New record of Chromis weberi (Actinopterygii: Ovalentaria: Pomacentridae) from Jeju Island, southern Korea

Discovering tropical marine species outside of their distribution limits is important for evaluating the impact of climate change on marine ecosystems. One specimen (31.6 mm standard length) of a tropical fish, Chromis weberi Fowler et Bean, 1928, representing the family Pomacentridae, was first recorded from Jeju Island, Korea, on 8 December 2021. It was characterized by black posterior margins of the preopercle and opercle and black upper and lower lobes of the caudal fin. A specimen of this species collected from Munseom was distinguished from Chromis xanthura (Bleeker, 1854) based on distinct differences in the tips of the upper and lower caudal fin lobes, which are not black in C. xanthura. In addition, C. weberi was easily distinguished from the other four species in the genus Chromis, by the mitochondrial DNA cytochrome c oxidase subunit I gene sequence (345 bp), with genetic distances ranging from 0.130 to 0.252. This study documents the first record of C. weberi in temperate Korean waters, implying a poleward range expansion for this species. The Korean name ‘geom-eun-jeom-ggo-ri-ja-ri-dom’ has been proposed for C. weberi

SALM4 suppresses excitatory synapse development by cis-inhibiting trans-synaptic SALM3-LAR adhesion

Synaptic adhesion molecules regulate various aspects of synapse development, function and plasticity. These functions mainly involve trans-synaptic interactions and positive regulations, whereas cis-interactions and negative regulation are less understood. Here we report that SALM4, a member of the SALM/Lrfn family of synaptic adhesion molecules, suppresses excitatory synapse development through cis inhibition of SALM3, another SALM family protein with synaptogenic activity. Salm4-mutant (Salm4) mice show increased excitatory synapse numbers in the hippocampus. SALM4 cis-interacts with SALM3, inhibits trans-synaptic SALM3 interaction with presynaptic LAR family receptor tyrosine phosphatases and suppresses SALM3-dependent presynaptic differentiation. Importantly, deletion of Salm3 in Salm4 mice (Salm3, Salm4) normalizes the increased excitatory synapse number. These results suggest that SALM4 negatively regulates excitatory synapses via cis inhibition of the trans-synaptic SALM3-LAR adhesion. © The Author(s) 2016110101sciescopu

Lack of Toll-like Receptor 4 and 2 Polymorphisms in Korean Patients with Bacteremia

Toll-like receptors (TLRs) are pattern-recognition receptors that are important in innate immune responses to bacterial infection. The purpose of this study is to describe the prevalence of TLRs genetic variations in the bacteremic patients in Korea. A total of 154 patients with bacteremia and 179 healthy volunteers were included. The Asp299Gly and Thr399Ile allele of the TLR4 gene and Arg753Gln and Arg677Trp allele of the TLR2 gene were tested by PCR-RFLP. The DNA sequences were determined to confirm the PCR-RFLP results. Contrary to the expectation, no genetic polymorphisms were detected in both groups of this study, suggesting that it is very rare in Korean

The First Very Long Baseline Interferometry Image of 44 GHz Methanol Maser with the KVN and VERA Array (KaVA)

We have carried out the first very long baseline interferometry (VLBI) imaging of 44 GHz class I methanol maser (7_{0}-6_{1}A^{+}) associated with a millimeter core MM2 in a massive star-forming region IRAS 18151-1208 with KaVA (KVN and VERA Array), which is a newly combined array of KVN (Korean VLBI Network) and VERA (VLBI Exploration of Radio Astrometry). We have succeeded in imaging compact maser features with a synthesized beam size of 2.7 milliarcseconds x 1.5 milliarcseconds (mas). These features are detected at a limited number of baselines within the length of shorter than approximately 650 km corresponding to 100 Mlambda in the uv-coverage. The central velocity and the velocity width of the 44 GHz methanol maser are consistent with those of the quiescent gas rather than the outflow traced by the SiO thermal line. The minimum component size among the maser features is ~ 5 mas x 2 mas, which corresponds to the linear size of ~ 15 AU x 6 AU assuming a distance of 3 kpc. The brightness temperatures of these features range from ~ 3.5 x 10^{8} to 1.0 x 10^{10} K, which are higher than estimated lower limit from a previous Very Large Array observation with the highest spatial resolution of ~ 50 mas. The 44 GHz class I methanol maser in IRAS 18151-1208 is found to be associated with the MM2 core, which is thought to be less evolved than another millimeter core MM1 associated with the 6.7 GHz class II methanol maser.Comment: 19 pages, 3 figure

Baseline Renal Function Predicts Hyponatremia in Liver Cirrhosis Patients Treated with Terlipressin for Variceal Bleeding

