Palmisano Alexandra N, Gould Thomas J, Astur Robert S
Department of Psychological Sciences.
Department of Biobehavioral Health.
Exp Clin Psychopharmacol. 2023 Apr;31(2):464-474. doi: 10.1037/pha0000592. Epub 2022 Sep 8.
Nicotine has been shown to facilitate hippocampal-dependent context fear conditioning (FC), but not hippocampal-independent delay cued fear conditioning. Studies examining the effects of nicotine on learned fear have been exclusively limited to nonhumans. The present study aimed to translate nonhuman findings by investigating the effects of nicotine on cued and context fear in humans using a virtual reality (VR) analog of the fear conditioning task. Sixty-seven nicotine-using undergraduates were randomly assigned to receive either a 2 mg nicotine or placebo lozenge prior to conditioning. During conditioning, participants were confined to a virtual room and were conditioned to green floodlight presentations (conditioned stimulus [CS +]) paired with a wrist shock (unconditioned stimulus [US]). A red floodlight served as the CS- during which no shock occurred. Delay cued and context fear testing immediately followed conditioning. Physiological skin conductance responses (SCRs) were recorded continuously throughout all sessions. Nicotine enhanced context fear conditioning such that SCRs to the shock-paired context were significantly greater for the nicotine group than the placebo group. Nicotine did not enhance delay cued fear. Exploratory analyses examining the relationship between fear conditioning and self-reported anxiety revealed that relative to those with lower levels of trait anxiety, nicotine-treated individuals with higher trait anxiety levels were less likely to demonstrate differential conditioning to the shock-paired cue. These findings support abundant nonhuman literature indicating that nicotine facilitates hippocampus-dependent versions of fear conditioning in humans. Results also suggest a role for dysregulated safety learning in pathological anxiety, which may be exacerbated by nicotine use. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
尼古丁已被证明有助于海马体依赖的情境恐惧条件反射（FC），但对海马体非依赖的延迟线索恐惧条件反射无效。研究尼古丁对习得性恐惧影响的研究仅局限于非人类。本研究旨在通过使用恐惧条件反射任务的虚拟现实（VR）模拟来调查尼古丁对人类线索和情境恐惧的影响，从而将非人类的研究结果转化应用。67名使用尼古丁的本科生在条件反射前被随机分配接受2毫克尼古丁或安慰剂含片。在条件反射过程中，参与者被限制在一个虚拟房间里，并对与手腕电击（无条件刺激[US]）配对的绿色泛光灯呈现（条件刺激[CS+]）形成条件反射。红色泛光灯作为CS-，在此期间不发生电击。条件反射后立即进行延迟线索和情境恐惧测试。在所有实验环节中持续记录生理皮肤电传导反应（SCR）。尼古丁增强了情境恐惧条件反射，使得尼古丁组对与电击配对情境的SCR显著大于安慰剂组。尼古丁并未增强延迟线索恐惧。探索性分析考察了恐惧条件反射与自我报告焦虑之间的关系，结果显示，相对于特质焦虑水平较低的人，特质焦虑水平较高的尼古丁治疗个体对与电击配对线索表现出差异条件反射的可能性较小。这些发现支持了大量非人类研究文献，表明尼古丁在人类中促进了海马体依赖型的恐惧条件反射。结果还表明，安全学习失调在病理性焦虑中起作用，而尼古丁使用可能会加剧这种情况。（PsycInfo数据库记录（c）2023美国心理学会，保留所有权利）
