快速眼动睡眠剥夺后大鼠脑内神经元骨架蛋白及超微结构的变化

目的探讨经历不同时间快速眼动（REM）睡眠剥夺对大鼠皮质及海马各区神经元形态结构的影响。方法选择微管相关蛋白（MAP2）和神经丝（NF）作为正常神经元结构的标识物，利用免疫组织化学法和Western blot技术观察REM睡眠剥夺1、3、5、7 d4个时间点大鼠皮质及海马MAP2和NF表达的时空变化规律。同时运用电镜技术观察睡眠剥夺后神经元超微结构的变化。我们的实验是用改良的多平台睡眠剥夺模型进行REM睡眠剥夺，结合免疫组织化学染色技术和蛋白质电泳以及电镜超微结构分析。结果REM睡眠剥夺后5d大鼠皮质、海马CA1及齿状回神经元结构蛋白MAP2和NF表达较对照组明显减少（P〈0．05）；电镜神经元核仁偏位，胞质中出现少量肿胀的线粒体和内质网；部分神经轴突的髓鞘溶解与浓集。环境对照组、REM睡眠剥夺5d和7d组，皮质中超微结构改变的神经元所占比例分别为1．2％、3．6％和5．8％。结论REM睡眠剥夺能够导致大鼠脑内神经元的超微结构发生异常变化。     

睡眠剥夺对大鼠海马和皮质IL-1β蛋白表达的影响

目的:研究完全睡眠剥夺对大鼠海马和皮质IL-1β蛋白表达的影响。方法:将大鼠放入1转/分钟转笼中,制作经历不同持续时间的完全睡眠剥夺(TSD)模型。30只大鼠随机分为5组:对照组(正常对照CC组,环境对照TC组)和睡眠剥夺组[TSD6h组,TSD1d组,TSD3d组(n=6只)]。采用免疫组化方法检测大鼠海马和皮质IL-1β蛋白表达。结果:IL-1β阳性细胞大多在细胞浆,胞核内也有表达;主要分布在海马CA3、CA1及齿状回细胞核和细胞浆,在大脑皮质分布于各层。结论:完全睡眠剥夺大鼠海马和皮质IL-1β蛋白表达增高,且随时间的延长而逐趋明显。睡眠短期剥夺,IL-1β蛋白表达增高可能对脑细胞具有应激性保护作用,而长期剥夺后IL-1β持续增高可能对神经元有损伤作用。     

γ-氨基丁酸能神经元在新生大鼠缺氧性痫性发作中的作用

目的 通过观察新生大鼠早期发育过程中及缺氧性痫性发作后海马组织病理改变以及原癌基因c-fos蛋白、谷氨酸脱羧酶(glutamate decarboxylase,GAD)的变化,探讨γ-氨基丁酸(γ-amino butylic acid,GABA)能神经元在缺氧性痫性发作中的作用及可能的影响机制.方法 采用出生后10d的SD大鼠建立改良Jensen缺氧诱导痫性发作模型,分为痫性发作后1d、3d、7d、14d 4组,并选取相应时间点正常大鼠为对照组,采用尼氏染色方法检测海马组织的组织病理变化,免疫组织化学法检测各组海马c-fos蛋白灰度值以及GAD阳性神经元数量的改变.结果 尼氏染色结果显示,各缺氧性痫性发作组海马区形态结构正常,细胞排列略稀疏,但未见明显的细胞丢失.免疫组化结果显示,与对照组比较,c-fos蛋白灰度值在痫性发作后7d,在缺氧性痫性发作组海马CA2、CA3和DG区明显地降低(P ＜0.05);GAD阳性细胞数在痫性发作后7～ 14d,缺氧性痫性发作组海马CA1、CA3和DG区明显地减少(P＜0.05).结论 缺氧性痫性发作后14d内并没有造成大鼠海马区及时或迟发性细胞丢失,但c-fos表达在大鼠海马区有迟发性增高;缺氧性痫性发作后海马GABA神经元数量的减少可能是新生大鼠缺氧诱导痫性发作后癫痫易感性升高的原因之一.     

血栓素A_2受体在正常大鼠脑内的分布定位

目的探讨血栓素A2受体(TP)在正常大鼠脑内的表达分布特点。方法正常成年SD大鼠脑组织冰冻切片,TP免疫荧光染色,TP/神经核蛋白(Neu N),TP/胶质纤维酸性蛋白(GFAP),TP/谷氨酸脱羧酶67(GAD67)免疫荧光双标染色,观察TP在脑内分布表达情况。结果 TP免疫阳性产物主要分布在扣带回皮质、皮层Ⅲ~V层、下丘和小脑的浦肯野细胞层;免疫荧光双标结果显示TP与神经元胞核特异性标记物Neu N共存,但不与星形胶质细胞标记物GFAP共存;同时,所有TP阳性神经元表达γ氨基丁酸(GABA)能神经元标记物GAD67。结论 TP表达于大鼠扣带回皮质、皮层Ⅲ~V层、下丘脑和小脑的浦肯野细胞层,主要分布于GABA能神经元,提示TP可能参与了大鼠大脑GABA能神经元的功能调节和病变过程。     

