Floor Plate Research Articles

The Matricellular Protein R-Spondin 2 Promotes Midbrain Dopaminergic Neurogenesis and Differentiation.

SummaryThe development of midbrain dopaminergic (mDA) neurons is controlled by multiple morphogens and transcription factors. However, little is known about the role of extracellular matrix proteins in this process. Here we examined the function of roof plate-specific spondins (RSPO1-4) and the floor plate-specific, spondin 1 (SPON1). Only RSPO2 and SPON1 were expressed at high levels during mDA neurogenesis, and the receptor LGR5 was expressed by midbrain floor plate progenitors. Surprisingly, RSPO2, but not SPON1, specifically promoted the differentiation of mDA neuroblasts into mDA neurons in mouse primary cultures and embryonic stem cells (ESCs). In addition, RSPO2 was found to promote not only mDA differentiation, but also mDA neurogenesis in human ESCs. Our results thus uncover an unexpected function of the matricellular protein RSPO2 and suggest an application to improve mDA neurogenesis and differentiation in human stem cell preparations destined to cell replacement therapy or drug discovery for Parkinson disease.

Differences in neural stem cell identity and differentiation capacity drive divergent regenerative outcomes in lizards and salamanders

While lizards and salamanders both exhibit the ability to regenerate amputated tails, the outcomes achieved by each are markedly different. Salamanders, such as Ambystoma mexicanum, regenerate nearly identical copies of original tails. Regenerated lizard tails, however, exhibit important morphological differences compared with originals. Some of these differences concern dorsoventral patterning of regenerated skeletal and spinal cord tissues; regenerated salamander tail tissues exhibit dorsoventral patterning, while regrown lizard tissues do not. Additionally, regenerated lizard tails lack characteristically roof plate-associated structures, such as dorsal root ganglia. We hypothesized that differences in neural stem cells (NSCs) found in the ependyma of regenerated spinal cords account for these divergent regenerative outcomes. Through a combination of immunofluorescent staining, RT-PCR, hedgehog regulation, and transcriptome analysis, we analyzed NSC-dependent tail regeneration. Both salamander and lizard Sox2+ NSCs form neurospheres in culture. While salamander neurospheres exhibit default roof plate identity, lizard neurospheres exhibit default floor plate. Hedgehog signaling regulates dorsalization/ventralization of salamander, but not lizard, NSCs. Examination of NSC differentiation potential in vitro showed that salamander NSCs are capable of neural differentiation into multiple lineages, whereas lizard NSCs are not, which was confirmed by in vivo spinal cord transplantations. Finally, salamander NSCs xenogeneically transplanted into regenerating lizard tail spinal cords were influenced by native lizard NSC hedgehog signals, which favored salamander NSC floor plate differentiation. These findings suggest that NSCs in regenerated lizard and salamander spinal cords are distinct cell populations, and these differences contribute to the vastly different outcomes observed in tail regeneration.

PERENCANAAN STRUKTUR RANGKA ATAS JEMBATAN RANGKA BAJA PADA GAMPONG LEUBOK PEMPENG KECAMATAN PEUREULAK KABUPATEN ACEH TIMUR

Steel frame bridge Gampong Leubok Pempeng districs Peureulak counties Aceh Timur is a connecting Leubok Pempeng village to Alue Batee village and others village in the peureulak districts with spans of 30 meters and width of 7 meters and including class B. This thesis aims to plan for building a bridge over a steel frame using a standard warren type which includea backrest, sidewalk, the vehicle floor plate, longitudinal girder, cross girder, main frame and bolt connection. To plan the loading bridge using RSNI T-02-2005 and steel structural design using RSNI T-03-2005, the calculation method using LRFD. Results obtained plannin backrest pipe diameter 48,6 mm, sidewalk of 25 cm thick reinfored concrete fc’ 25 Mpa, reinforced cocnrete slab 20 cm and the quality of steel profiles longitudinal girder using steel profiles H 350 x 175 x 7 x 11, cross girder using steel profiles H 488 xx 300 11 x 18. Top wind bracing using steel profiles H 125 x 125 x 6,9 x 9 and profiles L 125 x 125 x 12, while lower wind bracing using steel profiles L 125 x 125 x 12. Frame force calculated with matri method. Rods up, lower and diagonal using steel profiles H 300 x 300 x 10 x 15. Connecting bolts type A-325 diameter 1 inch and ½ inch. Longitudinal girder deflection is 3,130 mm < 8,333 mm, cross girder deflections is 1,002 cm < 2 cm and deflection in the main frame is 3,12 cm smaller than the allowable deflection 12,5 cm.Keyword : steel frame bridge, Matrix method

