Radon Inhalation Protects Against Transient Global Cerebral Ischemic Injury in Gerbils

Although brain disorders are not the main indication for radon therapy, our previous study suggested that radon inhalation therapy might mitigate brain disorders. In this study, we assessed whether radon inhalation protects against transient global cerebral ischemic injury in gerbils. Gerbils were treated with inhaled radon at a concentration of 2,000 Bq/m³ for 24 h. After radon inhalation, transient global cerebral ischemia was induced by bilateral occlusion of the common carotid artery. Results showed that transient global cerebral ischemia induced neuronal damage in hippocampal CA1, and the number of damaged neurons was significantly increased compared with control. However, radon treatment inhibited ischemic damage. Superoxide dismutase (SOD) activity in the radon-treated gerbil brain was significantly higher than that in sham-operated gerbils. These findings suggested that radon inhalation activates antioxidative function, especially SOD, thereby inhibiting transient global cerebral ischemic injury in gerbils.     

Rapamycin保护大鼠缺血性脑损伤和特定脑区神经新生有关

目的:探讨缺血前给予自噬诱导剂对脑缺血损伤的保护效应及可能机制。方法:双侧颈总动脉结扎建立全脑缺血模型,再灌注后24 h,评价动物神经行为功能,连续脑切片,采用Nissl染色定量检测皮层及海马CA1区细胞密度;通过免疫荧光技术检测Caspase-3阳性神经元,计数皮层及海马CA1凋亡细胞数量;激光共聚焦显微镜观察并计数海马齿状回颗粒下层内呈Ki67阳性、GFAP(胶质纤维酸性蛋白)阴性(Ki67+/GFAP-)细胞的数量。结果:Rapamycin术前预处理可以改善缺血导致的神经功能缺陷(P<0.05)。Nissl染色结果表明Ra-pamincy术前1 h给药可以减轻缺血导致的皮层(P<0.01)及海马CA1区(P<0.01)细胞丢失。同时,Rapamycin术前给药也显著减少了缺血导致的皮层及海马CA1区内Caspase-3阳性细胞的数量,组间比较有显著性差异(P<0.05)。Rapamycin术前1 h给药增加了海马齿状回内Ki67+/GFAP-细胞的数量,和缺血组比较差异有显著性(P<0.05)。结论:在全脑缺血模型上,通过自噬活化途径的缺血预处理可以保护缺血性脑损伤,这一作用和Rapamycin减少凋亡、增加新生神经细胞的数量有关。     

LAMP-2A ablation in hippocampal CA1 astrocytes confers cerebroprotection and ameliorates neuronal injury after global brain ischemia

Reactive astrogliosis and neuronal death are major features of brain tissue damage after transient global cerebral ischemia/reperfusion (I/R). The CA1 subfield in the hippocampus is particularly susceptible to cell death after I/R. Recently, attention has focused on the relationship between the autophagy–lysosomal pathway and cerebral ischemia. Lysosomal-associated membrane protein type-2A (LAMP-2A) is a key protein in chaperone-mediated autophagy (CMA). However, LAMP-2A expression in astrocytes of the hippocampus and its influence on brain injury following I/R remain unknown. Here, we show that LAMP-2A is elevated in astrocytes of the CA1 hippocampal subfield after I/R and in primary cultured astrocytes after transient oxygen–glucose deprivation (OGD). Conditional LAMP-2A knockdown in CA1 astrocytes inhibited astrocyte activation and prevented neuronal death by inhibiting the mitochondrial pathway of apoptosis after I/R, suggesting that elevated astrocytic LAMP-2A contributes to regional ischemic vulnerability. Furthermore, astrocytic LAMP-2A ablation ameliorated the spatial learning and memory deficits caused by I/R. Conditional astrocytic LAMP-2A knockdown also prevented the loss of hippocampal synapses and dendritic spines, improved the synaptic ultrastructure, and inhibited the reduced expression of synaptic proteins after ischemia. Thus, our findings demonstrate that astrocytic LAMP-2A expression increases upon I/R and that LAMP-2A ablation specifically in hippocampal astrocytes contributes to cerebroprotection, suggesting a novel neuroprotective strategy for patients with global ischemia.     

