Lenkov D N, Golubev A V, Mochenkov B P
Fiziol Zh SSSR Im I M Sechenova. 1985 Nov;71(11):1321-8.
Effects of local cooling of the neocortical zone around stimulating microelectrode upon thresholds of initiation of vibrissal motor responses to intracortical microstimulation were studied in alert rabbits. The thresholds increased from 10-50 mua to over 200 microA during the cooling of the deep cortical layers to 20 degrees C - the level of blocking the intracortical synaptic transmission within stimulated zone. A transient decrease of the thresholds of vibrissal responses initiation occurred in slow cooling (1 degree C per 1 min) within the temperature range from 30 degrees C to 25 degrees C on the cortical surface. The neuronal excitation evoked by means of low-threshold repetitive microstimulation seems to be due mainly to indirect transsynaptic ways. The same group of vibrissae, however, respond to stimulation currents about 100 microA as to low-threshold trains of stimuli, only the intensity of motor responses being enhanced. Thus, no involvement of long transcortical axons into excitation of cortical zone occurs with ordinary microstimulation which allows the mapping of motor representations in the neocortex without side-effects.
在清醒的兔子身上研究了围绕刺激微电极的新皮质区局部冷却对触须运动反应起始阈值的影响，该反应是对皮质内微刺激的反应。在将深层皮质层冷却至20℃（即阻断受刺激区内皮质内突触传递的水平）的过程中，阈值从10 - 50微安增加到超过200微安。在皮质表面温度从30℃缓慢冷却至25℃（每分钟1℃）的过程中，触须反应起始阈值出现短暂下降。通过低阈值重复微刺激诱发的神经元兴奋似乎主要是由于间接的跨突触途径。然而，同一组触须对约100微安的刺激电流的反应与对低阈值刺激序列的反应相同，只是运动反应的强度增强。因此，普通微刺激不会使长的跨皮质轴突参与皮质区的兴奋，这使得在没有副作用的情况下绘制新皮质中的运动表征成为可能。
