布美他尼对LPS诱导的小胶质细胞活化及炎性分泌的影响

目的观察钠-钾-氯共转运体(Na+-K+-2Cl-cotransporter 1,NKCC1)的特异性抑制剂布美他尼(Bumetanide)对LPS(脂多糖)诱导的小胶质细胞活化及炎性因子分泌的影响。方法差速贴壁法培养大鼠原代小胶质细胞,纯化的小胶质细胞分为对照组,LPS组(1.0μg/ml)和布美他尼干预组(NKCC1抑制剂,10μM),在干预1、3、6和12 h固定细胞爬片,免疫荧光双标显示小胶质细胞活化形态;各时间点收取上层培养基,用ELISA法测定各组培养基中TNF-α和IL-1β的水平。结果 LPS干预后小胶质细胞活化,体积增大,布美他尼干预后小胶质细胞活化受到抑制。小胶质细胞分泌的TNF-α和IL-1β在LPS干预1 h时开始明显增加,TNF-α的分泌在6 h达到最高峰;IL-1β的分泌在3 h时达到最高峰(P0.05)。布美他尼干预后与LPS组比较,TNF-α和IL-1β分泌明显减少,其中在3、6、12 h时TNF-α分泌显著降低(P0.05),而IL-1β的分泌在1、3、6、12 h时明显降低(P0.05)。结论布美他尼可减少LPS诱导的小胶质细胞活化及炎性因子分泌增加,提示NKCC1通路在小胶质细胞活化及炎性因子分泌中发挥了重要作用。     

米诺环素对慢性脑缺血大鼠脑内Notch信号通路的影响

目的 观察慢性脑缺血后米诺环素是否可以通过调节Notch信号通路而发挥脑保护作用。方法 将健康雄性SD大鼠40只随机分为5组(n=8):假手术(Sham)组、缺血模型(Model)组、DAPT组、米诺环素(Min)组、DAPT+米诺环素(DAPT+Min)组; 双侧颈总动脉永久性结扎(2-VO)建立慢性脑缺血模型,给药1月后行为学检测大鼠的学习记忆能力,免疫组化和Western blot检测VEGF及Notch信号通路下游物质Hes1的表达水平。结果 与假手术组比较,缺血模型组大鼠的学习记忆能力降低(P<0.05); 米诺环素组与DAPT组比较,VEGF及Hes1的表达水平存在显著差异(P<0.01); 米诺环素组分别于与缺血模型组和DAPT+米诺环素组比较,DAPT+米诺环素组与DAPT组比较,学习记忆能力、VEGF及Hes1的表达水平存在显著差异(P<0.05)。结论 米诺环素可能通过对慢性脑缺血大鼠脑内Notch信号通路的调节来促进脑缺血后血管的新生,进而发挥脑保护作用。     

ERK通路对体外培养星形胶质细胞缺氧/复氧后TNF-α分泌的影响

目的 分析ERK通路对缺氧/复氧后反应性星形胶质细胞TNF-α分泌的影响,从而探讨ERK通路在星形胶质细胞反应性改变的可能作用机制,为临床研究提供理论支持.方法 参照McCarthy方法星形胶质细胞（AC）原代培养,传至第3代,细胞自然纯化.将AC分为正常对照组（C组）、缺氧/复氧组（H/R组）、缺氧/复氧阻滞剂组（H/R＋M组）.每组设缺氧4 h、缺氧8 h、复氧6 h、12 h、24 h、48 h 6个时间点,建立AC缺氧/复氧模型.Western-blot法半定量分析T-ERK,P-ERK的表达情况,TNF-α ELISA试剂盒测定细胞凋亡情况.采用SPSS18.0统计软件包进行数据分析.结果 （1）Western-blot：缺氧组较正常组相比ERK表达明显升高（P＜0.05）,阻滞剂组较无阻滞剂组p-ERK蛋白表达量显著下降（P＜0.05）.（2）TNF-α ELISA：缺氧后TNF逐渐升高,复氧48 h时达高峰（P＜0.05）,加入ERK阻滞剂后升高更明显（P＜0.05）.结论 星形胶质细胞缺氧复氧后存在ERK通路的激活,ERK通路在星形胶质细胞缺氧损伤后反应中发挥生物学作用与TNF-α有关.     

