Zebrafish have quickly emerged as a species of choice in preclinical research, holding promise to advance the field of behavioral pharmacology through high-throughput experiments. Besides biological and heuristic considerations, zebrafish also constitute a fundamental tool that fosters the replacement of mammals with less sentient experimental subjects. Notwithstanding these features, experimental paradigms to investigate emotional and cognitive domains in zebrafish are still limited. Studies on emotional memories have provided sound methodologies to investigate fear conditioning in zebrafish, but these protocols may still benefit from a reconsideration of the independent variables adopted to elicit aversion. Here, we designed a fear-conditioning paradigm in which wild-type zebrafish were familiarized over six training sessions with an empty compartment and a fear-eliciting one. The fearful stimulus was represented by three zebrafish replicas exhibiting a fully synchronized and polarized motion as they were maneuvered along 3D trajectories by a robotic platform. When allowed to freely swim between the two compartments in the absence of the robotic stimulus (test session), zebrafish displayed a marked avoidance of the stimulus-paired one. To investigate whether fear conditioning was modulated by psychoactive compounds, two groups of zebrafish were administered ethanol (0.25% and 1.00%, ethanol/water, by volume) a few minutes before the test session. We observed that ethanol administration abolished the conditioned avoidance of the stimulus-paired compartment. Ultimately, this study confirms that robotic stimuli may be used in the design of fear-conditioning paradigms, which are sensitive to pharmacological manipulations.

斑马鱼已迅速成为临床前研究的首选物种，有望通过高通量实验推动行为药理学领域的发展。除了生物学和启发式方面的考虑，斑马鱼还构成了一种基本工具，可以促进用较少感知的实验对象取代哺乳动物。尽管有这些特征，研究斑马鱼情感和认知领域的实验范式仍然有限。对情绪记忆的研究为研究斑马鱼的恐惧条件反射提供了合理的方法，但这些协议可能仍然受益于重新考虑用于引发厌恶的自变量。这里，我们设计了一种恐惧调节范式，其中野生型斑马鱼在六个训练课程中熟悉，其中有一个空隔间和一个引起恐惧的隔间。可怕的刺激表现为三个斑马鱼复制品，当它们被机器人平台沿着 3D 轨迹操纵时，它们表现出完全同步和极化的运动。当允许在没有机器人刺激（测试会话）的情况下在两个隔间之间自由游泳时，斑马鱼表现出对刺激配对的明显回避。为了研究恐惧条件反射是否受精神活性化合物的调节，在测试前几分钟给两组斑马鱼注射乙醇（0.25% 和 1.00%，乙醇/水，体积比）。我们观察到乙醇管理废除了刺激配对隔间的条件回避。