Harris L T, McCall R B
Eur J Pharmacol. 1986 Aug 22;128(1-2):133-6. doi: 10.1016/0014-2999(86)90567-4.
Methysergide, a serotonin antagonist, and clonidine, an alpha 2-adrenoceptor agonist, lowered arterial blood pressure, heart rate and inferior cardiac sympathetic nerve activity in the anesthetized cat. Picrotoxin, a GABA antagonist, caused a reduction in the inhibition of sympathetic activity produced by methysergide. In contrast, picrotoxin did not effect the reduction of sympathetic nervous discharge resulting from administration of clonidine. These observations suggest that an interaction exists between GABAergic and serotonergic neurons which regulates central sympathetic pathways, possibly by a tonic GABAergic inhibition of serotonergic sympathoexcitatory pathways.
麦角新碱是一种5-羟色胺拮抗剂，可乐定是一种α2-肾上腺素能受体激动剂，它们可降低麻醉猫的动脉血压、心率及心脏下交感神经活动。印防己毒素是一种γ-氨基丁酸（GABA）拮抗剂，它可减弱麦角新碱对交感神经活动的抑制作用。相反，印防己毒素对可乐定引起的交感神经放电减少没有影响。这些观察结果表明，GABA能神经元与5-羟色胺能神经元之间存在相互作用，这种相互作用可能通过GABA能神经元对5-羟色胺能交感兴奋通路的紧张性抑制来调节中枢交感神经通路。
