中缝大核在肌梭传入镇痛中的作用

目的　观察中缝大核在肌梭传入镇痛中的作用。方法　用微电极细胞外记录技术 ,以大鼠脊髓背角 WDR神经元伤害性诱发反应为痛反应指标 ,观察了损毁中缝大核 (NRM)前后静脉注射琥珀胆碱 (SCH)诱发的肌梭传入活动对脊髓背角 WDR神经元伤害性诱发反应的影响。结果　在 34个 WDR神经元中 ,有 2 7个单位的晚串放电被静注 SCH诱发的肌梭传入所抑制 (占76.67% ) ,5个单位表现为兴奋 ,2个单位无反应 ,对有抑制作用的 1 9个单位进一步观察发现 ,损毁中缝大核后 ,静注 SCH诱发的肌梭传入对 WDR神经元伤害性诱发反应的抑制作用明显减弱 ,抑制率由损毁前的 31 .92 %降至 2 3.44%。结论　提示中缝大核在肌梭传入的镇痛中起着一定的作用

The role of nucleus raphe magnus in analgesia produced by the activation of muscle spindle afferent

Objective To observe the role of nucleus raphe magnus(NRM) in analgesia produced by the activation of muscle spindle afferent.Methods The C fiber responses of the wide dynamic range(WDR) neurons in the rat spinal cord dorsal horn were used as nociceptive responses.The inhibitory effects on C responses of WDR neurons elicited by injecting introvenously(SCH) which can evoke muscle spindle afferents were compared before and after electrolytic lesion of NRM.Results The results showed that there were 27 of 34 WDR neurons(76.67%) were inhibited by introvenously SCH and the further study(19unit) found that after lesion of NRM the inhibitory effects to WDR neurons of SCH were significant decreased,the inhibitory rate from 31.92%(before lesion of NRM) reduced to 23.44%.Conclusion It suggests that NRM play an important role in analgesia produced by the activation of muscle spindle afferents.