睡眠剥夺对小鼠脑组织超微结构和晚期糖基化终末产物受体表达的影响

目的 研究睡眠剥夺对小鼠脑组织超微结构晚期糖基化终末产物受体表达的影响。方法 30只3月龄健康昆明小鼠随机分为3组:睡眠剥夺组(SD)、平台对照组(TC)和空白对照组(BC),每组10只。应用无应激刺激物体识别试验(ORT)检测小鼠的学习和记忆能力,透射电镜观察小鼠海马CA1区和前额叶皮质的超微结构变化,免疫组织化学方法检测小鼠大脑海马CA1区和前额叶皮质的RAGE蛋白的表达。结果 神经行为学结果:SD组小鼠对新物体C的探索时间与探索A物体的时间无明显差异,而与TC、BC组比较下降明显(P0.05)。电镜结果:SD组海马和前额叶皮层神经元的数量减少,排列紊乱,部分轴索膜和髓鞘溶解、断裂,线粒体数量明显减少,突触囊泡形态不规则、稀疏。免疫组化结果:SD组海马CA1区和前额叶皮质RAGE蛋白免疫组化染色阳性细胞数明显增加(P0.05)。结论 睡眠剥夺可损害小鼠的认知功能,可能对小鼠海马CA1区及前额叶皮质脑组织超微结构造成损害,以及可能增加小鼠海马CA1区及前额叶皮质晚期糖基化终末产物受体(RAGE)的表达,致小鼠神经行为学改变。     

小鼠脑皮质撞击模型的构建和评估

目的 ;探索建立小鼠脑皮质撞击模型,为今后进一步开展小鼠颅脑创伤研究创造条件。方法雄性C57BL/6J小鼠36只,随机分为6组(包括实验组5组和对照组1组),应用NYU Impactor Ⅰ型脑皮质撞击仪,金属杆(重10g)从不同高度落下垂直打击小鼠脑皮质造成损伤,建立小鼠脑皮质撞击模型。致伤后观察小鼠神经反射及意识恢复时间。伤后24 h处死小鼠,取海马CA2/3区脑组织行退变神经元Fluoro-Jade B组织荧光染色,通过立体细胞计数观察退变神经元数量变化。结果打击高度为10~40 mm时,损伤侧脑组织病理改变的严重程度逐级加重,与损伤程度存在较好的相关性;打击高度为10 mm时可近似模拟轻型颅脑损伤;打击高度为20~30 mm时近似模拟中型颅脑损伤;打击高度为40 mm时近似模拟重型颅脑损伤。结论应用NYU Impactor Ⅰ型脑皮质撞击仪可以成功地制作出所需的小鼠脑皮质撞击模型,具有重复性好、简便易用的特点,是较理想的小鼠致伤模型。     

妥泰对海人酸致大鼠海马神经元线粒体损伤的保护作用

目的观察海人酸(KA)诱导的癫持续状态(SE)、大鼠海马CA3区神经元线粒体超微结构的损伤及妥泰(TPM)的保护作用。方法用TPM干预。用KA诱导大鼠SE 2h,并于癫终止后3h制作脑切片,用光镜观察神经元的大体损伤,并用电镜进一步观察线粒体的超微结构。结果KA组和TPM组大鼠均出现了线粒体超微结构的损伤,TPM组大鼠的损伤明显减轻。结论KA诱导的SE可导致海马神经元线粒体损伤,妥泰对此具有保护作用。     

妥泰对海人酸致癎大鼠海马神经元线粒体损伤的保护作用

目的观察海人酸（KA）诱导的癫痫持续状态（SE）、大鼠海马CA3区神经元线粒体超微结构的损伤及妥泰（TPM）的保护作用。方法用TPM干预。用KA诱导大鼠SE2h,并于癫痫终止后3h制作脑切片,用光镜观察神经元的大体损伤,并用电镜进一步观察线粒体的超微结构。结果KA组和TPM组大鼠均出现了线粒体超微结构的损伤,TPM组大鼠的损伤明显减轻。结论KA诱导的SE可导致海马神经元线粒体损伤,妥泰对此具有保护作用。     

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.     

脑源性神经营养因子基因修饰骨髓间质干细胞移植痴呆大鼠大脑皮质及海马tau蛋白、β-淀粉样蛋白及神经元超微结构的变化

目的：观察脑源性神经营养因子基因修饰的骨髓间质干细胞（MSCs）移植对阿尔茨海默病鼠大脑皮层及海马tau蛋白磷酸化、Aβ及海马CA1区神经元超微结构的影响。 方法：采用侧脑室立体定向注射β-淀粉样肽建立阿尔茨海默病动物模型,取单纯或经脑源性神经营养因子基因修饰的骨髓间质干细胞移植,1月后采用Western bloting 方法检测大脑皮层及海马组织总tau蛋白及磷酸化的tau蛋白,以ELISA方法检测Aβ0,42含量,同时观察海马CA1区神经元超微结构的变化。 结果：①损伤模型组大脑皮层及海马总tau蛋白及磷酸化的tau蛋白明显升高,脑源性神经营养因子修饰的骨髓间质干细胞能够降低其表达,与损伤模型组相比有显著性差异(P<0.01),与正常对照组、骨髓间质干细胞未修饰组相比无显著性差异（ P>0.05）。②损伤模型组大脑皮层及海马Aβ40,42明显升高,脑源性神经营养因子修饰的骨髓间质干细胞能够降低其表达,与损伤模型组及骨髓间质干细胞组相比有显著性差异（P<0.01或P<0.05）,与正常对照组相比无显著性差异（ P>0.05）。③损伤模型组大鼠海马CA1区神经元出现粗面内质网扩张、膜断裂,线粒体数目减少、线粒体肿胀、核膜不清等改变,脑源性神经营养因子基因修饰的骨髓间质干细胞对上述改变有减轻作用,较骨髓间质干细胞未修饰组明显。 结论：脑源性神经营养因子基因修饰的骨髓间质干细胞可以降低阿尔茨海默病模型鼠大脑皮层及海马组织tau蛋白磷酸化,减轻Aβ的含量,对海马CA1区神经元具有保护作用。     