Objectives. Terlipressin is safely used for acute variceal bleeding. However, side effects, such as hyponatremia, although very rare, can occur. We investigated the development of hyponatremia in cirrhotic patients who had acute variceal bleeding treated with terlipressin and the identification of the risk factors associated with the development of hyponatremia. Design and Methods. This retrospective, case-control study investigated 88 cirrhotic patients who developed hyponatremia and 176 controls that did not develop hyponatremia and were matched in terms of age and gender during the same period following terlipressin administration. Results. The overall change in serum sodium concentration and the mean lowest serum sodium concentration were 3.44 ± 9.55 and 132.44 ± 8.78 mEq/L during treatment, respectively. Multivariate analysis revealed that baseline serum sodium was an independent positive predictor, and the presence of baseline serum creatinine, HBV, DM, creatinine, and shock on admission was independent negative predictors of hyponatremia (P<0.05). Conclusion. The presence of HBV, DM, the baseline serum sodium, shock on admission, and especially baseline creatinine may be predictive of the development of hyponatremia after terlipressin treatment. Therefore, physicians conduct vigilant monitoring associated with severe hyponatremia when cirrhotic patients with preserved renal function are treated with terlipressin for variceal bleeding

Long-term regulation of voltage-gated Ca2+ channels by gabapentin

AbstractGabapentin (GBP) is a γ-aminobutyric acid analog effective in the treatment of seizures. A high-affinity interaction between GBP and the α2δ subunit of the voltage-gated Ca2+ channels has been documented. In this report, we examined the effects of the chronic treatment with GBP on neuronal recombinant P/Q-type Ca2+ channels expressed in Xenopus oocytes. GBP did not affect significantly the amplitude or the voltage dependence of the currents. Exposure to the drug did, however, slow down the kinetics of inactivation in a dose-dependent fashion. In addition, biochemical analysis showed that the integrity of Ca2+ channel complex is not apparently affected by GBP binding, suggesting that chronic treatment with the drug might cause the channel kinetic modification through subtle conformational changes of the protein complex

Stress-induced changes in social dominance are scaled by AMPA-type glutamate receptor phosphorylation in the medial prefrontal cortex

The establishment and maintenance of social dominance are critical for social stability and the survival and health of individual animals. Stress lead to depression and a decrease in the social status of depressed persons is a risk factor for suicide. Therefore, we explored the mechanistic and behavioral links among stress, depression, and social dominance and found that mice subjected to chronic restraint stress (CRS), an animal model of stress-induced depression, showed decreased social dominance as measured by a dominance tube test. Importantly, this submissive behavior was occluded by the antidepressant, fluoxetine, a selective serotonin reuptake inhibitor. It is known that social dominance is controlled by synaptic efficacy in the medial prefrontal cortex (mPFC) and that AMPA-type glutamate receptor (AMPA-R) is a key molecule for synaptic efficacy. We found that the phosphorylation on AMPA-R was bidirectionally changed by CRS and fluoxetine in the mPFC of mice with CRS. Moreover, we found a strong correlation between social dominance and AMPA-R phosphorylation that regulates synaptic efficacy by modulating the synaptic targeting of AMPA-R. Our correlational analysis of the behavior and biochemistry of the CRS model suggests that AMPA-R phosphorylation in the mPFC may serve as a biomarker of social dominance related to stress. (c) 2018, The Author(s)11Nsci

Neuronal calcium channel alpha(1) subunit interacts with AMPA receptor, increasing its cell surface localisation

Voltage-activated Ca2+ channels (Ca-v) play critical roles in excitable cells including neurons. Unlike the well-defined roles of Ca(v)2 for pre-synaptic neurotransmission, the post-synaptic function of Ca(v)2 is unclear. Based on our previous study demonstrating the postsynaptic association of the Ca(v)2 with the AMPA receptor (AMPA-R), in this study we sought to further analyse the Ca(v)2-AMPA-R association. We used a step-by-step dissociation of partially purified native Ca(v)2-AMPA-R complexes and co-immunoprecipitation of the Ca(v)2-AMPA-R complexes expressed in HEK293T cells to demonstrate that the main subunit of Ca-v, alpha(1), formed a complex with the AMPA-R without the auxiliary subunits beta, alpha(2)delta, gamma(2/3). The alpha(1) subunit increased the cell-surface localisation of the AMPA-R, which could be a post-synaptic function of the Ca(v)2. (C) 2018 Elsevier Inc. All rights reserved11Nsci

A functional AMPA receptor–calcium channel complex in the postsynaptic membrane

Ca(2+) channels play critical roles in the regulation of synaptic activity. In contrast to the well established function of voltage-activated Ca(2+) channels in the presynaptic membrane for neurotransmitter release, some studies are just beginning to elucidate the functions of the Ca(2+) channels in the postsynaptic membrane. In this study, we demonstrated the functional association of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors with the neuronal Ca(2+) channels. A series of biochemical studies showed the specific association of Ca(v)2.1 (α(1A)-class) and Ca(v)2.2 (α(1B)-class) with AMPA receptors in the postsynaptic membrane. Our electrophysiological and Ca(2+) imaging analyses of recombinant Ca(v)2.1 and AMPA receptors also showed functional coupling of the two channels. Considering the critical roles of postsynaptic intracellular concentration of Ca(2+) ([Ca(2+)](i)) increase and AMPA receptor trafficking for long-term potentiation (LTP) and long-term depression (LTD), the functional association of Ca(2+) channels with the AMPA receptors may provide new insights into the mechanism of synaptic plasticity