Ishimaru T, Shimada T, Sakumoto M, Miwa T, Kimura Y, Furukawa M
Department of Otorhinolaryngology, School of Medicine, Kanazawa University, Japan.
Chem Senses. 1997 Feb;22(1):77-81. doi: 10.1093/chemse/22.1.77.
Most physiological studies of the human olfactory system have concentrated on the cortical level; the olfactory bulbar level has been studied rarely. We attempted to stimulate the human olfactory mucosa by electrical pulse to detect the bulbar potentials. Electrical stimulation (2 mA, 0.5 ms) of the human olfactory mucosa evoked a change in potential recorded from the frontal sector of the head. A negative peak of the evoked potential that occurred at 19.4 ms (grand means, n = 5) after stimulation was the clearest. The highest amplitude of the potential was recorded from the frontal sector of the head on the stimulated side. Our findings were similar to the experimental results obtained from the olfactory bulbs of animals. This evoked potential was considered to be the human olfactory bulbar potential. When the subjects were stimulated by applying electricity to the olfactory mucosa, no sensation of smell occurred even though evoked potentials were recorded. Evoked potentials were recorded only when the stimulating electrode was located in the olfactory cleft. When the stimulating electrode was outside the olfactory cleft, the stimulation caused pain. The trigeminal nerve seemed to be stimulated by electricity. Olfactory evoked potentials produced by the electrical stimulation of the human olfactory mucosa should aid the research on human olfactory physiology, and may be applicable to clinical tests of olfactory dysfunction.
大多数关于人类嗅觉系统的生理学研究都集中在皮层水平；而对嗅球水平的研究则很少。我们试图通过电脉冲刺激人类嗅觉黏膜来检测嗅球电位。对人类嗅觉黏膜进行电刺激（2毫安，0.5毫秒）会引起从头部额叶区域记录到的电位变化。刺激后19.4毫秒出现的诱发电位负峰最为明显（总体均值，n = 5）。电位的最高幅值是在受刺激侧头部的额叶区域记录到的。我们的发现与从动物嗅球获得的实验结果相似。这种诱发电位被认为是人类嗅球电位。当通过对嗅觉黏膜施加电流来刺激受试者时，即使记录到了诱发电位，也没有嗅觉产生。只有当刺激电极位于嗅裂时才会记录到诱发电位。当刺激电极位于嗅裂之外时，刺激会引起疼痛。三叉神经似乎受到了电刺激。通过电刺激人类嗅觉黏膜产生的嗅觉诱发电位应该有助于人类嗅觉生理学的研究，并且可能适用于嗅觉功能障碍的临床测试。