GM1对脑血管痉挛后神经元及血管内皮细胞的影响

目的通过观察神经元及血管内皮细胞的形态学变化以探讨GM1防治脑血管痉挛(cerebrovascular spasm,CVS)的可能性.方法将25只Wistar大鼠随机分为5组:对照组、脑血管痉挛组(CVS组)、尼莫地平治疗组(Nim组)、单唾液酸神经节苷脂(GM1)治疗组(GM1-T组)、GM1预防组(GM1-P组).运用2次注血的方法诱发脑血管痉挛,6 h后处死大鼠,4%多聚甲醛灌注固定,光镜观察海马CA1区神经元;电镜观察各组颞叶皮质神经元及血管内皮细胞的超微结构.结果光镜观察:CVS组海马CA1区神经元肿胀、轮廓不清、排列紊乱,存在空泡样变性及核固缩;Nim组海马CA1区神经元轻度肿胀、排列较乱;GM1-T组的神经元轻度肿胀、排列较规律GM1-P组海马CA1区神经元排列较规律,尼氏小体可见.电镜观察:CVS组神经元损伤明显,线粒体、粗面内质网、核糖体少见,胞内出现空泡样结构,毛细血管周围间隙扩大、管腔内血小板聚集、粘附;Nim组神经元内见空泡样结构;GM1-T组神经元内仅见少量线粒体破坏,毛细血管内膜、基底膜完整;GM1-P组神经元结构正常,血管内皮细胞结构正常.结论本研究结果显示GM1可以明显减轻由于CVS所致的神经元及血管内皮细胞的损害.     

雌激素和姜黄素对海人酸杏仁核点燃大鼠行为学、脑电图及海马神经元损伤的影响

目的了解雌激素和姜黄素对海人酸(kainic acid,KA)杏仁核点燃大鼠癫痫发作的影响。方法给去势的雌性大鼠添加雌激素治疗,添加姜黄素治疗,或添加雌激素和姜黄素治疗,比较各组大鼠致痫后癫痫发作的行为学、脑电图和海马神经元损伤的变化。结果给雌激素治疗的大鼠重型发作(Racine 4/5级)评分最高,而雌激素加姜黄素治疗组评分最低(P<0.05)。脑电图的变化与行为学的改变基本一致。致痫后大鼠注射KA侧海马CA3区、CA4区可见到明显的细胞损伤,而该侧海马CA1区、齿状回区(DG)及对侧海马CA3区、CA1区及DG区神经元损害不明显。雌激素组大鼠双侧海马CA3区均出现加重的神经元损害,姜黄素组及雌激素加姜黄素组大鼠海马注射对侧CA3区存活神经元较雌激素组明显增加(P<0.01)。结论高水平的雌激素可以加重癫痫的发作,给姜黄素治疗可以减轻大鼠海马CA3区神经元损害。     

特异性抑制海马CA1区GABA能神经元NLRP3表达对小鼠TBI后认知障碍的改善作用研究

目的探讨海马CA1区γ-氨基丁酸(GABA)能神经元NOD样受体热蛋白结构域相关蛋白3(NLRP3)基因敲除对小鼠创伤性颅脑损伤(TBI)后认知障碍的改善作用。方法将48只清洁级健康雄性NLRP3flox/flox小鼠按随机数字表法分为假手术+对照病毒组(SV组)、假手术+GABA能神经元NLRP3基因特异性敲除组(SG组)、TBI+对照病毒组(TV组)及TBI+GABA能神经元NLRP3基因特异性敲除组(TG组), 每组12只。其中, TV组、TG组小鼠采用自由落体法构建TBI模型, SV组、SG组小鼠仅行头皮剪开及开骨窗等外科操作、不予打击, SG组、TG组小鼠于TBI造模前21 d于海马CA1区注射腺病毒制备GABA能神经元NLRP3基因特异性敲除模型, SV组、TV组小鼠仅于海马CA1区注射空载病毒作为对照。TBI造模后第30、31天应用新物体识别实验评价各组小鼠的认知功能, 第32～36天应用Morris水迷宫实验评估各组小鼠的学习及记忆功能, 第31天应用在体电生理记录小鼠在新物体识别实验中探索新物体时海马CA1区场电位。上述实验结束后, 处死小鼠并取材, 采用免疫荧光染色...     

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.     

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.     

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.     

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.     

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.     

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.