睡眠剥夺对大鼠海马和皮质IL-1βmRNA表达的影响

目的:研究完全睡眠剥夺对大鼠海马和皮质IL-1βmRNA表达的影响。方法:将大鼠放入1转／分钟转笼中,制作经历不同持续时间的完全睡眠剥夺(TSD)模型。30只大鼠随机分为5小组:对照组(正常对照CC组,环境对照 TC组)和睡眠剥夺组[TSD6h组,TSD1d组,TSD3d组(n=6只)]。采用RT-PCR方法检测大鼠海马和皮质IL- 1βmRNA表达。结果:大鼠海马区,TSD6h组和TSD1d组IL-1βmRNA的表达明显高于对照组,TSD3d组更为明显;皮质区TSD3d组表达也明显增多。结论:完全睡眠剥夺大鼠海马和皮质IL-1βmRNA表达增高,且随时间的延长而逐趋明显。睡眠短期剥夺IL-1βmRNA表达增高可能对脑细胞具有应激性保护作用,而长期剥夺后IL-1β持续增高可能对神经元有损伤作用。     

亚低温对局灶性脑缺血-再灌注大鼠脑皮质脑源性神经营养因子表达及神经元凋亡的影响

目的 观察局灶性脑缺血-再灌注后亚低温干预对大鼠脑源性神经营养因子表达及神经元凋亡的影响，并探讨脑源性神经营养因子在亚低温脑保护机制中的作用。方法 采用线栓法制备成年雄性SD大鼠左侧大脑中动脉闭塞局灶性脑缺血-再灌注改良模型，缺血时间2h。随机分为常温缺血组和亚低温缺血组。常温时大鼠脑温控制于36．5℃～37．5℃，肛温为35．9℃～36．9℃；亚低温时脑温维持于32．5℃～33．5℃，肛温为32．2℃～33．1℃。两组大鼠分别于脑缺血一再灌注及亚低温干预后2、6、24和72h进行神经功能缺损评分，并同时行三苯基氯化四唑（1TC）染色、HE染色、TUNEL染色、免疫组化染色及免疫组化与TUNEL双重染色，从而评估大鼠神经功能缺损状况；检测脑梗死体积及脑源性神经营养因子表达水平；观察组织病理学变化和神经元凋亡数量。结果 与常温缺血组相比，亚低温缺血组大鼠神经功能缺损评分低（P〈0．01），脑梗死体积小（P〈0．01），缺血灶周围脑皮质中的脑源性神经营养因子表达水平增高（P〈0．01），而且神经元凋亡数量少（P〈0．01）。在脑源性神经营养因子免疫组化染色呈阳性反应的神经元细胞核中，未发现TUNEL染色阳性者。结论 亚低温干预治疗可促进缺血灶周围的脑皮质对脑源性神经营养因子的表达，从而抑制神经元凋亡，减少大鼠脑梗死体积，改善神经功能缺损体征。     

大鼠胎脑皮质神经干细胞体外培养及诱导分化的实验研究

目的 从孕龄15d SD胚胎鼠脑皮质中分离并培养神经干细胞（neural stem cells。NSCs），观察其生长、增殖及分化。方法 采用包含碱性成纤维细胞生长因子（bFGF）和表皮细胞生长因子（EGF）的无血清培养及单细胞克隆技术，对胚胎鼠脑皮质神经干细胞进行原代、传代培养及诱导其分化。用Nestin染色鉴定神经干细胞特性，用免疫组化方法（β-Ⅲ-tubulin、GFAP染色）检测神经干细胞分化为神经元及神经胶质细胞状况。结果 从孕龄15dSD胚胎鼠脑皮质中分离的组织，经原代及传代培养均可形成细胞克隆．切具有增殖能力。原代及传代培养细胞呈Nestin（神经上皮干细胞蛋白）表达阳性．诱导分化后的细胞表达神经元细胞、星形胶质细胞的特异性抗原。结论 本实验分离、培养的孕龄15dSD胚胎鼠脑皮质细胞Nestin表达阳性．分化后表达神经元和星形胶质细胞的标记物，是大鼠的神经干细胞，并具有多向分化潜能。     

低剂量伽玛刀照射对致(癎)大鼠皮质及海马神经元c-fos和nNOS表达的影响

目的 通过观察低剂量伽玛刀照射对致(癎)大鼠大脑皮质及海马神经元c-fos和脑型一氧化氮合酶(nNOS)表达的影响,探讨伽玛刀治疗癫(癎)的作用机制.方法 将44只青霉素致(癎)大鼠模型等分为实验组和实验对照组大鼠各22只,另取4只正常大鼠作为正常对照组.实验组行伽玛刀照射(周边剂量12 Gy)后,应用免疫组化方法,观察大脑皮质及海马神经元c-fos和nNOS表达的变化.结果 无论是皮质还是海马,c-fos和nNOS在实验组与实验对照组动物之间,表达均有明显的差别,实验组表达明显少于实验对照组,而后者呈现双高峰现象.结论 c-fos和nNOS在伽玛刀治疗癫(癎)的机制中发挥了重要作用.     

