Willcockson W S, Chung J M, Hori Y, Lee K H, Willis W D
J Neurosci. 1984 Mar;4(3):732-40. doi: 10.1523/JNEUROSCI.04-03-00732.1984.
The effects of glutamate (Glu), gamma-aminobutyric acid (GABA), glycine (Gly), serotonin (5-HT), norepinephrine (NE), dopamine (DA), and acetylcholine (ACh) were examined in this study by iontophoretic application onto primate spinothalamic tract (STT) neurons identified antidromically by stimulation in the contralateral thalamus. Drugs were tested for effects on background activity, Glu-induced firing, and activity evoked by pinching of the skin. Whereas Glu excited STT cells and was thus used for tests of the other compounds, the amino acids GABA and Gly inhibited Glu- and pinch-induced activity in all STT cells examined. STT cells were also inhibited by 5-HT, NE, and DA. Only two cases of excitation by 5-HT were seen (of 58 cells tested). ACh also had inhibitory actions on STT cells, although 3 of 21 cells exhibited some enhancement of activity. The effects of these compounds on identified STT cells resemble previous demonstrations of the effects of these drugs on dorsal horn interneurons. The results suggest that GABA, Gly, 5-HT, NE, and DA may be inhibitory neurotransmitters on nociceptive STT cells.
本研究通过离子导入法，将谷氨酸（Glu）、γ-氨基丁酸（GABA）、甘氨酸（Gly）、5-羟色胺（5-HT）、去甲肾上腺素（NE）、多巴胺（DA）和乙酰胆碱（ACh）作用于经对侧丘脑刺激逆向鉴定的灵长类动物脊髓丘脑束（STT）神经元，以检测其作用效果。测试了这些药物对背景活动、Glu诱导的放电以及皮肤捏压诱发活动的影响。鉴于Glu可兴奋STT细胞，因此用于测试其他化合物，在所检测的所有STT细胞中，氨基酸GABA和Gly可抑制Glu和捏压诱导的活动。5-HT、NE和DA也可抑制STT细胞。仅观察到2例（在58个测试细胞中）5-HT引起的兴奋。ACh对STT细胞也有抑制作用，尽管在21个细胞中有3个细胞表现出活动的某种增强。这些化合物对已鉴定的STT细胞的作用类似于先前关于这些药物对背角中间神经元作用的证明。结果表明，GABA、Gly、5-HT、NE和DA可能是伤害性STT细胞上的抑制性神经递质。
