褪黑色素对缰核痛神经元单位放电的影响及可能机制

目的通过观察褪黑色素对缰核痛神经元单位放电的影响,进一步证明褪黑色素的中枢镇痛作用及可能机制。方法：应用细胞外神经元单位放电记录方法,记录缰核神经元痛相关神经元放电,并观察外侧缰核痛神经元在褪黑色素作用下电活动的改变,及对伤害性刺激痛敏感性的改变,在此基础上观察纳洛酮的翻转作用。结果：褪黑色素影响外侧缰核痛神经元的电活动,并使外侧缰核痛神经元对伤害性刺激敏感性降低,此种作用可被纳洛酮翻转。结论：褪黑色素可通过作用于外侧缰核的阿片受体而影响其痛相关神经元对痛刺激的反应,这可能是褪黑色素中枢镇痛机制之一。

Effect and possible mechanism of melatonin on the firing rate of pain neurons in lateral habenular nucleus

Aim: The effect and possible mechanism of Melatonin(MEL) on firing rate of pain neurons in lateral habenular nucleus of rats were investigated in the experiment.Methods: Single extracellular firing were recorded to study the firing rate changes of pain neurons and sensitivity changes to pain stimulation induced by MEL in LHb of rats.Reverse effect of naloxone on the analgesia induced by melatonin was also observed.Results: Melatonin showed the effects on the firing of pain neurons in the LHb and decreased the sensitivity of pain neurons to pain stimulation,which could be reversed by naloxone.Conclusion: Melatonin can change the responses of pain neurons to pain stimulation via opioid receptor in the LHb,which might be one of analgesic mechanisms by MEL.