Effects of different anesthetics on the paired-pulse depression of the H reflex in adult rat
Effects of different anesthetics on the paired-pulse depression of the H reflex in adult rat
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DOI：
10.1006/exnr.2002.8013
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发表时间：
2002-10-01
影响因子：
5.3
通讯作者：
Waite, PME
中科院分区：
文献类型：
--
作者：
Ho, SM;Waite, PME
反射亢进是脊髓损伤（SCI）的常见特征，并且已报道反射兴奋性的变化可用于评估脊髓损伤动物模型中的治疗。然而，已知脊髓反射依赖于麻醉水平。作为在SCI中使用的初步研究，在几种常用的麻醉剂下评估了霍夫曼反射（H反射）的兴奋性。H反射记录在远端足肌肉（背侧骨间）的成年大鼠，而足底外侧神经刺激。使用了五种不同的麻醉剂：氯胺酮、氟烷、戊巴比妥、依托咪酯和沙凡。将记录和刺激电极直接插入皮肤，以最大限度地减少每次实验的外科手术，允许每周在同一只动物中进行重复记录。使用双脉冲刺激测试H反射的抑制。氟烷和氯胺酮产生抑制H反应时，脉冲间期缩短到小于1秒。在依托咪酯、沙凡和戊巴比妥麻醉下记录的H反射抑制曲线对刺激率不太敏感，直到间隔为200 ms或更短时才出现减少。氟烷和氯胺酮的抑制曲线类似于未麻醉的人类，而在其他麻醉剂下的抑制曲线类似于在脊髓损伤动物中观察到的抑制曲线。结果表明，一些麻醉剂的优先行动，下行通路参与反射调制和麻醉剂，如氯胺酮或氟烷下评估反射兴奋性的重要性。(C)2002 Elsevier Science（美国）。
Hyperreflexia is a common feature of spinal cord injury (SCI), and changes in reflex excitability have been reported to be useful in assessing treatments in animal models of cord damage. However, spinal reflexes are known to be dependent on anesthetic level. As a preliminary to its use in SCI, the excitability of the Hoffman reflex (H reflex) has been assessed under several commonly used anesthetics. The H reflex was recorded in the distal foot muscles (dorsal interossei) of adult rats, while the lateral plantar nerve was stimulated. Five different anesthetics were used: ketamine, halothane, Nembutal, Etomidate, and Saffan. Recording and stimulating electrodes were inserted directly through the skin to minimize the surgical procedure for each experiment, allowing repeated recording to be made in the same animal on a weekly basis. Suppression of the H reflex was tested using twin-pulse stimulation. Halothane and ketamine produced suppression of the H response when interpulse intervals were shortened to less than 1 s. The H-reflex suppression profiles recorded under Etomidate, Saffan, and Nembutal anesthesia were less sensitive to the stimulation rate, with little reduction until intervals were 200 ms or less. The suppression profiles of halothane and ketamine resemble that seen in unanesthetized humans, whereas that under the other anesthetics tried here resembles that observed in spinal-cord-injured animals. The results suggest a preferential action of some anesthetics on descending pathways involved in reflex modulation and the importance of assessing reflex excitability under anesthetics such as ketamine or halothane. (C) 2002 Elsevier Science (USA).