人羊膜间充质干细胞联合神经生长因子及纤维蛋白胶移植治疗大鼠脑损伤

背景：以往对间充质干细胞分化的报道多为体外培养，甚少涉及宿主体内间充质干细胞的分化及辅助因子对其分化的影响。 目的：探讨人羊膜间充质干细胞移植对脑损伤大鼠行为学和空间学习记忆能力的影响，以及神经生长因子、纤维蛋白胶在人羊膜间充质干细胞移植中的作用。 设计、时间及地点：细胞学体内对照观察，于2006-07/2007-01在郑州大学医学院完成。 材料：正常足月剖腹产胎儿的胎盘由郑州大学第一附属医院妇产科提供。Wistar大鼠90只，随机分为5组：假手术组、模型对照组、细胞移植组、细胞+神经生长因子组、细胞+纤维蛋白胶组，18只/组。 方法：无菌条件下钝性分离胎盘脐带面的羊膜，经胰酶消化制成单细胞悬液，贴壁法纯化扩增，传至第3代的人羊膜间充质干细胞备用。假手术组只开颅钻孔不进行硬膜外撞击，其余4组大鼠均采用自由落体硬膜外撞击法建立脑损伤模型。造模1 d后，模型对照组在损伤区分点注射生理盐水40 μL；细胞移植组注射含1×107个人羊膜间充质干细胞的等量生理盐水；细胞+神经生长因子组在细胞移植组基础上于造模后连续2周每日腹腔注射0.5 μg神经生长因子；细胞+纤维蛋白胶组注射人羊膜间充质干细胞与纤维蛋白胶混合液40 μL；假手术组不行细胞移植。 主要观察指标：行为学评分，Morris水迷宫检测潜伏期，脑组织切片免疫组化染色检测神经元特异性烯醇化酶和胶质纤维酸性蛋白的表达。 结果：移植后7 d，与模型对照组比较，细胞移植组、细胞+神经生长因子组、细胞+纤维蛋白胶组行为学评分均明显升高，但细胞移植组升高幅度明显低于后2组（F=155.322，P < 0.05）。移植后3周，与模型对照组比较，细胞移植组、细胞+神经生长因子组、细胞+纤维蛋白胶组潜伏期均明显缩短，但细胞移植组缩短幅度明显小于后2组（F=22.678，P < 0.05）。移植后4周，人羊膜间充质干细胞能够在大鼠损伤脑组织内分化，与神经生长因子、纤维蛋白胶混合移植可提高神经元特异性烯醇化酶和胶质纤维酸性蛋白的阳性表达率（F=705.406，F=424.884，P < 0.05）。 结论：人羊膜间充质干细胞可改善脑损伤大鼠行为能力及空间学习记忆能力，分化后能表达神经元特异性烯醇化酶和胶质纤维酸性蛋白，神经生长因子与纤维蛋白胶均可增强细胞移植治疗效果。     

多种生长分化因子体外联合诱导人脐血间充质干细胞向肝样细胞的分化☆

背景：肝细胞自身增殖能力有限,近几年关于各类干细胞向肝细胞分化的成功报道很多,包括胚胎干细胞、骨髓细胞、胰腺干细胞、神经干细胞及各种来源的间充质干细胞等。 目的：探讨应用多种生长分化因子体外联合诱导人脐血间充质干细胞向肝样细胞分化的可行性。 设计、时间及地点：细胞学体外观察,于2005-10/2006-04在暨南大学医学院血液病研究所完成。 材料：胎儿脐带血来源于顺产及剖腹产的健康孕妇,由暨南大学第一附属医院产科提供,产妇均签署知情同意书。 方法：体外分离培养人脐血间充质干细胞,胰酶-EDTA消化传代。取传至第3代细胞,按5×104/cm2接种,48 h后去除原培养基,PBS洗涤后,第1阶段用含地塞米松、肝细胞生长因子、表皮生长因子、ITS的F12培养基诱导2周,第2阶段用含地塞米松、肝细胞生长因子、致瘤素M、ITS的F12培养基继续诱导2周。 主要观察指标：流式细胞仪检测脐血间充质干细胞表面标志的表达,RT-PCR检测肝细胞相关基因的表达,免疫荧光染色检测肝细胞相关蛋白的表达,透射电镜观察细胞超微结构。 结果：培养的细胞不表达造血细胞系标志CD34,CD45,CD14;亦不表达CD54,CD49f,HLA-DR;部分表达内皮细胞标志CD106;强表达CD29,CD44及CD13。诱导4周后,甲胎蛋白、白蛋白、ck-18及tat基因均呈阳性表达;免疫荧光染色显示细胞浆中甲胎蛋白、白蛋白、ck-18均呈阳性;细胞胞浆中出现脂滴及糖原的沉积,细胞表面有微绒毛,出现双核细胞,初步具备了肝细胞的超微结构特征。 结论：联合应用地塞米松、肝细胞生长因子、表皮生长因子、致瘤素M及ITS等多种生长分化因子,可在体外成功诱导人脐血间充质干细胞向肝样细胞分化。     

