Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.
Behav Brain Res. 2012 Mar 1;228(1):99-106. doi: 10.1016/j.bbr.2011.11.041. Epub 2011 Dec 6.
Zebrafish larvae are ideally suited for high-throughput analyses of vertebrate behavior. The larvae can be examined in multiwell plates and display a range of behaviors during early development. Previous studies have shown that zebrafish larvae display a preference for the edge of the well and several lines of evidence suggest this edge preference (thigmotaxis) may be a measure of anxiety. In the present study, we further examined the relation between edge preference and anxiety by imaging zebrafish larvae exposed to three psychoactive drugs diazepam (Valium), fluoxetine (Prozac), and caffeine. The edge preference was first examined in a five-fish assay, with and without visual stimuli. Diazepam, a benzodiazepine that binds to GABA receptors, reduced the larval edge preference, with or without visual stimuli. In contrast, fluoxetine, a selective serotonin reuptake inhibitor, did not affect the edge preference. Caffeine increased the preference for the edge in response to visual stimuli. Similar effects were observed in a two-fish assay; diazepam-exposed larvae showed a reduced edge preference and caffeine exposed larvae showed an increased edge preference. These results suggest that the edge preference in zebrafish larvae is a measure of anxiety and further illustrate that the pharmaceuticals used in the study have different mechanisms of action. Although there are substantial differences between zebrafish and human brains, our results indicate that the signals that regulate anxiety are similar on a molecular level. We propose that high-throughput assays in zebrafish may be used to uncover genetic or environmental factors that cause anxiety disorders and may contribute to the development of novel strategies to prevent or treat such disorders.
斑马鱼幼鱼非常适合用于脊椎动物行为的高通量分析。这些幼鱼可以在多孔板中进行检查，并且在早期发育过程中表现出多种行为。先前的研究表明，斑马鱼幼鱼表现出对孔壁边缘的偏好，并且有几条证据表明这种边缘偏好（壁癖）可能是焦虑的一种衡量标准。在本研究中，我们通过对暴露于三种精神活性药物（安定，氟西汀和咖啡因）的斑马鱼幼鱼进行成像，进一步研究了边缘偏好与焦虑之间的关系。首先在五鱼测定中检查了边缘偏好，有和没有视觉刺激。安定是一种与 GABA 受体结合的苯二氮䓬类药物，无论是否存在视觉刺激，都会降低幼鱼的边缘偏好。相比之下，氟西汀，一种选择性 5-羟色胺再摄取抑制剂，不会影响边缘偏好。咖啡因增加了对视觉刺激的边缘偏好。在双鱼测定中也观察到了类似的效果；暴露于安定的幼鱼显示出对边缘的偏好降低，而暴露于咖啡因的幼鱼则显示出对边缘的偏好增加。这些结果表明，斑马鱼幼鱼的边缘偏好是焦虑的一种衡量标准，并且进一步表明研究中使用的药物具有不同的作用机制。尽管斑马鱼和人类大脑之间存在很大差异，但我们的研究结果表明，调节焦虑的信号在分子水平上是相似的。我们提出，斑马鱼中的高通量测定可能用于发现引起焦虑症的遗传或环境因素，并有助于开发预防或治疗此类疾病的新策略。
