红藻氨酸诱导的大鼠癫痫模型中海马神经元caspase-9活性的变化

目的 :观察红藻氨酸 (kainicacid ,KA)诱导的癫大鼠海马神经元caspase 9活性的变化。方法 :应用KA腹腔注射诱导大鼠癫模型 ,检测癫大鼠海马神经元caspase 9的活性。caspase 9活性的测定采用荧光底物分析法。结果 :注射KA后 1h大鼠海马神经元caspase 9活性开始升高 ,但与对照组相比 ,无统计学差异 ;注射KA后 3h大鼠海马神经元caspase 9活性达到高峰 ,与对照组相比P <0 0 5 ;然后开始下降 ,于注射KA后 12h接近于正常对照组水平。结论 :在KA腹腔注射诱导的大鼠癫模型中 ,海马神经元caspase 9活性仅在早期表达升高 ,提示caspase 9活性升高可能启动了癫大鼠海马神经元的损伤     

杏仁核注射KA诱导的边缘叶发作致海马神经元凋亡及黄芩苷干预研究

目的：建立杏仁核注射红藻氨酸(kainic acid，KA)诱导的大鼠边缘叶发作模型，检测特异性脑电活动和脑血流与海马神经元凋亡的关系，以及黄芩苷对神经元损伤的保护作用。方法：采用脑立体定位注射技术，杏仁核注射KA诱导癫痫发作，以深部电极持续记录脑电和激光多普勒血流测定仪记录局部脑血流(regional cerebral blood flow，r—CBF)，发作1h后静脉注射30mg／kg安定终止发作，TUNEL染色观察应用黄芩苷和非用药组海马神经元的变化。结果：药物注射15—20min后动物均有癫痫发作，脑电图有高频高波伏丛集棘波，发作终止8h时，同侧海马CA3区出现TUNEL染色阳性细胞，24h达高峰，72h下降。黄芩苷治疗后TUNEL染色阳性细胞数明显减少。发作前后r—CBF无明显变化。高频高波伏丛集棘波时程越长，CA3区TUNEL染色阳性细胞越多。结论：癫痫发作导致选择性海马CA3区神经元凋亡，可能与特异性脑电活动有关，但与脑缺血无关。黄芩苷对癫痫发作导致的脑损伤有保护作用。     

杏仁核注射KA诱导的边缘叶发作致海马神经元凋亡及黄芩苷干预研究

目的:建立杏仁核注射红藻氨酸(kainic acid,KA)诱导的大鼠边缘叶发作模型,检测特异性脑电活动和脑血流与海马神经元凋亡的关系,以及黄芩苷对神经元损伤的保护作用.方法:采用脑立体定位注射技术,杏仁核注射KA诱导癫痫发作,以深部电极持续记录脑电和激光多普勒血流测定仪记录局部脑血流(regional cerebral blood flow,r-CBF),发作1h后静脉注射30 mg/kg安定终止发作,TUNEL染色观察应用黄芩苷和非用药组海马神经元的变化.结果:药物注射15～20 min后动物均有癫痫发作,脑电图有高频高波伏丛集棘波,发作终止8 h时,同侧海马CA3区出现TUNEL染色阳性细胞,24 h达高峰,72 h下降.黄芩苷治疗后TUNEL染色阳性细胞数明显减少.发作前后r-CBF无明显变化.高频高波伏丛集棘波时程越长,CA3区TUNEL染色阳性细胞越多.结论:癫痫发作导致选择性海马CA3区神经元凋亡,可能与特异性脑电活动有关,但与脑缺血无关.黄芩苷对癫痫发作导致的脑损伤有保护作用.     

癫痫发作大鼠海马神经元凋亡与caspase-3 mRNA表达的研究

目的 :研究癫大鼠海马神经元凋亡与caspase 3mRNA表达的关系。方法 :采用大鼠红藻氨酸 (KA)致模型 ,以原位末端标记 (TUNEL)检测癫后不同时间海马神经元凋亡 ;RT PCR检测caspase 3mRNA的表达。结果 :KA致后 1d ,海马CA1、CA3及CA4区开始出现凋亡细胞 ,3d时明显增多 ,7d时最多。KA致后 6h ,海马组织caspase 3mRNA表达显著增高 ,1、3、7d仍持续高水平表达。结论 :癫大鼠海马神经元凋亡与caspase 3mRNA的表达密切相关 ,caspase 3在神经元凋亡过程中起着重要的作用     

