Enhancing adult hippocampal neurogenesis with lysophosphatidic acid: a proposal for erasing cocaine contextual memory

Stimulating adult hippocampal neurogenesis (AHN) has been uncovered as a promising approach in the manipulation of retrograde memories. This work aims to study whether increasing AHN with lysophosphatidic acid (LPA, an endogenous lysophospholipid with proneurogenic actions) promotes the forgetting of previously established cocaine-contextual associations. C57BL/6J mice previously trained in a cocaine-induced conditioned place preference (CPP) paradigm were submitted to 23 days of withdrawal, during which they received repeated intracerebroventricular infusions of LPA, ki16425 (a selective LPA1/3 receptors antagonist), or vehicle solution. Then, CPP maintenance was assessed, and the causal role of AHN in this process was evaluated using a mediation analysis. In a complementary experiment, wild-type and LPA1-null mice were acutely infused with LPA or ki16425 to determine the involvement of the LPA1 receptor in the in vivo proneurogenic actions of LPA. The chronic LPA treatment significantly weakened the long-term retention of a previously acquired cocaine-CPP memory, an effect clearly mediated by a LPA-induced increase in the number of adult-born dentate granule cells. In contrast, the ki16425-treated mice displayed aberrant responses of initially decreased CPP retention that progressively increased CPP across the extinction sessions, in absence of effects on AHN. The histological studies suggested that the proneurogenic actions of LPA were related to the enhancement of cell proliferation and critically depended on the LPA1 receptor function. Our results suggest that the LPA/LPA1-pathway acts as a potent in vivo modulator of AHN, and highlight the usefulness of a post-learning increase of adult-born hippocampal neurons as a strategy to promote the forgetting of cocaine-context associations.Plan Propio de Investigación y Transferencia. Campus de Excelencia Internacional Andalucía Tech. Spanish Ministry of Economy and Competitiveness (Agencia Estatal de Investigación), co‐funded by the European Research Development Fund (AEI/FEDER, UE) (PSI2013‐44901‐P and PSI2017‐82604‐R to L.J.S. and PSI2015‐73156‐JIN to E.C.O.); by the National System of Health‐Instituto de Salud Carlos III, which is co‐funded by AEI/FEDER, UE (Red de Trastornos Adictivos; RD16/0017/0001 to F.R.d.F.); and by the Andalusian R&D&I Programme, Regional Ministry of Economy and Knowledge (PAIDI CTS643 to G.E.T.). D.L.G.M. hold a FPU grant from the Spanish Ministry of Education, Culture and Sports (FPU13/04819 ). F.R.d.F. and G.E.T. are supported by Nicolas Monardes Programme, from the Andalusian Regional Ministry of Health. E.C.O. holds a ‘Jóvenes Investigadores’ grant (code: PSI2015‐73156‐JIN) from the Spanish Ministry of Economy and Competitiveness (Agencia Estatal de Investigación), which is co‐funded by the AEI/FEDER, UE

Magnetic and structural characterization of thiol capped ferromagnetic Ag nanoparticles

Dodecanethiol capped Ag nanoparticles (NPs) have been independently synthesized by the well-known Brust method under the same physical-chemical conditions. The obtained NP present similar sizes ( ∼ 2 nm) but different magnetic behaviors. The extended x-ray absorption fine structure analyses at the K-edge of Ag did not reveal any noticeable structural nor topological differences among the samples. In clear contrast with the structure provided for thiol capped ferromagnetic Au NPs, the analysis also brings out the existence of Ag–S bonds in a diffuse region surrounding a reduced Ag core where the magnetism of the Ag NPs would be located. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

L1 transfer in the acquisition of manner and path in Spanish by native speakers of English

In this article the authors argue that L1 transfer from English is not only important in the early stages of L2 acquisition of Spanish, but remains influential in later stages if there is not enough positive evidence for the learners to progress in their development (Lefebvre, White, & Jourdan, 2006). The findings are based on analyses of path and manner of movement in stories told by British students of Spanish (N = 68) of three different proficiency levels. Verbs that conflate motion and path, on the one hand, are mastered early, possibly because the existence of Latinate path verbs, such as enter and ascend in English, facilitate their early acquisition by British learners of Spanish. Contrary to the findings of Cadierno (2004) and Cadierno and Ruiz (2006), the encoding of manner, in particular in boundary crossing contexts, seems to pose enormous difficulties, even among students who had been abroad on a placement in a Spanish-speaking country prior to the data collection. An analysis of the frequency of manner verbs in Spanish corpora shows that one of the key reasons why students struggle with manner is that manner verbs are so infrequent in Spanish. The authors claim that scarce positive evidence in the language exposed to and little or no negative evidence are responsible for the long-lasting effect of transfer on the expression of manner