骨髓间充质干细胞移植在大鼠急性肝损伤组织中的定植能力

背景：目前对于移植后的骨髓间充质干细胞在肝组织中的分化途径以及能够在多大程度上修复损伤的肝细胞等问题,尚未达成统一共识。 目的：观察经尾静脉移植的骨髓间充质干细胞在急性肝损伤大鼠肝组织中的定植分化情况。 设计、时间及地点：细胞学体内对照观察,于2007-12/2008-06在兰州大学中心实验室地点完成。 材料：清洁级6~8周龄雄性SD大鼠47只,取5只用于制备骨髓间充质干细胞,剩余42只随机分为3组：肝正常细胞移植组15只、肝损伤细胞移植组14只、肝损伤盐水对照组13只。 方法：肝损伤细胞移植组、肝损伤盐水对照组大鼠通过腹腔注射D-氨基半乳糖建立急性肝损伤模型。造模后24 h,肝损伤细胞移植组、肝正常细胞移植组经尾静脉注入BrdU标记的第3代大鼠骨髓间充质干细胞悬液1 mL,含(1.5~2.0)×106个细胞;肝损伤盐水对照组大鼠同法注入等量生理盐水。 主要观察指标：移植后肝功能恢复情况,肝脏免疫组织化学检测结果。 结果：与造模后24 h比较,移植后2,3周肝正常细胞移植组、肝损伤盐水对照组血清谷丙转氨酶活性无明显变化（P > 0.05）;肝损伤细胞移植组血清谷丙转氨酶活性明显降低(P < 0.05),肝功能恢复较好。与肝正常细胞移植组比较,肝损伤细胞移植组Brdu+细胞数明显增多(P < 0.01),多分布在汇管区及中央静脉周围,但随着时间延长BrdU+细胞数逐渐减少。 结论：经尾静脉移植的骨髓间充质干细胞可促进急性肝损伤大鼠的肝功能恢复,并能够在受损肝脏及正常肝脏中定植分化,且定植与分化的程度可能与肝脏损伤程度有关。     

大鼠骨髓间充质干细胞体外诱导为肝细胞样细胞***

背景：目前体外诱导骨髓间充质干细胞分化为肝细胞样细胞的研究主要集中在不同诱导因子的诱导作用,而微环境的诱导作用研究较少。 目的：观察肝细胞生长因子、胎肝细胞对骨髓间充质干细胞体外诱导分化为肝细胞样细胞的影响。 方法：采用密度梯度离心法分离大鼠骨髓间充质干细胞,反复贴壁法纯化扩增骨髓间充质干细胞;采用Ⅰ型胶原酶消化法分离孕3周大鼠胚胎肝脏细胞,差速贴壁法纯化肝脏细胞;阴性对照组骨髓间充质干细胞只加入含体积分数为10%胎牛血清的L-DMEM培养基。诱导组在阴性对照组基础上加入一定浓度肝细胞生长因子或者与胎肝细胞共培养进行诱导分化。 结果与结论：诱导组白蛋白、甲胎蛋白水平均高于非诱导组(P < 0.01),诱导组糖原染色阳性,免疫细胞化学染色CK-18阳性,而非诱导组糖原染色、CK-18均阴性。结果显示肝细胞生长因子和胎肝细胞均可在体外诱导大鼠骨髓间充质干细胞分化为具有肝细胞样细胞表型和功能的类肝细胞。     

