The benzodiazepine alprazolam dissociates contextual fear from cued fear in humans as assessed by fear-potentiated startle
The benzodiazepine alprazolam dissociates contextual fear from cued fear in humans as assessed by fear-potentiated startle
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DOI：
10.1016/j.biopsych.2005.11.027
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发表时间：
2006-10-01
影响因子：
10.6
通讯作者：
Levine, Jessica
中科院分区：
文献类型：
--
作者：
Grillon, Christian;Baas, Johanna M. P.;Levine, Jessica
背景：厌恶状态会增强惊吓反射。已经有人提出，对威胁线索的阶段性惊吓增强和对情境刺激的持续性惊吓增强反映了不同脑结构介导的不同过程。本研究验证了阿普唑仑将减少对情境威胁的持续惊吓增强，但不会降低对威胁线索的惊吓增强的假设。方法：16名健康受试者以交叉设计接受四种治疗：安慰剂、0.5 mg阿普唑仑、7 mg阿普唑仑和50 mg苯海拉明(苯海拉明)。参与者被暴露在三种情况下，其中一种情况是通过提示发出可预测的厌恶电击的信号，第二种情况是无法预测地施加电击，第三种情况是不会发生电击。结果：在可预测条件下，阿普唑仑不影响对威胁线索的时相惊吓增强。相反，在可预测和不可预测条件下，大剂量阿普唑仑显著减少了惊吓的持续增加。结论：对外显威胁线索和厌恶情境的惊吓反应在心理药理学上是不同的，这表明它们可能代表了功能上可分离的厌恶状态。
Background: The startle reflex is potentiated by aversive states. it has been, proposed that phasic startle potentiation to a threat cue and sustained startle potentiation to contextual stimuli reflect distinct processes mediated by different brain structures. The present study tested the hypothesis that alprazolam would reduce the sustained startle potentiation to contextual threats but not the startle potentiation to a threat cue.Methods: Sixteen healthy subjects received each of four treatments: placebo, .5 mg of alprazolam, 7 mg of alprazolam, and 50 mg of diphenhydramine (Benadryl) in a crossover design. Participants were exposed to three conditions, including one in which predictable aversive shocks were signaled by a cue, a second in which shocks were administered unpredictably, and a third condition in which no shocks were anticipated. Acoustic startle were delivered regularly across conditions.Results: Phasic startle potentiation to the threat cue in the predictable condition was not affected by alprazolam. in contrast, the sustained increase in startle in the predictable and unpredictable conditions was reduced significantly by the high dose of alprazolam.Conclusions: Startle responses to an explicit threat cue and to an aversive context are psychopharmacologically distinct, suggesting that they may represent functionally dissociable aversive states.