Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Germany.
Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Germany; Institute for Sex Research, Sexual Medicine and Forensic Psychiatry, Center of Psychosocial Medicine, University Medical Center Hamburg-Eppendorf, Germany.
Behav Res Ther. 2020 Jun;129:103605. doi: 10.1016/j.brat.2020.103605. Epub 2020 Mar 18.
Threat responses are often shaped by social information, such as observation of aversive outcomes for others. Yet, the neurochemistry regulating observational learning of threats is largely unknown. Here, we examined the impact of the GABAergic and noradrenergic system, which are central in regulating threat learning from first-hand experiences, on observational threat learning in humans. To this end, 61 participants received either 1 mg Lorazepam (enhancing GABAergic signalling N = 18), 20 mg Yohimbine (enhancing Noradrenergic transmission, N = 16), Placebo (double blind and randomized control for Lorazepam and Yohimbine, N = 12) or no treatment (N = 15) prior to observational threat conditioning. Participants acquired conditioned threat responses by observation of another individual who is presented with a conditioned stimulus (CS) and an aversive unconditioned stimulus (US). Participants' threat responses were tested by direct exposure to the CSs immediately after learning, as well as two days later (drug free). Our results indicate decreased fear ratings to socially acquired CSs by enhanced GABAergic transmission as compared to the control group (placebo and no treatment) during the immediate test. We could not provide evidence for noradrenergic modulation of socially acquired threat responses. Further, we found no differences in psychophysiological responses (Skin conductance responses) or long-term persistence of conditioned responses. Our results provide initial evidence for an impact of the GABAergic system on social acquisition of threats.
威胁反应通常受到社会信息的影响，例如观察到他人的不良后果。然而，调节威胁观察学习的神经化学物质在很大程度上是未知的。在这里，我们研究了 GABA 能和去甲肾上腺素能系统的影响，这两个系统在调节从第一手经验中学习威胁方面起着核心作用，对人类的观察性威胁学习产生影响。为此，61 名参与者接受了 1 毫克劳拉西泮（增强 GABA 能信号，N=18）、20 毫克育亨宾（增强去甲肾上腺素能传递，N=16）、安慰剂（劳拉西泮和育亨宾的双盲和随机对照，N=12）或未治疗（N=15），然后进行观察性威胁条件作用。参与者通过观察另一个人接受条件刺激（CS）和厌恶的非条件刺激（US）来获得条件性威胁反应。参与者的威胁反应在学习后立即（无药物）以及两天后（无药物）通过直接暴露于 CSs 进行测试。我们的结果表明，与对照组（安慰剂和未治疗组）相比，增强 GABA 能传递会导致社会获得的 CS 的恐惧评分降低，在即时测试中。我们没有提供去甲肾上腺素能调节社会获得的威胁反应的证据。此外，我们在心理生理反应（皮肤电导反应）或条件反应的长期持久性方面没有发现差异。我们的研究结果初步证明了 GABA 能系统对威胁的社会获得的影响。