Perencanaan Proyek Pembangunan Office Centre Anfen Jalan Pringgading – Semarang

AnFen Office Center building is used for office rentals, expected to be a place of business opportunity. The AnFen Office Center building includes office buildings that are used for professional business, administrative or commercial operations. This building has 5 floors with an area of ± 2023,44 m 2 . The roof of the building is planned using a concrete plate. The shear wall is planned to use the type of l frame wall from the ground floor to the 5th floor which aims to withstand the lateral force caused by the earthquake. Calculation of structures in AnFen Office Center building using SNI 03-1726-2012 for earthquake resistant building count and SNI 03-2847-2002 for construction calculation. Lower structure planning includes pile foundation, pile cap, tie beam, while the top structure includes floor plate, column, beam, roof plate, ladder and shear wall. In the calculation of moments and reactions that work on this building using software SAP 2000 Version 17.2.0. The result of design calculation of floor plate plate with thickness of 20 cm for ground floor plate and 12 cm for floor plate plate 1-5 up to roof plate. Design of beam design with dimensions B1 = 450 × 700, B2 = 300× 550. Design planning column with design K1 = 800 x 800. Design planning pile foundation diameter 60 cm at a depth of 12 m.

Perencanaan Struktur Gedung Fakultas Teknik Universitas Moren Jalan Kranggan Semarang

The construction of engineering faculty at the university of moren can be may be able to meet terms of education facilities .Building of engineering faculty university of moren is school buildings, so that including buildings class viii.The building has six floors of with total building area of 11.664 m 2 .The roof of the building planned use of concrete plate.The shear wall planned in central structure of the floor ground until the floor 5 to hold earthquake force direction x of 7609 kg.m and direction y of 6879 kg.m A structure for the faculty engineering university moren use 03-1726-2012 sni , SNI T-15-1991-03 , sni 2847-2013 , SNI03-1965-1990, and SNI 07-2529-1991.Planning the structure down include the stake , tiebeam , pilecap .While stuktur upper covering concrete plate , floor plates , stairs, beam , column , and shearwall .In counting the moments and reaction on buildings it uses 2000 v.14 sofware sap The results of result in planning the plate with thick 20 cm to floor ground and 12 cm pelat 1 until 5 to the floor and the roof .Design planning a beam B1 = 450 x 700, B2 = 350 x 500 , B3 =350 x 600, B4 = 300 x 450.Design planning a column K1 = 800 x 800.Design planning foundation piles 50 cm in the depth 18 meters

PERENCANAAN STRUKTUR ATAS ASRAMA PUTRI DI UNIVERSITAS KADIRI

ABSTRACTThe upper structure is the parts that make up buildings such as sloof, walls, columns, beams, and roofs. In this upper structure these components have a very important role. Today, civil engineering students are required to be able to plan well so that they are strong and durable for a long time.In planning this upper structure, of course there are many methods that can be used to calculate moments, one of them is ultimate moment method, which can be combined with a reference from SK SNI 2847,2013. For pouring images can be presented with CAD (Computer Aided Design) software called AutoCAD.The results of this plan are used for roof and floor plates used 100 mm and 120 mm thick with reinforcement used 12 mm main reinforcement and 8 mm stirrup reinforcement with a distance of 200 mm. For beams and Sloof used the same, which is 16 mm for basic reinforcement and 10 mm for reinforcement Sengkang with a distance of 200 mm. Whereas for columns, reinforcement 16 mm and Sengkang 12 mm with a distance of 200 mm are used. The load distribution that occurs is for the roof floor of 20.640,924 kgm, because the assumption of loading the 1st floor to 6th is the same, which is equal to 23.233,644 kgm. The moments that occur in this plan are on the plate occurred at 17.074,370 kgm, the beam occurred at 342.733,875 kgm and 493.536,780 kgm. In the column arises a fairly large moment, with a value of 551.697,600 kgm. From the calculation of the earthquake load get the result = 159843 (kNm).Keywords: Planning, Structure, CAD, SNI

Post-crossing segment of dI1 commissural axons forms collateral branches to motor neurons in the developing spinal cord.

