去甲肾上腺素对慢性压迫背根节神经元的兴奋作用

THE EXCITATORY EFFECT OF NOREPINEPHRINE ON CHRONICALLY COMPRESSED DORSAL ROOT GANGLION NEURONS IN THE RAT

摘要:

目的：观察去甲肾上腺素对大鼠正常及慢性压迫背根节中具有后去极化的神经元的兴奋性作用。方法：急性离散大鼠背根节(dorsal root ganglion，DRG)神经元后，以全细胞膜片钳技术记录了正常DRG神经元及慢性压迫DRG神经元的膜电位及放电数目在施加去甲肾上腺素(NE)前后的改变。结果：在NE的作用下，受损DRG内具有后去极化(afterdepolarize potential，ADP)的30个神经元中有13．3％出现自发放电，20％出现兴奋性增强；而检测的正常DRG内具有ADP的20个神经元在NE的作用下未出现自发放电，也无兴奋性增强。结论：受损DRG的ADP神经元对NE的反应显著增强，ADP可能参与交感神经维持痛的形成。

Abstract:

Objective: To investigate the effect of norepinephrine (NE) on normal and chronically compressed dorsal root ganglion (DRG) neurons exhibiting after depolarization (ADP) in the rat. Methods: Whole cell patch clamp recording was performed on freshly isolated normal DRG neurons and chronically compressed DRG (CCD) neurons before and after the application of NE. Results: After the application of NE, 13.3% neurons discharged spontaneously and 20% neurons showed increasing excitation among 30 injured DRG neurons with ADP; the excitability of 20 normal DRG neurons exhibiting ADP was unchanged. Conclusion: Injured DRG neurons with ADP are more sensitive to NE than normal ones, which indicates that ADP may be involved in sympathetic nerve maintained pain.