Exacerbation of ischemia-induced amyloid-β generation by diabetes is associated with autophagy activation in mice brain

To evaluate effect of diabetes on transient ischemia-induced brain damage and autophagy activity, streptozotocin (STZ)-induced diabetic mellitus (DM) mice were subjected to transient common carotid artery occlusion (CCAO) operation. After the operation, immunohistochemistry and transmission electron microscopy (EM) were performed to investigate the astrocytes activation, amyloid-β protein (Aβ) expression and accumulation of autophagy-like vacuoles containing electron-dense material (avd); and hallmarks of autophagy, the microtubule-associated protein light chain 3 (LC3)-II, was detected by western blot analysis. The results showed that DM amplified stroke-induced astrocytes activation and Aβ generation. Western blot analysis showed that LC3-II conjugate was drastically up-regulated at early stages post ischemia and it last for at least 72 h in DM mice brain. DM mice demonstrated increased baseline level of LC3-II as comparing to normal mice; DM also amplified stroke-induced LC3-II level. Under EM, avd was most markedly accumulated in neurons of DM mice brain after ischemia. Immunofluorescence double-staining showed that most Aβ and autophagosomes co-localized. Therefore, our results suggested that exacerbation of ischemia-induced Aβ generation by diabetes might be associated with autophagy activation in mice brain, and modulating neuronal autophagy might be a new therapeutic strategy to depress the risk of development of dementia in diabetic patients with stroke.     

Down-regulated Na+/K+-ATPase activity in ischemic penumbra after focal cerebral ischemia/reperfusion in rats

This study was aimed to examine whether the Na⁺/K⁺ adenosine triphosphatase (Na⁺/K⁺-ATPase) activity in ischemic penumbra is associated with the pathogenesis of ischemia/reperfusion-induced brain injury. An experimental model of cerebral ischemia/reperfusion was made by transient middle cerebral artery occlusion (tMCAO) in rats and the changes of Na⁺/K⁺-ATPase activity in the ischemic penumbra was examined by Enzyme Assay Kit. Extensive infarction was observed in the frontal and parietal cortical and subcortical areas at 6 h, 24 h, 48 h, 3 d and 7 d after tMCAO. Enzyme Assay analyses revealed the activity of Na⁺/K⁺-ATPase was decreased in the ischemic penumbra of model rats after focal cerebral ischemia/reperfusion compared with sham-operated rats, and reduced to its minimum at 48 h, while the infarct volume was enlarged gradually. In addition, accompanied by increased brain water content, apoptosis-related bcl-2 and Bax proteins, apoptotic index and neurologic deficits Longa scores, but fluctuated the ratio of bcl-2/Bax. Correlation analysis showed that the infarct volume, apoptotic index, neurologic deficits Longa scores and brain water content were negatively related with Na⁺/K⁺-ATPase activity, while the ratio of bcl-2/Bax was positively related with Na⁺/K⁺-ATPase activity. Our results suggest that down-regulated Na⁺/K⁺-ATPase activity in ischemic penumbra might be involved in the pathogenesis of cerebral ischemia/reperfusion injury presumably through the imbalance ratio of bcl-2/Bax and neuronal apoptosis, and identify novel target for neuroprotective therapeutic intervention in cerebral ischemic disease.     

亚低温对大鼠缺血性脑损伤后SOCS3表达的影响

目的观察大鼠局灶性脑缺血再灌注后不同时间点细胞因子信号转导抑制因子-3(supressor of cytokine signaling 3,SOCS3)的表达情况及实施亚低温后的变化,进一步探讨亚低温的脑保护作用。方法线栓法制作大鼠大脑中动脉栓塞局灶性脑缺血再灌注模型,同时给予亚低温治疗。HE染色观察病理形态改变,免疫组化法检测SOCS3的表达,TUNEL法检测凋亡细胞。结果与假手术组相比,常温缺血组于再灌注3 h后SOCS3的表达开始增强,至24 h达高峰,7天时仍有表达;亚低温缺血组各时间点表达均明显高于常温缺血组(P<0.05);常温缺血组凋亡阳性细胞数随再灌注时间的延长而逐渐增多,至72h达高峰;亚低温缺血组各时间点的表达均明显少于常温缺血组(P<0.05)。结论脑缺血再灌注损伤后SOCS3的表达增强,亚低温可能通过促进SOCS3的表达发挥缺血后抗神经元凋亡的作用。     