Besnoitiosis bovina: Estudio de los factores de riesgo asociados a la infección en una explotación del Pirineo aragonés (abstract)

La Besnoitiosis bovina es una enfermedad parasitaria de carácter reemergente causada por el protozoo Besnoitia besnoiti que en los últimos años ha experimentado un aumento en su prevalencia y una expansión geográfica en Europa (EFSA, 2010).Publishe

Two-step ATP-driven opening of cohesin head

The cohesin ring is a protein complex composed of four core subunits: Smc1A, Smc3, Rad21 and Stag1/2. It is involved in chromosome segregation, DNA repair, chromatin organization and transcription regulation. Opening of the ring occurs at the "head" structure, formed of the ATPase domains of Smc1A and Smc3 and Rad21. We investigate the mechanisms of the cohesin ring opening using techniques of free molecular dynamics (MD), steered MD and quantum mechanics/molecular mechanics MD (QM/MM MD). The study allows the thorough analysis of the opening events at the atomic scale: I) ATP hydrolysis at the Smc1A site, evaluating the role of the carboxy-terminal domain of Rad21 in the process; ii) the activation of the Smc3 site potentially mediated by the movement of specific amino acids; and iii) opening of the head domains after the two ATP hydrolysis events. Our study suggests that the cohesin ring opening is triggered by a sequential activation of the ATP sites in which ATP hydrolysis at the Smc1A site induces ATPase activity at the Smc3 site. Our analysis also provides an explanation for the effect of pathogenic variants related to cohesinopathies and cancer

Leptin levels were negatively associated with lumbar spine bone mineral content in children with overweight or obesity

Aim: Adipokines seem to play a role in bone morphogenesis, although this also depends on the mechanical forces applied to the skeleton. The aim was to assess the relationships of resting leptin and adiponectin with bone parameters and whether high muscular fitness levels affect these relationships in children with overweight or obesity. Methods: This cross-sectional study took part from 2014 to 2016 in Granada, Spain. Participants were recruited from University Hospitals, and we also used advertisements in local media and school contacts in the city. Adipokines were analysed in plasma. Muscular fitness was assessed by one repetition maximum in bench and leg press tests. Dual-energy X-ray absorptiometry was used to measure bone parameters. Results: We included 84 children (10.0 ± 1.2y; 63% boys) in this analysis. Leptin was negatively associated with lumbar spine bone mineral content (β = −0.162, p = 0.053)

Aperture effects on the oxygen abundance determinations from CALIFA data

This paper aims at providing aperture corrections for emission lines in a sample of spiral galaxies from the Calar Alto Legacy Integral Field Area Survey (CALIFA) database. In particular, we explore the behavior of the log([OIII]5007/Hbeta)/([NII]6583/Halpha) (O3N2) and log[NII]6583/Halpha (N2) flux ratios since they are closely connected to different empirical calibrations of the oxygen abundances in star forming galaxies. We compute median growth curves of Halpha, Halpha/Hbeta, O3N2 and N2 up to 2.5R_50 and 1.5 disk R_eff. The growth curves simulate the effect of observing galaxies through apertures of varying radii. The median growth curve of the Halpha/Hbeta ratio monotonically decreases from the center towards larger radii, showing for small apertures a maximum value of ~10% larger than the integrated one. The median growth curve of N2 shows a similar behavior, decreasing from the center towards larger radii. No strong dependence is seen with the inclination, morphological type and stellar mass for these growth curves. Finally, the median growth curve of O3N2 increases monotonically with radius. However, at small radii it shows systematically higher values for galaxies of earlier morphological types and for high stellar mass galaxies. Applying our aperture corrections to a sample of galaxies from the SDSS survey at 0.02<=z<=0.3 shows that the average difference between fiber-based and aperture corrected oxygen abundances, for different galaxy stellar mass and redshift ranges, reaches typically to ~11%, depending on the abundance calibration used. This average difference is found to be systematically biased, though still within the typical uncertainties of oxygen abundances derived from empirical calibrations. Caution must be exercised when using observations of galaxies for small radii (e.g. below 0.5R_eff) given the high dispersion shown around the median growth curves.Comment: Accepted for publication in Ap

Training memory without aversion: Appetitive hole-board spatial learning increases adult hippocampal neurogenesis.

