RESPONSES OF SPINOTHALAMIC TRACT CELLS TO MECHANICAL AND THERMAL-STIMULATION OF SKIN IN RATS WITH EXPERIMENTAL PERIPHERAL NEUROPATHY
RESPONSES OF SPINOTHALAMIC TRACT CELLS TO MECHANICAL AND THERMAL-STIMULATION OF SKIN IN RATS WITH EXPERIMENTAL PERIPHERAL NEUROPATHY
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DOI：
10.1152/jn.1992.67.6.1562
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发表时间：
1992-06-01
影响因子：
2.5
通讯作者：
WILLIS, WD
中科院分区：
文献类型：
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作者：
PALECEK, J;PALECKOVA, V;WILLIS, WD
1. 在乌拉坦和戊巴比妥麻醉下，记录 12 只对照大鼠和 20 只实验性神经病大鼠的脊髓丘脑束 (STT) 神经元对皮肤机械和热刺激的反应。通过在坐骨神经上放置四个松散的结扎线诱导神经病变后7、14和28天记录神经病变大鼠中STT细胞的活性。2．所有神经病动物都表现出对受伤后爪的保护作用，并且与假手术爪相比，神经病后爪的辐射热源的缩回潜伏期更短。3。神经病动物的 STT 神经元在神经结扎后 7 天和 14 天表现出最深刻的变化。与未手术动物的STT细胞相比，大约一半的神经元具有高背景活性，对无害刺激的反应在宽动态范围神经元的总诱发活动中占更大的百分比，并且对机械和热刺激的后放电的发生和幅度增加。4。神经病动物中 STT 细胞热诱发反应的平均阈值温度与对照动物细胞的平均阈值温度没有差异。然而，在神经病大鼠中，对微小热刺激做出反应的细胞通常已经出现后放电。5． STT 细胞背景活性的增加与该实验性神经病模型中自发性疼痛的行为观察结果一致。此外，STT 细胞的后放电可能与这些动物中看到的对有害刺激做出反应而长时间缩爪相平行，这是痛觉过敏的证据。然而，没有迹象表明如果动物患有热异常性疼痛，热刺激阈值可能会降低。机械性异常性疼痛可能是由于对无害机械刺激的反应性相对增加所致。然而，至少在结扎后 28 天，与对照相比，对有害机械刺激的反应有所减少。提出了神经病动物中 STT 细胞反应变化的外周和中枢机制。
1. Responses of spinothalamic tract (STT) neurons to mechanical and thermal stimulation of skin were recorded under urethane and pentobarbital anesthesia in 12 control rats and in 20 rats with experimental neuropathy. Activity of the STT cells in neuropathic rats was recorded 7, 14, and 28 days after inducing the neuropathy by placing four loose ligatures on the sciatic nerve.2. All neuropathic animals showed guarding of the injured hindpaw and a shorter withdrawal latency from a radiant heat source of the neuropathic hindpaw than that of the sham-operated paw.3. STT neurons in neuropathic animals showed the most profound changes 7 and 14 days after the nerve ligation. When compared with STT cells in unoperated animals, approximately half of the neurons had high background activity, responses to innocuous stimuli represented a larger percentage of the total evoked activity in wide dynamic range neurons, and the occurrence and magnitude of afterdischarges to mechanical and thermal stimuli were increased.4. The mean threshold temperatures of heat-evoked responses of the STT cells in neuropathic animals were not different than those of cells from control animals. However, in neuropathic rats, cells reacting to small heat stimuli usually already had afterdischarges.5. The increase in the background activity of STT cells is consistent with behavioral observations of spontaneous pain in this model of experimental neuropathy. Furthermore, the afterdischarges of STT cells may parallel the prolonged paw withdrawal in response to noxious stimuli that is seen in these animals and that is evidence for hyperalgesia. However, there was no indication of a lowered threshold for thermal stimuli as might be expected if the animals have thermal allodynia. Mechanical allodynia may have resulted from a relative increase in responsiveness to innocuous mechanical stimuli. However, responses to noxious mechanical stimuli were reduced compared with control, at least at 28 days after the ligation. Peripheral and central mechanisms responsible for the changes in responses of STT cells in neuropathic animals are suggested.