体外诱导羊膜来源间充质干细胞分化为血管内皮细胞

背景：羊膜来源间充质干细胞植入机体不同类型组织后是否可以分化为相应组织靶细胞呢？ 目的：检测血管内皮细胞生长因子在体外诱导人羊膜间充质干细胞分化为血管内皮细胞的可行性。 方法：分离培养羊膜间充质干细胞,鉴定其表面抗原表达,用含体积分数2%胎牛血清以及50 μg/L血管内皮生长因子的条件培养基诱导,诱导后细胞通过内皮细胞标志物血管内皮生长因子受体2以及v-WF染色鉴定。 结果与结论：羊膜间充质干细胞表面抗原CD29、CD44、CD105阳性,CD34、CD45、CD106以及HLA-DR阴性。诱导后细胞形态明显改变,内皮细胞标志物血管内皮细胞生长因子受体2以及v-WF染色结果阳性。提示羊膜间充质干细胞在体外具有分化为血管内皮细胞的能力。     

脐带源间充质干细胞与大鼠胰腺细胞共培养向胰岛样细胞分化及移植治疗1型糖尿病★

背景：脐带Wharton’s Jelly中间充质干细胞可以向胰岛样细胞诱导分化。 目的：验证脐带源间充质干细胞与大鼠胰腺细胞共培养向胰岛样细胞诱导分化的可能性，并观察移植后对糖尿病大鼠血糖的影响。 方法：分离、诱导、传代脐带Wharton’s Jelly中间充质干细胞，再与大鼠胰腺细胞共培养，诱导成胰岛细胞团样组织。将大鼠分为3组，正常对照组不进行移植及造模；模型组仅制备糖尿病大鼠模型；实验组造模后将胰岛样细胞移植入糖尿病大鼠肾脏包膜。 结果与结论：脐带Wharton’s Jelly细胞培养中有细胞从组织块中爬出，第7天形态发生变化，贴壁细胞部分变成梭形。分离培养的细胞表达具有间充质干细胞表面特有标志CD44、CD29、CD105，不表达CD34、CD45、CD14。诱导第7，10天PDX-1及人胰岛素强染色；胰岛素及C-肽浓度较单纯培养组明显升高；PDX-1及人胰岛素mRNA诱导第7、10天较高表达。移植第1周大鼠尾尖血糖链脲佐菌素实验组明显低于模型组(P < 0.01)，但明显高于正常照组(P < 0.01)。8周链脲佐菌素实验组肾脏被膜下发现胞核染棕色染色的Brdu阳性、胞浆棕色染色的胰岛素阳性细胞。结果表明，脐带Wharton’s Jelly中存在脐带源间充质干细胞，与大鼠胰腺细胞共培养可促进间充质干细胞向胰岛样细胞诱导分化，移植入糖尿病大鼠肾脏被膜下，可显著降低糖尿病大鼠血糖。     

人脐带间充质干细胞体外长期培养及向肝样细胞的分化

目的：观察人脐带间充质干细胞体外长期培养的生物学特性,探讨其向肝样细胞分化的可能性。 方法：脐带来源于天津市第三中心医院住院的健康足月产妇,采用酶消化法分离培养人脐带间充质干细胞,待细胞生长至80%~90%融合时传代。取传至第9代细胞接种于12孔板内,调整细胞浓度为5×1010 L-1,加入含肝细胞生长因子、成纤维生长因子4、抑瘤素的DMEM培养基,诱导28 d。MTT法测定细胞生长活性,流式细胞仪检测细胞周期,免疫细胞化学及流式细胞仪鉴定细胞表型;免疫细胞化学染色鉴定诱导后肝细胞特异表面标志物的表达,以及糖原染色结果。 结果：从人脐带中分离得到的间充质干细胞贴壁生长,形态类似于成纤维细胞,80%以上处于G0/G1期,具有良好的生长活性,可在体外稳定传代20次以上;CD29,CD90,CD105,Vimentin呈阳性表达,基本不表达造血细胞标志CD34和内皮细胞标志CD31。随诱导时间的延长,圆形细胞逐渐增多,形态似肝细胞;诱导1周时细胞开始表达肝细胞表面标志物甲胎蛋白、细胞胶蛋白18、细胞胶蛋白19;诱导3周时开始表达成熟肝细胞标志白蛋白;诱导4周时白蛋白表达增强,且诱导细胞糖原染色呈阳性。 结论：从人脐带中可成功分离出间充质干细胞,实现体外长期培养,并可诱导分化为肝样细胞。     