Purmorphamine对BV2细胞帕金森病相关基因Nurr1表达的影响

目的探讨Purmorphamine(PM)激活小胶质细胞瘤BV2细胞中Sonic hedgehog(SHH)信号通路对帕金森病(PD)相关基因Nurr1表达的影响。方法体外培养BV2小胶质细胞并分为对照组、脂多糖(LPS)处理组、PM+LPS处理组以及PM处理组,运用荧光定量PCR(Q-PCR)检测经LPS处理后BV2细胞中SHH信号通路Smoothened(Smo)、Gli1及Nurr1基因mRNA表达情况;PM激活SHH信号通路后,Q-PCR检测Nurr1mRNA含量以及炎性反应因子白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)的mRNA表达情况。结果(1)与对照组相比,LPS处理后4h和24h时Smo和Gli1mRNA表达均升高(P0.01,P0.05);(2)与对照组相比,PM处理组细胞Smo和Gli1mRNA表达升高(P0.01),LPS组Nurr1、IL-1β、TNF-αmRNA表达亦均升高(均P0.01);而PM+LPS组Nurr1、IL-1β、TNF-αmRNA表达均较LPS处理组下降(均P0.01)。结论PM激活SHH信号通路能够抑制BV2细胞中Nurr1的表达,并能发挥抑制炎性反应作用。     

异甘草素对SHG44人脑胶质瘤干细胞增殖和分化的影响

目的探讨不同浓度异甘草素对SHG44人脑胶质瘤干细胞增殖和分化的影响及机制。方法实验分为二甲基亚砜(dimethyl sulfoxide,DMSO)对照组,异甘草素(10~160μmol/L)诱导组,氮-[氮-(3,5-二氟苯乙酰)-L-丙氨酰]-S-苯基甘氨酸丁酯(N-[N-(3,5-difluorophenacetyl)-1-alanyl]-S-ph,DAPT)(2.0μmol/L)阻断剂组,异甘草素+阻断剂组(10~160μmol/L+2.0μmol/L DAPT),采用CCK-8法、免疫荧光染色、Western blot及Real-time PCR分别检测细胞抑制率、相关分化蛋白及Notch1通路相关基因表达情况。结果异甘草素在12~48 h,随着浓度增加,细胞抑制率减弱(P0.05),且分化细胞越多,干细胞减少;72 h后随着浓度增加,细胞抑制率增强(P0.05),分化细胞及干细胞同时减少;隔日加药至第7 d时,经统计分析胶质瘤干细胞球数目减少、直径减小(与对照组比),且P0.05。异甘草素作用72 h后:与对照组比较,随着异甘草素浓度的增加Nestin蛋白表达量逐渐下调(P0.05);与对照组比较,10、40、160μmol/L组GFAP蛋白表达水平均上调(P0.05),且40μmol/L组GFAP蛋白表达量较其他浓度组均较高,(P0.05);与对照组比较,10、40、160μmol/L组β-TubulinⅢ蛋白表达水平均上调(P0.05),且10μmol/L组β-TubulinⅢ蛋白表达量较其他浓度组均较高(P0.05)。Notch1通路阻断剂作用后,与对照组比较,各异甘草素组和阻断剂组Notch1、RBP-JK及Hes1基因表达均显著下调(P0.05);与异甘草素组比较,Notch1、RBP-JK及Hes1基因表达在异甘草素加DAPT组及阻断剂组显著下调(P0.05);与阻断剂组比较,Notch1、RBP-JK及Hes1基因表达在异甘草素加DAPT组显著下调(P0.05)。结论异甘草素能诱导SHG44人脑胶质瘤干细胞向星形胶质细胞和神经元细胞分化,且能抑制其增殖,可能与下调Notch1信号通路中的Notch1、RBP-JK及Hes1有关。     

溶血磷脂酸对小胶质细胞炎性分泌的影响

目的观察溶血磷脂酸(LPA)对小胶质细胞活化及其炎性因子分泌的影响。方法小胶质细胞系BV2细胞复苏后传代培养,分为对照组和LPA组,在30 min、1、3和6 h收取上层培养基,用ELISA法测定各组培养基中IL-1β和TNF-α的浓度。结果 LPA干预后BV2细胞分泌的IL-1β和TNF-α在1 h开始明显增加,IL-1β的分泌在3 h达到最高峰而TNF-α的分泌在6 h内持续升高(P<0.01)。结论 LPA可显著促进BV2细胞IL-1β和TNF-α的分泌,在3 h时促进作用最为显著。LPA可诱导BV2细胞活化及炎性因子分泌增加,提示LPA在小胶质细胞活化及炎性因子分泌中发挥了重要作用。     

