Arakawa K, Peachey N S, Celesia G, Rubboli G
Department of Neurology, Stricth School of Medicine, Loyola University Chicago, Maywood, IL 60153.
Exp Brain Res. 1993;95(2):271-6. doi: 10.1007/BF00229785.
Pattern visual evoked potentials (VEPs) were recorded from the pial surface of the cat primary visual cortex prior to and following the intravenous administration of physostigmine, an agent which blocks the enzyme responsible for the breakdown of synaptically released acetylcholine. The control VEP was composed of a small initial positive deflection (P1), a subsequent large negative wave (N1) and a second large positive wave (P2). Following physostigmine, the amplitude of P1-N1 was diminished whereas that of N1-P2 increased. These effects were long lasting and were blocked by prior treatment with scopolamine, a result consistent with mediation by a muscarinic cholinergic pathway. Waveform subtraction revealed that the physostigmine-sensitive component had a slow, negative polarity waveform while the physostigmine-insensitive component was also slow, but positive in polarity. The fundamental nature of these components remains to be assessed. Nevertheless, the results indicate that waveforms of different polarity combine algebraically to yield the conventional VEP.
在静脉注射毒扁豆碱前后，从猫初级视觉皮层的软膜表面记录图形视觉诱发电位（VEP）。毒扁豆碱是一种能阻断负责分解突触释放的乙酰胆碱的酶的药物。对照VEP由一个小的初始正偏转（P1）、随后的一个大负波（N1）和第二个大正波（P2）组成。注射毒扁豆碱后，P1-N1的振幅减小，而N1-P2的振幅增加。这些效应持续时间长，并且被预先用东莨菪碱处理所阻断，这一结果与毒蕈碱胆碱能途径介导一致。波形减法显示，对毒扁豆碱敏感的成分具有缓慢的负极性波形，而对毒扁豆碱不敏感的成分也很缓慢，但极性为正。这些成分的基本性质仍有待评估。然而，结果表明，不同极性的波形以代数方式组合产生传统的VEP。