Learning experiences are potent modulators of adult hippocampal neurogenesis (AHN). However, the vast majority of findings on the learning-induced regulation of AHN derive from aversively-motivated tasks, mainly the water maze paradigm, in which stress is a confounding factor that affects the AHN outcome. Currently, little is known regarding the effect of appetitively-motivated training on AHN. Hence we studied how spatial learning to find food rewards in a hole-board maze modulates AHN (cell proliferation and immature neurons) and AHN-related hippocampal neuroplasticity markers (BDNF, IGF-II and CREB phosphorylation) in mice. The 'Trained' mice were tested for both spatial reference and working memory and compared to 'Pseudotrained' mice (exposed to different baited holes in each session, thus avoiding the reference memory component of the task) and 'Control' mice (exposed to the maze without rewards). In contrast to Pseudotrained and Control mice, Trained mice reduced the number of proliferating hippocampal cells but they notably increased their population of immature neurons assessed by immunohistochemistry. This evidence shows that hole-board spatial reference learning diminishes cell proliferation in favor of enhancing young neurons' survival. Interestingly, the enhanced AHN in the Trained mice (specifically in the suprapyramidal blade) positively correlated with their reference memory performance, but not with their working memory. Furthermore, the Trained animals increased the hippocampal protein expression of all the neuroplasticity markers analyzed by western blot. Results show that the appetitively-motivated hole-board task is an useful paradigm to potentiate and/or investigate AHN and hippocampal plasticity minimizing aversive variables such as fear or stress.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This study was funded by grants from the Spanish Ministry of Economy and Competitiveness (Agencia Estatal de Investigación) co-funded by the European Research Development Fund -AEI/FEDER, UE- (PSI2015-73156-JIN ‘Jóvenes Investigadores grant’ to E.C.O. and PSI2013-44901-P to L.J.S. and C.P.), from ‘Junta de Andalucía’ SEJ1863 to C.P. and from University of Málaga (Plan Propio 2017 – ‘Ayudas para proyectos puente’) to M.G.F. Author P.S.P. holds a ‘Juan de la Cierva-formación‘grant from the Spanish Ministry of Economy, Industry and Competitiveness (code: FJCI-2015-23925) and a ‘D.3. Estancia de investigadores de reconocido prestigio en la UMA‘ grant from the University of Málaga. Authors R.D.M.F. and D.L.G.M. hold ‘FPU’ grants from the Spanish Ministry of Education, Culture and Sports (code: FPU14-01610 and FPU13/04819, respectively). Author F.J.P. holds a ‘Miguel Servet’ grant (code: CP14/00212) from the National System of Health-Instituto de Salud Carlos-III co-funded by FEDER, UE

Stellar Population gradients in galaxy discs from the CALIFA survey

While studies of gas-phase metallicity gradients in disc galaxies are common, very little has been done in the acquisition of stellar abundance gradients in the same regions. We present here a comparative study of the stellar metallicity and age distributions in a sample of 62 nearly face-on, spiral galaxies with and without bars, using data from the CALIFA survey. We measure the slopes of the gradients and study their relation with other properties of the galaxies. We find that the mean stellar age and metallicity gradients in the disc are shallow and negative. Furthermore, when normalized to the effective radius of the disc, the slope of the stellar population gradients does not correlate with the mass or with the morphological type of the galaxies. Contrary to this, the values of both age and metallicity at $\sim$2.5 scale-lengths correlate with the central velocity dispersion in a similar manner to the central values of the bulges, although bulges show, on average, older ages and higher metallicities than the discs. One of the goals of the present paper is to test the theoretical prediction that non-linear coupling between the bar and the spiral arms is an efficient mechanism for producing radial migrations across significant distances within discs. The process of radial migration should flatten the stellar metallicity gradient with time and, therefore, we would expect flatter stellar metallicity gradients in barred galaxies. However, we do not find any difference in the metallicity or age gradients in galaxies with without bars. We discuss possible scenarios that can lead to this absence of difference.Comment: 24 pages, 17 figures, accepted for publication in A&