Alpsan D
Electroencephalogr Clin Neurophysiol. 1981 Jun;51(6):589-98. doi: 10.1016/0013-4694(81)90203-0.
Contralateral and ipsilateral cortical somatosensory evoked potentials to selective activation of different diameter sural nerve fiber groups were recorded in cats. Activation of alpha fibers evoked a well defined positive-negative primary potential at the contralateral somatosensory area II. Activation of delta fibers in addition to alpha fibers resulted in another positive-negative wave of comparable amplitude with a latency approximately twice that of the early component. Isolation of the peripheral input to the delta fibers alone, by blocking the alpha fiber activity with the use of triangular pulses, caused the complete disappearance of the initial wave, leaving the second with no latency or amplitude changes. This demonstrated that the latter potential was evoked by delta fibers. Ipsilateral responses followed the same pattern, however with higher peripheral thresholds, longer latencies and smaller amplitudes. No cortical potentials could be recorded to activation of C fibers. The results of this study are at variance with previous observations about the cortical responses to small myelinated nerve fiber activity. The rationale of the use of triangular pulses for selectively activating nerve fiber groups is also discussed.
在猫身上记录了对不同直径腓肠神经纤维群进行选择性激活时的对侧和同侧皮质体感诱发电位。激活α纤维在对侧体感区II诱发了明确的正负初级电位。除α纤维外，激活δ纤维还产生了另一个振幅相当的正负波，其潜伏期约为早期成分的两倍。通过使用三角脉冲阻断α纤维活动来单独分离对δ纤维的外周输入，导致初始波完全消失，而第二个波的潜伏期和振幅没有变化。这表明后一个电位是由δ纤维诱发的。同侧反应遵循相同模式，但外周阈值更高、潜伏期更长且振幅更小。激活C纤维时未记录到皮质电位。本研究结果与先前关于皮质对小髓鞘神经纤维活动反应的观察结果不同。还讨论了使用三角脉冲选择性激活神经纤维群的原理。
