Yoshioka M, Matsumoto M, Togashi H, Saito H
First Department of Pharmacology, Hokkaido University School of Medicine, Sapporo, Japan.
Pharmacol Biochem Behav. 1995 Jun-Jul;51(2-3):515-9. doi: 10.1016/0091-3057(95)00045-x.
The effects of conditioned fear stress (CFS) on 5-HT release in the medial prefrontal cortex were studied by in vivo microdialysis. CFS (exposure to an environment in which foot-shock had been delivered previously) induced a marked suppression of motility-that is, freezing behavior. The extracellular concentration of 5-HT in the medial prefrontal cortex increased during this freezing behavior, but no significant changes were observed in the concentration of its metabolite, 5-HIAA. The increased 5-HT concentration returned to pretreatment levels when the animals were returned to their home cages. Diazepam (0.5 mg/kg, intraperitoneally) reduced the CFS-induced freezing behavior and prevented the increases in extracellular 5-HT levels. A 5-HT3 receptor antagonist, tropisetron (10 and 100 micrograms/kg), also inhibited both the CFS-induced increase in 5-HT release and the freezing behavior. These findings suggest that there is a relationship between anxiety and 5-HT release in the prefrontal cortex and that the 5-HT3 receptor antagonist tropisetron might have anxiolytic properties.
通过体内微透析研究了条件性恐惧应激（CFS）对内侧前额叶皮质中5-羟色胺（5-HT）释放的影响。CFS（暴露于先前曾施加过足部电击的环境）引起运动明显抑制，即僵住行为。在这种僵住行为期间，内侧前额叶皮质中5-HT的细胞外浓度增加，但其代谢产物5-羟吲哚乙酸（5-HIAA）的浓度未观察到显著变化。当动物回到其饲养笼时，升高的5-HT浓度恢复到预处理水平。地西泮（0.5毫克/千克，腹腔注射）减少了CFS诱导的僵住行为，并防止了细胞外5-HT水平的升高。一种5-HT3受体拮抗剂，托烷司琼（10和100微克/千克），也抑制了CFS诱导的5-HT释放增加和僵住行为。这些发现表明，焦虑与前额叶皮质中5-HT释放之间存在关联，并且5-HT3受体拮抗剂托烷司琼可能具有抗焦虑特性。
