Steady-State Visual Evoked Potentials Elicited from Early Visual Cortex Reflect Both Perceptual Color Space and Cone-Opponent Mechanisms

Funding Japan Society for the Promotion of Science (JSPS KAKENHI grant number JP18K13365 to S.K., JP18H04995 to I.K.) Notes S.K. was also supported by the grant from Building of Consortia for the Development of Human Resources in Science and Technology program by Japan Science and Technology Agency. S.K.A. is very grateful to Satoshi Shioiri for inviting him to Tohoku University, which enabled this collaboration. Part of this study has appeared in the form of conference proceedings (Kaneko et al. 2018). Data and codes used in this study are available at https://osf.io/m47df/.Peer reviewedPublisher PD

フテキカク キョウイン ヲ ウミダス メカニズム ニカンスル イチコウサツ

論

Alteration Reaction and Mass Transfer via Fluids with Progress of Fracturing along the Median Tectonic Line, Mie Prefecture, Southwest Japan

We have analyzed mass transfer in the cataclasite samples collected from the Median Tectonic Line, southwest Japan, in which the degree of fracturing is well correlated with the bulk rock chemical compositions determined by the X-ray fluorescence (XRF) analysis. The results of “isocon” analysis indicate not only a large volume increase up to 110% but also the two-stage mass transfer during cataclasis. At the first stage from the very weakly to weakly fractured rocks, the weight percents of SiO2, Na2O, and K2O increase, while those of TiO2, FeO, MnO, MgO, and CaO decrease. At the second stage from the weakly to moderately and strongly fractured rocks, the trend of mass transfer is reversed. The principal component analysis reveals that the variation of chemical compositions in the cataclasite samples can be mostly interpreted by the mass transfer via fluids and by the difference in chemical composition in the protolith rocks to lesser degree. Finally, the changes in the modal composition of minerals with increasing cataclasis analyzed by the X-ray diffraction (XRD) with the aid of “RockJock” software clearly elucidate that the mass transfer of chemical elements was caused by dissolution and precipitation of minerals via fluids in the cataclasite samples

Genetic diseases of renal phosphate handling

リンは，普遍的に存在するミネラルである。ヒトにおける生理学的重要性にもかかわらず，リン代謝に関する多くの見解が明らかになってきたのは比較的最近である。特に，FGF23 はリン恒常性の調節に関係する重要なホルモンであることがわかってきた。遺伝性リン代謝異常症の研究は，全体的なリン調節の複雑性を浮き彫りにし，これからの研究における新しい領域を開拓してきた。 これらは，低リン血症性くる病/骨軟化症の病態のみならず，慢性腎臓病にみられるリン代謝異常と心血管障害との関係の理解に新しい知見を提示することが期待される

カタショウナビ ホゴシャ ノタメノ カタオカショウガッコウ ガイドブック ヅクリ カラ ミエルモノ

論

血中ヘモグロビン濃度及び血中乳酸濃度に対する鉄摂取の影響

ヘモグロビン（Hb）の構成要素である鉄は、ヒトにとって不可欠な栄養素である。Hb は全身に酸素を供給する役割を担っており、鉄の摂取不足は、結果として筋肉への酸素供給の不足を引き起こす。一方、長距離走者のトレーニング効果を評価する生理的指標として血中乳酸濃度が主に用いられているが、鉄の摂取状況と安静時血中乳酸濃度の関係はほとんど明らかとなってない。そこで本研究では鉄欠乏、あるいは鉄過剰食を２週間与えた発育期ラットを用いて、Hb 濃度及び血中乳酸濃度に対する鉄摂取の影響を検討した。鉄欠乏群の体重変化は対照群と比し、小さくなる傾向がみられた。実験最終日の肝臓重量は有意（p＜０.０５）に低下し、腎臓、精巣も低下傾向を示した。一方、心臓重量は有意（p＜０.０１）に増加し、心肥大が認められた。欠乏群の Hb 濃度は経日的に減少し、実験最終日には貧血状態を示した。また、血中乳酸濃度は対照群に比較して約２.５倍の上昇が認められた。逆に、過剰群では Hb 濃度は６日目より著しく上昇し、血中乳酸濃度は低下傾向を示した。以上より、長距離走者における鉄の摂取不足は血中乳酸濃度の上昇をきたすため、身体持久力の低下を引き起こす可能性が大きく、身体能力を維持する上で日常の食生活における十分な鉄の摂取が不可欠であることが示唆された

Optimal vitamin D spurs serotonin : 1,25-dihydroxyvitamin D represses serotonin reuptake transport (SERT) and degradation (MAO-A) gene expression in cultured rat serotonergic neuronal cell lines

