The sequence in appearance and disappearance of impressiones gyrorum cerebri and cerebelli

We investigated the sequence and the intensity in the appearance and the disappearance of the impressiones gyrorum cerebri and cerebelli, of juga cerebralia and cerebellaria and of juga cerebellaria interlobularia in the collection of 34 macerated and disarticulated skull bones from the newborn to 30 years of age (68 specimens/halves of skulls) and 19 skulls in the period from 30 to 80 years of age (38 specimens). Juga cerebralia on the squama of the temporal bone and cerebral lamina of the frontal bone appeared already in the course of the first year of life, much earlier than cited in the literature. The intensity of the development of juga cerebralia increased to the third decade. After that age, the intensity decreased gradually, and the juga cerebralia disappeared completely in parietal bones, in the cerebral fossae of the occipital bones and finally in most cases also on the cerebral lamina of the frontal bones. Juga cerebellaria and impressiones gyrorum cerebelli appeared in the middle of the second year of age and persisted to the ten years of age, which coincides with the closure of the fissures among the parts of the occipital bone. Jugum cerebellare intersemilunare appeared in the first year of life and persisted in its complete length, or interrupted in different sections of its course, during the whole life. The intensity in appearance of juga is partly influenced by the increasing thickness of the diploe.     

Aberrant growth of maxillary canine teeth in male babirusa (genus Babyrousa)

A worldwide survey of babirusa skulls curated in museum and private collections located 431 that were from adult males and had retained at least one maxillary canine tooth. Eighty-three of these skulls were identified as exhibiting aberrant maxillary canine tooth growth. Twenty-four of the skulls represented babirusa from Buru and the Sula Islands, and forty-five skulls represented babirusa from Sulawesi and the Togian Islands. The remaining series of fourteen babirusa skulls originally came from zoo animals. Fifteen skulls showed anomalous alveolar and tooth rotation in a median plane. Twenty-nine skulls had maxillary canine teeth that did not grow symmetrically towards the median plane of the cranium. Fourteen skulls showed evidence that the tips of one or both maxillary canine teeth had eroded the nasal bones. Twenty-one skulls had maxillary canine teeth that had eroded the frontal bones. The teeth of two skulls had eroded a parietal bone. One skull had two maxillary canines arising from an adjacent pair of alveoli on the left side of the cranium. Three skulls exhibited alveoli with no formed maxillary canine teeth in them. Analysis suggested that approximately 12% of the adult male babirusa in the wild experience erosion of the cranial bony tissues as a result of maxillary canine tooth growth. There was no skeletal evidence that maxillary canine teeth penetrate the eye.     

Craniometry of cranial vault bones in newborn infants

10 craniometric measurements of the skull bones' fornix have been performed on 89 dried infant skulls. The authors have shown that the craniometric variability of the skull bone's fornix is connected with the skull length rather than with its height. The skull length is determined mostly by the squama of the temporal bone and occipital squama. The shape of the skull vault is determined mainly by parietal bone and squama of the frontal bone. Parietal bones shut unpaired fontanelle, but the remaining bones, under investigation, contribute to the closure of anterolateral and postero-lateral fontanelle.     

Kinematics of cranial vault growth in rabbits

To characterize mathematically the spatial rearrangement of cranial vault bones of the rabbit during growth, a longitudinal study was undertaken from age 4-20 weeks. Initially, at least three nonlinear tantalum bone markers were implanted in the parietal, frontal, and the combined nasal bones. Thereafter, the animals were followed regularly with roentgen stereophotogrammetrical analysis. The parietal bones were found to rotate laterally upward (3 degrees), while the frontal bones rotated downward (2 degrees) relative to their contralaterals. The frontal bones rotated rostrally upward (12 degrees) and outward (3 degrees) as well as laterally downward (5 degrees) in relation to the parietal bones. Due to the morphology of the rabbit head, the examination positioning used in this study, and the direction of the growth process, growth at the coronal suture correlated fairly well with longitudinal axis translations; but the growth at the frontonasal suture relative to the frontal bones was directed about 45 degrees downward. This points to the importance of the bone-marker positioning, so that their connecting line is directed along the axis of growth. Also, this approach makes it possible to obtain new information on the development and treatment of craniofacial aberrations.     

