神经信息学的原理与展望

神经信息学是研究神经系统信息的载体形式,神经信息的产生、传输、加工、编码、存储与提取机理,以及建立神经数据库系统的科学。它是脑科学,信息科学和计算机科学相互交叉的边缘学科。神经信息学可分为分子神经信息学和系统神经信息学两个层次。神经信息编码可分为神经元脉冲序列的数字编码和突触联结权重编码两种编码方式。对21世纪神经信息学可能取得的新进展进行分析和预测,并论证开展人类神经组计划（HuNP）和建立神经数据库系统的必要性与可行性。对人类神经计划与人类脑计划的异同步,进行比较和讨论。     

日韩两国神经信息学的研究

第八届国际神经信息加工大会 (ＩＣＯＮＩＰ２００１)于２００１年１１月１４日 -１８日在上海举行［１］,这次会议由复旦大学主办 ,会议收到三百余篇论文 ,选出２９５篇作为会议发言和大字报展出 ,来自３１个国家和地区的代表出席会议 ,其中日本代表９５名。Ｉ ＣＯＮＩＰ２００１会后 ,在杭州召开中、日、韩三国神经生物学和神经信息学卫星会［２］ ,中日韩各有１０位代表(５位来自神经生物学 ,５位来自神经信息学 )在会上发言。作者有幸出席这二次会议 ,并代表中方就神经信息学的一个方面作发言。作者在会上遇到不少日韩两国的老朋友 ,据…     

人类蛋白质组计划正式启动

中国科学家首次领衔国际重大协作计划。继人类基因组计划之后又一大规模的国际性科技工程———人类蛋白质组计划(HPP),12月15日在北京宣布正式启动。据悉,这一工程的两个首批行动计划之一将由中国科学家牵头执行,这也是我国科研人员第1次领导重大国际协作计划。国际人类蛋白质组组织(HUPO)主席萨米尔·哈那什出席了今天的会议,并亲自宣布人类蛋白质组计划的正式启动。12月15日同时举行了北京蛋白质组研究中心,即HLPP总部的成立仪式。该中心主任将由中国科学院院士、军事医学科学院副院长贺福初担任。HLPP是国际上第1个人类组织/器官…     

内源性神经干细胞与脑老化的治疗

近十几年研究发现成年人脑神经元可以再生,使人们重新认识老年脑神经细胞的可塑性,它为脑损伤的修复带来新的希望。最新研究表明,神经再生可被调控,是一种新的修复机制。这使得利用内源性神经干细胞治疗老龄相关的神经退行性疾病成为可能。     

人类神经Tau蛋白结构与功能研究进展

Ｔａｕ属微管结合蛋白,对神经细胞的生长发育,物质运输及信息传导起着重要作用。该分子不具有明显的二级结构,其生物学功能的调节功能主要是通过磷酸化和去磷酸化来实现。目前的研究表明,早老性痴呆等疾病与Ｔａｕ分子高级结构的异常改变和功能丧失有关。     

人类表观基因组计划

DNA甲基化所致基因表观遗传学转录失活已经成为肿瘤表观基因组学研究的重点内容。基因组水平上研究DNA甲基化模式对于肿瘤疾病的诊断、治疗和预后判断具有重要的实用价值。为此,人类表观基因组协会(HEC)于2003年宣布正式启动为期五年的人类表观基因组计划(HEP)。HEP的实施标志着人类表观基因组学研究又跨上了一个新台阶。     

神经工程与脑-机接口

神经工程是近年来在生物医学工程领域备受关注的学科发展新方向。它运用神经科学和工程学的方法来分析神经功能并为神经功能缺失与紊乱的修复提供新的解决问题的方案;而脑-机接口则是当前神经工程领域中最活跃的研究方向之一。脑-机接口是在脑与计算机或其他外部设备之间建立的直接的通信和交流通道。在脑-机接口系统中,具有特定模式的脑信号携带着受试者希望表达的意愿,计算机将接收到的脑信号转换成相应的控制命令,于是那些有运动障碍的残疾人就可以利用脑-机接口系统来实现与外界的交流与对外部设备的控制。在基于脑电信号的脑-机接口系统中,受试者产生的脑信号大致可以分为内源性（endogenous）和外源性（exogenous）两类。其中外源性的成分主要取决于外部物理刺激（视觉、听觉或触觉）的参数而与认知行为无关;而内源性成分则主要由认知行为产生而与外部的物理刺激无关。在许多情况下,脑－机接口中的瞬态诱发电位通常都同时包含着内源性和外源性两种成分。寻找新的脑－机接口模式使之能显著提升记录脑电信号中的内源性与外源性成分在脑－机接口研究中具有重要意义。本文中将介绍一种基于运动起始时刻（motion—onset）的新的脑-机接口实验范式。本文的最后还探讨了脑－机接口未来发展的趋势与展望。     

