Interaction of neuron-specific K+-Cl− cotransporter, KCC2, with brain-type creatine kinase

Abstractγ-Aminobutyric acid, a major inhibitory neurotransmitter within the adult central nervous system, is also known to be excitatory at early developmental stages due to the elevated intracellular Cl− concentration. This functional change is primarily attributable to a K+-Cl− cotransporter, KCC2, the expression of which is developmentally regulated in neurons. However, little detail information is available concerning the intracellular regulation of KCC2 function. Here, we identify an interaction between KCC2 and brain-type creatine kinase by means of yeast two-hybrid screening. This interaction, which was also detected in cultured cells and brain extracts, might contribute to KCC2-mediated modulation of Cl− homeostasis

Functional deficiency of MHC class i enhances LTP and abolishes LTD in the nucleus accumbens of mice

Major histocompatibility complex class I (MHCI) molecules were recently identified as novel regulators of synaptic plasticity. These molecules are expressed in various brain areas, especially in regions undergoing activity-dependent synaptic plasticity, but their role in the nucleus accumbens (NAc) is unknown. In this study, we investigated the effects of genetic disruption of MHCI function, through deletion of β2-microblobulin, which causes lack of cell surface expression of MHCI. First, we confirmed that MHCI molecules are expressed in the NAc core in wild-type mice. Second, we performed electrophysiological recordings with NAc core slices from wild-type and β2-microglobulin knock-out mice lacking cell surface expression of MHCI. We found that low frequency stimulation induced long-term depression in wild-type but not knock-out mice, whereas high frequency stimulation induced long-term potentiation in both genotypes, with a larger magnitude in knock-out mice. Furthermore, we demonstrated that knock-out mice showed more persistent behavioral sensitization to cocaine, which is a NAc-related behavior. Using this model, we analyzed the density of total AMPA receptors and their subunits GluR1 and GluR2 in the NAc core, by SDS-digested freeze-fracture replica labeling. After repeated cocaine exposure, the density of GluR1 was increased, but there was no change in total AMPA receptors and GluR2 levels in wildtype mice. In contrast, following repeated cocaine exposure, increased densities of total AMPA receptors, GluR1 and GluR2 were observed in knock-out mice. These results indicate that functional deficiency of MHCI enhances synaptic potentiation, induced by electrical and pharmacological stimulation

Orientational order of a ferroelectric liquid crystal with small layer contraction

We present spectroscopic and optical studies of a non-layer-shrinkage ferroelectric liquid crystal DSiKN65. The orientational order parameters S, measured with respect to the smectic layer normal using IR spectroscopy on a sample aligned homeotropically, does not exhibit any significant variation between the smectic-A* and smectic-C* phases. In contrast the birefringence of a planar homogenous sample abruptly increases at the smectic-A* to smectic-C* transition. This suggests a general increase in the orientational order, which can be described by the orientational order parameters S\u27 defined with respect to the director. Simultaneous increase of S\u27 and the director tilt θ may explain the low shrinkage of smectic layers, which is consistent with recent theoretical models describing the smectic-A* to smectic-C* transition for such materials

Factorization, reduction and embedding in integrable cellular automata

Factorized dynamics in soliton cellular automata with quantum group symmetry is identified with a motion of particles and anti-particles exhibiting pair creation and annihilation. An embedding scheme is presented showing that the D^{(1)}_n-automaton contains, as certain subsectors, the box-ball systems and all the other automata associated with the crystal bases of non-exceptional affine Lie algebras. The results extend the earlier ones to higher representations by a certain reduction and to a wider class of boundary conditions.Comment: LaTeX2e, 20 page

Unexpected electric-field-induced antiferroelectric liquid crystal phase in the Sm C*α temperature range and the discrete flexoelectric effect

The unique nanometer-sized helical structure in SmCα∗ may sometimes evolve continuously to the micrometer-sized one in SmC∗; conceivably ferroelectric SmCα∗ is to be unwound by an applied electric field. By drawing electric-field-induced birefringence contours in the field-temperature phase diagram and by studying the superlattice structure of the field-induced subphase with resonant x-ray scattering, we established that an applied field unexpectedly stabilizes the well-known antiferroelectric four-layer biaxial subphase as well as the other prototypal ferrielectric three-layer one in the SmCα∗ temperature range; the effective long-range interlayer interaction due to the discrete flexoelectric effect actually plays an important role in stabilizing not only the biaxial subphases but also the optically uniaxial SmCα∗ subphase, contrary to the notion that the competition between the direct interactions of the nearest-neighbor layers and those of the next-nearest-neighbor layers should be required for the nanometer-sized helical structure

Bethe ansatz at q=0 and periodic box-ball systems

A class of periodic soliton cellular automata is introduced associated with crystals of non-exceptional quantum affine algebras. Based on the Bethe ansatz at q=0, we propose explicit formulas for the dynamical period and the size of certain orbits under the time evolution in A^{(1)}_n case.Comment: 12 pages, Introduction expanded, Summary added and minor modifications mad

