Belcher G, Ryall R W, Schaffner R
Brain Res. 1978 Aug 4;151(2):307-21. doi: 10.1016/0006-8993(78)90887-9.
The effects of 5-hydroxytryptamine (5-HT), noradrenaline (NA) and stimulation of the inferior central nucleus of the raphe (RN) were examined on nociceptive and non-nociceptive spinal neurones in anaesthetized cats. 5-HT reduced excitation evoked by noxious stimulation, but increased spontaneous firing and firing evoked by DL-homocysteic acid (DLH) on both nociceptive and non-nociceptive cells. NA reduced spontaneous activity, DLH-evoked excitation and excitation evoked by a noxious stimulus on nociceptive neurones, but had little action on non-nociceptive units. RN inhibited spontaneous, stimulus-evoked and DLH-evoked firing of nociceptive cells and caused briefer inhibitions of non-nociceptive cells. Excitatory effects were also observed. Strychnine antagonized short-duration inhibitions from RN of non-nociceptive cells responding to hair movement, but failed to antagonize any of the other effects of RN. No antagonism of the inhibitory effect of RN was observed with phenoxybenzamine, phentolamine, sotalol, bicuculline or methysergide. However, methysergide antagonized some excitatory effects of 5-HT and RN, but also produced non-specific actions on some cells. It was concluded that, although glycine may mediate some of the brief duration inhibitions evoked by RN, the longer duration inhibitions were unlikely to have been mediated by either glycine or GABA. 5-HT may be a mediator of raphe-spinal actions but may have presynaptic inhibitory actions coupled with postsynaptic excitatory effects. NA could mediate some descending inhibition of nociceptive neurones.
在麻醉猫身上，研究了5-羟色胺（5-HT）、去甲肾上腺素（NA）以及刺激中缝核下部（RN）对伤害性和非伤害性脊髓神经元的影响。5-HT可减少伤害性刺激诱发的兴奋，但增加伤害性和非伤害性细胞的自发放电以及由DL-高半胱氨酸（DLH）诱发的放电。NA可减少伤害性神经元的自发放电、DLH诱发的兴奋以及伤害性刺激诱发的兴奋，但对非伤害性单位作用很小。RN可抑制伤害性细胞的自发、刺激诱发和DLH诱发的放电，并对非伤害性细胞产生短暂抑制。也观察到了兴奋作用。士的宁可拮抗RN对感受毛发运动的非伤害性细胞的短暂抑制作用，但不能拮抗RN的任何其他作用。用酚苄明、酚妥拉明、索他洛尔、荷包牡丹碱或麦角新碱均未观察到对RN抑制作用的拮抗。然而，麦角新碱可拮抗5-HT和RN的一些兴奋作用，但也对一些细胞产生非特异性作用。得出的结论是，虽然甘氨酸可能介导RN诱发的一些短暂抑制，但较长时间的抑制不太可能由甘氨酸或GABA介导。5-HT可能是中缝脊髓作用的介质，但可能具有突触前抑制作用并伴有突触后兴奋作用。NA可介导对伤害性神经元的一些下行抑制。
