静脉注射受体阻断剂酚妥拉明、赛庚啶和纳洛酮对LRN下行性抑制作用的影响

The Effect of Intravenous Receptor Antaganists on the Descending Inhibition from LRN

本实验采用微电极细胞外记录方法，以清醒大鼠脊髓背角广动力范围（ＷＤＲ）神经元的伤害性诱发放电频率（即晚串放电频率）为指标，观察静脉注射受体阻断剂酚妥拉明、赛庚啶及纳洛酮对延髓外侧网状核（ＬＲＮ）下行抑制作用的影响。结果表明，刺激ＬＲＮ对ＷＤＲ神经元的下行抑制作用部分是通过ＮＥ和５－ＨＴ实现的，ＬＲＮ的这种下行抑制作用可能并不涉及内源性阿片肽。

Recent studies have revealed that the lateral reticular nucleus(LRN) in the caudal nedulla oblongata plays a very important role in the descending inhibitory controls of nociception. The present study was designed to examine the effect of intravenous receptor antaganists on the descending inhibition from LRN by the method of recording unit discharges of WDR neurones in the rat spinal dorsal horn, 20 WDR neurones were studied. Intravenous phentolamine as well as cypraheptadine could attenucte the descending inhibition produced by LRN stimulation but naloxone had little effect, indicating that the stimulation-produced inhibition from LRN on WDR neurones is partly mediated by NE and 5-HT, and endogeneous opioid peptides appear not to be involved.