GABA_A receptors, members of the pentameric ligand-gated ion channel superfamily, are widely expressed in the central nervous system and mediate a broad range of pharmaco-toxicological effects including bidirectional changes to seizure threshold. Thus, detection of GABA_A receptor-mediated seizure liabilities is a big, partly unmet need in early preclinical drug development. This is in part due to the plethora of allosteric binding sites that are present on different subtypes of GABA_A receptors and the critical lack of screening methods that detect interactions with any of these sites. To improve in silico screening methods, we assembled an inventory of allosteric binding sites based on structural data. Pharmacophore models representing several of the binding sites were constructed. These models from the NeuroDeRisk IL Profiler were used for in silico screening of a compiled collection of drugs with known GABA_A receptor interactions to generate testable hypotheses. Amoxapine was one of the hits identified and subjected to an array of in vitro assays to examine molecular and cellular effects on neuronal excitability and in vivo locomotor pattern changes in zebrafish larvae. An additional level of analysis for our compound collection is provided by pharmacovigilance alerts using FAERS data. Inspired by the Adverse Outcome Pathway framework, we postulate several candidate pathways leading from specific binding sites to acute seizure induction. The whole workflow can be utilized for any compound collection and should inform about GABA_A receptor-mediated seizure risks more comprehensively compared to standard displacement screens, as it rests chiefly on functional data.

GABA _A受体是五聚体配体门控离子通道超家族的成员，在中枢神经系统中广泛表达，并介导广泛的药物毒理学作用，包括癫痫阈值的双向变化。因此，检测 GABA _A受体介导的癫痫发作是早期临床前药物开发中一个很大的、部分未得到满足的需求。_{这部分是由于 GABA A}受体的不同亚型上存在过多的变构结合位点，并且严重缺乏检测与这些位点相互作用的筛选方法。为了改进计算机筛选方法，我们根据结构数据收集了变构结合位点清单。构建了代表几个结合位点的药效团模型。NeuroDeRisk IL Profiler 中的这些模型用于对具有已知 GABA _A受体相互作用的一组药物进行计算机筛选，以生成可测试的假设。阿莫沙平是其中之一，并进行了一系列体外测定，以检查分子和细胞对斑马鱼幼虫神经元兴奋性和体内运动模式变化的影响。使用 FAERS 数据的药物警戒警报为我们的化合物集合提供了额外级别的分析。受不良结果途径框架的启发，我们假设了从特定结合位点到急性癫痫发作诱导的几种候选途径。整个工作流程可用于任何化合物收集，并且与标准位移筛选相比，应该更全面地了解 GABA _A受体介导的癫痫风险，因为它主要依赖于功能数据。