An ectocranial lesion on the Middle Pleistocene human cranium from Hulu Cave, Nanjing, China

The earlier Middle Pleistocene human partial cranium from Hulu Cave, Tangshan, Nanjing (Hulu 1) exhibits an ectocranial lesion which covers most of the anterior neurocranium, largely between the temporal lines and extending from the supratoral sulcus to the anterior parietal bone. The endocranial surfaces and the remainder of the cranium (upper facial skeleton, lateral frontal bone, posterior parietal bones, and mid-occipital bone) are normal. The healed lesion exhibits both resorption and the laying down of new bone. Differential diagnosis suggests that the lesion was caused by either trauma (broad compressive trauma, tensile trauma to the scalp, or partial scalp removal) or burning (with damage to scalp and superficial neurocranium). Dietary deficiencies, infection, and neoplastic disorders do not fit the lesion characteristics. The Hulu 1 specimen therefore joins a growing sample of Pleistocene Homo remains with nonfatal and nontrivial disorders.     

Nasal region polymorphism frequencies in the FrankfurtPan troglodytes verus collection

The results of a morphometric study on the mid-facial region in a collection of 278Pan troglodytes verus skulls are reported. Upwardly divergent nasal bones were found in 35 of the 124 specimens (28.2%) in which this feature could be analyzed. Appreciable separation (1 cm. or more) between nasion and glabella characterized 13 of the 154 skulls (8.4%) in which both these osteometric points could be observed. These findings document the wide ranges of variation that are normally to be found in modest-sized population samples of hominoid primates, and point to the inherent unreliability of cladistic analyses based on the hypothesis that hominoid primate taxa are monomorphic for these character states in the nasal region.     

Analysis of a bone assemblage made by chimpanzees at Gombe National Park, Tanzania

Chimpanzee hunting provides information on prey characteristics and constraints acting on a large-bodied primate lacking a hunting technology, and has important implications for modeling hunting by fossil hominids. Analysis of the remains of five red colobus monkeys captured and consumed by Gombe chimpanzees in a single hunting bout provides one of the first opportunities to investigate the characteristics of prey bones surviving chimpanzee consumption. Four of the five individuals (an older infant, two juveniles and one subadult) were preserved in the bone assemblage; a neonate was entirely consumed. Cranial and mandibular fragments had the highest survivorships, followed by the scapulae and long bones. Post-cranial axial elements had the lowest survivorships. A high percentage (80%) of the long bones and ribs surviving consumption were damaged, most commonly through crenulation and step fracturing of bone ends. One of two partially reconstructed crania preserves a canine puncture through its left parietal. Proposed characteristics of faunal assemblages formed through chimpanzee-like hunting include small modal prey size, limited taxonomic diversity, a high proportion of immature individuals and a high frequency of skull bones. These characteristics would not uniquely identify hunting by fossil primates in the geological record, necessitating a contextual approach to diagnose hunting by hominids not forming an archeological record.Hominid utilization of vertebrate tissue is first unambiguously documented at 2.5 m.y.a. Rather than representing a strict "scavenging phase" in the evolution of hominid-prey interactions, Oldowan hominid carnivory may represent the overlay of large mammal scavenging on a tradition of small mammal hunting having a low archeological visibility.     

Strain patterns in the horncores, cranial bones and sutures of goats (Capra hircus) during impact loading

The design of bovid horns and skulls for the function of head-to-head fighting has been well studied using mechanical and kinematic analyses, but actual strain measurements from the horncores, cranium and sutures during impact loading have never been made. During in vitro impact loading of one or both horns on the heads of female domestic goats, principal strains were measured from the surfaces of the horncore bases, frontal and parietal bones, and interfrontal and frontoparietal sutures. Impact produced a bending moment at the bases of the horncores, with compressive strains on the posterior surfaces more than doubling the anterior tensile strains. These ratios of compression to tension exceed our predictions (and those in the literature) based on curved beam theory. Principal strains in the cranial bones dropped by as much as 50% crossing the sutures, which acted like springs or hinges to allow cranial bone movement. Sutures also experienced very high strain magnitudes, being more than 10 times greater than those of the surrounding cranial bones. Sutural strains during impact loading of the horns also greatly exceeded the strain levels recorded during mastication in other studies. The decrease in strain between adjacent cranial bones across a suture and the large strains at the sutures indicate that the sutures function as shock absorbers during impact.     