辛醇预处理对红藻氨酸诱导的癫疒间大鼠海马神经元凋亡和胶质纤维酸性蛋白表达的影响

目的观察缝隙连接阻断剂辛醇预处理对红藻氨酸(KA)诱导的癫疒间大鼠海马神经元凋亡和胶质纤维酸性蛋白(GFAP)表达的影响。方法 160只雄性SD大鼠随机分为KA组、辛醇组、生理盐水(NS)组和二甲基亚砜(DMSO)组,应用KA右侧杏仁核注射制作癫疒间大鼠模型;制模前30 min辛醇组腹腔注射辛醇溶液;制模后3 h、6 h、12 h、24 h和7 d应用原位末端标记(TUNEL)法和免疫组化染色法分别检测各组大鼠海马CA3区TUNEL和GFAP阳性细胞数。结果 KA组制模后6 h海马CA3区有TUNEL阳性细胞表达,并逐渐增多,7 d达高峰;辛醇组制模后在6 h～7 d TUNEL阳性细胞数明显少于KA组(均P<0.01);KA组海马CA3区GFAP阳性细胞数随时间而逐渐增多,各时间点明显多于辛醇组(均P<0.01)。结论辛醇神经保护作用的机制可能与抑制细胞缝隙连接间通讯,切断凋亡信号传播,以减少神经元凋亡有关。     

辛醇预处理对红藻氨酸诱导的癫(癎)大鼠海马神经元凋亡和胶质纤维酸性蛋白表达的影响

目的 观察缝隙连接阻断剂辛醇预处理对红藻氨酸(KA)诱导的癫(癎)大鼠海马神经元凋亡和胶质纤维酸性蛋白(GFAP)表达的影响.方法 160只雄性SD大鼠随机分为KA组、辛醇组、生理盐水(NS)组和二甲基亚砜(DMSO)组,应用KA右侧杏仁核注射制作癫(癎)大鼠模型;制模前30 min辛醇组腹腔注射辛醇溶液;制模后3h、6h、12 h、24 h和7d应用原位末端标记(TUNEL)法和免疫组化染色法分别检测各组大鼠海马CA3区TUNEL和GFAP阳性细胞数.结果 KA组制模后6h海马CA3区有TUNEL阳性细胞表达,并逐渐增多,7d达高峰;辛醇组制模后在6 h～7 d TUNEL阳性细胞数明显少于KA组(均P＜0.01);KA组海马CA3区GFAP阳性细胞数随时间而逐渐增多,各时间点明显多于辛醇组(均P＜0.01).结论 辛醇神经保护作用的机制可能与抑制细胞缝隙连接间通讯,切断凋亡信号传播,以减少神经元凋亡有关.     

海藻氨酸致癫癎状态大鼠海马区神经元损伤与Mg2+作用的研究

目的观察海藻氨酸(KA)诱导的癫癎状态(SE)大鼠海马神经元的形态学改变和Mg2+的神经保护作用.方法选用成年雄性Wistar大鼠75只,随机分为KA组、Mg2+组和生理盐水对照组.用KA诱导大鼠SE 3 h,Mg2+组大鼠在注射KA前腹腔内注射硫酸镁100 mg/kg,在癫癎发作终止后72 h将动物处死,分别用光镜和电镜观察海马神经元形态学改变.结果 KA组大鼠注射KA后(16.1±4.7)min出现癫癎发作,Mg2+组大鼠为(25.4±6.2)min,两组比较差异有显著性(P<0.05).KA组和Mg2+组大鼠在海马区均出现了嗜酸性神经元,Mg2+组大鼠神经元损伤程度明显低于KA组.结论 KA诱导的SE可导致海马神经元坏死,而 Mg2+作为兴奋性氨基酸拮抗剂对海马神经元具有保护作用.     

海藻氨酸致癫痫状态大鼠海马区神经元损伤与Mg^2＋作用的研究

目的观察海藻氨酸(KA)诱导的癫癎状态(SE)大鼠海马神经元的形态学改变和Mg2+的神经保护作用.方法选用成年雄性Wistar大鼠75只,随机分为KA组、Mg2+组和生理盐水对照组.用KA诱导大鼠SE 3 h,Mg2+组大鼠在注射KA前腹腔内注射硫酸镁100 mg/kg,在癫癎发作终止后72 h将动物处死,分别用光镜和电镜观察海马神经元形态学改变.结果 KA组大鼠注射KA后(16.1±4.7)min出现癫癎发作,Mg2+组大鼠为(25.4±6.2)min,两组比较差异有显著性(P<0.05).KA组和Mg2+组大鼠在海马区均出现了嗜酸性神经元,Mg2+组大鼠神经元损伤程度明显低于KA组.结论 KA诱导的SE可导致海马神经元坏死,而 Mg2+作为兴奋性氨基酸拮抗剂对海马神经元具有保护作用.     

