The endocast of MH1, Australopithecus sediba

The virtual endocast of MH1 (Australopithecus sediba), obtained from high-quality synchrotron scanning, reveals generally australopith-like convolutional patterns on the frontal lobes but also some foreshadowing of features of the human frontal lobes, such as posterior repositioning of the olfactory bulbs. Principal component analysis of orbitofrontal dimensions on australopith endocasts (MH1, Sts 5, and Sts 60) indicates that among these, MH1 orbitofrontal shape and organization align most closely with human endocasts. These results are consistent with gradual neural reorganization of the orbitofrontal region in the transition from Australopithecus to Homo, but given the small volume of the MH1 endocast, they are not consistent with gradual brain enlargement before the transition.     

The brain of LB1, Homo floresiensis

The brain of Homo floresiensis was assessed by comparing a virtual endocast from the type specimen (LB1) with endocasts from great apes, Homo erectus, Homo sapiens, a human pygmy, a human microcephalic, specimen number Sts 5 (Australopithecus africanus), and specimen number WT 17000 (Paranthropus aethiopicus). Morphometric, allometric, and shape data indicate that LB1 is not a microcephalic or pygmy. LB1's brain/body size ratio scales like that of an australopithecine, but its endocast shape resembles that of Homo erectus. LB1 has derived frontal and temporal lobes and a lunate sulcus in a derived position, which are consistent with capabilities for higher cognitive processing.     

Interdigitation of contralateral and ipsilateral columnar projections to frontal association cortex in primates

The combined use of two anterograde axonal transport methods reveals that in the prefrontal association cortex of macaque monkeys, associational projections from the parietal lobe of one hemisphere interdigitate with callosal projections from the opposite frontal lobe, forming adjacent columns 300 to 750 micrometers wide. The finding of separate and alternating ipsilateral and contralateral inputs in the frontal association cortex opens up new possibilities for the functional analysis of this large but unexplored area of the primate brain.     

基于fNIRS的符号和非符号数量加工的脑机制研究

为探讨符号和非符号数量加工的特异性和非特异性问题以及二者间相互转换的神经机制,利用功能性近红外光谱成像技术(fNIRS)对30名成人进行测量,实验中让被试完成数量适应范式任务,结果发现:(1)非符号数量加工主要激活脑区为右顶上叶、右额上回和左右额中回,而符号数量加工则主要在左额中回有显著激活,且只有符号数量加工中出现了距离效应;(2)非符号向符号数量转换由左右顶上叶、左额上回和左右额中回负责,而符号向非符号数量转换则是由左顶上叶和左右额上回负责.研究结果既支持了符号和非符号数量加工的特异性观点,又进一步揭示符号和非符号数量相互转换有着不同的神经机制.     

羊驼头骨外形的研究

采用大体解剖学方法对羊驼头骨的外形进行观察、研究,并与马、牛、骆驼等家畜比较。结果发现:羊驼头骨的主要特征是:颅顶部主要由额骨和顶骨构成;颞骨发达,鳞部为蚌壳状隆起的扁骨;泪骨、鼻骨、额骨和上颌骨交界处形成一圆孔;下颌骨头后下方有一钩状突起;左右枕骨髁背侧窝中各有一大的乳突孔。结论:羊驼的头骨与马、骆驼相似,但有其自己的特征。     

Down's syndrome in adults: brain metabolism

The cerebral metabolic rate for glucose, as measured with positron emission tomography and fluorine-18-labeled 2-deoxy-D-glucose, was significantly higher in four healthy young subjects with trisomy 21 syndrome (Down's syndrome) than the mean rate in healthy young controls. The rate of cerebral glucose utilization in the frontal lobe of a 51-year-old subject with Down's syndrome was significantly lower than the rate in the young subjects with this syndrome, but approximated the rate in middle-aged controls. Thus glucose utilization by the brain appears to be excessive in young adults with Down's syndrome but may decline with age in some brain regions.     