顶骨凹陷变薄的形态学研究

本文从1480个颅骨中发现顶骨凹陷变薄的有16例。对其性别、年龄、颅形以及凹陷的形状、深度和骨质厚度作了观测,利用骨磨片和X线摄片对凹陷部分骨质进行了研究。结果表明此种凹陷均见于老年人,多数为双侧性。凹陷是由外板内凹而成,不涉及周围组织。X线侧位片显示凹陷处有宽带状低密度阴影。骨组织磨片显示在骨改建过程中,出现未满围骨单位增多,骨陷窝闭塞,造成局部的骨萎缩。     

国人颅骨弧弦周长的测量及其性别的判别分析

本文对青岛地区出土、已知性别的成年颅骨249个(男142,女107)进行了弧、弦、周长的测量,计算了有关指数,对额、顶、枕骨的弧长作了比较和分型,并用判别分析方法鉴定颅骨性别。     

Tissue origins and interactions in the mammalian skull vault.

During mammalian evolution, expansion of the cerebral hemispheres was accompanied by expansion of the frontal and parietal bones of the skull vault and deployment of the coronal (fronto-parietal) and sagittal (parietal-parietal) sutures as major growth centres. Using a transgenic mouse with a permanent neural crest cell lineage marker, Wnt1-Cre/R26R, we show that both sutures are formed at a neural crest-mesoderm interface: the frontal bones are neural crest-derived and the parietal bones mesodermal, with a tongue of neural crest between the two parietal bones. By detailed analysis of neural crest migration pathways using X-gal staining, and mesodermal tracing by DiI labelling, we show that the neural crest-mesodermal tissue juxtaposition that later forms the coronal suture is established at E9.5 as the caudal boundary of the frontonasal mesenchyme. As the cerebral hemispheres expand, they extend caudally, passing beneath the neural crest-mesodermal interface within the dermis, carrying with them a layer of neural crest cells that forms their meningeal covering. Exposure of embryos to retinoic acid at E10.0 reduces this meningeal neural crest and inhibits parietal ossification, suggesting that intramembranous ossification of this mesodermal bone requires interaction with neural crest-derived meninges, whereas ossification of the neural crest-derived frontal bone is autonomous. These observations provide new perspectives on skull evolution and on human genetic abnormalities of skull growth and ossification.     

应用Fourier变换对东北地区成人颅骨性别差异的研究

本研究所用材料为已知性别、已知年龄的东北地区汉族成人干燥颅骨。应用Fourier变换,将额骨矢状弧的形态转变成Fourier极数,然后应用多元逐步判别分析求得性别判别函数,判别符合率达到90.10％。对31例已知性别汉族成人颅骨盲测,正确率达到84.21% (男性) 和83.33％ (女性) 。研究表明,颅骨的大小和年龄对本方法的判别结果无显著影响。     

Lesions of the frontal bone in American Indians

Over 1,400 adult skulls from archeological sites along the Atlantic Seaboard, in the Midwest and in the Southwest were examined for frontal lesions. A late prehistoric site in Delaware yielded the highest frequency. Next was a late prehistoric site in Illinois, but here the high frequency may reflect in part the collector's special interest in bone pathology. By contrast, the historic and early prehistoric sites yielded the lowest frequencies. Like Hooton and Snow, the only previous American investigators who have recorded frontal lesions in detail, the present authors agree that most of the occurrences in skulls from Archaic and early Pueblo sites are due to trauma. However, in the other groups studied most of the lesions appear to be inflammatory and to have a rather constant location on the frontal. Some are accompanied by lesions on the parietals and on certain long bones. After healing bone remodelling gradually eliminates much of the original disfigurement. Examples of lesions in different stages are illustrated. The appearance of some of the inflammatory lesions suggests syphilis, but satisfactory proof of this is not yet forthcoming. Hopefully, these findings will rekindle interest in the problem and stimulate further efforts to reach correct diagnoses.     