锂-匹罗卡品致大鼠癫癎持续状态后脑内神经元的凋亡

探讨癫持续状态 (StatusEpilepticus,SE)时细胞凋亡的发生及其与海马硬化的关系。采用锂 匹罗卡品诱发大鼠SE模型 ,在SE的不同时点采大鼠脑标本 ,利用TUNEL染色方法检测大鼠海马皮质神经元的凋亡出现情况。结果发现 ,正常对照组大鼠大脑皮质可见散在的TUNEL阳性细胞 ,海马区未见TUNEL阳性细胞。SE1h ,皮质TUNEL阳性细胞数即开始增加 ,SE后 8h ,海马区开始出现TUNEL阳性细胞 ,SE后 1d ,大脑皮质TUNEL阳性细胞数开始明显增加 ,海马区也可见到较多TUNEL阳性细胞。SE后 5d ,皮质及海马的TUNEL阳性细胞数达到高峰。 7d时皮质及海马TUNEL阳性数均明显下降。结果提示 ,SE可引起神经元凋亡 ,5d时达到高峰 ,7d时已明显下降。神经元凋亡与SE引起的迟发性神经元死亡有关 ,并参与了海马硬化的形成。     

红藻氨酸诱导癫(癎)发作大鼠海马星形胶质细胞C-FOS基因表达的研究

目的研究癫发作大鼠海马星形胶细胞C-FOS基因表达的变化,探讨其对癫发作的维持与复发的影响。方法将83只成年雄性SD大鼠随机分为实验组58只,对照组25只。实验组在海马CA3区注射红藻氨酸(Kainicacid,KA)建立癫模型,对照组在相同部位注射等量生理盐水。利用免疫组织化学双重染色技术,分别在癫发作后1h、3h、6h、12h和24h观察大鼠海马星形胶质细胞C-FOS基因的表达。结果与对照组大鼠比较,癫模型鼠海马CA1区CFAP/C-FOS双标记阳性细胞百分率于癫发作后1h(12.70±0.03)、3h(17.10±0.05)、6h(24.92±0.04)明显升高(P<0.01),在6h达到高峰,在12h下降,但是仍较对照组高(10.71±0.06;1.59±0.02,P<0.01),在24h下降至对照组水平(2.00±0.02;2.08±0.03,P>0.05)。结论KA诱导大鼠癫发作,导致海马星形胶质细胞C-FOS基因相对持续的高表达,从而激活星形胶质细胞,产生高致性的病理环境,可能是癫发作的维持以及复发的病理生理机制之一。     

Inhibition of caspase-8 attenuates neuronal death induced by limbic seizures in a cytochrome c-dependent and Smac/DIABLO-independent way

There is increasing evidence that neuronal cell death induced by seizures occurs via extrinsic (death receptors) and intrinsic (mitochondria) pathways. Caspase-8 cleaves Bid, which releases cytochrome c, bridging the "extrinsic" and "intrinsic" pathways. Cleavage of Bid may amplify caspase-8-induced neuronal cell death following seizures. In the present study, we explored the effect of an inhibitor of caspase-8 (z-IETD-fmk) on the release of Smac/DIABLO and cytochrome c from mitochondria. Rats received intra-amygdaloid injection of kainic acid (KA) to induce seizures for 1 h. The seizures were then terminated by diazepam (30 mg/kg). The damaged and surviving neurons in hippocampus were observed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and cresyl violet staining, the expression of caspase-8, Bid, XIAP, caspase-9, cytochrome c and Smac/DIABLO were detected with immunofluorescence and Western blot. The cleavage of caspase-8 and Bid increased at 0 h, cytosolic fraction of cytochrome c and Smac/DIABLO increased by 2 h, cleavage of caspase-9 was detected by 4 h, TUNEL-positive neurons appeared at 8 h and reached a maximum at 24 h following administration of diazepam in the ipsilateral CA3 subfield of hippocampus. Inhibition of caspase-8 significantly decreased neuronal cell death, accompanied by reduction of t-Bid, cleaved caspase-9 and cytosol cytochrome c. Smac/DIABLO from mitochondria was not affected. These results suggest that seizures can lead the translocation of cytochrome c into the cytosol, and the activation of caspase-8 occurs upstream the mitochondria release of cytochrome c and Smac/DIABLO. Inhibition of caspase-8 attenuated neuronal cell death following seizures by decreasing mitochondria release of cytochrome c but not Smac/DIABLO.     