从炎症机制探讨Notch通路抑制剂对小鼠脑缺血模型的神经保护作用

目的 探讨Notch通路抑制剂对小鼠脑缺血模型的神经保护作用。方法 78只成年BALB/c小鼠按简单随机抽样方法分为Sham组、二甲基亚砜(DMSO)组、γ-分泌酶抑制剂(DAPT)组,每组26只;线栓法制作小鼠脑缺血模型,其中Sham组小鼠接受相同手术,但未插入缝线;DAPT组小鼠在大脑中动脉闭塞前3h腹腔注射DAPT溶液(5 mL·kg^-1),Sham组、二甲基亚砜(DMSO)组小鼠注射等剂量DMSO溶液,将Longa评分1～3分的小鼠作为实验小鼠;应用尼氏染色及TUNEL/NeuN免疫荧光双标染色鉴定右额叶皮质神经元,免疫荧光检测缺血半脑右半脑皮质Notch1、胶质纤维酸性蛋白(GFAP)阳性细胞,Westermblot检测缺血半脑右半脑皮质Hes1蛋白、Hes5蛋白表达,透射电镜观察各组右额叶皮质神经元超微结构变化,ELISA检测右前额叶皮质白细胞介素6 (IL-6)、肿瘤坏死因子(TNF-α)水平。结果 与Sham组比较,DMSO组、DAPT组皮质神经元存活数显著下降,皮质神经元凋亡数显著上升(P <0.05);与DMSO组比较,DAPT组皮质神经...     

p38MAPK在体外培养星形胶质细胞缺氧/复氧损伤中的表达

目的 建立SD大鼠星形胶质细胞缺氧复氧损伤模型,探讨p38MAPK活性变化与星形胶质细胞损伤的关系.方法 体外培养新生SD大鼠星形胶质细胞,实验设正常对照组（N）、SB203580组（SB组,10 μmol/L）、缺氧/复氧组（H/R组）和缺氧/复氧组＋SB203580阻断p38MAPK组（H/R＋SB组）.应用MTT法、WB法、ELISA法检测缺氧4 h、8 h、复氧6 h、12 h、24 h、48 h时细胞存活率,p38MAPK、p-p38（磷酸化p38MAPK）及TNF-α的变化.结果 培养星形胶质细胞GFAP阳性表达率大于97%.缺氧/复氧使星形胶质细胞活力降低,SB203580阻断p38MAPK细胞活力高于H/R组,各组星形胶质细胞总p38MAPK水平无显著变化,缺氧复氧干预后p-p38表达上调,TNF-α水平显著增高.用SB203580阻断p38MAPK通路后,SB＋H/R组较H/R组p-p38、TNF-α水平降低.SB组总p38MAPK、p-p38、TNF-α水平与N组比较无显著变化.结论 p38MAPK信号通路参与了星形胶质细胞缺氧复氧损伤过程.     

TLR4-P38MAPK信号通路在LPS诱导BV2细胞中的表达及意义

目的观察LPS诱导小胶质细胞后信号通路Toll样受体4(TLR4)-p38蛋白激酶(p38MAPK)的表达及意义。方法体外培养BV2小胶质细胞,分为对照组、LPS诱导组(LPS刺激12h及24h)及SB203580干预组(LPS+SB203580诱导12h及24h),应用ELISA法检测各组TNF-α、IL-6水平,RT-PCR法检测各组TLR4mRNA和p38MAPK mRNA的表达变化。结果 LPS诱导组细胞分泌TNF-α、IL-6水平显著提高,诱导24h后细胞上清液含量分别为(513.67±14.05)pg/mg和(396.84±15.41)pg/mg。给予SB203580抑制剂后TLR4mRNA和p38MAPK mRNA表达明显减弱,细胞分泌TNF-α、IL-6含量表达与感染组比较也明显降低。结论 LPS刺激小胶质细胞可引起TLR4-p38MAPK信号通路的活化并释放炎性细胞因子,而SB203580则对其有明显的抑制作用,证明TLR4-p38MAPK信号通路与小胶质细胞的炎性活化密切相关。     