The dI1 commissural axons in the developing spinal cord, upon crossing the midline through the floor plate, make a sharp turn to grow rostrally. These post-crossing axons initially just extend adjacent to the floor plate without entering nearby motor columns. However, it remains poorly characterized how these post-crossing dI1 axons behave subsequently to this process. In the present study, to address this issue, we examined in detail the behavior of post-crossing dI1 axons in mice, using the Atoh1 enhancer-based conditional expression system that enables selective and sparse labeling of individual dI1 axons, together with Hb9 and ChAT immunohistochemistry for precise identification of spinal motor neurons (MNs). We found unexpectedly that the post-crossing segment of dI1 axons later gave off collateral branches that extended laterally to invade motor columns. Interestingly, these collateral branches emerged at around the time when their primary growth cones initiated invasion into motor columns. In addition, although the length of the laterally growing collateral branches increased with age, the majority of them remained within motor columns. Strikingly, these collateral branches further gave rise to multiple secondary branches in the region of MNs that innervate muscles close to the body axis. Moreover, these axonal branches formed presynaptic terminals on MNs. These observations demonstrate that dI1 commissural neurons develop axonal projection to spinal MNs via collateral branches arising later from the post-crossing segment of these axons. Our findings thus reveal a previously unrecognized projection of dI1 commissural axons that may contribute directly to generating proper motor output.

Transcriptional synergy as an emergent property defining cell subpopulation identity enables population shift

Single-cell RNA sequencing allows defining molecularly distinct cell subpopulations. However, the identification of specific sets of transcription factors (TFs) that define the identity of these subpopulations remains a challenge. Here we propose that subpopulation identity emerges from the synergistic activity of multiple TFs. Based on this concept, we develop a computational platform (TransSyn) for identifying synergistic transcriptional cores that determine cell subpopulation identities. TransSyn leverages single-cell RNA-seq data, and performs a dynamic search for an optimal synergistic transcriptional core using an information theoretic measure of synergy. A large-scale TransSyn analysis identifies transcriptional cores for 186 subpopulations, and predicts identity conversion TFs between 3786 pairs of cell subpopulations. Finally, TransSyn predictions enable experimental conversion of human hindbrain neuroepithelial cells into medial floor plate midbrain progenitors, capable of rapidly differentiating into dopaminergic neurons. Thus, TransSyn can facilitate designing strategies for conversion of cell subpopulation identities with potential applications in regenerative medicine.

A Zeb2-miR-200c loop controls midbrain dopaminergic neuron neurogenesis and migration

Zeb2 is a homeodomain transcription factor that plays pleiotropic functions during embryogenesis, but its role for midbrain dopaminergic (mDA) neuron development is unknown. Here we report that Zeb2 is highly expressed in progenitor cells in the ventricular zone of the midbrain floor plate and downregulated in postmitotic neuroblasts. Functional experiments show that Zeb2 expression in the embryonic ventral midbrain is dynamically regulated by a negative feedback loop that involves miR-200c. We also find that Zeb2 overexpression reduces the levels of CXCR4, NR4A2, and PITX3 in the developing ventral midbrain in vivo, resulting in migration and mDA differentiation defects. This phenotype was recapitulated by miR-200c knockdown, suggesting that the Zeb2-miR-200c loop prevents the premature differentiation of mDA progenitors into postmitotic cells and their migration. Together, our study establishes Zeb2 and miR-200c as critical regulators that maintain the balance between mDA progenitor proliferation and neurogenesis.