骨髓间充质干细胞移植急性放射性肝损伤大鼠α-平滑肌肌动蛋白的表达*☆

背景：放射性肝损伤极大限制了放射治疗的临床应用。研究发现,肝损伤环境是骨髓间充质干细胞适宜的分化环境,提示通过骨髓间充质干细胞移植治疗放射性肝损伤成为可能。 目的：验证骨髓间充质干细胞移植对大鼠急性放射性肝损伤中α-平滑肌肌动蛋白表达水平的影响。 方法：分离培养雄性大鼠的骨髓间充质干细胞,取P3代细胞作为移植细胞。建立雌性SD大鼠急性放射性肝损伤模型。随机分成两组,在放疗结束后4 h内,干预组经尾静脉输注骨髓间充质干细胞悬液,对照组输注等量生理盐水。采用免疫组织化学技术检测肝脏组织中的α-平滑肌肌动蛋白的阳性表达水平;采用原位杂交技术检测肝脏组织中性别决定基因Y (SrY)的存在;光镜观察肝脏组织的病理形态学变化。 结果与结论：干预组大鼠肝右叶中α-SMA的平均阳性表达率低于对照组(P < 0.05)。干预组大鼠肝右叶检测到携带SrY的阳性细胞多于肝脏左叶(P < 0.05),对照组中未检测到携带SrY的阳性细胞。干预组大鼠肝右叶的损伤程度比对照组轻。结果证实,急性放射性肝损伤可以诱导雄性大鼠的骨髓间充质干细胞的“归巢”,骨髓间充质干细胞对大鼠急性放射性肝损伤中ɑ-平滑肌肌动蛋白表达水平有下调作用。     

肝纤维化大鼠血清体外诱导骨髓间充质干细胞向肝细胞的分化

背景：近年来临床运用骨髓间充质干细胞移植治疗晚期肝纤维化取得了较好疗效,但由于肝源稀少,骨髓干细胞体外分化为成熟肝细胞的技术仍然不成熟。 目的：探讨骨髓间充质干细胞体外诱导其分化为肝细胞的可行性。 方法：构建大鼠肝纤维化模型,分离、纯化并鉴定大鼠骨髓间充质干细胞,制备正常及肝纤维化大鼠血清,取第3代骨髓间充质干细胞分组培养,分别加入以下培养基：DMEM+体积分数10%胎牛血清;肝细胞生长培养基(HGM)+体积分数5%胎牛血清;HGM+5%正常大鼠血清;HGM+5%肝纤维化大鼠血清;HGM+5%肝纤维化大鼠血清+25 μg肝细胞生长因子。观察各组细胞形态变化,MTT法测定细胞生长曲线,采用Realtime-PCR检测甲胎蛋白和细胞角蛋白18的表达,溴甲酚绿法检测上清液中白蛋白水平,ELISA法检测培养上清液中转化生长因子β1表达。 结果与结论：正常大鼠血清能促进骨髓间充质干细胞的增殖;肝纤维化大鼠血清对骨髓间充质干细胞促增殖作用最好,且能有效诱导其向肝细胞分化,联合使用肝细胞生长培养基能提高分化率。     

人羊膜间充质干细胞移植治疗帕金森病模型大鼠的疗效评价

目的观察不同途径移植人羊膜间充质干细胞(human amniotic mesenchymal stem cells,h AMSCs)对帕金森病(Parkinson’s disease,PD)模型大鼠的生物学效应及其在体内的分化。方法采用胰蛋白酶-胶原酶消化法分离hAMSCs,流式细胞术分析表型。40只雌性Wistar大鼠随机分为假手术组、模型组、hAMSCs静脉移植组和原位移植组。采用单侧前脑内侧束(MFB)注射6-羟基多巴胺建立PD大鼠模型。通过舌下静脉或于MFB原位移植3×105个hAMSCs。腹腔注射阿朴吗啡诱导旋转观察大鼠的行为变化,免疫荧光染色法检测人细胞核抗原及神经元微管结合蛋白(microtubule-associated protein 2,MAP-2)的表达,免疫组化染色法检测酪氨酸羟化酶(tyrosine hydroxylase,TH)的表达。结果与模型组比较,hAMSCs静脉移植组和原位移植组大鼠旋转次数均明显减少(均P<0.05),前者行为学改善可持续至移植后6 w,后者则至8 w;免疫荧光染色显示,hAMSCs在原位移植区可存活至少12 w,并表达MAP-2;免疫组化染色显示静脉和原位移植hAMSCs均可上调PD模型大鼠黑质TH表达,但后者强于前者。结论 hAMSCs能改善PD模型大鼠的运动行为,原位移植优于静脉移植,其机制可能与上调黑质TH表达有关。hAMSCs可在原位移植部位分化为多巴胺能神经元样细胞。     

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.