Background: Diminished brain levels of two neurohormones, 5-hydroxytryptamine (5-HT; serotonin) and 1,25-dihydroxyvitamin D3 (1,25D; active vitamin D metabolite), are proposed to play a role in the atypical social behaviors associated with psychological conditions including autism spectrum disorders and depression. We reported previously that 1,25D induces expression of tryptophan hydroxylase-2 (TPH2), the initial and rate-limiting enzyme in the biosynthetic pathway to 5-HT, in cultured rat serotonergic neuronal cells. However, other enzymes and transporters in the pathway of tryptophan metabolism had yet to be examined with respect to the actions of vitamin D. Herein, we probed the response of neuronal cells to 1,25D by quantifying mRNA expression of serotonin synthesis isozymes, TPH1 and TPH2, as well as expression of the serotonin reuptake transporter (SERT), and the enzyme responsible for serotonin catabolism, monoamine oxidase-A (MAO-A). We also assessed the direct production of serotonin in cell culture in response to 1,25D. Results: Employing quantitative real-time PCR, we demonstrate that TPH-1/-2 mRNAs are 28- to 33-fold induced by 10 nM 1,25D treatment of cultured rat serotonergic neuronal cells (RN46A-B14), and the enhancement of TPH2 mRNA by 1,25D is dependent on the degree of neuron-like character of the cells. In contrast, examination of SERT, the gene product of which is a target for the SSRI-class of antidepressants, and MAO-A, which encodes the predominant catabolic enzyme in the serotonin pathway, reveals that their mRNAs are 51–59% repressed by 10 nM 1,25D treatment of RN46AB14 cells. Finally, serotonin concentrations are significantly enhanced (2.9-fold) by 10 nM 1,25D in this system. Conclusions: These results are consistent with the concept that vitamin D maintains extracellular fluid serotonin concentrations in the brain, thereby offering an explanation for how vitamin D could influence the trajectory and development of neuropsychiatric disorders. Given the profile of gene regulation in cultured RN46A-B14 serotonergic neurons, we conclude that 1,25D acts not only to induce serotonin synthesis, but also functions at an indirect, molecular-genomic stage to mimic SSRIs and MAO inhibitors, likely elevating serotonin in the CNS. These data suggest that optimal vitamin D status may contribute to improving behavioral pathophysiologies resulting from dysregulation of serotonergic neurotransmission

Bipolar localization of putative photoreceptor protein for phototaxis in thermophilic cyanobacterium Synechococcus elongatus

Funding Information: This work was supported in part by Grants-in-Aid for scientific research from the Ministry of Education, Science, Sports and Culture, Japan (no. 11640653 to K.M.).We identified an open reading frame from a database of the entire genome of Synechococcus elongatus, the product of which was very similar to pixJ1, which was proposed as photoreceptor gene for phototaxis in Synechocystis sp. PCC6803 [Yoshihara et al. (2000) Plant Cell Physiol. 41: 1299]. The mRNA of S. elongatus pixJ (SepixJ) was expressed in vivo as a part of the product of an operon. SePixJ was detected exclusively in the membrane fraction after cell fractionation. Immunogold labeling of SePixJ in ultra-thin sections indicated that it existed only in both ends of the rod-shaped cell; probably bound with the cytoplasmic membrane.publishersversionPeer reviewe

SURFIN is a polymorphic antigen expressed on Plasmodium falciparum merozoites and infected erythrocytes

The surfaces of the infected erythrocyte (IE) and the merozoite, two developmental stages of malaria parasites, expose antigenic determinants to the host immune system. We report on surface-associated interspersed genes (surf genes), which encode a novel polymorphic protein family, SURFINs, present on both IEs and merozoites. A SURFIN expressed in 3D7 parasites, SURFIN4.2, was identified by mass spectrometric analysis of peptides cleaved off the surface of live IEs with trypsin. SURFINs are encoded by a family of 10 surf genes, including three predicted pseudogenes, located within or close to the subtelomeres of five of the chromosomes. SURFINs show structural and sequence similarities with exported surface-exposed proteins (PvSTP1, PkSICAvar, PvVIR, Pf332, and PfEMP1) of several Plasmodium species. SURFIN4.2 of a parasite other than 3D7 (FCR3S1.2) showed polymorphisms in the extracellular domain, suggesting sequence variability between genotypes. SURFIN4.2 not only was found cotransported with PfEMP1 and RIFIN to the IE surface, but also accumulated in the parasitophorous vacuole. In released merozoites, SURFIN4.2 was present in an amorphous cap at the parasite apex, where it may be involved in the invasion of erythrocytes. By exposing shared polymorphic antigens on IEs and merozoites, the parasite may coordinate the antigenic composition of these attachment surfaces during growth in the bloodstream