Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium.
PLoS One. 2013;8(1):e54166. doi: 10.1371/journal.pone.0054166. Epub 2013 Jan 14.
Zebrafish have recently emerged as an attractive in vivo model for epilepsy. Seven-day-old zebrafish larvae exposed to the GABA(A) antagonist pentylenetetrazol (PTZ) exhibit increased locomotor activity, seizure-like behavior, and epileptiform electrographic activity. A previous study showed that 12 out of 13 antiepileptic drugs (AEDs) suppressed PTZ-mediated increases in larval movement, indicating the potential utility of zebrafish as a high-throughput in vivo model for AED discovery. However, a question remained as to whether an AED-induced decrease in locomotion is truly indicative of anticonvulsant activity, as some drugs may impair larval movement through other mechanisms such as general toxicity or sedation. We therefore carried out a study in PTZ-treated zebrafish larvae, to directly compare the ability of AEDs to inhibit seizure-like behavioral manifestations with their capacity to suppress epileptiform electrographic activity. We re-tested the 13 AEDs of which 12 were previously reported to inhibit convulsions in the larval movement tracking assay, administering concentrations that did not, on their own, impair locomotion. In parallel, we carried out open-field recordings on larval brains after treatment with each AED. For the majority of AEDs we obtained the same response in both the behavioral and electrographic assays. Overall our data correlate well with those reported in the literature for acute rodent PTZ tests, indicating that the larval zebrafish brain is more discriminatory than previously thought in its response to AEDs with different modes of action. Our results underscore the validity of using the zebrafish larval locomotor assay as a rapid first-pass screening tool in assessing the anticonvulsant and/or proconvulsant activity of compounds, but also highlight the importance of performing adequate validation when using in vivo models.
斑马鱼最近成为癫痫研究的一种有吸引力的活体模型。将 7 天大的斑马鱼幼虫暴露于 GABA(A) 拮抗剂戊四氮（PTZ）中，会导致其运动活动增加、类似癫痫发作的行为和癫痫样电图活动。先前的研究表明，13 种抗癫痫药物（AEDs）中有 12 种抑制了幼虫运动中 PTZ 介导的增加，这表明斑马鱼作为一种高通量体内 AED 发现模型具有潜在的应用价值。然而，一个问题仍然存在，即运动减少是否真正表明具有抗惊厥活性，因为一些药物可能通过其他机制（如一般毒性或镇静作用）损害幼虫的运动。因此，我们在 PTZ 处理的斑马鱼幼虫中进行了一项研究，直接比较 AED 抑制类似癫痫行为表现的能力与其抑制癫痫样电图活动的能力。我们重新测试了之前在幼虫运动跟踪测定中报告的 13 种 AED，使用的浓度不会自行损害运动。同时，我们在每种 AED 处理后对幼虫大脑进行了开放式记录。对于大多数 AED，我们在行为和电图表征测定中都获得了相同的反应。总的来说，我们的数据与文献中报告的急性啮齿动物 PTZ 测试结果高度相关，这表明与具有不同作用机制的 AED 相比，幼虫斑马鱼大脑在其反应中更为敏感。我们的研究结果强调了使用斑马鱼幼虫运动测定作为评估化合物抗惊厥和/或致惊厥活性的快速初筛工具的有效性，但也强调了在使用体内模型时进行充分验证的重要性。