Brief communication: The size of the human frontal sinuses in adults presenting complete persistence of the metopic suture

The notion of absence of the frontal sinuses in human individuals presenting a persistence of the metopic suture is considered as classical in many treatises of reference; however, precise studies are very rare and even controversial. The purpose of this study was thus to provide original data to confirm or refute this classical affirmation with the perspective of some original insights into biological significance of the frontal sinuses and the factors influencing their exceptional polymorphism. The material consisted of 143 dry skulls of adult individuals (European Homo sapiens), distributed in two groups: 80 skulls presenting a complete frontal closure with total disappearance of the metopic suture, and 63 skulls presenting a complete persistence of the metopic suture. Each skull was radiographed in oblique projection using the occipitomental view. A simple morphological quantification of the sinus size was defined with four categories: (1) aplasia, (2) hypoplasia, (3) medium size, (4) hyperplasia. Statistically significant difference in frontal sinusal size was found between both groups of skulls. Absent and small sinuses were considerably more frequent in skulls with persistence of the metopic suture (57.9 vs. 11.9%): small frontal sinuses (hypoplasia) were much more frequent (50.8 vs. 9.4%), although the frequency of absence of frontal sinuses (aplasia) was only slightly higher (7.1 vs. 2.5%). Am J Phys Anthropol 154:621–627, 2014. © 2014 Wiley Periodicals, Inc.     

南京2号人类头骨化石的复位和形态

南京2号人类头骨化石仅保留部分的额骨、顶骨、枕骨和颞骨,为一不完整的颅盖骨。其顶骨和枕骨有数条断裂缝,各断块之间有程度不一的错动,致使该颅盖骨显得外形异常。本项研究是对该颅盖骨的错动部分进行复位,结果表明,南京2号头骨有较大的顶骨、较小的上枕鳞相对宽度、可能较大的颅容量。这些形态提示该头骨与直立人有所不同而与早期智人相近。该头骨所具有的角圆枕、颞鳞顶缘形状、枕骨圆枕发育程度、枕骨的枕平面与项平面过渡情况、枕内隆突点与枕外隆突点的距离、头骨骨壁厚度、脑膜中动脉分支情况、头骨枕面观之轮廓线样式等形态细节,还很难作为可靠的依据把南京2号头骨鉴定为直立人。南京2号头骨很大可能是属于智人亚种(Homo sapiens sapiens)中的一员。     

Main patterns and individual differences in baboon skull split-lines and theories of causes of split-line orientation in bone

Split-line patterns are reported in skulls of five adult male baboons. While variations in pattern occur in all parts of the skull, these variations are relatively minor in the following regions: supraorbital, lateral orbital, medial orbital, nasal bones, zygomatico-alveolar crest, nasal opening, alveolar process of maxilla and mandible. Wide differences in pattern occur in these regions: infraorbital, zygomatic bone, body of maxilla, and frontal bone posterior to the supraorbital area. The major variability in split-line orientation indicates that oversimplified interpretations of the patterns in terms of (1) conformity to gross structure, or (2) direction of bone growth, are untenable. The variations do not contradict a functional interpretation in which mechanical forces and skull form interact to different degrees in different individuals, however. Skulls of a variety of primates are useful for functional analysis, because they have similar structural plans, but the differences are well outside the normal range of variation for a single species.     

