Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA.
Department of Neurology, University of Virginia, Charlottesville, Virginia, USA.
Epilepsia. 2020 Oct;61(10):2277-2288. doi: 10.1111/epi.16651. Epub 2020 Sep 21.
Development of novel therapies for temporal lobe epilepsy is hindered by a lack of models suitable for drug screening. While testing the hypothesis that "inhibiting inhibitory neurons" was sufficient to induce seizures, it was discovered that a mild electrical kindling protocol of VGAT-Cre mice led to spontaneous motor and electrographic seizures. This study characterizes these seizures and investigates the mechanism.
Mice were implanted with electroencephalographic (EEG) headsets that included a stimulating electrode in the hippocampus before being electrically kindled. Seizures were evaluated by review of EEG recordings and behavior. γ-Aminobutyric acidergic (GABAergic) neurotransmission was evaluated by quantitative polymerase chain reaction, immunocytochemistry, Western blot, and electrophysiology.
Electrical kindling of VGAT-Cre mice induces spontaneous recurring seizures after a short latency (6 days). Seizures occur 1-2 times per day in both male and female mice, with only minimal neuronal death. These mice express Cre recombinase under the control of the vesicular GABA transporter (VGAT), a gene that is specifically expressed in GABAergic inhibitory neurons. The insertion of Cre disrupts the expression of VGAT mRNA and protein, and impairs GABAergic synaptic transmission in the hippocampus.
Kindled VGAT-Cre mice can be used to study the mechanisms involved in epileptogenesis and may be useful for screening novel therapeutics.
由于缺乏适合药物筛选的模型，颞叶癫痫的新型治疗方法的开发受到阻碍。在测试“抑制抑制性神经元”足以引发癫痫的假设时，发现 VGAT-Cre 小鼠的轻度电点燃方案会导致自发性运动和脑电图发作。本研究对这些发作进行了特征描述，并研究了其机制。
在对海马进行电刺激之前，将脑电图（EEG）耳机植入小鼠体内，并植入 EEG 耳机。通过 EEG 记录和行为评估来评估癫痫发作。通过定量聚合酶链反应、免疫细胞化学、Western blot 和电生理学评估γ-氨基丁酸能（GABAergic）神经传递。
VGAT-Cre 小鼠的电点燃会在短潜伏期（6 天）后引发自发性复发性癫痫。雄性和雌性小鼠每天都会发作 1-2 次，只有很少的神经元死亡。这些小鼠在囊泡 GABA 转运体（VGAT）的控制下表达 Cre 重组酶，该基因特异性表达于 GABA 能抑制性神经元。Cre 的插入会破坏 VGAT mRNA 和蛋白的表达，并损害海马中的 GABA 能突触传递。
点燃的 VGAT-Cre 小鼠可用于研究癫痫发生的机制，并且可能对筛选新型治疗方法有用。