Tetramethylpyrazine reduces ischemic brain injury in rats

Tetramethylpyrazine (TMP), which is widely used in the treatment of ischemic stroke by Chinese herbalists, is one of the most important active ingredients of the traditional Chinese herbal medicine, Ligusticum wallichii Franchat (Chung Xiong). However, the mechanism by which TMP protects the brain is still not clear. We examined neuroprotective effects of TMP after transient focal cerebral ischemia using common carotid artery and middle cerebral artery occlusion model in rats and evaluated the involvement of anti-inflammation. TMP administrated intraperitoneally significantly protected the brain against ischemic insult as evidenced by the reduction in infarction volume, preservation of neurons, and decrease in brain edema. TMP markedly reduced cerebral ischemia/reperfusion-induced inflammatory cell activation and proinflammatory mediator production. Moreover, TMP suppressed lipopolysaccharide/interferon-gamma-induced inflammation and prostaglandin E(2) production in cultured glial cells. Our findings suggest that one of neuroprotective effects of TMP against ischemic brain injury might involve its anti-inflammatory potential.     

Ischemic preconditioning prevents protein aggregation after transient cerebral ischemia

Transient cerebral ischemia leads to protein aggregation mainly in neurons destined to undergo delayed neuronal death after ischemia. This study utilized a rat transient cerebral ischemia model to investigate whether ischemic preconditioning is able to alleviate neuronal protein aggregation, thereby protecting neurons from ischemic neuronal damage. Ischemic preconditioning was introduced by a sublethal 3 min period of ischemia followed by 48 h of recovery. Brains from rats with either ischemic preconditioning or sham-surgery were then subjected to a subsequent 7 min period of ischemia followed by 30 min, 4, 24, 48 and 72 h of reperfusion. Protein aggregation and neuronal death were studied by electron and confocal microscopy, as well as by biochemical analyses. Seven minutes of cerebral ischemia alone induced severe protein aggregation after 4 h of reperfusion mainly in CA1 neurons destined to undergo delayed neuronal death (which took place after 72 h of reperfusion). Ischemic preconditioning reduced significantly protein aggregation and virtually eliminated neuronal death in CA1 neurons. Biochemical analyses revealed that ischemic preconditioning decreased accumulation of ubiquitin-conjugated proteins (ubi-proteins) and reduced free ubiquitin depletion after brain ischemia. Furthermore, ischemic preconditioning also reduced redistribution of heat shock cognate protein 70 and Hdj1 from cytosolic fraction to protein aggregate-containing fraction after brain ischemia. These results suggest that ischemic preconditioning decreases protein aggregation after brain ischemia.     

阿托品减轻大鼠脑缺血后再灌流损害机制的初步探讨

为探讨乙酰胆碱（ａｃｅｔｙｌｃｈｏｌｉｎｅ，Ａｃｈ）在神经元缺血性损害中的作用和机制，本实验观察了Ａｃｈ能Ｍ受体拮抗剂阿托品对大鼠脑缺血再灌注损害的影响，发现阿托品（２５ｍｇ／ｋｇ，ｂｗ，ｉｐ）可明显减轻大鼠前脑缺血后再灌流所致海马ＣＡ１区神经元迟发性损害，减小大鼠大脑中动脉阻塞后再灌流损害范围，而对局部皮质血流变化无影响，表明阿托品对缺血脑组织的保护作用不是由于改善了局部脑血流，提示Ａｃｈ参与神     

Anti-oxidative effects of d-allose, a rare sugar, on ischemia-reperfusion damage following focal cerebral ischemia in rat

The present study investigates the anti-oxidative effects of D-allose on ischemic damage. Rats were subjected to transient middle cerebral artery occlusion (MCAO) for 1 h under pentobarbital anesthesia. D-allose was intravenously infused during occlusion and a further 1 h after reperfusion (400 mg/kg). The effects of D-allose on focal cerebral ischemia were examined by measuring brain damage (infarction and atrophy volume) and behavioral deficits 7 days after MCAO. In another set of rats, apurnic/apyrimidic abasic sites (AP-sites) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), oxidative stress markers, were investigated 24 h after MCAO to examine the anti-oxidative effects of D-allose. Brain damage and behavioral deficits were significantly decreased by D-allose administration compared to vehicle. The number of AP-sites and 8-OHdG levels were also reduced by D-allose. Thus, the present study suggests that D-allose has anti-oxidative effects and induces neuroprotection in focal cerebral ischemia.     

