Sox11 balances dendritic morphogenesis with neuronal migration in the developing cerebral cortex

The coordinated mechanisms balancing promotion and suppression of dendritic morphogenesis are crucial for the development of the cerebral cortex. Although previous studies have revealed important transcription factors that promote dendritic morphogenesis during development, those that suppress dendritic morphogenesis are still largely unknown. Here we found that the expression levels of the transcription factor Sox11 decreased dramatically during dendritic morphogenesis. Our loss- and gain-of-function studies using postnatal electroporation and in utero electroporation indicate that Sox11 is necessary and sufficient for inhibiting dendritic morphogenesis of excitatory neurons in the mouse cerebral cortex during development. Interestingly, we found that precocious suppression of Sox11 expression caused precocious branching of neurites and a neuronal migration defect. We also found that the end of radial migration induced the reduction of Sox11 expression. These findings indicate that suppression of dendritic morphogenesis by Sox11 during radial migration is crucial for the formation of the cerebral cortex. © 2016 the authors

Classic cadherins mediate selective intracortical circuit formation in the mouse neocortex

Understanding the molecular mechanisms underlying the formation of selective intracortical circuitry is one of the important questions in neuroscience research. "Barrel nets" are recently identified intracortical axonal trajectories derived from layer 2/3 neurons in layer 4 of the primary somatosensory (barrel) cortex. Axons of layer 2/3 neurons are preferentially distributed in the septal regions of layer 4 of the barrel cortex, where they show whisker-related patterns. Because cadherins have been viewed as potential candidates that mediate the formation of selective neuronal circuits, here we examined the role of cadherins in the formation of barrel nets. We disrupted the function of cadherins by expressing dominant-negative cadherin (dn-cadherin) using in utero electroporation and found that barrel nets were severely disrupted. Confocal microscopic analysis revealed that expression of dn-cadherin reduced the density of axons in septal regions in layer 4 of the barrel cortex. We also found that cadherins were important for the formation, rather than the maintenance, of barrel nets. Our results uncover an important role of cadherins in the formation of local intracortical circuitry in the neocortex. © 2014 The Author

リュウシケイ オヨビ ソセイ オ セイギョ スル コト ニヨル ユビキタス ブッシツ ノ コウキノウカ : LaTiO2N ケイ サンチッカブツ ノ コウガク トクセイ ノ セイギョ

Some Perovskite-type LaTiO2+xN1-x with anion nonstoichiometry were prepared by heating an oxide precursor under ammonia atmosphere and successively annealed under diluted ammonia. Increasing O/N ratio enhances the optical bandgap of the oxynitrides. A series of perovskite-type LaTiO2N materials with compositions a slightly deviated from the stoichiometric metal composition was also prepared. Increasing Ti/La ratio in La1-xTi1+xTiO2N results in deterioration of reflectivity in the longer wavelength region above the absorption edge. A substitution of La by Sr was effective in the enhancement of reflectivity there. Though the increase of O/N ratio in the LaTiO2+xN1-x series was found to cause oxidation of titanium by means of XPS spectroscopy, the valence state of titanium did not change in either the La1-xTi1+xO2N or the La1-xSrxTiO2N series. The increase in Ti/La ratio in the La1-xTi1+xO2N brought the grain/particle growth, which seemed to result in the deterioration of reflectivity

Pathophysiological analyses of cortical malformation using gyrencephalic mammals

One of the most prominent features of the cerebral cortex of higher mammals is the presence of gyri. Because malformations of the cortical gyri are associated with severe disability in brain function, the mechanisms underlying malformations of the cortical gyri have been of great interest. Combining gyrencephalic carnivore ferrets and genetic manipulations using in utero electroporation, here we successfully recapitulated the cortical phenotypes of thanatophoric dysplasia (TD) by expressing fibroblast growth factor 8 in the ferret cerebral cortex. Strikingly, in contrast to TD mice, our TD ferret model showed not only megalencephaly but also polymicrogyria. We further uncovered that outer radial glial cells (oRGs) and intermediate progenitor cells (IPs) were markedly increased. Because it has been proposed that increased oRGs and/or IPs resulted in the appearance of cortical gyri during evolution, it seemed possible that increased oRGs and IPs underlie the pathogenesis of polymicrogyria. Our findings should help shed light on the molecular mechanisms underlying the formation and malformation of cortical gyri in higher mammals. © 2015 Macmillan Publishers Limited

Competitive Binding Assay with an Umbelliferone-Based Fluorescent Rexinoid for Retinoid X Receptor Ligand Screening

Ligands for retinoid X receptors (RXRs), "rexinoids", are attracting interest as candidates for therapy of type 2 diabetes and Alzheimer's and Parkinson's diseases. However, current screening methods for rexinoids are slow and require special apparatus or facilities. Here, we created 7-hydroxy-2-oxo-6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-2H-chromene-3-carboxylic acid (10, CU-6PMN) as a new fluorescent RXR agonist and developed a screening system of rexinoids using 10. Compound 10 was designed based on the fact that umbelliferone emits strong fluorescence in a hydrophilic environment, but the fluorescence intensity decreases in hydrophobic environments such as the interior of proteins. The developed assay using 10 enabled screening of rexinoids to be performed easily within a few hours by monitoring changes of fluorescence intensity with widely available fluorescence microplate readers, without the need for processes such as filtration

栽培方法，抽出条件の異なる緑茶抽出液によるin vitroでのビフィズス菌の増殖への影響

In this study green tea leaves harvested in Kyoto（June 2014）and grown with or without shading were extracted with boiled or 80℃ water, examining for their effects in vitro on the growth of Bifidobacterium bifidum. In addition, catechins and other components included in each sample were assayed by the HPLC method. The results demonstrated that all of the extracts increased the growth of the strain. Compared with water（control）, the growth-promoting effects on the strain were 517 times higher than those with the boiled-water extract from the leaves grown without shading, 322 times than those with the boiled-water extract from the leaves grown with shading, and 308 times than those with the 80℃ extract from the leaves grown with shading. The total amount of catechins in the extracts was 343.29 mg/100 ml, 240.57 mg/100 ml, and 128.87 mg/100 ml, respectively. Thus, the green tea extracts used in this experiment may have promoted an increase in strain growth in vitro, but the degree of the effects was not necessarily proportional to catechin content.研究ノー

Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies

Objectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease. Background: Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of ∼10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and the interest in using this technology is growing. Incorporation of IVOCT in research and daily clinical practice can be facilitated by the development of uniform terminology and consensus-based standards on use of the technology, interpretation of the images, and reporting of IVOCT results. Methods: The IWG-IVOCT, comprising more than 260 academic and industry members from Asia, Europe, and the United States, formed in 2008 and convened on the topic of IVOCT standardization through a series of 9 national and international meetings. Results: Knowledge and recommendations from this group on key areas within the IVOCT field were assembled to generate this consensus document, authored by the Writing Committee, composed of academicians who have participated in meetings and/or writing of the text. Conclusions: This document may be broadly used as a standard reference regarding the current state of the IVOCT imaging modality, intended for researchers and clinicians who use IVOCT and analyze IVOCT data