趋化因子CC配基2对α?Synuclein诱导的小胶质细胞增殖及神经元凋亡的影响

目的探讨趋化因子CC配基2(CCL2)对α?突触核蛋白(α?Synuclein)介导的小胶质细胞增殖及神经元凋亡的影响。方法体外分离培养原代小胶质细胞和原代神经元。小胶质细胞分为4组,依次为对照组、CCL2组、α?Synuclein组、CCL2+α?Synuclein组。对照组中加入等量的PBS,CCL2组细胞中加入含有CCL2浓度为0.05ng/μL的培养液。α?Synuclein组细胞中加入含有α?Synuclein浓度为0.2ng/μL的培养液。CCL2+α?Synuclein组中加入含有0.05ng/μL CCL2、0.2ng/μLα?Synuclein的细胞培养液。培养24h后,检测小胶质细胞增殖情况及细胞中α?Synuclein蛋白水平,同时检测细胞培养液中TNF-α、IL-1β、NO含量。用各组小胶质细胞培养液培养原代神经元,观察神经元凋亡情况及神经元中Cleaved Caspase-3、Akt、p-Akt水平。结果 CCL2组、α?Synuclein组、CCL2+α?Synuclein组小胶质细胞增殖活性及分泌TNF-α、IL-1β、NO水平明显高于对照组(P0.05)。CCL2组、CCL2+α?Synuclein组小胶质细胞中α?Synuclein水平明显高于对照组(P0.01)。CCL2组、α?Synuclein组、CCL2+α?Synuclein组小胶质细胞培养液作用后的神经元凋亡率及Cleaved Caspase-3蛋白水平明显高于对照组,pAkt水平低于对照组(P0.01)。结论 CCL2促进α?Synuclein引起的小胶质细胞增殖和分泌TNF-α、IL-1β、NO的能力,对α?Synuclein引起的神经元凋亡也具有促进作用,促凋亡作用机制可能与Akt信号通路有关。     

视频脑电图在小儿癫痫诊断中的应用

目的评价视频脑电图(video-EEG)在小儿癫诊断中的应用价值。方法对126例具有发作性症状的患儿进行连续8h的包括清醒、睡眠、诱发试验及必要的认知测验的视频脑电图监测。结果经发作期视频脑电图证实,39例初诊为癫性发作的患儿中14例(35%)为非癫性发作;15例其他症状发作中13例(86%)为非癫性发作。64例样放电患儿中51例(80%)确定发作类型,22例(34%)确定癫类型。视频脑电图可发现短暂轻微的癫发作及样放电引起的一过性认知损伤。结论视频脑电图在排除非癫性发作、确定癫性发作的类型、评价脑电-临床关系方面可提供准确可靠的证据,进一步提高癫的临床诊断水平。     

Neuroprotective properties of memantine in different in vitro and in vivo models of excitotoxicity

The pathogenesis of stroke, trauma and chronic degenerative diseases, such as Alzheimer's disease (AD), has been linked to excitotoxic processes due to inappropriate stimulation of the N-methyl-D-aspartate receptor (NMDA-R). Attempts to use potent competitive NMDA-R antagonists as neuroprotectants have shown serious side-effects in patients. As an alternative approach, we were interested in the anti-excitotoxic properties of memantine, a well-tolerated low affinity uncompetitive NMDA-R antagonist presently used as an anti-dementia agent. We explored in a series of models of increasing complexity, whether this voltage-dependent channel blocker had neuroprotective properties at clinically relevant concentrations. As expected, memantine protected neurons in organotypic hippocampal slices or dissociated cultures from direct NMDA-induced excitotoxicity. However, low concentrations of memantine were also effective in neuronal (cortical neurons and cerebellar granule cells) stress models dependent on endogenous glutamate stimulation and mitochondrial stress, i.e. exposure to hypoxia, the mitochondrial toxin 1-methyl-4-phenylpyridinium (MPP+) or a nitric oxide (NO) donor. Furthermore, memantine reduced lethality and brain damage in vivo in a model of neonatal hypoxia-ischemia (HI). Finally, we investigated functional rescue (neuronal capacity to migrate along radial glia) by memantine in cerebellar microexplant cultures exposed to the indirect excitotoxin 3-nitropropionic acid (3-NP). Potent NMDA-R antagonists, such as (+)MK-801, are known to block neuronal migration in microexplant cultures. Interestingly, memantine significantly restored the number of neurons able to migrate out of the stressed microexplants. These findings suggest that inhibition of the NMDA-R by memantine is sufficient to block excitotoxicity, while still allowing some degree of signalling.     