Spatio-temporal profile of DNA fragmentation and its relationship to patterns of epileptiform activity following focally evoked limbic seizures

The specific electrographic activity responsible for seizure-induced DNA damage remains little explored. We therefore examined the regional and temporal appearance of DNA fragmentation and cell death and its relationship to specific electrographic seizure patterns in a rat model of focally evoked limbic epilepsy. Animals received intra-amygdaloid injection of kainic acid (KA) to induce seizures for 45 min during continuous electroencephalographic (EEG) monitoring, after which diazepam (30 mg/kg) was administered. DNA polymerase I-mediated biotin-dATP nick translation (PANT) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) were used to detect single- and double-stranded DNA breaks, respectively. Injection of 0.01 microg KA induced seizures characterized by ictal fast activity but without consequent brain injury. By contrast, 0.1 microg KA induced an additional pattern of seizure activity characterized by bursts of high frequency polyspike paroxysmal discharges. In these animals, there was a significant reduction in numbers of pyramidal neurons within the ipsilateral and contralateral CA3 subfield of the hippocampus, detectable as little as 4 h following seizures. PANT- and TUNEL-positive cells appeared in similar numbers 16 h following seizure cessation within the CA3, declining after 72-96 h. Varying the duration of polyspike paroxysmal discharges determined that as little as 30 s elicited maximal injury. These data suggest single- and double-stranded DNA breaks are generated during the cell death process and are consequent on a specific component of seizure activity electrographically determined.     

In vivo delivery of a XIAP (BIR3-RING) fusion protein containing the protein transduction domain protects against neuronal death induced by seizures

The prevention of cell apoptosis is a promising strategy for neuroprotection against brain injury in seizures. X-linked inhibitor of apoptosis protein (XIAP) is regarded as the most potent inhibitor of cell apoptosis. In the present study, we fused the protein transduction domain (PTD) of Antennapedia Homeodomain of Drosophila (AntpHD) to XIAP (BIR3-RING) and explored the neuroprotective effect of XIAP in rats with seizures induced by kainic acid (KA). KA triggered neuronal death in the ipsilateral CA3 subfield of the hippocampus and activation of caspase-3 and -9. PTD-XIAP fusion protein can be delivered into cos7 cells in vitro. We used intraperitoneal injection to deliver the PTD-XIAP fusion protein which can enter into brain, significantly decrease the TUNEL positive cells and increase the number of surviving cells in the ipsilateral CA3 subfield of the hippocampus at 24 h after KA-induced seizures. Furthermore, PTD-XIAP fusion protein attenuated activated caspase-3 and -9. These results demonstrate the neuroprotective effect of PTD-XIAP fusion protein against brain injury possibly through the inhibition of caspase. The significance of these findings in the treatment of epilepsy still needs to be extensively studied.     

红藻氨酸致痫大鼠海马神经元凋亡及其与caspase-3关系的研究

目的　研究大鼠癫痫发作后海马神经元凋亡及其与天冬氨酸特异性半胱氨酸蛋白酶 -3 (cysteinylasparate-specific proteinase,caspase-3 )表达的关系。方法　采用红藻氨酸 (kainic acid,KA)诱导大鼠癫痫模型 ,以原位末端标记 (TUNEL)及透射电镜检测癫痫发作后 6h及 1、3、7d海马神经元凋亡 ;半定量 RT-PCR及免疫组化法检测 caspase-3 m RNA及 caspase-3阳性表达。结果　KA致痫后 1 d,海马 CA1、CA3及 CA4区开始出现凋亡细胞 ,3 d时明显增多 ,7d时最多。 3个时间组相应区域间凋亡神经元数比较差异均有显著性 (P<0 .0 0 1 )。透射电镜观察可见典型的凋亡细胞形态学改变。 RT-PCR结果显示 ,KA致痫后 6h,海马组织 caspase-3 m RNA表达较对照组显著增高 (P <0 .0 5 ) ,1、3、7d caspase-3 m RNA仍持续高水平表达 (P <0 .0 5 )。免疫组化结果显示 ,KA致痫后 1 d,海马 CA1、CA3、CA4区开始出现 caspase-3阳性表达 ,3 d时阳性表达进一步增强 ,7d时表达最强。结论　凋亡参与 KA致痫大鼠癫痫发作后海马神经元迟发性死亡过程 ,caspase-3可能在癫痫后神经元凋亡过程中具重要的作用。     

