DEAFFERATION AND TRIGEMINAL AFFERENT PROJECTIONS

我们已经完成了对成年人的影响的研究， 眶下（IO）横断对三叉神经生理学的影响 神经节细胞 458个神经节细胞， 用玻璃或钨微电极记录，至少在60 10天后，IO神经切断。 我们发现这种损伤 导致1）伤害感受单位数量增加，2） 对无害物质敏感的细胞的相对百分比的变化 刺激，3）具有异常感受野的许多细胞和4） 上颌骨分区内地形的显著改变。 总IO触须单位百分比从正常 值从77%增加到28%，而守卫毛发单位从12%增加到20%。 在正常的动物中为36%。 与此同时， IO伤害性单位的数量从正常值的6%增加到 百分之二十 我们还遇到了15个单位， 刺激电极，但没有外周感受野（无 我们的正常单位表现出这种特性）。 除了增加伤害性和警卫的数量外， 毛单位，成人IO神经横断也导致了一些 感受野异常的三叉神经节细胞。 这些 异常单位包括5个不连续的感受器细胞， 场（两个响应偏转超过触须），一个 对触须和周围保护物的运动敏感的单位 毛发和八个细胞只对深部压力有反应， IO孔区。

We have completed an examination of the effects of adult infraorbital (IO) transection on the physiology of trigeminal ganglion cells. Four hundred fifty-eight ganglion cells were recorded with glass or tungsten microelectrodes at least at 60 days after IO nerve transection. We have found that this injury results in 1) an increase in the number of nociceptive units, 2) a shift in the relative percentages of cells sensitive to innocuous stimuli, 3) a number of cells with abnormal receptive fields and 4) a significant alteration of maxillary intradivisional topography. The percentage of total IO vibrissa units decreased from a normal value 77% to 28%, while the guard hair units increased from 12% in the normal animals to 36%. At the same time, the percentage of IO nociceptive units increased from the normal value of 6% to 20%. We also encountered 15 units which were driven by the IO stimulating electrode but had not peripheral receptive field (none of our normal units exhibited this characteristic). In addition to an increase in the number of nociceptive and guard hair units, adult IO nerve transection also resulted in a number of trigeminal ganglion cells with abnormal receptive fields. These unusual units included five cells with discontinuous receptive fields (two responding to deflection of more than on vibrissa), a unit sensitive to movement of a vibrissa and surrounding guard hairs and eight cells that responded only to deep pressure in the region of the IO foramen.