diego, La Jolla 92093.
Brain Res Bull. 1993;31(6):689-96. doi: 10.1016/0361-9230(93)90142-x.
Two experiments examined the effects of the alpha-2 antagonist L657,743 on monkey electroencephalographic (EEG) and event-related potential (ERP) activity following auditory and visual stimuli. In the first experiment, EEG was recorded before and after the administration of a saline placebo or L657,743 (0.01, 0.05 mg/kg IM). No drug effects occurred on EEG spectral frequencies. In the second experiment, ERPs were recorded during an 80-10-10 passive oddball paradigm. The paradigm consisted of a repetitive tone as background, a different-pitch tone as the auditory oddball, and a yellow rectangle as an infrequent visual stimulus. Waveforms were collected before and after the administration of placebo or drug (0.01, 0.03, 0.05 mg/kg IM). Both auditory oddball and visual stimuli elicited large P3-like potentials with different distributions, suggesting different sources. However, their magnitudes were similarly reduced by drug administration. These effects were significant at parietal but unchanged at other sites. The data support the hypothesis that norepinephrine is a modulatory neurotransmitter common to auditory and visual P3s in parietal areas. On the other hand, midline and temporal P3s are unaffected by manipulations of noradrenergic activity, supporting the existence of two independent P3 sources.
两项实验研究了α-2拮抗剂L657,743对猴子在听觉和视觉刺激后脑电图（EEG）及事件相关电位（ERP）活动的影响。在第一个实验中，在给予生理盐水安慰剂或L657,743（0.01、0.05毫克/千克，肌肉注射）前后记录脑电图。未发现药物对脑电频谱频率有影响。在第二个实验中，在80-10-10被动式oddball范式期间记录事件相关电位。该范式包括一个重复的音调作为背景、一个不同音高的音调作为听觉oddball以及一个黄色矩形作为罕见的视觉刺激。在给予安慰剂或药物（0.01、0.03、0.05毫克/千克，肌肉注射）前后收集波形。听觉oddball和视觉刺激均引发了具有不同分布的大的P3样电位，表明来源不同。然而，给药后它们的幅度均同样降低。这些效应在顶叶显著，但在其他部位未改变。数据支持这样的假设，即去甲肾上腺素是顶叶区域听觉和视觉P3共有的调节性神经递质。另一方面，中线和颞叶的P3不受去甲肾上腺素能活动操纵的影响，支持存在两个独立的P3来源。
