Study on the mechanism of high-frequency stimulation inhibiting low-Mg²⁺-induced epileptiform discharges in juvenile rat hippocampal slices

High-frequency stimulation (HFS) has been demonstrated to be an effective treatment for inhibiting epilepsy in some clinical and laboratory studies. However, the mechanisms underlying the therapeutic effects of HFS are not yet fully understood. In our present study, epileptiform discharges (EDs) in acutely isolated hippocampal slices of male Sprague–Dawley (SD) juvenile rats induced by low-Mg²⁺ artificial cerebrospinal fluid (ACSF), and electrical stimulation (square wave, 900 pulses, 50 % duty-cycle, 130 Hz) was performed on the CA3 using concentric bipolar electrodes. EDs of neurons in hippocampal were recorded by multi-electrode arrays (MEA). After stable EDs events had been recorded for at least 20 min, HFS was added, followed by 10 μmol/L gamma-aminobutyric acid type A (GABA_A) receptors blocker bicuculline (BIC). The results show that the HFS can increase the discharges frequency of inter-ictal discharges (IIDs) and decrease the duration of ictal discharges (IDs). However, the HFS had no effect on the slices with 10 μmol/L BIC. These results indicated that the GABA_A receptors are activated when HFS inhibited EDs, thereby achieving the inhibition of low-Mg²⁺-induced EDs in slices.

高频刺激抑制幼鼠海马切片低Mg ²⁺诱发癫痫样放电的机制研究

在一些临床和实验室研究中，高频刺激 (HFS) 已被证明是抑制癫痫的有效治疗方法。然而，HFS 治疗效果的潜在机制尚不完全清楚。在我们目前的研究中，由低镁²⁺人工脑脊液 (ACSF) 和电刺激（方波，900 脉冲，50 % 占空比，130 Hz）使用同心双极电极在 CA3 上进行。通过多电极阵列（MEA）记录海马神经元的ED。在记录稳定的 EDs 事件至少 20 分钟后，添加 HFS，然后添加 10 μmol/L γ-氨基丁酸_A型（GABA _A) 受体阻滞剂荷包牡丹碱 (BIC)。结果表明HFS可以增加发作间放电（IIDs）的放电频率并减少发作间放电（IDs）的持续时间。然而，HFS 对具有 10 μmol/L BIC 的切片没有影响。这些结果表明，当HFS抑制EDs时，GABA _A受体被激活，从而实现对切片中低Mg ²⁺诱导的EDs的抑制。