5-HT3 receptors partially mediate halothane depression of spinal dorsal horn sensory neurons
5-HT3 receptors partially mediate halothane depression of spinal dorsal horn sensory neurons
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DOI：
10.1213/01.ane.0000050769.34933.03
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发表时间：
2003-04-01
影响因子：
5.7
通讯作者：
Collins, JG
中科院分区：
文献类型：
--
作者：
Koshizaki, M;Kawamata, M;Collins, JG
我们最近报道，γ-氨基丁酸A型和士的宁敏感的甘氨酸受体系统部分介导氟烷抑制脊髓背角低阈值神经元。5-羟色胺亚型3（5-HT 3）受体与γ-氨基丁酸A型和士的宁敏感的甘氨酸受体属于相同的配体激活的离子通道家族，因此我们研究了5-HT受体系统在脊髓感觉神经元的氟烷抑制中的可能参与。脊髓低阈值神经元的细胞外记录在去大脑，脊髓横断大鼠。在存在或不存在5-HT拮抗剂和存在或不存在1.1%（1个最小肺泡麻醉剂浓度）氟烷的情况下记录感受野大小和刷毛诱导的活动。在没有氟烷的情况下，拮抗剂对感受野大小或刷诱导的活性没有影响。在氟烷，麦角新碱，一种非选择性5-HT拮抗剂，和托烷司琼，一种选择性5-HT 3拮抗剂的存在下，显着逆转氟烷诱导的感受野大小的减少，但没有改变氟烷抑郁刷诱导的活动。5-HT 1拮抗剂甲硫替平和5-HT 2拮抗剂酮色林不能逆转氟烷抑制。这些结果支持了5-HT_3受体部分介导氟烷对脊髓背角神经元抑制作用的假说。
We recently reported that gamma-aminobutyric acid type A- and strychnine-sensitive glycine receptor systems partially mediate halothane depression of spinal dorsal horn low-threshold neurons. Serotonin subtype 3 (5-HT3) receptors belong to the same ligand-activated ion-channel family as gamma-aminobutyric acid type A- and strychnine-sensitive glycine receptors, so we examined the possible involvement of 5-HT receptor systems in halothane depression of spinal sensory neurons. Extracellular recordings of spinal low-threshold neurons were obtained in decerebrate, spinally transected rats. Receptive field size and brush-induced activity were recorded in the presence or absence of 5-HT antagonists and in the presence or absence of 1.1% (1 minimum alveolar anesthetic concentration) halothane. In the absence of halothane, antagonists had no effect on receptive field size or brush-induced activity. In the presence of halothane, methysergide, a nonselective 5-HT antagonist, and tropisetron, a selective 5-HT3 antagonist, significantly reversed the halothane-induced reduction in receptive field size but did not alter halothane depression of brush-induced activity. Methiothepin, a 5-HT1 antagonist, and ketanserin, a 5-HT2 antagonist, did not reverse halothane depression. These results support the hypothesis that 5-HT3 receptors partially mediate some inhibitory effects of halothane on spinal dorsal horn neurons.