Epilepsy, a common neurological disorder, is featured with recurrent seizures. Its underlying pathological mechanisms remain elusive. Here, we provide evidence for loss of neogenin (NEO1), a coreceptor for multiple ligands, including netrins and bone morphological proteins, in the development of epilepsy. NEO1 is reduced in hippocampi from patients with epilepsy based on transcriptome and proteomic analyses. Neo1 knocking out (KO) in mouse brains displays elevated epileptiform spikes and seizure susceptibility. These phenotypes were undetectable in mice, with selectively depleted NEO1 in excitatory (NeuroD6-Cre⁺) or inhibitory (parvalbumin⁺) neurons, but present in mice with specific hippocampal astrocytic Neo1 KO. Additionally, neurons in hippocampal dentate gyrus, a vulnerable region in epilepsy, in mice with astrocyte-specific Neo1 KO show reductions in inhibitory synaptic vesicles and the frequency of miniature inhibitory postsynaptic current(mIPSC), but increase of the duration of miniature excitatory postsynaptic current and tonic NMDA receptor currents, suggesting impairments in both GABAergic transmission and extracellular glutamate clearance. Further proteomic and cell biological analyses of cell-surface proteins identified GLAST, a glutamate–aspartate transporter that is marked reduced in Neo1 KO astrocytes and the hippocampus. NEO1 interacts with GLAST and promotes GLAST surface distribution in astrocytes. Expressing NEO1 or GLAST in Neo1 KO astrocytes in the hippocampus abolishes the epileptic phenotype. Taken together, these results uncover an unrecognized pathway of NEO1-GLAST in hippocampal GFAP⁺ astrocytes, which is critical for GLAST surface distribution and function, and GABAergic transmission, unveiling NEO1 as a valuable therapeutic target to protect the brain from epilepsy.

癫痫是一种常见的神经系统疾病，以反复发作为特征。其潜在的病理机制仍然难以捉摸。在这里，我们提供了在癫痫的发展过程中丢失 Neogenin (NEO1) 的证据，NEO1 是多种配体的辅助受体，包括 netrins 和骨形态蛋白。根据转录组和蛋白质组学分析，癫痫患者海马中的 NEO1 减少。小鼠大脑中的Neo1敲除 (KO) 显示出升高的癫痫样尖峰和癫痫发作易感性。这些表型在小鼠中无法检测到，在兴奋性 (NeuroD6-Cre ⁺ ) 或抑制性 (parvalbumin ⁺ ) 神经元中选择性消耗 NEO1 ，但存在于具有特定海马星形胶质细胞Neo1 的小鼠中KO。此外，在星形胶质细胞特异性Neo1 KO小鼠中，海马齿状回（癫痫的脆弱区域）中的神经元显示抑制性突触小泡和微型抑制性突触后电流 (mIPSC) 的频率减少，但微型兴奋性突触后电流的持续时间增加和强直 NMDA 受体电流，表明 GABA 能传递和细胞外谷氨酸清除受损。对细胞表面蛋白的进一步蛋白质组学和细胞生物学分析确定了 GLAST，一种谷氨酸-天冬氨酸转运蛋白，在Neo1 KO 星形胶质细胞和海马体中显着减少。NEO1 与 GLAST 相互作用并促进星形胶质细胞中的 GLAST 表面分布。在Neo1 中表达 NEO1 或 GLAST海马中的 KO 星形胶质细胞消除了癫痫表型。总之，这些结果揭示了海马 GFAP ⁺星形胶质细胞中 NEO1-GLAST 的一条未被识别的通路，这对 GLAST 表面分布和功能以及 GABA 能传递至关重要，揭示了 NEO1 作为保护大脑免受癫痫病的宝贵治疗靶点。