514 research outputs found
Network-Level Control of Frequency Tuning in Auditory Cortex
Lateral inhibition is a fundamental circuit operation that sharpens the tuning properties of cortical neurons. This operation is classically attributed to an increase in GABAergic synaptic input triggered by non-preferred stimuli. Here we use in vivo whole-cell recording and two-photon Ca imaging in awake mice to show that lateral inhibition shapes frequency tuning in primary auditory cortex via an unconventional mechanism: non-preferred tones suppress both excitatory and inhibitory synaptic inputs onto layer 2/3 cells ("network suppression"). Moreover, optogenetic inactivation of inhibitory interneurons elicits a paradoxical increase in inhibitory synaptic input. These results indicate that GABAergic interneurons regulate cortical activity indirectly via the suppression of recurrent excitation. Furthermore, the network suppression underlying lateral inhibition was blocked by inactivation of somatostatin-expressing interneurons (SOM cells), but not parvalbumin-expressing interneurons (PV cells). Together, these findings reveal that SOM cells govern lateral inhibition and control cortical frequency tuning through the regulation of reverberating recurrent circuits
Fear Learning Regulates Cortical Sensory Representations by Suppressing Habituation
Projections from auditory cortex to the amygdala are thought to contribute to the induction of auditory fear learning. In addition, fear conditioning has been found to enhance cortical responses to conditioned tones, suggesting that cortical plasticity contributes to fear learning. However, the functional role of auditory cortex in the retrieval of fear memories is unclear and how fear learning regulates cortical sensory representations is not well understood. To address these questions, we use acute optogenetic silencing and chronic two-photon calcium imaging in mouse auditory cortex during fear learning. Longitudinal imaging of neuronal ensemble activity reveals that discriminative fear learning modulates cortical sensory representations via the suppression of cortical habituation
Anti-glycopeptide mAb LpMab-21 against Podoplanin
Human podoplanin (hPDPN), which binds to Cātype lectinālike receptorā2 (CLECā2), is involved in platelet aggregation and cancer metastasis. The expression of hPDPN in cancer cells or cancerāassociated fibroblasts indicates poor prognosis. Human lymphatic endothelial cells, lungātype I alveolar cells, and renal glomerular epithelial cells express hPDPN. Although numerous monoclonal antibodies (mA bs) against hPDPN are available, they recognize peptide epitopes of hPDPN. Here, we generated a novel antiāhPDPN mA b, LpMabā21. To characterize the hPDPN epitope recognized by the LpMabā21, we established glycanādeficient CHOāS and HEKā293T cell lines, using the CRISPR/Cas9 or TALEN. Flow cytometric analysis revealed that the minimum hPDPN epitope, in which sialic acid is linked to Thr76, recognized by LpMabā21 is Thr76āArg79. LpMabā21 detected hPDPN expression in glioblastoma, oral squamous carcinoma, and seminoma cells as well as in normal lymphatic endothelial cells. However, LpMabā21 did not react with renal glomerular epithelial cells or lung type I alveolar cells, indicating that sialylation of hPDPN Thr76 is cellātypeāspecific. LpMabā21 combined with other antiāhPDPN antibodies that recognize different epitopes may therefore be useful for determining the physiological function of sialylated hPDPN
Persistent current of two-chain Hubbard model with impurities
The interplay between impurities and interactions is studied in the gapless
phase of two-chain Hubbard model in order to see how the screening of impurity
potentials due to repulsive interactions in single-chain model will be changed
by increasing the number of channels. Renormalization group calculations show
that charge stiffness, and hence persistent current, of the two-chain model are
less enhanced by interactions than single chain case.Comment: 4 Pages, RevTeX, No figures, Submitted to PR
Localizations in coupled electronic chains
We studied effects of random potentials and roles of electron-electron
interactions in the gapless phase of coupled Hubbard chains, using a
renormalization group technique. For non-interacting electrons, we obtained the
localization length proportional to the number of chains, as already shown in
the other approaches. For interacting electrons, the localization length is
longer for stronger interactions, that is, the interactions counteract the
random potentials. Accordingly, the localization length is not a simple linear
function of the number of chains. This interaction effect is strongest when
there is only a single chain. We also calculate the effects of interactions and
random potentials on charge stiffness.Comment: no figure, to appear in Phys. Rev.
Precise Measurement of dp Elastic Scattering at 270 MeV and Three-Nucleon Force Effects
The cross section, the deuteron vector Ayd and tensor analyzing powers Aij, the polarization transfer coefficients Kijyā², and the induced polarization Pyā² were measured for the dp elastic scattering at 270 MeV. The cross section and Ayd are well reproduced by Faddeev calculations with modern data-equivalent nucleon-nucleon forces plus the Tucson-Melbourne three-nucleon force. In contrast, Aij, Kijyā², or Pyā² are not described by such calculations. These facts indicate the deficiencies in the spin dependence of the Tucson-Melbourne force and call for extended three-nucleon force models
Observation of visible forbidden lines of tungsten highly charged ions in LHD core plasmas and its application to ion distribution analysis
ļ»æVisible emission lines of tungsten ions are useful for analysis of tungsten ion distributions at ITER because the radiation shielding of detectors is not basically necessary by using optical fibers. Here we report the result on observation of visible magnetic-dipole (M1) lines of highly-charged tungsten ions in the Large Helical Device (LHD) by tungsten pellet injection and its first application to the ion distribution analysis. Based on the measured spatial profile of an M1 line intensity of W27+, tungsten ion distributions in LHD core plasmas are quantitatively analyzed using a collisional-radiative model. Strong enhancement of the M1 line intensity due to proton collisions is predicted by the present calculation. Poloidal asymmetry of the tungsten density distribution in the core plasma is inferred from the present analysis. Peak tungsten concentration at the plasma center is evaluated to be as high as 10-2. Tungsten diffusion from the core plasma is observed in time variation of the deduced density profiles
Primary adenocarcinoma of the stomach in von Recklinghausen's disease with high serum levels of multiple tumor markers: a case report
<p>Abstract</p> <p>Introduction</p> <p>Gastric tumors in patients affected by neurofibromatosis type 1 are usually carcinoids or stromal tumors, and rarely adenocarcinomas.</p> <p>Case presentation</p> <p>We report a case of an adenocarcinoma of the stomach in a 53-year-old Japanese man with neurofibromatosis type 1. An abdominal computed tomography scan and ultrasonography showed tumors in his liver. Gastric fibroscopy revealed a Borrmann type III tumor on his cardia that had spread to his esophagus and was highly suspicious for malignancy. Multiple biopsies showed an adenocarcinoma of the stomach, which was evaluated as gastric cancer, stage IV. Chemotherapy with TS-1 was performed. Our patient died four weeks after initial admission. Histological examination of a liver needle biopsy showed metastatic adenocarcinoma in his liver.</p> <p>Conclusion</p> <p>To the best of our knowledge, high serum levels of Ī±-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen 72-4, resulting from gastric adenocarcinoma, have not been reported previously in a patient with neurofibromatosis type 1. We report this rare case along with a review of the literature.</p
Application of mesenchymal stem cells (MSC) to regenerative dentistry and identification of molecular markers for MSC
We characterized human bone marrow-derived mesenchymal stem cells (MSC) by identification of molecular markers and used these markers in clinical studies for treatment of periodontal disease: Auto-transplantation of MSC into periodontal defects enhanced regeneration of cementum, periodontal ligament and alveolar bone. Stem cell therapy could be a new frontier in dentistry
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