The Postmigratory Alar Topography of Visceral Cranial Nerve Efferents Challenges the Classical Model of Hindbrain Columns

The classic columnar model of cranial nerve central representation assumes that all motor and sensory hindbrain neurons develop within four radial migration domains, held to be separated by a sulcal alar-basal boundary (sulcus limitans). This essay reviews a number of developmental data that challenge these concepts. These results are interpreted within the framework of present day neuromeric conception of the brainstem (the prosomeric model). Advances in dorsoventral patterning of the spinal cord and hindbrain now show that there exist up to eight alar microzones and five basal microzones (molecularly and histogenetically distinct longitudinal progenitor domains). This reveals that the classic tetracolumnar model is excessively simplistic. There is both older and recent data revealing that the visceral efferent neurons of the cranial nerves (preganglionic and branchiomotor neurons) are generated next to the floor plate and later migrate dorsalwards before adopting their final topography in the mantle, contrary to the purely radial migration assumed in the classic model. Moreover, various results support the conclusion that at least the branchiomotor neurons end their migration and mature within the alar region of the mantle. Evidence on this point obtained in chick embryos is reviewed in detail, and novel evidence in mouse embryos is presented. Anat Rec, 302:485-504, 2019. © 2018 Wiley Periodicals, Inc.

ANALYSIS STRUCTURE OF THE BOARDING HOUSE TEGAL PARANG AT SOUTH JAKARTA

Jakarta City is a city that became the heart of the unitary State of the Republic of indonesia has potential as the city develops. Jakarta is already good enough if compared to its neighboring cities – city, seen from there is a lot of building skyscrapers. Therefore the population in this city is very solid plus the number of communities outside the city looking for work, education and so on, and many choose to find a place the residence then the role of the existence of an agency that handles problems a place to live and help with much needed to help the business community in order to be better, as there are Houses kost. Currently, the central building were built as high as five floors with one basement, exactly on JL. TegalParang Utara, South Jakarta. To meet the criteria of safety and service required the existence of a design careful planning. Therefore the imposition of planning process must comply with the SNI 1727-2013 as well as planning the structure of the building should be referred to with the SNI-2847-2013 reinforced concrete, which is the latest peratuaran which refers to the AISC and has adapted to the the latest materials technology development. In the calculation of earthquake engineering, this refers to the SNI 1726 – 2012.  Based on data obtained from a Home Building project, tegalparangkost has an area of approximately 3224.86 m2. The author will meredesain a building material by using the concrete structure which consists of 5 (four) along with the basement 1 floor.  Analysis of the structure of the used software SAP2000, a material used for reinforced concrete beams, columns, roof and floor plates are plates. The results obtained in the form of analysis and design drawings of the structure of the building House kosttegalparang.   Key Words : Analysis, Boarding House TegalParang, Material, Reinforced Concrete, Columns, Beams, Plate.

Zika Virus Can Strongly Infect and Disrupt Secondary Organizers in the Ventricular Zone of the Embryonic Chicken Brain

SummaryZika virus (ZIKV) is associated with severe neurodevelopmental 0impairments in human fetuses, including microencephaly. Previous reports examining neural progenitor tropism of ZIKV in organoid and animal models did not address whether the virus infects all neural progenitors uniformly. To explore this, ZIKV was injected into the neural tube of 2-day-old chicken embryos, resulting in nonuniform periventricular infection 3 days later. Recurrent foci of intense infection were present at specific signaling centers that influence neuroepithelial patterning at a distance through secretion of morphogens. ZIKV infection reduced transcript levels for 3 morphogens, SHH, BMP7, and FGF8 expressed at the midbrain basal plate, hypothalamic floor plate, and isthmus, respectively. Levels of Patched1, a SHH-pathway downstream gene, were also reduced, and a SHH-dependent cell population in the ventral midbrain was shifted in position. Thus, the diminishment of signaling centers through ZIKV-mediated apoptosis may yield broader, non-cell-autonomous changes in brain patterning.

Nrf2 Activation Rescues Dendritic Pathology in hPSC‐Derived And Primary Neuron Based Models of Parkinson's Disease

