Jones R S
Neuropharmacology. 1982 Mar;21(3):209-14. doi: 10.1016/0028-3908(82)90189-7.
Tryptamine, applied iontophoretically to cortical neurones, had predominantly depressant effects. In contrast 5-hydroxytryptamine (5HT) exhibited excitatory effects on many neurons. On over 40% of neurones responsive to both 5HT and tryptamine the amines had opposite effects. A comparison of the magnitude of the depressant responses revealed that tryptamine was a much more effective depressant agent than 5HT. The iontophoretic transport numbers for 5HT and tryptamine were similar, indicating that the apparently greater potency of tryptamine was genuine. Electrolytic lesions of the medial forebrain bundle did not alter the relative effects of the amines, suggesting that there was a post-synaptic origin for the difference. Finally, the indoleamine antagonist metergoline was found to block selectively the tryptamine responses with little effect on 5HT responses, at low concentrations. The results suggest that tryptamine may possess post-synaptic effects unrelated to direct agonist actions at 5HT receptors.
将色胺通过离子导入法作用于皮层神经元时，主要产生抑制作用。相比之下，5-羟色胺（5HT）对许多神经元表现出兴奋作用。在对5HT和色胺均有反应的超过40%的神经元上，这两种胺产生相反的作用。对抑制反应强度的比较显示，色胺是比5HT更有效的抑制剂。5HT和色胺的离子导入转运数相似，表明色胺明显更高的效力是真实存在的。内侧前脑束的电解损伤并未改变这两种胺的相对作用，提示这种差异源于突触后。最后，发现吲哚胺拮抗剂麦角林在低浓度时能选择性阻断色胺反应，而对5HT反应影响很小。结果表明，色胺可能具有与5HT受体直接激动剂作用无关的突触后效应。
