ALTERATIONS IN THE IPSI-LATERAL AND CONTRALATERAL AFFERENT INPUTS OF DORSAL HORN CELLS PRODUCED BY CAPSAICIN TREATMENT OF ONE SCIATIC-NERVE IN THE RAT
ALTERATIONS IN THE IPSI-LATERAL AND CONTRALATERAL AFFERENT INPUTS OF DORSAL HORN CELLS PRODUCED BY CAPSAICIN TREATMENT OF ONE SCIATIC-NERVE IN THE RAT
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DOI：
10.1016/0006-8993(82)91151-9
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发表时间：
1982-01-01
期刊：
影响因子：
2.9
通讯作者：
FITZGERALD, M
中科院分区：
文献类型：
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作者：
FITZGERALD, M
用辣椒素局部注射坐骨神经后7~21d，对去脑脊髓大鼠腰段脊髓背角细胞进行了观察。众所周知，这种局部辣椒素治疗不会影响传入的A和C纤维传入截击的大小。对脊髓两侧细胞的感受野特性和初级传入传入进行了观察。在治疗侧，经辣椒素处理的神经的C纤维兴奋的细胞百分比是正常的30%，对皮肤感受野的伤害性加热反应的细胞数量减少了50%。纤维输入和低、高阈值机械输入是正常的。经处理的神经支配的许多细胞的感受野较大。在被处理的神经的对面，对未被处理的肢体的伤害性和非伤害性刺激的反应不受影响，来自未被处理的坐骨神经的输入也不受影响。感受野比正常稍大。对侧刺激也能观察到影响。脊髓两侧的细胞都有兴奋性的对侧感受区，并对高强度刺激对侧坐骨神经产生兴奋性反应。在未经治疗的动物中，这种对侧刺激的效果是抑制的。结果表明，周围神经辣椒素治疗导致输入到治疗侧背角细胞的C纤维长期减少。然而，它也导致脊髓两侧细胞的抑制性和兴奋性感受场的变化。
Dorsal horn cells in the lumbar spinal cord of decerebrate spinal rats were examined 7–21 days following local application of capsaicin to the sciatic nerve. Such local capsaicin treatment is known not to influence the size of the incoming A and C fibre afferent volley. The receptive field properties and primary afferent input of cells on both sides of the cord, that is ipsi- and contralateral to the treated nerve, were examined. On the treated side, the percentage of cells excited by C fibres from the capsaicin treated nerve was 30% of normal and the number of cells responding to noxious heating of the cutaneous receptive field was reduced by 50%. A fibre input and low and high threshold mechanical input were normal. The receptive field size was larger in many cells innervated by the treated nerve. On the side opposite to the treated nerve, responses to noxious and non-noxious stimulation of the untreated limb were unaffected as was the input from the untreated sciatic nerve. Receptive fields were somewhat larger than normal.Effects were also observed from contralateral stimuli. Cells on both sides of the cord were found with excitatory contralateral receptive fields and excitatory responses to trains of high intensity stimulation to the contralateral sciatic nerve. In untreated animals the effect of such contralateral stimulation is inhibitory.The results show that peripheral nerve capsaicin treatment causes long lasting reduction of the C fibre input to dorsal horn cells on the treated side. However, it also results in changes in the inhibitory and excitatory receptive fields of cells on both sides of the cord.