IntroductionNeuronal loss in Parkinson's disease (PD) is associated with impaired proteostasis and increased oxidative stress in dopaminergic neurons of the substantia nigra pars compacta. In a healthy cell, redox imbalance is controlled by enzymes that detoxify the cell of free radicals. These enzymes are transcriptionally activated as part of the cells antioxidant response. The master regulator of this pathway is a transcription factor called Nrf2 (a.k.a NFE2L2). Aggregated α‐synuclein (α‐syn) is the major constituent of Lewy Bodies (the disease hallmark), however the mechanisms linking α‐syn aggregation with generation of reactive oxygen species (ROS) have been difficult to ascertain. We therefore asked whether a deficit in the antioxidant response might explain the increased susceptibility of PD neurons to ROS generation and dendritic pathology following α‐syn aggregation.MethodsTo study these events, we contrasted human pluripotent stem cells (hPSCs) that harbor the α‐syn‐A53T mutation against isogenic controls. A9‐type dopaminergic neurons (the specific neurons lost in PD) were generated from hPSCs by following a floor plate differentiation paradigm. α‐syn‐A53T neurons show accumulation of insoluble α‐syn consistent with an early disease phenotype. We similarly contrasted rat primary neurons against neurons exposed to α‐syn pre‐formed fibrils (PFF). PFF exposed neurons accumulate large intracellular aggregates of α‐syn consistent with advanced synucleinopathy. We show that aberrant accumulation of α‐syn in both systems promotes increased ROS production coupled to increased dendritic pathology and decreased dendritic length and complexity.ResultsTo evaluate the role of Nrf2 in dendritic pathology we measured Nrf2 protein stability and phospho‐activation in A53T‐mutant and PFF exposed neurons. We found that α‐syn accumulation impaired Nrf2 phospho‐activation leading to the subsequent loss of expression of Nrf2 target genes. To determine whether Nrf2‐mediated activation of Antioxidant Response Elements (AREs) could rescue the observed dendritic pathology, we tested the effects of both Nrf2 overexpression and pharmaceutical modulation of Nrf2 activity on dendritic pathology. We found that Nrf2‐activation increased expression of detoxifying enzymes and reduced ROS levels in both A53T‐mutant and PFF exposed neurons, leading to a significant decrease in dendritic pathology.SignificanceThis investigation established that the Nrf2 transcriptional pathway is impaired by aberrant accumulation of α‐syn in both A53T‐mutant and PFF exposed neurons and determined that restoration of the anti‐oxidant pathway protects PD neurons from dendritic pathology.Support or Funding InformationFunding: This work was supported in part by the Parkinson Society of Canada (2014‐685 to SDR), the Natural Sciences and Engineering Research Council of Canada (RG060805 to SDR)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Nitration of Microtubules Blocks Axonal Mitochondrial Transport in a Human Pluripotent Stem Cell Model of Parkinson's Disease

IntroductionNeuronal loss in Parkinson's disease (PD) is associated with both accumulation of aggregated α‐synuclein (α‐syn) and impaired mitochondrial function in dopaminergic neurons of the substantia nigra. These impairments are closely associated with the accumulation of reactive nitrogen species (RNS) such as nitric oxide and peroxynitrite. Moreover, exposure to mitochondrial toxins, such as the agrochemicals paraquat, maneb and rotenone, are associated with at least a 2.5‐fold increased risk of PD. Further, in patients with a familial mutation in the α‐syn gene (eg. SNCA‐A53T), agrochemical exposure correlates with disease onset at an earlier age. While a mechanistic link between α‐syn aggregation and mitochondrial dysfunction has been difficult to ascertain, events seem to center on RNS generation. We thus explore a “two‐hit” hypothesis whereby an α‐syn mutation makes neurons susceptible to mitochondrial dysfunction following agrochemical exposure.ApproachUsing patient derived induced pluripotent stem cells harbouring the SNCA‐A53T mutation and genetically corrected (SNCA‐Corr) isogenic controls, we tested whether there exists a gene‐by‐environment interaction in PD neurons that results in defective mitochondrial transport. Stem cells were transformed to stably express a mitochondria‐targeted DSRed fluorophore, allowing for live imaging of mitochondrial dynamics. Cells were then differentiated to dopaminergic neurons using a differentiation paradigm that mirrors floor plate development. Subsequently, neurons were exposed to agrochemicals at levels below EPA‐reported lowest observable effect levels (LOEL).ResultsAlthough there was no observable difference in the percentage of motile mitochondria between SNCA‐A53T and SNCA‐Corr neurons under basal conditions, agrochemical exposure impaired anterograde mitochondrial transport specifically in SNCA‐A53T neurons. We further demonstrate that agrochemical exposure resulted in increased RNS production in SNCA‐A53T neurons, leading to nitration of microtubules in SNCA‐A53T neurons. This modification inhibited KIF5, an important member of the anterograde mitochondrial transport complex, from associating with microtubules. This impairment was rescued by blocking RNS accumulation with the nitric oxide synthase inhibitor, l‐NAME.SignificanceCollectively, our results are the first to demonstrate a gene‐by‐environment interaction in PD whereby agrochemical exposure selectively triggers a deficit in mitochondrial transport in PD patient‐derived neurons harboring the SNCA‐A53T mutation.Support or Funding InformationThis work was supported in part by the Parkinson Society of Canada (2014‐685 to SDR), the Natural Sciences and Engineering Research Council of Canada (RG060805 to SDR) and an Ontario Graduate Scholarship to MGS.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Non-destructive Testing Robots (NDTBOTs) for In-Service Storage Tank Inspection