Storage of lipofuscin in neurons in mucopolysaccharidosis

Summary A histochemical and ultrastructural study was made on the brain of a 23-year-old man with Sanfilippo's syndrome. In accordance with previous reports the cortical nerve cells contained a PAS-positive lipid storage substance. This showed intense autofluorescence in UV-light and was positive with various stains for lipofuscin. The storage material appeared ultrastructurally as inclusion bodies composed of short lamellated membranes, granular material, and vacuoles. In addition, concentrically and transversely lamellated membranous cytoplasmic bodies were observed in the nerve cells. It is concluded that the PAS-positive lipid storage material in the neurons was composed partly of lipofuscin in addition to other lipids presumably glycosphingolipids.Supported by a grant from the Expressen Prenatal Research Foundation     

脑电图预测痫性发作研究进展

癫痫(epilepsy)是由脑部神经元高度同步化异常放电所致的临床综合征,系神经系统的常见病,困扰着全世界约1%的人群.每次神经元的阵发性放电或短暂的脑功能异常称为痫性发作(seizures).     

Midazolam in treatment of various types of seizures in children

Midazolam is a recently developed water-soluble benzodiazepine that shares anxiolytic, muscle relaxant, hypnotic and anticonvulsant actions with other members of this class. There are limited studies that midazolam can be used successfully to treat seizures in adults and children. In this study, 0.2 mg/kg intramuscular (IM) midazolam was administered to 11 children (eight boys and three girls), aged 3 days to 4 years (mean age 1.8±1.4 years), with seizures of various types. In all but one child, seizures stopped in 15 s–5 min after injection. No side effects were observed. These results suggest that IM administration of midazolam may be useful in a variety of seizures during childhood, especially in case of intravenous (IV) line problem.     

Role of vincristine in the inhibition of angiogenesis in glioblastoma

Objective: Vincristine, a microtubule-destabilizing drug, was found to exhibit anti-angiogenic effects and anti-tumoral activity. However, the precise mechanism by which vincristine inhibits angiogenesis in glioblastomas is not well understood. Our aim was to investigate whether vincristine affects vascular endothelial growth factor (VEGF) expression in glioblastoma cells and determine whether it is mediated by the downregulation of hypoxia-inducible factor-1α (HIF-1α).

Methods: We investigated the expression of HIF-1α in glioblastoma tissues resected from patients and in human glioblastoma cell lines using immunohistochemistry, Western blot analysis, and immunocytochemistry. In addition to an MTT assay assessing the effect of vincristine on cell proliferation and viability, the effects of vincristine on VEGF mRNA expression and HIF-1α protein were examined using real-time RT-PCR and Western blot analysis under 1% O₂ (hypoxia).

Results: HIF-1α was expressed in the majority of glioblastoma tissues and was detected mainly in the nucleus. Strong immunoreactivity for HIF- 1 α was found often in the hypercellular zones. Under hypoxic conditions, HIF-1α protein levels in the glioblastoma cell lines increased, primarily localizing into the nucleus similar to glioblastoma tissues. Exposure of glioblastoma cells to vincristine resulted in enrichment of the G₂-M fraction of the cell cycle, which suggests that vincristine-mediated growth inhibition of glioblastoma is correlated with mitotic inhibition. Using doses lower than those found to reduce the viability and proliferation of cells by 50% (IC₅₀), vincristine decreased both the expression of VEGF mRNA and the level of HIF-1α protein in hypoxic glioblastoma cells. In addition, following exposure to vincristine, the expression of VEGF mRNA was correlated with HIF-1α protein levels.

Conclusions: Our results suggest that the mechanism by which vincristine elicits an anti-angiogenic effect in glioblastomas under hypoxic conditions might be mediated, in part, by HIF-1α inhibition.     

The Burden of Agoraphobia in Worsening Quality of Life in a Community Survey in Italy

