Evaluación de la participación del 17β-estradiol y el receptor 5- ht₁A en las alteraciones conductuales en un modelo animal de depresión

En la actualidad, la depresión es una de las enfermedades mentales más comunes e incapacitantes, constituye un grave problema de salud a nivel mundial. El tratamiento neonatal con clomipramina (CMI) en ratas se ha considerado como un modelo de depresión, ya que en la edad adulta produce alteraciones que se asemejan a signos de la depresión en humanos. Dichas alteraciones han sido atribuidas a deficiencias en sistemas de neurotransmisión como; el noradrenérgico y serotoninérgico provocadas por el tratamiento en etapas críticas del desarrollo. Dentro de las alteraciones en el sistema serotoninérgico encontramos niveles disminuidos de serotonina (5-HT) en áreas límbicas, un incremento de la conducta de inmovilidad acompañado de disminución del nado en la prueba de nado forzado (PNF) y alteraciones en la expresión de ARNm del receptor 5-HT₁A en núcleo del rafe, hipotálamo e hipocampo. Por otro lado, ratas tratadas con CMI muestran un deterioro de la conducta sexual masculina (CSM), cuyo despliegue es controlado por hormonas como la testosterona (T), que se metaboliza a dihidrotestosterona (DHT) y 17-β estradiol (E₂), esta última ha sido relacionada con los efectos centrales de la T sobre la cópula, así como de regular procesos fisiológicos como el estado de ánimo. El interés del presente trabajo fue analizar el papel del receptor 5-HT₁A y del E₂ en las alteraciones conductuales que presentan las ratas tratadas neonatalmente con CMI. Para lo cual se utilizaron ratas Wistar a las que se les administro CMI o solución salina en la etapa neonatal (8-21 días de edad). Tres meses después se dividieron en grupos para realizar los siguientes objetivos; 1) Análisis de la participación de los receptores 5-HT₁A pre y post sináptico en el efecto del agonista 8-hydroxy-2-(di-npropylamino) tertralina (8-OH-DPAT) en la PNF, 2) Análisis del posible efecto antidepresivo de E₂ a través de la PNF en ratas CMI, 3) Efecto del tratamiento neonatal con CMI sobre la motivación sexual, 4) Efecto de la administración de E₂ y DHT sobre la motivación en ratas tratadas neonatalmente con CMI, 5) Efecto de la administración neonatal con CMI sobre las concentraciones séricas de T y E₂ y 6) Análisis del efecto del tratamiento con CMI sobre a expresión de receptores a estrógenos α y β en núcleo del rafe, hipotálamo e hipocampo. Nuestros resultados indican que el efecto antidepresivo de 8-OH-DPAT es mediado por el receptor 5-HT1A post-sináptico ya que no se altera por el bloqueo de la síntesis de 5-HT. Por otro lado, el tratamiento neonatal con CMI afecta el despliegue conductual en la PNF, incrementando la inmovilidad y disminuyendo la conducta de nado, alteraciones que se ven revertidas por la administración de E₂; efecto que posiblemente esta mediado por una mejora en la función de la neurotransmisión serotoninérgica. Así también la administración de CMI provoca diminución en la motivación sexual, la cual se ve revertida por la administración de E₂ y DHT. Además, el tratamiento neonatal no produce cambios en las concentraciones séricas de T y E₂, sin embargo se requieren mediciones de la producción de estas hormonas a nivel cerebral para dar resultados concluyentes. Por otro lado el tratamiento con CMI induce una disminución en la expresión de los REβ en núcleo del rafe dorsal y región CA3 del hipocampo que se acompaña de un aumento en la expresión de REα y REβ en NPOm indicando que este podría ser uno de los mecanismos por el cual CMI produce las alteraciones en la CSM y la motivación. Sin embargo es necesario el análisis de los receptores en otras áreas cerebrales relacionadas con la conducta sexual y la regulación de estado de ánimo

Determinantes perceptuales de la intención de uso de Internet para el desarrollo del capital humano

En el marco de la Teoría del Capital Humano (TCH) y las Tecnologías de Información y Comunicación (TIC) se plantea la relación entre el uso de Internet y las percepciones de utilidad, facilidad y autoeficacia. Los resultados muestran que el determinante principal del uso de Internet es la percepción de utilidad (β = .46). El modelo obtuvo un adecuado ajuste con respecto al modelo de relaciones hipotéticas entre las variables perceptuales y actitudinales sobre la variable intencional. Se discuten las implicaciones del modelo en torno al desarrollo del capital humano y satisfacción del cliente en los ambientes laborales