Petrochemical storage tanks are generally inspected when the tank is offline mostly to assess the extent of underside corrosion on the tank floor. Emptying, cleaning and opening a tank for inspection takes many months and is very expensive. Inspection costs can be reduced significantly by inserting robots through manholes on the tank roof to perform non-destructive testing. The challenge is to develop robots that can operate safely in explosive and hazardous environments and measure the thickness of floor plates using ultrasound sensors. This paper reports on the development of a small and inexpensive prototype robot (NDTBOT) which is designed to be intrinsically safe for zone zero operation. The robot “hops” across the floor to make measurements, without any external moving parts. The paper describes the design, experimental testing of the NDTBOT and presents results of steel plate thickness measurements made under water.

FGF signaling controls Shh-dependent oligodendroglial fate specification in the ventral spinal cord

BackgroundMost oligodendrocytes of the spinal cord originate from ventral progenitor cells of the pMN domain, characterized by expression of the transcription factor Olig2. A minority of oligodendrocytes is also recognized to emerge from dorsal progenitors during fetal development. The prevailing view is that generation of ventral oligodendrocytes depends on Sonic hedgehog (Shh) while dorsal oligodendrocytes develop under the influence of Fibroblast Growth Factors (FGFs).ResultsUsing the well-established model of the chicken embryo, we show that ventral spinal progenitor cells activate FGF signaling at the onset of oligodendrocyte precursor cell (OPC) generation. Inhibition of FGF receptors at that time appears sufficient to prevent generation of ventral OPCs, highlighting that, in addition to Shh, FGF signaling is required also for generation of ventral OPCs. We further reveal an unsuspected interplay between Shh and FGF signaling by showing that FGFs serve dual essential functions in ventral OPC specification. FGFs are responsible for timely induction of a secondary Shh signaling center, the lateral floor plate, a crucial step to create the burst of Shh required for OPC specification. At the same time, FGFs prevent down-regulation of Olig2 in pMN progenitor cells as these cells receive higher threshold of the Shh signal. Finally, we bring arguments favoring a key role of newly differentiated neurons acting as providers of the FGF signal required to trigger OPC generation in the ventral spinal cord.ConclusionAltogether our data reveal that the FGF signaling pathway is activated and required for OPC commitment in the ventral spinal cord. More generally, our data may prove important in defining strategies to produce large populations of determined oligodendrocyte precursor cells from undetermined neural progenitors, including stem cells. In the long run, these new data could be useful in attempts to stimulate the oligodendrocyte fate in residing neural stem cells.

Highly segregated localization of the functionally related vps10p receptors sortilin and SorCS2 during neurodevelopment.

Nervous system development is a precisely orchestrated series of events requiring a multitude of intrinsic and extrinsic cues. Sortilin and SorCS2 are members of the Vps10p receptor family with complementary influence on some of these cues including the neurotrophins (NTs). However, the developmental time points where sortilin and SorCS2 exert their activities in conjunction or independently still remain unclear. In this study we present the characterization of the spatiotemporal expression pattern of sortilin and SorCS2 in the developing murine nervous system. Sortilin is highly expressed in the fetal nervous system with expression localized to distinct cell populations. Expression was high in neurons of the cortical plate and developing allocortex, as well as subpallial structures. Furthermore, the neuroepithelium lining the ventricles and the choroid plexus showed high expression of sortilin, together with the developing retina, spinal ganglia, and sympathetic ganglia. In contrast, SorCS2 was confined in a marked degree to the thalamus and, at E13.5, the floor plate from midbrain rostrally to spinal cord caudally. SorCS2 was also found in the ventricular zones of the ventral hippocampus and nucleus accumbens areas, in the meninges and in Schwann cells. Hence, sortilin and SorCS2 are extensively present in several distinct anatomical areas in the developing nervous system and are rarely co-expressed. Possible functions of sortilin and SorCS2 pertain to NT signaling, axon guidance and beyond. The present data will form the basis for hypotheses and study designs for unravelling the functions of sortilin and SorCS2 during the establishment of neuronal structures and connections.

