Activin in the Brain Modulates Anxiety-Related Behavior and Adult Neurogenesis

Activin, a member of the transforming growth factor-β superfamily, is an endocrine hormone that regulates differentiation and proliferation of a wide variety of cells. In the brain, activin protects neurons from ischemic damage. In this study, we demonstrate that activin modulates anxiety-related behavior by analyzing ACM4 and FSM transgenic mice in which activin and follistatin (which antagonizes the activin signal), respectively, were overexpressed in a forebrain-specific manner under the control of the αCaMKII promoter. Behavioral analyses revealed that FSM mice exhibited enhanced anxiety compared to wild-type littermates, while ACM4 mice showed reduced anxiety. Importantly, survival of newly formed neurons in the subgranular zone of adult hippocampus was significantly decreased in FSM mice, which was partially rescued in ACM4/FSM double transgenic mice. Our findings demonstrate that the level of activin in the adult brain bi-directionally influences anxiety-related behavior. These results further suggest that decreases in postnatal neurogenesis caused by activin inhibition affect an anxiety-related behavior in adulthood. Activin and its signaling pathway may represent novel therapeutic targets for anxiety disorder as well as ischemic brain injury

Significant photoresponsivity enhancement of polycrystalline BaSi2 films formed on heated Si(111) substrates by sputtering

We fabricated approximately 200-nm-thick BaSi2 films on Si(111) substrates at 600 °C. The formation of BaSi2 was demonstrated by X-ray diffraction and Raman spectroscopy. A reduction in the electron concentration (n = 2 × 1016 cm−3) by 3 orders of magnitude compared to that previously reported (n = 7 × 1019 cm−3) and resultant photoresponsivity enhancement by more than two orders of magnitude were achieved. The photoresponsivity increased with the bias voltage V bias applied between the top and bottom electrodes, and reached approximately 0.19 A/W at 2.0 eV, room temperature, and |V bias| = 0.5 V

Cloning of cDNA and genomic DNA for human cytochrome P-45011β

AbstractA full-length cDNA clone encoding steroid 11β-hydroxylase (P-45011β) has been isolated from a cDNA library derived from human adrenal tumor. The insert of the clone contains an open reading frame encoding a protein of 503 amino acid residues together with a 4 bp 5'-untranslated region and a 576 bp 3'-untranslated region to which a poly(A) tract is attached. The promoter region of the P-45011β gene has also been isolated from a genomic library derived from human pre-B cells. It contains a TATA box, a putative cAMP-responsive element, several repeated sequences and two sequence elements similar to the consensus sequence for binding of AP-1. A transient expression assay in Y-1 adrenal tumor cells demonstrates that the promoter activity is remarkably enhanced by treatment of the cells with cAMP. In addition, analysis using deletion mutants containing various lengths of the 5'-flanking region of the gene suggests that several cis-acting elements participate in transcriptional regulation of human P-45011β gene

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研究報

Variational state based on the Bethe ansatz solution and a correlated singlet liquid state in the one-dimensional t-J model

The one-dimensional t-J model is investigated by the variational Monte Carlo method. A variational wave function based on the Bethe ansatz solution is newly proposed, where the spin-charge separation is realized, and a long-range correlation factor of Jastrow-type is included. In most regions of the phase diagram, this wave function provides an excellent description of the ground-state properties characterized as a Tomonaga-Luttinger liquid; Both of the amplitude and exponent of correlation functions are correctly reproduced. For the spin-gap phase, another trial state of correlated singlet pairs with a Jastrow factor is introduced. This wave function shows generalized Luther-Emery liquid behavior, exhibiting enhanced superconducting correlations and exponential decay of the spin correlation function. Using these two variational wave functions, the whole phase diagram is determined. In addition, relations between the correlation exponent and variational parameters in the trial functions are derived.Comment: REVTeX 3.0, 27 pages. 7 figures available upon request ([email protected]). To be published in Phys. Rev. B 5

Measurement of evaporation-residue cross sections with light beams and deformed lanthanide target nuclei

To obtain a better understanding of the fusion reaction, we have focused on reactions involving deformed nuclei. Evaporation residue cross sections of the 169Tm+20Ne reaction were measured, from which we extracted the fusion excitation function. This is compared with literature data of the 169Tm+16O and 165Ho+20Ne systems. Irradiation with 20Ne ion beam has been carried out at the incident energy near the Coulomb barrier, where the effect of nuclear deformation is prominent. The results are consistent with the idea that the degree of deformation has an effect on the threshold value of the excitation functions near the Coulomb barrier