快速眼动睡眠剥夺后大鼠皮质及海马 HSP70表达的研究

目的探讨不同时间的快速眼动(REM)睡眠剥夺对大鼠皮质及海马各区的热休克蛋白70(HSP70)表达的影响及意义。方法60只Wistar大鼠，随机分为睡眠剥夺组(SD)、环境对照组(TC)和空白对照组(CC)。其中SD组又分为1d、3d、5d、7d4个时点。用改良多平台睡眠剥夺法进行REM睡眠剥夺，运用免疫组织化学方法观察REM睡眠剥夺后大鼠额叶、顶叶皮质及海马各区HSP70表达的分布规律及时空变化；同时结合蛋白质免疫印记(Western Blot)实验对额叶皮质及全海马HSP70蛋白作了选择性的半定量分析。结果REM睡眠剥夺后1d脑内HSP70表达一过性增强。以后逐渐下降。Western Blot实验印证了这一结果。结论REM睡眠剥夺能够引起大鼠皮质及海马神经元内HSP70表达增强，可能是一种自身稳定调节的保护机制。     

L-NAME对大鼠局灶性脑缺血灌注损伤Fos蛋白表达的影响

目的观察一氧化氮含量的变化对缺血再灌注损伤后Fos蛋白表达的影响。方法采用线拴法制作大鼠局灶性脑缺血再灌注损伤模型,利用NADPH组化和Fos蛋白免疫组化双标技术研究NOS抑制剂L－NAME对大鼠局灶性脑缺血再灌注损伤脑皮层Fos蛋白表达的影响。结果缺血60min再灌注3h后损伤侧脑组织皮质一氧化氮合酶阳性神经元较正常增多并深染,Fos蛋白表达增加,L－NAME（3mg／kg）治疗组脑皮质神经元Fos蛋白的表达量较对照组减少,L－NAME（10mg/kg）治疗组脑皮质神经元Fos蛋白的表达量较对照组明显减少,同时也可见给予L－NAME后脑组织皮质内NOS阳性神经元无论在数量上还是在细胞着色、胞体突起均明显减少。结论c－fos基因表达也可能部分参与了NO的致神经细胞损伤过程。     

Epilepsy and anomalies of neuronal migration: MRI and clinical aspects

Neuronal migration disorders are the result of disturbed brain development. In such disorders, neurons are abnormally located. In diagnosing these conditions, magnetic resonance imaging is superior to any other imaging technique. This enables us to improve our knowledge of the clinical correlates of neuronal migration. With reference to migrational disorder, a retrospective study of all 303 patients with epileptic seizures referred for magnetic resonance imaging during a 3-year period was performed, 13 patients (aged 12-41, mean age 27) were identified. They represent 4.3% of the entire study group. Of the patients with known epilepsy, 6.7% and of the mentally retarded, 13.7% had migrational disorders. Four patients had schizencephaly as the dominant finding, one was classified as hemimegalencephaly, 2 had isolated heterotopias, and 6 had localized pachy- and/or poly-microgyria. The clinical pictures are complex. Ectopias of grey matter are recognised foci of epilepsy, but from an epileptological and a clinical viewpoint little attention has been given to these disorders. The present study shows that malmigration is not rare in epilepsy patients, especially not in the mentally retarded.     

Hepatic Considerations in the Use of Antiepileptic Drugs

Summary: Virtually all of the major antiepileptic drugs (AEDs) can cause hepatotoxicity, although fatal hepatic reactions are rare. The mechanisms, incidences, and risk profiles for such reactions differ from drug to drug. With carbamazepine and phenytoin, hepatotoxicity may be due to drug hypersensitivity. Although the profiles of patients at risk have not been well-defined for these two antiepileptic drugs, it would appear from reports in the literature that older adolescents and adults are at higher risk than children of developing serious or fatal hepatotoxicity. Once hepatotoxicity develops, mortality rates are 10–38% with phenytoin and 25% for carbamazepine. The risk profile for valproate fatal hepatotoxicity has been more clearly defined. Those at primary risk of fatal hepatic dysfunction are children under the age of 2 years who are receiving multiple anticonvulsants and also have significant medical problems in addition to severe epilepsy. The risk is considerably lower for patients over the age of 2 years on valproate monotherapy. In contrast to the risk profile with other AEDs, adults receiving valproate as monotherapy have the lowest risk of hepatotoxicity. Fatal hepatic dysfunction coincident with valproate may be the result of aberrant drug metabolism. Concomitant use of AEDs that induce microsomal P450 enzymes (e.g., phenytoin and phenobarbital) may enhance the production of a toxic metabolite, and hence the greater risk of hepatotoxicity with polypharmacy.     