Characterization of neuronal death induced by focally evoked limbic seizures in the C57BL/6 mouse

Research into the molecular mechanisms of epileptic brain injury is hampered by the resistance of key mouse strains to seizure-induced neuronal death evoked by systemically administered excitotoxins such as kainic acid. Because C57BL/6 mice are extensively employed as the genetic background for transgenic/knockout modeling in cell death research but are seizure resistant, we sought to develop a seizure model in this strain characterized by injury to the hippocampal CA subfields. Adult male C57BL/6 mice underwent focally evoked seizures induced by intraamygdala microinjection of kainic acid. Kainic acid (KA) effectively elicited ipsilateral CA3 pyramidal neuronal death within a narrow dose range of 0.1-0.3 microg, with mortality < 10%. With employment of the most consistent (0.3 microg) dose, seizures were terminated 15, 30, 60, or 90 min after KA by diazepam. Damage was largely restricted to the ipsilateral CA3 subfield of the hippocampus, but injury was also consistent within CA1, suggesting that this mouse model better reflects the hippocampal neuropathology of human temporal lobe epilepsy than does the rat, in which CA1 is typically spared. Confirming this CA1 injury as seizure specific and not a consequence of ischemia, we used laser-Doppler flowmetry to determine that cerebral perfusion did not significantly change (97% to 118%) over control. Degenerating cells were > 95% neuronal as determined by neuron-specific nuclear protein (NeuN) counterstaining of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeled (TUNEL) brain sections. Furthermore, TUNEL-positive cells often exhibited the morphological features of apoptosis, and small numbers were positive for cleaved caspase-3. These data establish a mouse model of focally evoked seizures in the C57BL/6 strain associated with a restricted pattern of apoptotic neurodegeneration within the hippocampal subfields that may be applied to research into the molecular basis of neuronal death after seizures.     

Expression, interaction, and proteolysis of death-associated protein kinase and p53 within vulnerable and resistant hippocampal subfields following seizures

Death-associated protein (DAP) kinase is a novel regulator of cell death whose in vivo target(s) and role in neuronal cell death remain uncertain. Since DAP kinase has been implicated in p53-mediated apoptosis, a pathway activated following epileptic brain injury, we examined the relationship between DAP kinase and p53 following seizures. Rats underwent brief (40-min) seizures evoked by intraamygdala kainic acid, which caused the death of ipsilateral CA3 neurons while preserving the contralateral CA3 subfield. Seizures caused a small decline in levels of the approximately 160-kD DAP kinase within injured ipsilateral hippocampus, commensurate with the appearance of an approximately 60-kD fragment, and proteolysis of the p53 inhibitor, murine double minute gene 2 (MDM2). Expression of p53 increased within the ipsilateral hippocampus, and DAP kinase was detected within p53 immunoprecipitates. In contrast, DAP kinase and MDM2 were not proteolyzed within the seizure damage-resistant contralateral hippocampus. Furthermore, DAP kinase and p53 did not interact within the contralateral hippocampus, and p53 cellular localization redistributed from the nucleus to cytoplasm commensurate with p53 proteolysis. These data suggest that DAP kinase may be involved in the p53 pathway during seizure-induced neuronal death.     

