【作者】 刘扬；

【导师】 肖波；

【作者基本信息】 中南大学 ， 临床医学， 2013， 博士

【摘要】 第一部分低频电刺激抑制杏仁核电点燃大鼠痫样发作剌激时长的研究目的：本实验通过大鼠杏仁核电点燃癫痫模型,在电点燃癫痫形成过程中和癫痫大发作后给予杏仁核不同持续时间的低频率电刺激,探讨低频率电刺激(LFS, low frequency stimulation)持续时间对其抗癫痫作用的影响。方法：1.电极置入手术和电点燃模型的建立大鼠暴露颅骨后,将电极置入大鼠右侧基底节旁杏仁核。牙科水泥固定后,将电极连于一微型插座上。实验前,需测定大鼠后放电阈值。根据阈值,将大鼠平均分为六组。每24小时对大鼠进行一次电点燃刺激(1s, lms波宽,100-300μA,60Hz)。2.杏仁核电点燃形成过程中和大发作后给予大鼠杏仁核低频率电刺激在电点燃癫痫形成过程和大发作后,分别对各组发放不同持续时间的低频率电刺激(0.1ms波宽,150μA,1Hz)。实验中观察大鼠行为学发作等级,并记录大鼠脑电。结果：1.在大鼠杏仁核电点燃癫痫形成过程中,低频率电刺激杏仁核15分钟和30分钟能显著降低动物发作等级,缩短后放电时间,且降低杏仁核区delta波段能量。然而间断性给予同侧杏仁核LFS15分钟,LFS1分钟和LFS5分钟都没有没有抑制癫痫电点燃形成过程的作用。2.在大鼠杏仁核电点燃癫痫大发作实验中,点燃刺激后立即给予同侧杏仁核LFS15分钟和LFS30分钟能显著抑制大鼠大发作等级,减少大发作累积时间,缩短后放电时间,同时伴有杏仁核区delta波段能量降低,而LFS1分钟和LFS5分钟没有作用。结论：在大鼠杏仁核电点燃癫痫模型下,持续性地发放低频率电刺激15分钟和30分钟能显著减少大鼠癫痫发作的时间和等级,并且累积刺激的时长是影响其抗癫痫效果的要素。第二部分低频电刺激抑制杏仁核电点燃大鼠痫样发作的刺激模式研究目的：本实验通过大鼠杏仁核电点燃癫痫模型,采用相同的刺激时间和靶点,在电点燃癫痫形成过程中给予杏仁核不同刺激模式的低频率电刺激,探讨低频率电刺激的刺激模式对其抗癫痫作用的影响。方法：1.电极置入手术和电点燃模型的建立大鼠暴露颅骨后,将电极置入大鼠右侧基底节旁杏仁核。牙科水泥固定后,将电极连于一微型插座上。实验前,需测定大鼠后放电阈值。根据阈值,将大鼠平均分为五组。每天进行一次电点燃刺激(1s,lms波宽,100-30μA,60Hz)。2.杏仁核电点燃形成过程中给予大鼠杏仁核低频率电刺激在电点燃癫痫形成过程中,分别对各组进行低频率电刺激(0.1ms波宽,150μA,1Hz)。实验中观察大鼠行为学发作等级,并记录大鼠脑电。结果：1.LFS的后发放模式(posttreatment-LFS)能够有效地抑制杏仁核电点燃大鼠癫痫形成过程,降低癫痫发作等级以及缩短后放电时长。预发放模式(pretreatment-LFS)模式不能有效地抑制杏仁核电点燃大鼠癫痫形成过程,甚至逆转了电点燃刺激开始后posttreatment-LFS模式单独存在所产生的抑制癫痫发作的效果。2.在posttreatment-LFS模式中,即使只在电点燃癫痫形成过程中的前5天发放LFS,仍能显著降低大鼠癫痫发作的等级,并且这种抑制作用主要表现在对部分性发作(stage1-3)的抑制。结论：在大鼠杏仁核电点燃癫痫模型下,低频电刺激抑制大鼠杏仁核电点燃癫痫存在一种模式依赖效应。只有后发放低频率电刺激这种模式才能发挥抗癫痫作用。第三部分低频率电刺激单侧外苍白球对大鼠杏仁核电点燃癫痫及戊四氮诱导癫痫的作用研究目的：本实验通过大鼠杏仁核电点燃癫痫模型和戊四氮诱导癫痫模型,选取苍白球作为深部脑刺激的靶点,探讨在不同模型下电刺激苍白球对癫痫发作的影响。方法：1.电极置入手术和电点燃模型的建立大鼠暴露颅骨后,将电极置入大鼠右侧基底节旁杏仁核和左侧外苍白球。实验前,需测定大鼠后放电阈值。根据阈值,将大鼠平均分为三组。每天进行一次电点燃刺激(Is,1ms波宽,100-300μA,60Hz)。2.杏仁核电点燃形成过程中给予大鼠左侧外苍白球脑深部电刺激在电点燃癫痫形成过程中,分别对各组进行低频率电刺激(0.1ms波宽,150μA,1Hz)和高频率电刺激(100ms波宽,120Hz)。实验中观察大鼠行为学发作等级。3.戊四氮模型癫痫模型建立和对大鼠外苍白球低频率电刺激每48小时对大鼠进行亚惊厥剂量的戊四氮(35mg/kg)腹腔注射后,对大鼠外苍白球进行低频率电刺激,观察30分钟内出现的强直阵挛情况,并记录发作潜时。结果：1.在大鼠杏仁核电点燃癫痫形成过程中,给予左侧外苍白球低频率电刺激和高频率电刺激均能有效地抑制杏仁核电点燃大鼠癫痫形成过程,降低癫痫发作等级以及缩短后放电时长。2.在戊四氮诱导癫痫的实验中,低频率电刺激未能降低动物的癫痫发作等级,却明显地延长动物发作的潜时。结论：在大鼠电点燃模型下低频率电刺激不仅能在杏仁核,海马这些灶点区域发挥抗癫痫作用,在灶点外如苍白球脑区同样能够可以发挥抗癫痫作用。更多还原