年龄对SAMP8小鼠不同脑区NSF含量的影响

采用免疫印迹技术检测NSF蛋白和内参蛋白GAPDH在SAMP8小鼠背侧海马、腹侧海马、额叶、顶叶和嗅球的表达。结果显示在背海马、额叶和顶叶中,13月龄SAMP8小鼠NSF的相对含量显著高于5月龄(Ps<0.05),且13月龄背侧海马NSF含量也高于9月龄鼠(P<0.05),而在腹海马和嗅球NSF的含量在各个年龄段间差异无统计学意义(Ps>0.05)。以上结果提示在正常衰老过程中,SAMP8小鼠NSF含量在脑内某些区域呈现年龄相关性增高。     

Predatory Dinosaurs from the Sahara and Late Cretaceous Faunal Differentiation

Late Cretaceous (Cenomanian) fossils discovered in the Kem Kem region of Morocco include large predatory dinosaurs that inhabited Africa as it drifted into geographic isolation. One, represented by a skull approximately 1.6 meters in length, is an advanced allosauroid referable to the African genus Carcharodontosaurus. Another, represented by a partial skeleton with slender proportions, is a new basal coelurosaur closely resembling the Egyptian genus Bahariasaurus. Comparisons with Cretaceous theropods from other continents reveal a previously unrecognized global radiation of carcharodontosaurid predators. Substantial geographic differentiation of dinosaurian faunas in response to continental drift appears to have arisen abruptly at the beginning of the Late Cretaceous.     

A role for the macaque anterior cingulate gyrus in social valuation

Complex human social interaction is disrupted when the frontal lobe is damaged in disease, and in extreme cases patients are described as having acquired sociopathy. We compared, in macaques, the effects of lesions in subdivisions of the anterior cingulate and the orbitofrontal cortices believed to be anatomically homologous to those damaged in such patients. We show that the anterior cingulate gyrus in male macaques is critical for normal patterns of social interest in other individual male or female macaques. Conversely, the orbitofrontal cortex lesion had a marked effect only on responses to mildly fear-inducing stimuli. These results suggest that damage to the anterior cingulate gyrus may be the cause of changes in social interaction seen after frontal lobe damage.     

胎鼠额叶皮质神经干细胞的分离培养与分化

目的:探索从胚胎小鼠额叶皮质分离培养神经干细胞的方法。方法:无菌条件下分离孕13～15d小鼠胚胎额叶皮质脑组织,经消化及机械吹打成单细胞后接种于含有B27、bFGF的DMEM/F12培养基,培养扩增;倒置显微镜观察比较生长状况;机械分离法传代;10%血清接种分化;免疫细胞化学方法染色鉴定神经干细胞及其子代细胞的分化方向,结果:培养的部分细胞体外分裂增殖,同时表达神经干细胞特异性抗原nestin,并向神经细胞和胶质细胞分化。结论:小鼠胚脑存在具有多分化潜能的神经干细胞,它们能在体外稳定培养、传代和分化,为细胞替代治疗提供了理想的细胞来源。     

Discovery of the oldest known anthropoidean skull from the paleogene of Egypt

A group of primate fossils newly discovered in the Fayum badlands of Egypt is probably of Eocene age. The site is much older than the localities of previously known Egyptian early Tertiary primates. These finds include a crushed cranium that is the oldest skull found to date of a higher primate. This skull shows four characteristics of higher primates: a catarrhine dental formula, an ectotympanic at the rim of the auditory bulla, a fused frontal bone, and postorbital closure. Details of tooth structure (premolars and molars) and a possibly unfused mandibular symphysis resemble these parts in certain Eocene prosimians.     

Learned behavior of Rhesus monkeys following neonatal bilateral prefrontal lobotomy

Bilateral ablation of dorsolateral frontal cortex in the newborn animal failed to produce the frontal lobe syndrome typical of the adolescent and adult stages. The crucial tests (delayed response, string tests, and discrimination learning) were performed 3 to 4 months postoperatively. At this time, no significant differences between normal animals and animals with prefrontal lesions were found.     

狼颅骨及牙齿形态结构

对捕捉于东北地区的１０只狼颅骨及牙齿形态结构进行了研究并与家养大型狗比较。结果表明：狼颅骨及牙齿外形结构和狗的十分相近，齿式相同；仅在某些方面存在着一些可鉴别差异。根据测量数据分析，狼的颅骨比狗的大１８％左右；颞窝比狗的更宽，有助于容纳更发达的咀嚼肌；听泡形状比狗的更隆突而近球形；牙齿更强壮，排列更紧密等。并就狼与狗颅骨及牙齿的形态结构方面的差别与生活习性及演化之间的关系进行了分析。     