Old Building Structure Reinforcement Design and Construction

While making the reinforcement design, the means of surface cast-in-situ and carbon cloth are applied to strengthen the floor plates; the additional beam is applied to reduce the span of floor plates and to transmit the new load of the floor plates; the technology of magnifying cross section is applied to fulfill the request of the load of the frame beam; and the reinforcement technology of wrapping pillar with steel is applied to satisfy the request of the vertical load of the structural column. Meanwhile this paper briefly states the construction points of different reinforcement technology. Through the comprehensive application of reinforcement technology, we will explore a simple and feasible reinforcement method for the transformation of schools’ old buildings in the future.

Loss of Dcc in the spinal cord is sufficient to cause a deficit in lateralized motor control and the switch to a hopping gait.

Humans with heterozygous mutations in the axon guidance receptor DCC display congenital mirror movements (MMs), which are involuntary movements of body parts, such as fingers, on one side of the body that mirror voluntary movement of the opposite side. In mice, the homozygous Dcckanga mutant allele causes synchronous MM-like hindlimb movements during locomotion, resulting in hopping. In both human and mice, the neuroanatomical defect responsible for the deficit in lateralized motor control remains to be elucidated. Using the HoxB8-Cre line to specifically remove Dcc from the spinal cord, we found misrouting of commissural axons during their migration toward the floor plate, resulting in fewer axons crossing the midline. These mice also have a hopping gait, indicating that spinal cord guidance defects alone are sufficient to cause hopping. Dcc plays a role in the development of local spinal networks to ensure proper lateralization of motor control during locomotion. Local spinal cord defects following loss of Dcc cause a hopping gait in mice and may contribute to MM in humans. Developmental Dynamics 247:620-629, 2018. © 2017 Wiley Periodicals, Inc.

Divergent axial morphogenesis and early shh expression in vertebrate prospective floor plate

BackgroundThe notochord has organizer properties and is required for floor plate induction and dorsoventral patterning of the neural tube. This activity has been attributed to sonic hedgehog (shh) signaling, which originates in the notochord, forms a gradient, and autoinduces shh expression in the floor plate. However, reported data are inconsistent and the spatiotemporal development of the relevant shh expression domains has not been studied in detail. We therefore studied the expression dynamics of shh in rabbit, chicken and Xenopus laevis embryos (as well as indian hedgehog and desert hedgehog as possible alternative functional candidates in the chicken).ResultsOur analysis reveals a markedly divergent pattern within these vertebrates: whereas in the rabbit shh is first expressed in the notochord and its floor plate domain is then induced during subsequent somitogenesis stages, in the chick embryo shh is expressed in the prospective neuroectoderm prior to the notochord formation and, interestingly, prior to mesoderm immigration. Neither indian hedgehog nor desert hedgehog are expressed in these midline structures although mRNA of both genes was detected in other structures of the early chick embryo. In X. laevis, shh is expressed at the beginning of gastrulation in a distinct area dorsal to the dorsal blastopore lip and adjacent to the prospective neuroectoderm, whereas the floor plate expresses shh at the end of gastrulation.ConclusionsWhile shh expression patterns in rabbit and X. laevis embryos are roughly compatible with the classical view of “ventral to dorsal induction” of the floor plate, the early shh expression in the chick floor plate challenges this model. Intriguingly, this alternative sequence of domain induction is related to the asymmetrical morphogenesis of the primitive node and other axial organs in the chick. Our results indicate that the floor plate in X. laevis and chick embryos may be initially induced by planar interaction within the ectoderm or epiblast. Furthermore, we propose that the mode of the floor plate induction adapts to the variant topography of interacting tissues during gastrulation and notochord formation and thereby reveals evolutionary plasticity of early embryonic induction.