Ketogenic diet reduces Smac/Diablo and cytochrome c release and attenuates neuronal death in a mouse model of limbic epilepsy

The ketogenic diet (KD) is effective in the treatment of refractory epilepsy, yet the molecular mechanisms underlying its antiepileptic effects have not been determined. There is increasing evidence that neuronal cell death induced by seizures via mitochondrial pathway and seizures can lead to mitochondrial release of cytochrome c, and we have shown previously that translocation of Smac/DIABLO into the cytosol play a role in the brain damage in a model of limbic seizure. In the present study, we explored the neuroprotective effect of KD in C57BL/6 mice with seizures induced by kainic acid (KA). Status epilepticus triggered by intra-amygdaloid microinjection of KA lead to neuronal death in the selective ipsilateral CA3 subfield of the hippocampus and mitochondrial release of Smac/DIABLO and cytochrome c. We found that KD significantly decreased neuronal death in the ipsilateral CA3 at 24h after KA-induced seizures. Furthermore, KD reduced Smac/DIABLO and cytochrome c release from mitochondria, attenuated activation of casepase-9 and caspase-3 following seizures. These results demonstrate that the neuroprotective effect of KD against brain injury induced by limbic seizures, at least partially, is associated with inhibition of mitochondrial release of Smac/DIABLO and cytochrome c.     

Differential activation of c-fos and caspase-3 in hippocampal neuron subpopulations following neonatal hypoxia-ischemia

Neonatal hypoxia-ischemia (HI) induces immediate early gene (IEG) c-fos expression as well as neuron death. The precise role of IEGs in neonatal HI is unclear. We investigated the temporal and spatial patterns of c-Fos expression in postnatal day 7 mice after unilateral carotid ligation and exposure to 8% oxygen. mRNA levels of c-fos quantitated by real-time polymerase chain reaction (PCR) increased nearly 40-fold (log 1.2 +/- 0.4) in the ipsilateral hippocampus 3 hr following neonatal HI, then returned to basal levels within 12 hr, although no change was observed in c-jun mRNA. Frozen coronal brain sections were stained with cresyl violet or used for immunohistochemical detection of c-Fos, cleaved caspase-3, glial fibrillary acidic protein (GFAP), and the mature neuron marker NeuN. c-Fos immunoreactivity increased throughout the injured hippocampus 3 hr after HI but became restricted to the CA2-3 subregion and the dentate gyrus (DG) at 6-12 hr and declined by 24 hr. In contrast, cleaved (activated) caspase-3 immunoreactivity was most abundant in the ipsilateral CA1 region at 3-6 hr after neonatal HI, then became more prominent in CA2-3 and DG. Double-labeling experiments showed c-Fos and cleaved caspase-3 immunoreactivity localized in spatially distinct neuron subpopulations. Prominent c-Fos immunoreactivity was observed in surviving CA2-3 and external granular DG neurons, and robust cleaved caspase-3 immunoreactivity was observed in pyknotic CA1, CA2-3, and subgranular DG neurons. The differential expression of c-Fos in HI-resistant hippocampal subpopulations vs. cleaved caspase-3 in dying neurons suggests a neuroprotective role for c-Fos expression in neonatal HI.     

Inactivation of caspase-1 in rodent brain: a novel anticonvulsive strategy

PURPOSE: Cytokines and related inflammatory mediators are rapidly synthesized in the brain during seizures. We previously found that intracerebral administration of interleukin-1 (IL-1)-beta has proconvulsant effects, whereas its endogenous receptor antagonist (IL-1Ra) mediates potent anticonvulsant actions in various models of limbic seizures. In this study, we investigated whether seizures can be effectively inhibited by blocking the brain production of IL-1beta, by using selective inhibitors of interleukin-converting enzyme (ICE/caspase-1) or through caspase-1 gene deletion. METHODS: Caspase-1 was selectively blocked by using pralnacasan or VX-765. IL-1beta release was induced in mouse organotypic hippocampal slice cultures by proinflammatory stimuli [lipopolysaccharide (LPS) + adenosine triphosphate (ATP)] and measured with enzyme-linked immunosorbent assay (ELISA). IL-1beta production during seizures was measured in the rat hippocampus by Western blot. Seizures were induced in freely moving mice and rats by intrahippocampal injection of kainic acid and recorded by EEG analysis. RESULTS: Caspase-1 inhibition reduced the release of IL-1beta in organotypic slices exposed to LPS+ATP. Administration of pralnacasan (intracerebroventricular, 50 microg) or VX-765 (intraperitoneal, 25-200 mg/kg) to rats blocked seizure-induced production of IL-1beta in the hippocampus, and resulted in a twofold delay in seizure onset and 50% reduction in seizure duration. Mice with caspase-1 gene deletion showed a 70% reduction in seizures and an approximate fourfold delay in their onset. CONCLUSIONS: Inhibition of caspase-1 represents an effective and novel anticonvulsive strategy, which acts by selectively reducing the brain availability of IL-1beta.