Crystal interpretation of Kerov-Kirillov-Reshetikhin bijection

The Kerov-Kirillov-Reshetikhin (KKR) bijection is the crux in proving fermionic formulas. It is defined by a combinatorial algorithm on rigged configurations and highest paths. We reformulate the KKR bijection as a vertex operator by purely using combinatorial R in crystal base theory. The result is viewed as a nested Bethe ansatz at q=0 as well as the direct and the inverse scattering (Gel'fand-Levitan) map in the associated soliton cellular automaton.Comment: 28 page

Estimation of Completion of Dormancy in Grapevine Bud Based on Cumulative Temperature

　This study was conducted to investigate the relationship between completion of dormancy of grapevine bud and temperature. Canes of ‘Kyoho’ and ‘Pione’ grapevines (Vitis labrusca×V. vinifera) grown in 7 vineyards with different temperature conditions, in Nagano, Northern Okayama, Yamanashi, Okayama, Okayama University, Fukuoka and Miyazaki, were collected at three different chilling exposures, December, January and February. These were then sent to Okayama University all at the same time. Cuttings with one bud were put into growth chambers kept at 25 or 30°C with 14 hours daylength, and budbreak in each cutting was surveyed at two day intervals for 60 days. Cumulative chilling hours (CCH) of exposure to below 7.2°C in each treatment time was largest in Nagano, followed in order by Northern Okayama, Yamanashi, Okayama, Okayama University, Fukuoka and Miyazaki. The CCH in Nagano was 2.5 to 4.8 times larger than in Miyazaki depending on the treatment time. The later the treatment time and the higher the temperature, the fewer were the number of days to first budbreak (NDFB) after treatment, irrespective of cultivar. A similar trend was observed in the number of days to 60% budbreak. In ‘Kyoho’ the NDFB was short in Nagano, Okayama University and Miyazaki, and longer in Okayama, Yamanashi and Fukuoka. In ‘Pione’ the NDFB was short in Fukuoka and Okayama University, and longer in Yamanashi and Okayama. The result was a weak negative correlation observed between CCH and NDFB in 4 of 7 vineyards. However, there was a strong positive correlation between NDFB and cumulative temperature (CT), a summation of temperature and hours of exposure to above 0°C from November 1 to treatment time and hours of exposure to 25 or 30°C from start of treatment to budbreak in each plot, in 6 vineyards excluding Miyazaki. The importance of estimating the completion of dormancy in grapevine bud based on CT is discussed.ブドウの芽の休眠完了と温度との関係を調査するため，温度条件の異なる７園（中信農試，山梨果試，岡山農試，岡山農試北部支場，岡山大学，福岡農試および宮崎）で栽培されている‘巨峰’と‘ピオーネ’から低温遭遇量の異なる３時期（12月，１月，２月）に結果母枝を採取した．直ちに岡山大学に送り，１芽を持つ挿し穂に調整した後，25または30℃のインキュベーター（14時間日長）に入れ，２日間隔で60日間発芽を調査した．処理開始時の7.2℃以下の遭遇量は中信農試で最も多く，次いで岡山農試北部支場，山梨果試，岡山農試，岡山大学，福岡農試，宮崎の順で，中信農試と宮崎では処理時期により2.5～4.8倍の差があった．発芽所要日数は，両品種とも処理時期が遅いほど，また温度が高いほど少なく，60％発芽所要日数もほぼ同様の傾向であった．‘巨峰’の発芽所用日数は中信農試，岡山大学および宮崎で少ない一方，岡山農試，山梨果試および福岡農試で多く，また‘ピオーネ’では福岡農試と岡山大学で少なく，山梨果試と岡山農試で多かった．７園のうち４園で低温遭遇量と発芽所要日数との間に負の相関がみられたが，相関係数は低かった．一方，11月以降処理開始までの０℃以上の温度の積算値と処理開始から発芽までの25または30℃での積算値を合計した積算温度と発芽所要日数との間には１園を除き極めて高い正の相関が認められた．これらの結果を基に，積算温度によるブドウの休眠完了予測の可能性を考察した

Combinatorial Bethe ansatz and ultradiscrete Riemann theta function with rational characteristics

The U_q(\hat{sl}_2) vertex model at q=0 with periodic boundary condition is an integrable cellular automaton in one-dimension. By the combinatorial Bethe ansatz, the initial value problem is solved for arbitrary states in terms of an ultradiscrete analogue of the Riemann theta function with rational characteristics.Comment: 9 page

Tau functions in combinatorial Bethe ansatz

We introduce ultradiscrete tau functions associated with rigged configurations for A^{(1)}_n. They satisfy an ultradiscrete version of the Hirota bilinear equation and play a role analogous to a corner transfer matrix for the box-ball system. As an application, we establish a piecewise linear formula for the Kerov-Kirillov-Reshetikhin bijection in the combinatorial Bethe ansatz. They also lead to general N-soliton solutions of the box-ball system.Comment: 52 page