42 research outputs found

    Sublayer- and cell-type-specific neurodegenerative transcriptional trajectories in hippocampal sclerosis

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    Hippocampal sclerosis, the major neuropathological hallmark of temporal lobe epilepsy, is characterized by different patterns of neuronal loss. The mechanisms of cell-type-specific vulnerability and their progression and histopathological classification remain controversial. Using single-cell electrophysiology in vivo and immediate-early gene expression, we reveal that superficial CA1 pyramidal neurons are overactive in epileptic rodents. Bulk tissue and single-nucleus expression profiling disclose sublayer-specific transcriptomic signatures and robust microglial pro-inflammatory responses. Transcripts regulating neuronal processes such as voltage channels, synaptic signaling, and cell adhesion are deregulated differently by epilepsy across sublayers, whereas neurodegenerative signatures primarily involve superficial cells. Pseudotime analysis of gene expression in single nuclei and in situ validation reveal separated trajectories from health to epilepsy across cell types and identify a subset of superficial cells undergoing a later stage in neurodegeneration. Our findings indicate that sublayer- and cell-type-specific changes associated with selective CA1 neuronal damage contribute to progression of hippocampal sclerosis.This work was supported by grants from MICINN (RTI2018-098581-B-I00 to L.M.P.), Fundación Tatiana Pérez de Guzman el Bueno, and the SynCogDis Network (SAF2014-52624-REDT and SAF2017- 90664-REDT to L.M.P. and A. Bayes). Collaboration between L.M.d.l.P. and Y.H. was supported by Human Frontiers Science Program (HFSP) grant RGP0022/2013. J.P.L.-A. was supported by grants from MICIU co-financed by ERDF (RYC-2015-18056 and RTI2018-102260-B-I00) and Severo Ochoa grant SEV-2017-0723. R.R.-V. and A. Bayes were supported by MINECO BFU2015-69717-P and RTI2018-097037-B-100 and a Marie Curie career integration grant (ref. 304111). A.V.M. was supported by MICINN (SAF2017- 85717-R) and Fundación Alicia Koplowitz. A. Barco was supported by grants SAF2017-87928-R from MICINN co-financed by ERDF and RGP0039/2017 from the Human Frontiers Science Program Organization. The Instituto de Neurociencias is a ‘‘Centre of Excellence Severo Ochoa.’’ D.G.-D. and C.M.N. hold PhD fellowships from MICINN (BES-2013-064171 and BES2016-076281, respectively).Peer reviewe

    Common Features at the Start of the Neurodegeneration Cascade

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    A single-molecule study reveals that neurotoxic proteins share common structural features that may trigger neurodegeneration, thus identifying new targets for therapy and diagnosis

    The CARMENES search for exoplanets around M dwarfs High-resolution optical and near-infrared spectroscopy of 324 survey stars

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    The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520–1710 nm at a resolution of at least R >80 000, and we measure its RV, Hα emission, and projected rotation velocity. We present an atlas of high-resolution M-dwarf spectra and compare the spectra to atmospheric models. To quantify the RV precision that can be achieved in low-mass stars over the CARMENES wavelength range, we analyze our empirical information on the RV precision from more than 6500 observations. We compare our high-resolution M-dwarf spectra to atmospheric models where we determine the spectroscopic RV information content, Q, and signal-to-noise ratio. We find that for all M-type dwarfs, the highest RV precision can be reached in the wavelength range 700–900 nm. Observations at longer wavelengths are equally precise only at the very latest spectral types (M8 and M9). We demonstrate that in this spectroscopic range, the large amount of absorption features compensates for the intrinsic faintness of an M7 star. To reach an RV precision of 1 m s−1 in very low mass M dwarfs at longer wavelengths likely requires the use of a 10 m class telescope. For spectral types M6 and earlier, the combination of a red visual and a near-infrared spectrograph is ideal to search for low-mass planets and to distinguish between planets and stellar variability. At a 4 m class telescope, an instrument like CARMENES has the potential to push the RV precision well below the typical jitter level of 3–4 m s−1

    The CARMENES search for exoplanets around M dwarfs HD147379 b: A nearby Neptune in the temperate zone of an early-M dwarf