【Abstract】 Part I The study on the stimulate duration of low-frequency stimulation that inhibit amygdaloid-kindling seizures in ratsObjectiveThe present work was undertaken in order to study the effects of LFS when delivered different stimulus duration (especially after discharge duration in electroencephalogram), using amygdaloid-kindling seizures ra modelst in rats.Methods:1. The electrode placement operation and amygdaloid-kindling seizures model.After exposure of skull, electrodes were implanted into the right basolateral amygdala. It was fixed to the skull and connects to a miniature socket. Before the trial, we measure the after discharge threshold in rats. According to the average threshold value, rats were divided into six groups and given an electric stimulation every day.(1s and1ms wave wide,100-300μA,60Hz).2. LFS with different stimulation duration on kindling acquisition and kindled seizures.In kindling acquisition and kindled seizures experiments, low frequency electrical stimulation (0.1ms wave width,150μA1Hz) rats and observe the seizure severity and record electroencephalogram.Results:1.Low frequency electric stimulation for15minutes and30minutes can significantly slowed the progression of behavioral seizure stages and reduced mean ADD during kindling acquisition and kindled seizures while LFS for1minutes and5minutes have no effect.LFS was intermittently delivered for15minutes cannot inhibit the seizure progress.2. Low frequency electric stimulation for15minutes and30minutes can significantly slowed the progression of behavioral seizure stages and reduced mean ADD during kindled seizure in rats and reduced the power in delta.Conclusions:Consecutive15min and30min is necessary for LFS to inhibit amygdaloid-kindling seizure in rats, indicating the stimulation duration may be a key fact affecting the clinical effect of LFS on epilepsy. Part II The study on the stimulate mode of low frequency stimulation that inhibit amygdaloid-kindling seizures in ratsObjective:The present work was undertaken in order to study which mode of stimulation is more suitable for low frequency electric stimulation play the antiepileptic effect in amygdaloid-kindling seizures rats,hoping to help chossing LFS in clinical treatment of refractory epilepsy.Methods:1. The electrode placement operation and amygdaloid-kindling seizures modelAfter exposure of skull, electrodes were implanted into the right basolateral amygdala. It was fixed to the skull and connects to a miniature socket. Before the trial, we measure the after discharge threshold in rats. According to the average threshold value, rats were divided into five groups and given an electric stimulation (1s and1ms wave wide,100-300μA,60Hz).2. LFS with different stimulation duration on kindling acquisitionIn kindling acquisition experiments, low frequency electrical stimulation (0.1ms wave width,150μA,1Hz) rats and observes the seizure severity and record electroencephalogram rats.Results:1. The posttreatment-LFS mode reduced the seizure stages and shorten the after discharge duration during kindling acquisition. The pretreatment-LFS mode cannot effectively antiepilepsy in rats and even reverse the inhibit effect of seizures when the posttreatment-LFS mode exist alone.2. In posttreatment-LFS mode, LFS were only delivered for five days can significantly slowed the progression of behavioral seizure stages and the inhibit effect main on seizure stage1-3. Conclusions:LFS has a mode-dependent effect that inhibits amygdaloid-kindling seizures in rats. The posttreatment-LFS mode has a antiepileptic effect while the posttreatment-LFS mode has no effect. Part III The study on the inhibitory effects of LFS at the external segment of the globus pallid us on amygdaloid-kindling seizures and pentylenetetrazole (PTZ)-induced seizures in ratsObjective:The present work was undertaken in order to study the effect of low frequency electric stimulation delivered into globus pallidus using amygdaloid-kindling seizures model and PTZ-kindled seizures model.Methods:1. The electrode placement operation and amygdaloid-kindling seizures modelAfter exposure of skull, electrodes was implanted into the right basolateral amygdala and left the external segment of the globus pallidus.It were fixed to the skull and connect to a miniature socket. Before the trial, we measure the after discharge threshold in rats. According to the average threshold value, rats were divided into there groups and given an electric stimulation (1s and1ms wave wide,100-300μA,60Hz).In kindling acquisition experiments, low frequency electrical stimulation (0.1ms wave width,150μA,1Hz) and high frequency electrical stimulation were delivered to rats and observe the seizure severity.2. Effect of LFS on PTZ-kindled seizuresTo induce kindling, a subconvulsant dose (35mg/kg) of pentylenetetrazole was i.p. injected every48h.Low frequency electrical stimulation (0.1ms wave width,150μA,1Hz) was delivered to rats.Results:1. In kindling animals, LFS delivered immediately after cessation of the kindling stimulus inhibited the seizure stages and shorten the after discharge duration during kindling acquisition.2. In PTZ-induced seizures rats, LFS cannot inhibited the seizure stages, but significantly prolong animal seizure latency.Conclusions:When select the appropriate stimulus parameters, DBS at the external segment of the globus pallidus can effectively suppress seizure.更多还原