第一届脑功能与脑疾病学术研讨会通知

<正>2010年10月24日-27日,北京由中国科学院生物物理研究所脑与认知科学国家重点实验室、中国生物物理学会神经生物物理与神经信息学专业委员会和中国科学院脑功能与脑疾病重点实验室(中国科技大学)     

第一届脑功能与脑疾病学术研讨会通知

<正>2010年10月24日-27日,北京由中国科学院生物物理研究所脑与认知科学国家重点实验室、中国生物物理学会神经生物物理与神经信息学专业委员会和中国科学院脑功能与脑疾病重点实验室(中国科技大学)联合主办的"第一届脑功能与脑疾病学术研讨会"将于2010年在北京召开。     

人脑醛糖还原酶的纯化和一些基本性质

使用DEAE纤维素柱层析、PBE-94层析聚焦、NADP~+-Sepharose 4B亲合层析及SephadexG-100凝胶过滤分离纯化了人脑醛糖还原酶。在DEAE层析中,用咪唑-HCI缓冲液替代了磷酸缓冲液,改善了分离效果。在聚丙烯酰胺及SDS聚丙烯酰胺凝胶电泳中,纯化的人脑醛糖还原酶均呈一条区带。它的pI为5.6,最适pH为6.5,分子量为36,000,底物特异性和氨基酸组成与其它哺乳动物的醛糖还原酶有相似性。开链式醛糖是醛糖还原酶的真正底物,它在开链式和半缩醛的平衡体系中占比例极小,因而推知醛糖还原酶对此底物有很高的K_(cat)和K_(cat)/K_m值,能有效地将它们还原成相应的醇。     

人脑胶质瘤细胞质膜的制备和鉴定

 本文介绍以手术摘除的人脑胶质瘤为标本,应用蔗糖梯度离心建立的一种较为简便的人脑胶质瘤细胞质膜制备法。经标记酶测定,化学组成分析及电镜检查,证实质膜具有一定的纯度。质膜中5’-核苷酸酶(质膜标记酶)活性为全匀浆的8.2倍,其它亚细胞组份污染较小。质膜收量为24.6％。生化测定还显示质膜5’-核苷酸酶活性随着胶质瘤恶性程度升高而下降。     

TAURINE IN THE BRAIN AND LIVER OF THE DEVELOPING HUMAN AND MONKEY

—The concentrations of taurine in brain and liver from human fetuses (2nd trimester) and adults and from Rhesus monkeys from mid-gestation, through birth and neonatal life to maturity have been measured. The concentration of taurine in human and monkey fetal brain was 4-5-fold higher than that in adult monkey brain. In human fetal brain the concentration of taurine decreased linearly with increasing crown-rump length (r=−0·75; P < 0·001). In fetal monkey brain, no correlation with gestational age was found. After birth, the concentration of taurine in monkey brain decreased linearly with increasing age (r=−0·96; P < 0·001) until values comparable to those found in the adult were reached 8-9 months after birth, approximately the end of weaning. The concentration of taurine in liver both from fetal humans and from fetal monkeys was approximately twice that in mature liver. Concentrations of taurine similar to those found in adult liver were reached within a few days of birth, compared to several months for brain. These results suggest that taurine may be associated with brain development in addition to any functional role it may play in the mature brain.     

THE N-ACETYL-β-d-HEXOSAMINIDASES OF CALF AND HUMAN BRAIN

Abstract— Multiple forms of calf brain N -acetyl-β-hexosaminidases (β-2-acetamido-2- deoxy- d -glucoside acetamidodeoxyglucohydrolase EC 3.2.1.30) were separated on starch gel electrophoresis at pH 5.8. The organ specific electrophoretic patterns did not depend on the cell fraction studied. Much of the activity is only separated with difficulty from particulate matter. Two major and one minor component were separated on DEAE-cellulose chromatography at pH 5.8. Each component had both N -acetyl-β-galactosaminidase and N -acetyl-β-glucosaminidase activity. The ratio of these two activities was unaffected by the presence of N -ethylmaleimide or dithiothreitol. The forms were also examined by isoelectric focusing when at least four components were recognized: isoelectric at 4.9, 6.0, 6.3 and 6.8. Interconversion of the 4.9 form to that isoelectric at pH 6.0 was noted during vacuum dialysis. Samples from normal human brain and from cases of Tay-Sachs disease were also examined and the results compared.     