Vascular Malformations and Epilepsy: Clinical Considerations and Basic Mechanisms

Summary: Vascular malformations (VMs) are associated with epilepsy. The natural history of the various VMs, clinical presentation, and tendency to provoke epilepsy determine treatment strategies. Investigations have probed the mechanisms of epileptogenesis associated with these lesions. Electrophysiologic changes are associated with epileptogenic cortex adjacent to VMs. Putative pathophysiologic mechanisms of epileptogenesis include neuronal cell loss, glial proliferation and abnormal glial physiology, altered neurotransmitter levels, free radical formation, and aberrant second messenger physiology.     

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES.     

Carbamazepine Efficacy and Utilization in Children

Summary: Carbamazepine is effective for preventing partial and generalized tonic-clonic seizures in children. Although absence epilepsies are more common in children than adults, an estimated 80% of children with epilepsy have seizure types or epilepsies that are potentially responsive to carbamazepine. The differential diagnosis of ictal staring is an especially important issue in children because absence and atypical absence seizures are more prevalent in children than adults. Age-related pharmacokinetic differences and drug interactions are major considerations in children. On average, children have higher clearance rates of carbamazepine, shorter half-lives, and higher ratios of carbamazepine-10, 11-epoxide to carbamazepine than adults. In addition, children with severe epilepsy are more likely to require multiple-drug therapy, which can lead to complex drug interactions. When carbamazepine is administered along with valproate, drug protein binding interactions can cause intermittent side effects.     

Neonatal Seizures: Problems in Diagnosis and Classification

Summary: The clinical identification of neonatal seizures is critical for the recognition of brain dysfunction; however, diagnosis is often difficult because of the poorly organized and varied nature of these behaviors. Current classification systems are limited in their ability to communicate motor, autonomic, and electroencephalo-graphic features of seizures precisely and to provide a basis for uniform effective diagnosis, therapy, and determination of prognosis. Recent investigations of neonates, utilizing bedside electroencephalographic/polygraphic/ video monitoring techniques, have provided the basis for improved diagnosis and classification of seizures in the newborn. These studies have demonstrated that not all clinical phenomena currently considered to be seizures require electrocortical epileptiform activity for their initiation or elaboration. In addition, the specific clinical character of the phenomena considered to be seizures, the clinical state of the infant, and the character of the EEG indicate the probable pathophysiological mechanisms involved and suggest probable etiologies, prognosis, and therapy. Similarities between animal models that demonstrate reflex physiology and neonates with motor automatisms and tonic posturing suggest that these clinical behaviors may not be epileptic in origin but, rather, primitive movements of progression and posture mediated by brainstem mechanisms. Although not all clinical behaviors currently considered to be neonatal seizures may have similar pathophysiological mechanisms, they are clinically significant because they all indicate brain dysfunction.     

Valproate Monotherapy in the Management of Generalized and Partial Seizures

Summary: For decades, therapeutic tradition has promoted the concept of polypharmacy in the management of epilepsy. In recent years, however, studies have shown that, for most patients, monotherapy can provide comparable or better seizure control than administration of multiple anticonvulsants, while diminishing the potential for adverse reactions, drug interactions, and poor compliance. Valproate is an important monotherapeutic agent that is highly effective in the control of idiopathic primary and secondarily generalized epilepsies, and partial seizures that do not generalize. Comparative studies have found that valproate is at least as effective as phenytoin and carbamazepine in the treatment of generalized and partial seizures. Given the similar efficacy, other factors such as pharmacokinetics and side effects may therefore determine anticonvulsant selection for monotherapy.     

Un nouveau cadre conceptuel de travail pour la psychiatrie

In an attempt to place psychiatric thinking and the training of future psychiatrists more centrally into the context of modern biology, the author outlines the beginnings of a new intellectual framework for psychiatry that derives from current biological thinking about the relationship of mind to brain. The purpose of this framework is twofold. First, it is designed to emphasize that the professional requirements for future psychiatrists will demand a greater knowledge of the structure and functioning of the brain than is currently available in most training programs. Second, it is designed to illustrate that the unique domain which psychiatry occupies within academic medicine, the analysis of the interaction between social and biological determinants of behavior, can best be studied by also having a full understanding of the biological components of behavior.