AngⅡ在脑缺血大鼠大脑皮质中的表达及依达拉奉对其干预的影响

目的:研究大鼠局灶性脑缺血后AngⅡ在脑组织中的表达变化规律及应用自由基清除剂-依达拉奉干预治疗对脑组织中AngⅡ表达的影响,探讨脑缺血后脑内AngⅡ表达的生物学作用及依达拉奉对缺血性脑损伤的保护作用。方法:采用微创开颅法建立大鼠大脑中动脉闭塞(MCAO)模型,分为正常对照组、假手术组、脑缺血组和药物干预组。应用免疫组织化学及尼氏染色方法分别观察脑缺血后和依达拉奉干预后AngⅡ在脑内的表达和神经元的变化。结果:在缺血半暗区可见大量AngⅡ阳性细胞,以缺血后1周数目最多,且免疫阳性反应最强,与对照组相比有显著性差异(P<0.05);尼氏染色显示,缺血半暗区可见大量变性坏死神经元,其中以1周组数量最多,与对照组相比有统计学意义(P<0.05);经依达拉奉干预后半暗区AngⅡ阳性细胞数量、光密度值及变性坏死神经元数量明显减少,与对照组比较有统计学差异,以治疗后3 d最为显著(P<0.01)。结论:①大鼠局灶性脑缺血后缺血半暗区AngⅡ表达增强,可能与缺血后神经元的病理变化有一定联系;②脑损伤后,依达拉奉可能通过抑制AngⅡ的表达而减少神经元的坏死,发挥脑保护作用。     

Cilostazol protects against hemorrhagic transformation in mice transient focal cerebral ischemia-induced brain damage

Cilostazol, an antiplatelet drug used to treat intermittent claudication, has been reported to offer neuroprotection and endothelial protection in animals with ischemic brain injury. Here, we evaluated the protection afforded by cilostazol against ischemic brain injury and hemorrhagic transformation. Mice subjected to a 2-h filamental middle cerebral artery (MCA) occlusion were treated with cilostazol (10 mg/kg, intraperitoneally just after the occlusion) or with vehicle. Histological outcomes (infarct volume and hemorrhagic transformation) and Evans blue extravasation were assessed after reperfusion. Mean infarct volume, hemorrhagic transformation, and Evans blue extravasation were all significantly reduced in the cilostazol-treated group. Thus, cilostazol protected against ischemic brain injury and hemorrhagic transformation in mice subjected to transient focal cerebral ischemia.     

Delayed treatment of Na+/H+ exchange inhibitor SM-20220 reduces infarct size in both transient and permanent middle cerebral artery occlusion in rats

SM-20220 (N-(aminoiminomethyl)-1-methyl-1H-indole-2-carboxamide methanesulfonate) is a Na+/H+ exchanger (NHE) inhibitor which has been shown to attenuate cerebral edema in the rat transient focal ischemia model. However, to date, the effect of SM-20220 on cerebral infarction has not been examined. The present experiments were designed to investigate these effects, using both transient and permanent middle cerebral artery (MCA) occlusion models in rats. A dose of 1 mg/kg given intravenously 30 min after the onset of transient MCA occlusion reduced the infarcted area. In the permanent MCA occlusion model, SM-20220 reduced the infarcted area when treatment was delayed for 5, 30 or 60 min after the onset of ischemia. The present results show that NHE has a crucial role in the pathogenesis of ischemic brain damage. This NHE inhibitor may be useful for treating stroke because of its effectiveness with both forms of ischemia and because of its postischemic administration.     