ObjectiveCurrent nosology redefined agoraphobia as an autonomous diagnosis distinct from panic disorder. We investigated the lifetime prevalence of agoraphobia, its association with other mental disorders, and its impact on the health-related quality of life (HR-QoL). MethodsCommunity survey in 2,338 randomly selected adult subjects. Participants were interviewed with the Advanced Neuropsychiatric Tools and Assessment Schedule (ANTAS), administered by clinicians. The diagnoses were based on the ICD-10 criteria. The Short-Form Health Survey (SF-12) was used to quantify HR-QoL. ResultsIn the sample, 35 subjects met the criteria for agoraphobia (1.5%), with greater prevalence among women (2.0%) than men (0.9%): odds ratio (OR) 2.23; 95% CI: 1.0-5–2. Agoraphobia was more often seen among those with (n=26; 1.1%) than without (n=9; 0.4%) panic disorder: OR=8.3; 2.9–24.4. Co-morbidity with other mental disorders was substantial. The mean score of SF-12 in people with agoraphobia was 35.2±7.8, with similar levels of HR-QoL in people with (35.3±7.9) or without (34.8±7.3) panic disorder: ANOVA: F(1;33)=0.0; p=1.00. ConclusionOne out of seventy people may suffer from agoraphobia in their lifetime. The attributable burden in terms of HR-QoL is substantial and comparable to the one observed for chronic mental disorders such as major depression, post-traumatic stress disorder, or obsessive-compulsive disorder.     

Characteristics of nociceptors in the periodontium--an in vitro study in rats

Recent studies have indicated that nociceptors can be classified into various types according to their physiological properties. These studies have clarified that the frequency distribution of various nociceptor types is different among body sites and animal species. In the present study, we investigated the physiological properties of rat's periodontal nociceptors in an in vitro jaw-nerve preparation. Responses were recorded from functional single filaments in the inferior alveolar nerve. To determine the nociceptor type, calibrated von Frey filaments, heat, and bradykinin (BK) stimuli were used. We found five subtypes of nociceptors in the periodontal ligaments of the lower incisor: Adelta-high threshold mechanonociceptors (Adelta-HTM, n=28), Adelta-mechanoheat nociceptors (Adelta-MH, n=6), Adelta-polymodal nociceptors (Adelta-POLY, n=26), C-high threshold mechanonociceptors (C-HTM, n=3) and C-polymodal nociceptors (C-POLY, n=4). Most nociceptors were Adelta-innervated, while only a small number of C-innervated nociceptors were found. The present results suggest that periodontal nociceptors transmit mainly fast pain, and may thus play a role in rapid detection of injure-related stimuli during mastication.     

自噬参与帕金森病发病的研究进展

近年来,蛋白质的降解障碍被认为是帕金森病（Parkinson’Sdisease,PD）发病过程中的重要因素,人们已经公认泛素一蛋白酶体系统（ubiquitin--pro—teasomesystem,UPS）功能异常或衰竭能够导致细胞内异常蛋白蓄积、细胞功能障碍,甚至细胞凋亡。与此同时,蛋白降解的另一条途径——自噬-溶酶体途径（autophagy—lysosomepathway,ALP）也已成为了生命科学领域的研究热点,自噬与神经变性疾病,尤其是PD的关系日益受到人们的重视。     

Developmental effects of in vivo and in vitro inhibition of nitric oxide synthase in neurons

The diffusible chemical messenger nitric oxide (NO) is involved in neuronal plasticity and it is, therefore, supposed to play a role in brain development. A shortage of NO during the critical period of brain maturation may theoretically have long-lasting consequences on the organization of the adult brain. We have performed in neonatal rats a chronic inhibition of the enzyme responsible for NO production, nitric oxide synthase (NOS), from postnatal day 3 to postnatal day 23, through administration of the competitive antagonist N-nitro-L-arginine methylester (L-NAME). The calcium-dependent catalytic activity resulted almost completely inhibited throughout the period of treatment and it took more than 4 days after its suspension to get a full recovery. The expression of the neuronal isoform of the enzyme (nNOS), revealed by immunoblotting, was unchanged during the treatment and after it. The histochemical reaction for NADPH diaphorase was reduced at the end of the treatment and recovered in concomitance with the recovery of the catalytic NOS activity. No gross structural alterations were detected in brain morphology. The levels of three neurotransmitter-related and one astrocytic marker were unchanged in the cerebellum, hippocampus and cortex of 60-day-old rats which had been neonatally treated. A similar lack of significant effects on neurochemical brain maturation was also noticed in a parallel series of experiments, in which a short pulse of NOS inhibition was performed at a critical prenatal time of brain development, from gestational day 14 to gestational day 19. In vitro, chronic exposure of cerebellar granule cells to L-NAME (500 microM) resulted in slight decrease of surviving neurons after 8 days in culture and in better resistance to the challenge of stressful culture conditions. The present results suggest that the basic plan of brain organization can be achieved despite an almost complete NOS inhibition during the maturation period. In vitro, NOS inhibition may bring to more pronounced consequences on neuronal viability and function.