Zheng X, Chen Z, Shi H, Xu W
Dept. of Physiology, China Academy of Traditional Chinese Medicine, Beijing.
Zhen Ci Yan Jiu. 1994;19(2):21-5.
Fibers from the cortical somatosensory area II (SII) or motor cortex (MCtx) to intralaminar nuclei (ILN) have been proven to exist, and SII was found to be connected with MCtx by cortico-cortical fibers. The present work was undertaken to study whether MCtx participated in SII producing descending modulation of ILN. All experiments were performed on sodium pentobarbitone anaesthetised cats. Single unit activities of ILN neurons were extracellularly recorded by glass microelectrodes. The effects of stimulating SII on nociceptive responses of ILN neurons were observed before and after cooling MCtx. The nociceptive responses of ILN neurons were attenuated by stimulating SII. There was a statistically significant difference at 0'-2' after the stimulation (n = 14, P < 0.05). The inhibitory effect of stimulating SII was reduced after cooling MCtx (19 degrees C-20 degrees C) in 8 neurons, and abolished in other neurons when the temperature was below 18 degrees C. MCtx was involved in SII producing descending modulation of ILN.
已证实存在从皮质体感区II（SII）或运动皮质（MCtx）到板内核（ILN）的纤维，并且发现SII通过皮质 - 皮质纤维与MCtx相连。开展本研究以探讨MCtx是否参与SII对ILN产生下行调制。所有实验均在戊巴比妥钠麻醉的猫身上进行。用玻璃微电极细胞外记录ILN神经元的单单位活动。在冷却MCtx之前和之后观察刺激SII对ILN神经元伤害性反应的影响。刺激SII可减弱ILN神经元的伤害性反应。刺激后0'-2'时存在统计学显著差异（n = 14，P < 0.05）。冷却MCtx（19℃-20℃）后，8个神经元中刺激SII的抑制作用减弱，当温度低于18℃时，其他神经元的抑制作用消失。MCtx参与SII对ILN产生下行调制。