Notch信号通路对脑缺血大鼠神经干细胞移植后神经再生的影响

目的 探讨抑制Notch信号通路促进脑缺血大鼠神经干细胞（NSCs）移植后神经再生的机制。方法 采用大脑中动脉阻塞MCAO）方法构建局灶性脑缺血模型,体外培养NSCs,移植入纹状体缺血区。将40只SD大鼠随机分为假手术组、模型组、移植组（移植神经干细胞）、氮-［氮-(3,5-二氟苯乙酰)-L-丙氨酰］-S-苯基甘氨酸丁酯］（DAPT）+移植组。采用HE染色观察各组大鼠神经元损伤程度,利用免疫组织化学、Western blotting检测各组大鼠脑组织中Notch1、Hes1及Hes5的表达情况。结果 与假手术组相比,模型组神经元损伤严重,出现核固缩和核溶解,Notch1、Hes1及Hes5阳性细胞表达明显增多,Notch1、Hes1及Hes5蛋白表达显著上调（P＜0.05）。与模型组相比,移植组和DAPT+移植组神经元损伤均不同程度缓解,Notch1、Hes1及Hes5阳性细胞均有部分表达,各项蛋白表达均有所降低（P＜0.05）;DAPT+移植组神经元损伤明显恢复,较移植组各项蛋白阳性细胞和蛋白表达进一步降低(P＜0.05)。结论 抑制Notch信号通路可促进脑缺血大鼠神经干细胞移植后的神经再生,其机制主要与下调Notch1、Hes1及Hes5的表达有关。     

脑缺血合并高脂血症模型大鼠脑组织的病理改变

背景：大多数脑缺血是在高血压、高脂血症、糖尿病等基础病变条件下发生的。因此,构建高脂血症复合脑缺血大鼠模型,研究基础性病变对脑缺血的影响具有重要意义。 目的：观察高脂血症复合脑缺血大鼠模型脑组织病理学改变,及其高脂血症病理因素对脑缺血的影响。 方法：实验以高脂饲料喂养大鼠制备高脂血症大鼠模型,然后线栓法制备局灶性脑缺血大鼠模型,建模成功后3,7 d,采用TTC染色的方法,观察各组大鼠脑组织缺血部位体积,苏木精-伊红染色观察各组大鼠脑组织缺血边缘区组织病理学改变,透射电镜观察各组大鼠脑组织缺血边缘区细胞超微结构改变。 结果与结论：TTC染色结果显示高脂+脑缺血7 d组大鼠的脑缺血部位体积明显减小。苏木精-伊红染色结果显示所有脑缺血模型都呈典型的缺血性改变,脑缺血7 d的小胶质细胞数量比3 d的明显减少,高脂+脑缺血7d相对于3 d的变化更明显。超微结构显示所有脑缺血模型的神经元和胶质细胞核膜皱缩,线粒体嵴基本完全消失,内皮细胞线粒体减少,神经突触的突触小泡大部分溶解,缺血7 d,尤其是高脂+脑缺血7 d的上述损伤减轻,神经元变性、坏死减少,线粒体损伤恢复,线粒体嵴也明显增多,神经突触的突触小泡明显恢复。说明高脂血症促进了脑缺血损伤的恢复,其原因可能是高脂血症因素激活了体内某种保护机制。     

Protective effect of quercetin, a natural flavonoid against neuronal damage after transient global cerebral ischemia

Previous studies have demonstrated that quercetin, a bioflavonoid shows the inhibitory effect against ischemia and reperfusion-induced injury in various tissues including neural tissue. Quercetin is also reported to have an inhibitory effect against matrix metalloproteinases (MMPs). Because MMPs are known to play a main role in the pathophysiology of brain ischemic insult, their mechanisms of possible protective effect of quercetin against brain ischemia remain to be clarified. In the present study, C57BL/6 mice were subjected to 20 min transient global brain ischemia. Cerebral blood flow was monitored by laser doppler flowmeter. Animals were sacrificed 72 h after ischemia. Quercetin (50 mg/kg, dissolved in saline) was intraperitoneally administered to mice at 30 min before and immediately after ischemia and from the second day, quercetin was then administered once daily until sacrifice. The present study was undertaken to test the effect of quercetin on neuronal damage after transient cerebral ischemia. Neuronal damages were remarkable in the medial portion of CA1 and CA2 areas after ischemic insult. In quercetin-treated mice, delayed neuronal damage was significantly decreased compared with vehicle-treated mice. Mice treated with quercetin showed attenuated brain MMP-9 activity. Gelatin gel zymography showed an induction of MMP-9 protein after ischemia. Quercetin significantly inhibited ischemia-induced elevation of MMP-9. In situ zymography showed elevations in gelatinase activities after brain ischemia. Quercetin also inhibited TdT-mediated dUTP nick end labeling (TUNEL) staining in CA1 and CA2 areas. These results demonstrate that quercetin, a natural flavonoid reduces global ischemia-induced neuronal damage through inhibition of MMP-9 activity.     