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    We report on the first star discovered to host a planet detected by radial velocity (RV) observations obtained within the CARMENES survey for exoplanets around M dwarfs. HD 147379 (V = 8.9 mag, M = 0.58 ± 0.08 M⊙), a bright M0.0 V star at a distance of 10.7 pc, is found to undergo periodic RV variations with a semi-amplitude of K = 5.1 ± 0.4 m s−1 and a period of P = 86.54 ± 0.06 d. The RV signal is found in our CARMENES data, which were taken between 2016 and 2017, and is supported by HIRES/Keck observations that were obtained since 2000. The RV variations are interpreted as resulting from a planet of minimum mass mP sin i = 25 ± 2 M⊕, 1.5 times the mass of Neptune, with an orbital semi-major axis a = 0.32 au and low eccentricity (e < 0.13). HD 147379 b is orbiting inside the temperate zone around the star, where water could exist in liquid form. The RV time-series and various spectroscopic indicators show additional hints of variations at an approximate period of 21.1 d (and its first harmonic), which we attribute to the rotation period of the star.FEDER/ERF FICTS-2011-02 fundsMajor Research Instrumentation Programme and DFG Research Unit FOR2544 “Blue Planets around Red StarsEuropean Research Council (ERC-279347), Deutsche Forschungsgemeinschaft (RE 1664/12-1, RE 2694/4-1), Bundesministerium für Bildung und Forschung (BMBF-05A14MG3, BMBF-05A17MG3), Spanish Ministry of Economy and Competitiveness (MINECO, grants AYA2015-68012-C2-2-P, AYA2016-79425-C3-1,2,3-P, AYA2015-69350-C3-2-P, AYA2014-54348-C03- 01, AYA2014-56359-P, AYA2014-54348-C3-2-R, AYA2016-79425-C3-3-P and 2013 Ramòn y Cajal program RYC-2013-14875), Fondo Europeo de Desarrollo Regional (FEDER, grant ESP2016-80435-C2-1-R, ESP2015-65712-C5- 5-R), Generalitat de Catalunya/CERCA programme, Spanish Ministerio de Educación, Cultura y Deporte, programa de Formación de Profesorado Universitario (grant FPU15/01476), Deutsches Zentrum für Luft- und Raumfahrt (grants 50OW0204 and 50OO1501), Office of Naval Research Global (award no. N62909-15-1-2011), Mexican CONACyT grant CB-2012-183007

    CARMENES: high-resolution spectra and precise radial velocities in the red and infrared

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    SPIE Astronomical Telescopes + Instrumentation (2018, Austin, Texas, United States

    Summary of the nanomechanical analysis of NPs.

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    <p>SMFS experiments were performed on pFS-2 polyprotein constructs, although the data reported only refer to the guest NPs. The calculation of the associated experimental errors is described in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001335#pbio.1001335.s018" target="_blank">Text S1</a> and they are only indicated when they are different to zero. Due to the small number of events, the frequency of hM conformers in the NPs (a subset of the M set, operationally defined with a high <i>F</i> cut off) is not statistically significant. However it correlates very well with the %M. Furthermore, statistical analysis shows that, with the exception of polyQ tracts (for which the number of M, events is too low), the differences in the %M events for NP guests are statistically significant for the following pairs: NP and non-NP, NP and familial NP, NP (except for Arc Aβ42) and NP+QBP1. These differences are not statistically significant for the following pairs: Aβ42 and Aβ42+SV111, Arc Aβ42 and Arc Aβ42+QBP1, and non NPs. The numbers in parenthesis are half of the 95% confidence interval for the %M (or NM, modeled as a Bernoulli distribution) while the numbers after ± are the SMFS experimental errors. Note that the % numbers here are the estimation for the population while the % numbers in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001335#pbio-1001335-g002" target="_blank">Figures 2</a>–<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001335#pbio-1001335-g003" target="_blank"></a><a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001335#pbio-1001335-g004" target="_blank"></a><a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001335#pbio-1001335-g005" target="_blank">5</a> correspond to the raw samples.</p><p><i>n</i>, sample size. NM, no force peaks detected: <i>F</i>≤20 pN; M, at least one force peak: <i>F</i>>20 pN; hM, subset of M conformers with at least one force peak with <i>F</i>≥400 pN.</p
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