Actions of norepinephrine and isoflurane on inhibitory synaptic transmission in adult rat spinal cord substantia gelatinosa neurons
Actions of norepinephrine and isoflurane on inhibitory synaptic transmission in adult rat spinal cord substantia gelatinosa neurons
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DOI：
10.1213/01.ane.0000184829.25310.38
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发表时间：
2006-01-01
影响因子：
5.7
通讯作者：
Baba, H
中科院分区：
文献类型：
--
作者：
Georgiev, SK;Wakai, A;Baba, H
在临床实践中，挥发性吸入麻醉剂和一氧化二氮(N2O)经常一起使用来产生止痛。由于N2O的镇痛作用至少部分是通过脊髓内去甲肾上腺素(NE)的释放来实现的，因此我们从中枢伤害性信息处理的角度研究了异氟醚(ISO)和NE在成年大鼠脊髓中的相互作用。采用盲法全细胞膜片钳方法，观察临床相关浓度的ISO(1MAC)和NE(20mM)对胶状质(SG)神经元自发抑制传递的影响。ISO延长自发抑制性突触后电流的衰减时间，增加其总电荷转移。去甲肾上腺素可增加突触后抑制性电流的频率和平均幅度，增加电荷传递。联合应用这两种药物导致电荷转移的增加和抑制性突触后电流的频发时间总和。结论：ISO和NE均能增强大鼠脑海马神经元抑制性突触传递，且两者之间的相互作用是相加的，提示ISO可能在脊髓背角水平上增加了N2O的镇痛作用。
Volatile inhaled anesthetics and nitrous oxide (N2O) are often used together in clinical practice to produce analgesia. Because the analgesic effect of N2O is, at least in part, mediated by norepinephrine (NE) release in the spinal cord, we examined the interaction between isoflurane (ISO) and NE in the adult rat spinal cord with respect to central nociceptive information processing. The effects of clinically relevant concentrations of ISO (1 MAC) and NE (20 mu M) on spontaneous inhibitory transmission in substantia gelatinosa (SG) neurons were examined using the blind whole-cell patch-clamp method. ISO prolonged the decay time and increased the total charge transfer of spontaneous inhibitory postsynaptic currents. NE increased the frequency and mean amplitude of inhibitory postsynaptic currents and the charge transfer as well. Coapplication of both drugs led to an additive increase of the charge transfer and frequent temporal summation of inhibitory postsynaptic currents. We conclude that both ISO and NE enhance the inhibitory synaptic transmission in the rat SG neurons and their interaction is additive, suggesting that ISO may add to the analgesic action of N2O at the spinal cord dorsal horn level.