虫草素对大脑中动脉局灶性脑缺血模型大鼠氧化应激和脑损伤的影响

目的　研究虫草素对大脑中动脉局灶性脑缺血模型大鼠氧化应激指标和脑组织Caspase-3和p53表达的影响。 方法　首先，给药组大鼠每天分别腹腔注射虫草素5、10、20 mg/kg，连续10 d；然后，采用改良Zea Longa线栓法制备大脑中动脉闭塞（middle cerebral artery occlusion，MCAO）模型；造模24 h后，盲法进行神经功能评分，称重法检测脑含水量，HE染色观察脑组织病理损伤，Tunnel染色检测脑细胞凋亡，RT-PCR检测Bcl-2、Bax、Caspase-3和p53 mRNA表达，Western blotting检测Bcl-2、Bax、Caspase-3和p53蛋白表达，试剂盒检测SOD，MDA，GSH水平。 结果　给药组与MCAO组相比，神经功能评分显著降低，脑含水量显著减少，细胞损伤减轻，细胞凋亡率显著减少，Bax mRNA及蛋白表达显著下调，Bcl-2 mRNA及蛋白表达显著上调，MDA含量显著下降，SOD和GSH含量显著上升，Caspase-3和p53 mRNA及蛋白表达显著下调，且这些效果随着虫草素给药量的增加更加显著。 结论　虫草素能够缓解大脑中动脉局灶性脑缺血引起的神经功能障碍和降低脑缺血引起的脑含水量升高，并能抑制大脑中动脉局灶性脑缺血模型大鼠氧化应激和细胞凋亡，从而减缓大脑中动脉局灶性脑缺血造成的损伤。     

Evaluation of late cognitive impairment and anxiety states following traumatic brain injury in mice: the effect of minocycline

Inflammation and oxidative stress play an important role in cerebral ischemic pathogenesis. It has been well established that atorvastatin and probucol could elicit a variety of biological effects through its anti-inflammatory and anti-oxidant properties respectively. This study was to examine whether probucol and atorvastatin in combination had the enhanced protective effect against cerebral ischemia. Male Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO). Experiment 1 was used to evaluate the time course expression of Peroxiredoxin2 (Prx2) and Foxo3a after cerebral ischemia. Experiment 2 was used to detect neuroprotective effect of atorvastatin and probucol in cerebral ischemia. At 24 h or 72 h, neurologic deficit, brain water content and infarct size were measured. Immunohistochemistry, RT-PCR, Western blot and confocal microscope were used to analyze the expressions of Prx2, Foxo3a and nuclear factor erythroid 2-related factor 2 (Nrf2). Compared with the normal-control group, the expressions of Prx2 and Foxo3a were down-regulated in ischemic brain. Compared with the use of probucol or atorvastatin alone, the combined treatment dramatically reduced the brain water content and the infarct volume (P < 0.05). Meanwhile, the decrease of Prx2, Foxo3a and Nrf2 was significantly alleviated in combined treatment group. Probucol combined with atorvastatin can get the augmented neuroprotection from the damage caused by MCAO, this effect may be through up-regulation of Prx2, Foxo3a and Nrf2.     

Cyclooxygenase-2 immunoreactivity in the ischemic neonatal human brain. An autopsy study

Cyclooxygenase-2 (COX-2) is known to be expressed in rat brain and up-regulated by ischemia. The administration of COX inhibitors before as well as soon after the ischemic insult reduces the extension of cerebral damage in rats. Overexpression of COX-2 has also been shown in the ischemic brain of adult human patients, while no information concerning COX-2 expression in neonatal ischemia is available. Intrapartum asphyxia and perinatal brain injury may result in cerebral palsy, mental retardation or epilepsy. COX-2 expression in the brain of neonates delivered after severe birth asphyxia was investigated using immunohistochemistry. Meningeal vessel walls of term and preterm babies widely expressed COX-2 immunoreactivity, as did periventricular large vessels in preterms. A number of brain cells (mature and immature cortical, periventricular and basal ganglia neurons, and oligodendrocytes of the cerebral white matter in brains from term neonates) also expressed COX-2. The present findings suggest that COX-2 may take part in enhancing neonatal brain damage via different mechanisms, such as those involving excitotoxicity and production of reactive oxygen species.