Cognitive memory: cellular and network machineries and their top-down control

A brain-wide distributed network orchestrates cognitive memorizing and remembering of explicit memory (i.e., memory of facts and events). The network was initially identified in humans and is being systematically investigated in molecular/genetic, single-unit, lesion, and imaging studies in animals. The types of memory identified in humans are extended into animals as episodic-like (event) memory or semantic-like (fact) memory. The unique configurational association between environmental stimuli and behavioral context, which is likely the basis of episodic-like memory, depends on neural circuits in the medial temporal lobe, whereas memory traces representing repeated associations, which is likely the basis of semantic-like memory, are consolidated in the domain-specific regions in the temporal cortex. These regions are reactivated during remembering and contribute to the contents of a memory. Two types of retrieval signal reach the cortical representations. One runs from the frontal cortex for active (or effortful) retrieval (top-down signal), and the other spreads backward from the medial temporal lobe for automatic retrieval. By sending the top-down signal to the temporal cortex, frontal regions manipulate and organize to-be-remembered information, devise strategies for retrieval, and also monitor the outcome, with dissociated frontal regions making functionally separate contributions. The challenge is to understand the hierarchical interactions between these multiple cortical areas, not only with a correlational analysis but also with an interventional study demonstrating the causal necessity and the direction of the causality.     

牦牛头骨解剖

运用大体解剖学方法,对１５头牦牛的头骨进行了研究,并与普通牛作了比较。牦牛头骨的主要特征是：头骨短而宽,面骨发达;角突粗而长,额部宽,鼻部较平,颌前部前缘较直;腭部相对较长,腭骨水平部相对较短;腹鼻甲骨发达,鼻前孔和鼻后孔宽。     

Predatory dinosaur remains from madagascar: implications for the cretaceous biogeography of gondwana

Recent discoveries of fossil vertebrates from the Late Cretaceous of Madagascar include several specimens of a large theropod dinosaur. One specimen includes a nearly complete and exquisitely preserved skull with thickened pneumatic nasals, a median frontal horn, and a dorsal projection on the parietals. The new materials are assigned to the enigmatic theropod group Abelisauridae on the basis of a number of unique features. Fossil remains attributable to abelisaurids are restricted to three Gondwanan landmasses: South America, Madagascar, and the Indian subcontinent. This distribution is consistent with a revised paleogeographic reconstruction that posits prolonged links between these landmasses (via Antarctica), perhaps until late in the Late Cretaceous.     

普氏野马头骨观察研究

野马属世界上最珍贵动物之一。本文对新疆野马繁殖中心因心脏病死亡的908号母马头骨进行了观察测量,并与家马头骨进行了比较,发现野马头长与体长之比大于家马头长与体长之比,野马脑区体积在马属动物中仅属中等程度,但脸区却明显大于家马。野马下颌骨较家马的粗大,翼肌窝较家马的深,上、下臼齿列也明显比家马长。以上特点和野马的野生习性相适应。另外908号野马在神经出入颅腔的孔道上与家马差异大,908号野马岩颞骨乳突部下方与鼓室间无茎乳突孔,面神经是和鼓索神经一起自岩鼓裂出颅腔。     

内蒙古五趾跳鼠种下数量分类初步研究

五趾跳鼠是内蒙古境内分布范围最广的鼠种之一。本文根据区内五趾跳鼠的形态差异，通过对其体长、耳长、尾长等5项外部性状特征及头骨14项特征的测量，运用SPSS11．0统计软件主成分分析和系统聚类分析，将所收集到的标本进行数值分类。结果表明，其前6个因子的累积方差贡献率已达到71．423％，通过分析各项测量指标在前6个因子上的因子负荷量最终确定了系统聚类所用的指标。根据聚类分析结果并结合各类群的分布特征将内蒙古地区的五趾跳鼠分为四大类，即应有四个亚种。     

Performance monitoring by the anterior cingulate cortex during saccade countermanding

Consensus is emerging that the medial frontal lobe of the brain is involved in monitoring performance, but precisely what is monitored remains unclear. A saccade-countermanding task affords an experimental dissociation of neural signals of error, reinforcement, and conflict. Single-unit activity was monitored in the anterior cingulate cortex of monkeys performing this task. Neurons that signaled errors were found, half of which responded to the omission of earned reinforcement. A further diversity of neurons signaled earned or unexpected reinforcement. No neurons signaled the form of conflict engendered by interruption of saccade preparation produced in this task. These results are consistent with the hypothesis that the anterior cingulate cortex monitors the consequences of actions.     

驯鹿头髓解剖

运用大体解剖的方法对驯鹿头骨进行了形态学观察，并将其与双峰驼牛、马的头骨进行了比较。结果表明：驯鹿的梨骨特别发达。泪骨，额骨和鼻骨之间围成一个狭长的筛鼻甲窦（部）。下凳骨比牛、马、驼窄而长，下颌角钝圆。泪骨的形态较特殊，颜而形成纵形深窝，泪孔有两个，位于眶缘上，并有尖状的泪突分开，眶缘与颧骨交界处有一个深切迹，无泪囊窝。