近代人群头骨颞线的分型和变异

颞线作为头骨表面咀嚼肌颞肌的附着痕迹,其形态变异对探讨人类体质特征及咀嚼功能具有一定意义。为了解颞线在现代人群中的变异情况,本文选取亚洲、非洲和欧洲278例近现代成年人头骨为研究材料,通过对颞线的颞弧形态、宽度、发育程度、粗糙度及末端位置的观察和分析,明确颞线的分类及其定义标准,获取颞线各种表现形式的侧别、性别和地区间变异的数据,为体质人类学的研究提供参考资料。研究结果显示：1)颞线无显著侧别间差异;2)颞弧形态和发育程度无显著性别和地区间差异;3)顶部颞线宽度及粗糙度有显著性别间差异：男性顶部颞线整体较宽,粗糙型个体大多为男性;4)额部和顶部颞线宽度及粗糙度有显著地区间差异：超宽条带状颞线只出现在云南和华北地区标本,欧洲地区标本脊状颞线和粗糙型比例较高,非洲地区脊状颞线比例较高但粗糙型较低;5)颞线末端止于枕骨的类型极少;6)颞线宽度在额部和顶部及其与颞弧形态显著相关,颞线发育程度在额部与顶部显著相关。     

Modelling Visual Neglect: Computational Insights into Conscious Perception

Background

Visual neglect is an attentional deficit typically resulting from parietal cortex lesion and sometimes frontal lesion. Patients fail to attend to objects and events in the visual hemifield contralateral to their lesion during visual search.

Methodology/Principal Finding

The aim of this work was to examine the effects of parietal and frontal lesion in an existing computational model of visual attention and search and simulate visual search behaviour under lesion conditions. We find that unilateral parietal lesion in this model leads to symptoms of visual neglect in simulated search scan paths, including an inhibition of return (IOR) deficit, while frontal lesion leads to milder neglect and to more severe deficits in IOR and perseveration in the scan path. During simulations of search under unilateral parietal lesion, the model''s extrastriate ventral stream area exhibits lower activity for stimuli in the neglected hemifield compared to that for stimuli in the normally perceived hemifield. This could represent a computational correlate of differences observed in neuroimaging for unconscious versus conscious perception following parietal lesion.

Conclusions/Significance

Our results lead to the prediction, supported by effective connectivity evidence, that connections between the dorsal and ventral visual streams may be an important factor in the explanation of perceptual deficits in parietal lesion patients and of conscious perception in general.     

Activation of FGF signaling mediates proliferative and osteogenic differences between neural crest derived frontal and mesoderm parietal derived bone

Background

As a culmination of efforts over the last years, our knowledge of the embryonic origins of the mammalian frontal and parietal cranial bones is unambiguous. Progenitor cells that subsequently give rise to frontal bone are of neural crest origin, while parietal bone progenitors arise from paraxial mesoderm. Given the unique qualities of neural crest cells and the clear delineation of the embryonic origins of the calvarial bones, we sought to determine whether mouse neural crest derived frontal bone differs in biology from mesoderm derived parietal bone.

Methods

BrdU incorporation, immunoblotting and osteogenic differentiation assays were performed to investigate the proliferative rate and osteogenic potential of embryonic and postnatal osteoblasts derived from mouse frontal and parietal bones. Co-culture experiments and treatment with conditioned medium harvested from both types of osteoblasts were performed to investigate potential interactions between the two different tissue origin osteoblasts. Immunoblotting techniques were used to investigate the endogenous level of FGF-2 and the activation of three major FGF signaling pathways. Knockdown of FGF Receptor 1 (FgfR1) was employed to inactivate the FGF signaling.

Results

Our results demonstrated that striking differences in cell proliferation and osteogenic differentiation between the frontal and parietal bone can be detected already at embryonic stages. The greater proliferation rate, as well as osteogenic capacity of frontal bone derived osteoblasts, were paralleled by an elevated level of FGF-2 protein synthesis. Moreover, an enhanced activation of FGF-signaling pathways was observed in frontal bone derived osteoblasts. Finally, the greater osteogenic potential of frontal derived osteoblasts was dramatically impaired by knocking down FgfR1.

Conclusions

Osteoblasts from mouse neural crest derived frontal bone displayed a greater proliferative and osteogenic potential and endogenous enhanced activation of FGF signaling compared to osteoblasts from mesoderm derived parietal bone. FGF signaling plays a key role in determining biological differences between the two types of osteoblasts.