Reevaluating the Seven Levels of the Japanese Language Classes Based on the ACTFL-OPI

　岡山大学言語教育センターの全学日本語コースでは，初級から上級まで7レベルのクラスを提供しているが，このレベル設定の妥当性を検討するには外部基準に照らすことが適当と考え，そのひとつとして，ACTFL(American Council for Teaching of Foreign Languages) のOPI (Oral Proficiency Interview) を行った。ACTFL-OPI は様々な言語の「話す能力」測定法として確立され活用されているインタビュー方式の試験であり，ACTFL に認定されたテスターによってなされる。本稿では，全学日本語コース履修生を対象に行ったACTFLOPIの実施方法及び結果を報告し，全学日本語コースの各レベルと ACTFL-OPI の対応について述べる

Japanese Language Curriculum Reform at Okayama University

　近年岡山大学の全学日本語コースでは，従来の研究生や大学院生に加え，短期留学生の数が増加し，受講生の多様化が進んでいる。本コースでは毎年カリキュラムの見直しを行ってきたが，この度，受講生の多様なニーズに対応するため，大規模なカリキュラム改編を行った。この改編の大きな特徴は，従来の総合クラスに加え，さまざまなレベルに対応したトピック別の選択クラスを開講し，受講生の状況や興味に合った科目数と科目内容 の選択を可能にしたことにある。本稿では2013年度の大規模なカリキュラム改編にいたる背景とその準備過程，改編前と改編後のカリキュラムの相違点，改編後に行ったアンケート調査の結果概略，今後の課題について述べる

Intracellular Calcium Spikes in Rat Suprachiasmatic Nucleus Neurons Induced by BAPTA-Based Calcium Dyes

Background: Circadian rhythms in spontaneous action potential (AP) firing frequencies and in cytosolic free calcium concentrations have been reported for mammalian circadian pacemaker neurons located within the hypothalamic suprachiasmatic nucleus (SCN). Also reported is the existence of "Ca2+ spikes" (i.e., [Ca2+]c transients having a bandwidth of 10～100 seconds) in SCN neurons, but it is unclear if these SCN Ca2+ spikes are related to the slow circadian rhythms. Methodology/Principal Findings: We addressed this issue based on a Ca2+ indicator dye (fluo-4) and a protein Ca2+ sensor (yellow cameleon). Using fluo-4 AM dye, we found spontaneous Ca2+ spikes in 18% of rat SCN cells in acute brain slices, but the Ca2+ spiking frequencies showed no day/night variation. We repeated the same experiments with rat (and mouse) SCN slice cultures that expressed yellow cameleon genes for a number of different circadian phases and, surprisingly, spontaneous Ca2+ spike was barely observed (<3%). When fluo-4 AM or BAPTA-AM was loaded in addition to the cameleon-expressing SCN cultures, however, the number of cells exhibiting Ca2+ spikes was increased to 13～14%. Conclusions/Significance: Despite our extensive set of experiments, no evidence of a circadian rhythm was found in the spontaneous Ca2+ spiking activity of SCN. Furthermore, our study strongly suggests that the spontaneous Ca2+ spiking activity is caused by the Ca2+ chelating effect of the BAPTA-based fluo-4 dye. Therefore, this induced activity seems irrelevant to the intrinsic circadian rhythm of [Ca2+]c in SCN neurons. The problems with BAPTA based dyes are widely known and our study provides a clear case for concern, in particular, for SCN Ca2+ spikes. On the other hand, our study neither invalidates the use of these dyes as a whole, nor undermines the potential role of SCN Ca2+ spikes in the function of SCN

抗ヒスタミン薬ケトチフェンの連日投与による体内時計位相調節

富山大学・富生命博甲第90号・AHMAD ALSAWAF・2017/03/23Sleep and Biological Rhythms,2016.1,14(1),117-120,doi: 10.1007/s41105-015-0021-yに掲載。富山大学201

Mitochondrial LETM1 drives ionic and molecular clock rhythms in circadian pacemaker neurons

The mechanisms that generate robust ionic oscillation in circadian pacemaker neurons are under investigation. Here, we demonstrate critical functions of the mitochondrial cation antiporter leucine zipper- EF-hand-containing transmembrane protein 1 (LETM1), which exchanges K+/H+ in Drosophila and Ca2+/H+ in mammals, in circadian pacemaker neurons. Letm1 knockdown in Drosophila pacemaker neurons reduced circadian cytosolic H+ rhythms and prolonged nuclear PERIOD/TIMELESS expression rhythms and locomotor activity rhythms. In rat pacemaker neurons in the hypothalamic suprachiasmatic nucleus (SCN), circadian rhythms in cytosolic Ca2+ and Bmal1 transcription were dampened by Letm1 knockdown. Mitochondrial Ca2+ uptake peaks late during the day were also observed in rat SCN neurons following photolytic elevation of cytosolic Ca2+. Since cation transport by LETM1 is coupled to mitochondrial energy synthesis, we propose that LETM1 integrates metabolic, ionic, and molecular clock rhythms in the central clock system in both invertebrates and vertebrates

Histamine Regulates Molecular Clock Oscillations in Human Retinal Pigment Epithelial Cells via H1 Receptors

Vertebrate eyes are known to contain circadian clocks, but their regulatory mechanisms remain largely unknown. To address this, we used a cell line from human retinal pigment epithelium (hRPE-YC) with stable coexpression of reporters for molecular clock oscillations (Bmal1-luciferase) and intracellular Ca2+ concentrations (YC3.6). We observed concentration-dependent increases in cytosolic Ca2+ concentrations after treatment with histamine (1–100 µM) and complete suppression of histamine-induced Ca2+ mobilizations by H1 histamine receptor (H1R) antagonist d-chlorpheniramine (d-CPA) in hRPE-YC cells. Consistently, real-time RT-PCR assays revealed that H1R showed the highest expression among the four subtypes (H1–H4) of histamine receptors in hRPE-YC cells. Stimulation of hRPE-YC cells with histamine transiently increased nuclear localization of phosphorylated Ca2+/cAMP-response element-binding protein that regulates clock gene transcriptions. Administration of histamine also shifted the Bmal1-luciferase rhythms with a type-1 phase-response curve, similar to previous results with carbachol stimulations. Treatment of hRPE-YC cells with d-CPA or with more specific H1R antagonist, ketotifen, blocked the histamine-induced phase shifts. Furthermore, an H2 histamine receptor agonist, amthamine, had little effect on the Bmal1-luciferase rhythms. Although the function of the in vivo histaminergic system within the eye remains obscure, the present results suggest histaminergic control of the molecular clock via H1R in retinal pigment epithelial cells. Also, since d-CPA and ketotifen have been widely used (e.g., to treat allergy and inflammation) in our daily life and thus raise a possible cause for circadian rhythm disorders by improper use of antihistamines