THE EFFECT OF GROWTH AND DEVELOPMENT ON THE PHOSPHOLIPIDS OF THE HUMAN BRAIN

Abstract— The phospholipid content and composition of the different regions of the developing human brain were studied. Brains from 25 fetuses and 9 infants, aged 13 weeks gestation to 26 months, were analysed. The concentration of total lipid-P was highest in the brain stem and lowest in the cerebellum at any age. Compared with the forebrain or brain stem, the cerebellum had a sharp phospholipid growth spurt between 3 months before and 6 months after birth. Before birth, the phospholipid pattern was similar in each part of the brain, with choline phosphoglycerides as the major phospholipid. After birth, the pattern in the brain stem changed further and ethanolamine phosphoglycerides became the dominant phospholipid, while in the other two there was little change. In all parts of the brain the proportion of sphingomyelin increased. The relative proportion of serine and inositol phosphoglycerides remained almost constant throughout the whole period of development. The possible significances of the changes in the phospholipids in neurological development are discussed.     

THE HUMAN CIRCADIAN CLOCK AND AGING

The suprachiasmatic nucleus (SCN) of the hypothalamus is implicatedin the timing of a wide variety of circadian processes. Since the environmentallight-dark cycle is the main zeitgeber for many of the rhythms, photic informationmay have a synchronizing effect on the endogenous clock of the SCN by inducingperiodic changes in the biological activity of certain groups of neurons.By studying the brains obtained at autopsy of human subjects, marked diurnaloscillations were observed in the neuropeptide content of the SCN. Vasopressin,for example, one of the most abundant peptides in the human SCN, exhibiteda diurnal rhythm, with low values at night and peak values during the earlymorning. However, with advancing age, these diurnal fluctuations deteriorated,leading to a disrupted cycle with a reduced amplitude in elderly people. Thesefindings suggest that the synthesis of some peptides in the human SCN exhibitsan endogenous circadian rhythmicity, and that the temporal organization ofthese rhythms becomes progressively disturbed in senescence. (ChronobiologyInternational, 17(3), 245–259, 2000)     

REGIONAL DISTRIBUTION OF MONOAMINES AND THEIR METABOLITES IN THE HUMAN BRAIN

Abstract— Noradrenaline (NA), dopamine (DA). 5-hydroxytryptamine (5-HT), 4-hydroxy, 3-methoxy-phenylethylene glycol (MHPG), homovanillic acid (HVA), 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindolylacetic acid (5-HIAA) were measured in twenty areas of post-mortem brain from ten psychiatrically and neurologically normal patients. There was a marked difference, which did not appear to be related to sex, medication, cause of death or time between death and dissection, in amine and metabolite concentrations between brains. In the cortex, 5-HT, MHPG, HVA. DOPAC and S-HIAA were approximately even in their distribution; NA and DA could not be detected. In sub-cortical areas there were clear differences in the distribution of the three amines accompanied by less marked differences in the distribution of their respective metabolites.     

THE EVOLUTIONARY HISTORY OF CETACEAN BRAIN AND BODY SIZE

Cetaceans rival primates in brain size relative to body size and include species with the largest brains and biggest bodies to have ever evolved. Cetaceans are remarkably diverse, varying in both phenotypes by several orders of magnitude, with notable differences between the two extant suborders, Mysticeti and Odontoceti. We analyzed the evolutionary history of brain and body mass, and relative brain size measured by the encephalization quotient (EQ), using a data set of extinct and extant taxa to capture temporal variation in the mode and direction of evolution. Our results suggest that cetacean brain and body mass evolved under strong directional trends to increase through time, but decreases in EQ were widespread. Mysticetes have significantly lower EQs than odontocetes due to a shift in brain:body allometry following the divergence of the suborders, caused by rapid increases in body mass in Mysticeti and a period of body mass reduction in Odontoceti. The pattern in Cetacea contrasts with that in primates, which experienced strong trends to increase brain mass and relative brain size, but not body mass. We discuss what these analyses reveal about the convergent evolution of large brains, and highlight that until recently the most encephalized mammals were odontocetes, not primates.