Abstract: Objective To explore the different effects of electrophysiological characteristics of pyramidal neurons and interneurons in epileptic patients. Methods A total of 13 brain tissue samples were selected from patients with focal drug-resistant underwent epileptogenic lesion resection in Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University from June to December 2016. Using perfusion method, the brain tissue slice temperature was quickly reduced to 20 ℃ in a step manner, then rewarmed to 30 ℃, and maintained at 30 ℃ for 10 min (the target temperature was changed by 5 ℃ every 10 min). Patch clamping technique was used to record the resting membrane potential, synaptic activity and action potential of pyramidal neurons (n = 18) and interneurons (n = 6) in epileptic cerebral cortex. Results 1) Resting membrane when the temperature dropped to 20 ℃, the resting membrane potential of the two kinds of neurons showed slight depolarization, but there was no statistical significance in the changes of resting membrane at different temperatures and the changes of resting membrane potential of the two kinds of neurons at the same temperature (P > 0.05, for all). 2) Synaptic activity: after cooling, the amplitude of excitatory postsynaptic current (EPSC) of interneuron was smaller (F = 5.332, P = 0.034). The normalized percentages of EPSC (F = 8.811, P = 0.000) and inhibitory postsynaptic current (IPSC; F = 9.843, P = 0.000) amplitude, EPSC event interval (F = 7.065, P = 0.001), EPSC (F = 6.281, P = 0.002) and IPSC (F = 8.266, P = 0.000) peak area were statistically significant. 3) Action potential: there were no significant differences in the effects of temperature change on the normalized percentages of the threshold, frequency, amplitude and half-width time of the action potential of the two kinds of neurons (P > 0.05, for all). However, the differences of normalized percentages of action potential frequency (F = 4.801, P = 0.008), amplitude (F = 3.680, P = 0.015) (F = 28.951, P = 0.000) of neuronal action potentials at different temperatures statistically significant. Conclusions When the temperature was reduced to 20 ℃, the electrophysiological activities of the two kinds of neurons were significantly inhibited. The inhibition of EPSC amplitude of synaptic activity in interneurons was stronger than that in pyramidal neurons. Inhibition of interneuron activity may be one of the reasons for hypothermia prevention and termination of epilepsy.

Key words: Epilepsy, Hypothermia, induced, Pyramidal cells, Interneurons, Electrophysiological phenomena

摘要： 目的 探讨快速低温对癫痫患者锥体神经元和中间神经元电生理学特性的影响。方法 选择2016 年6-12 月在首都医科大学宣武医院功能神经外科行手术切除的局灶性耐药性癫痫患者皮质致痫灶组织标本共13 份（13 例），经人工脑脊液灌注使其温度呈阶梯式快速降至20 ℃，随后阶梯式复温至 30 ℃并维持 10 min（每 10 min 目标温度改变 5 ℃）；应用膜片钳技术记录温度变化过程中锥体神经元（18 个）和中间神经元（6 个）静息膜电位、突触活动和动作电位变化。结果 （1）静息膜电位：当温度降至20 ℃时，两种神经元静息膜电位呈轻微去极化，但不同温度以及同一温度下二者变化差异未达到统计学意义（均 P > 0.05）。（2）突触活动：随着温度降低，中间神经元兴奋性突触后电流（EPSC）波幅更小（F = 5.332，P = 0.034）；且两种神经元EPSC（F = 8.811，P = 0.000）和抑制性突触后电流（IPSC；F = 9.843， P = 0.000）波幅、EPSC 事件间隔时间（F = 7.065，P = 0.001）、EPSC（F = 6.281，P = 0.002）和IPSC（F = 8.266，P = 0.000）峰面积标准化百分比差异均有统计学意义。（3）动作电位：温度变化对两种神经元动作电位阈值、频率、波幅、半宽时间标准化百分比的影响差异无统计学意义（均P > 0.05）；但不同温度下神经元动作电位频率（F = 4.801，P = 0.008）、波幅（F = 3.680，P = 0.015）、半宽时间（F = 28.951，P = 0.000）标准化百分比差异具有统计学意义。结论 当温度降至20 ℃时，锥体神经元和中间神经元电生理活动被明显抑制，且对中间神经元突触活动EPSC 波幅的抑制作用更强，提示快速低温对中间神经元电活动的强抑制作用可能是其预防癫痫发生、终止癫痫发作的机制之一。

关键词: 癫痫, 低温, 人工, 锥体细胞, 中间神经元, 电生理学现象