Female rat sexual behavior is unaffected by perinatal fluoxetine exposure

Serotonin plays an important role in adult female sexual behavior, however little is known about the influence of serotonin during early development on sexual functioning in adulthood. During early development, serotonin acts as neurotrophic factor, while it functions as a modulatory neurotransmitter in adulthood. The occurrence of serotonin release, could thus have different effects on behavioral outcomes, depending on the developmental period in which serotonin is released. Because serotonin is involved in the development of the HPG axis which is required for puberty establishment, serotonin could also alter expression patterns of for instance the estrogen receptor ɑ (ERɑ). The aim of our study was to investigate the effects of increased serotonin levels during early development on adult female rat sexual behavior during the full behavioral estrus in a seminatural environment. To do so, rats were perinatally exposed with the selective serotonin reuptake inhibitor (SSRI) fluoxetine (10 mg/kg FLX) and sexual performance was tested during adulthood. All facets of female sexual behavior between the first and last lordosis (behavioral estrus), and within each copulation bout of the behavioral estrus were analyzed. Besides the length and onset of the behavioral estrus and the sexual behaviors patterns, other social and conflict behavior were also investigated. In addition, we studied the effects of perinatal FLX exposure on ERɑ expression patterns in the medial preoptic nucleus, ventromedial nucleus of the hypothalamus, medial amygdala, bed nucleus of the stria terminalis, and the dorsal raphé nucleus. The results showed that perinatal fluoxetine exposure has no effect on adult female sexual behavior. The behavioral estrus of FLX-females had the same length and pattern as CTR-females. In addition, FLX- and CTR-females showed the same amount of paracopulatory behavior and lordosis, both during the full behavioral estrus and the "most active bout". Furthermore, no differences were found in the display of social and conflict behaviors, nor in ERɑ expression patterns in the brain. We conclude that increases in serotonin levels during early development do not have long-term consequences for female sexual behavior in adulthood.</p

Measurement of the Forward-Backward Asymmetry in the B -> K(*) mu+ mu- Decay and First Observation of the Bs -> phi mu+ mu- Decay

We reconstruct the rare decays $B^+ \to K^+\mu^+\mu^-$, $B^0 \to K^{*}(892)^0\mu^+\mu^-$, and $B^0_s \to \phi(1020)\mu^+\mu^-$ in a data sample corresponding to $4.4 {\rm fb^{-1}}$ collected in $p\bar{p}$ collisions at $\sqrt{s}=1.96 {\rm TeV}$ by the CDF II detector at the Fermilab Tevatron Collider. Using $121 \pm 16$ $B^+ \to K^+\mu^+\mu^-$ and $101 \pm 12$ $B^0 \to K^{*0}\mu^+\mu^-$ decays we report the branching ratios. In addition, we report the measurement of the differential branching ratio and the muon forward-backward asymmetry in the $B^+$ and $B^0$ decay modes, and the $K^{*0}$ longitudinal polarization in the $B^0$ decay mode with respect to the squared dimuon mass. These are consistent with the theoretical prediction from the standard model, and most recent determinations from other experiments and of comparable accuracy. We also report the first observation of the $B^0_s \to \phi\mu^+\mu^- decay and measure its branching ratio${\mathcal{B}}(B^0_s \to \phi\mu^+\mu^-) = [1.44 \pm 0.33 \pm 0.46] \times 10^{-6}$using$27 \pm 6$signal events. This is currently the most rare$B^0_s$ decay observed.Comment: 7 pages, 2 figures, 3 tables. Submitted to Phys. Rev. Let

Measurements of the properties of Lambda_c(2595), Lambda_c(2625), Sigma_c(2455), and Sigma_c(2520) baryons

We report measurements of the resonance properties of Lambda_c(2595)+ and Lambda_c(2625)+ baryons in their decays to Lambda_c+ pi+ pi- as well as Sigma_c(2455)++,0 and Sigma_c(2520)++,0 baryons in their decays to Lambda_c+ pi+/- final states. These measurements are performed using data corresponding to 5.2/fb of integrated luminosity from ppbar collisions at sqrt(s) = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. Exploiting the largest available charmed baryon sample, we measure masses and decay widths with uncertainties comparable to the world averages for Sigma_c states, and significantly smaller uncertainties than the world averages for excited Lambda_c+ states.Comment: added one reference and one table, changed order of figures, 17 pages, 15 figure

Search for a New Heavy Gauge Boson Wprime with Electron + missing ET Event Signature in ppbar collisions at sqrt(s)=1.96 TeV

We present a search for a new heavy charged vector boson $W^\prime$ decaying to an electron-neutrino pair in $p\bar{p}$ collisions at a center-of-mass energy of 1.96\unit{TeV}. The data were collected with the CDF II detector and correspond to an integrated luminosity of 5.3\unit{fb}^{-1}. No significant excess above the standard model expectation is observed and we set upper limits on $\sigma\cdot{\cal B}(W^\prime\to e\nu)$. Assuming standard model couplings to fermions and the neutrino from the $W^\prime$ boson decay to be light, we exclude a $W^\prime$ boson with mass less than 1.12\unit{TeV/}c^2 at the 95\unit{%} confidence level.Comment: 7 pages, 2 figures Submitted to PR

A survey for variable young stars with small telescopes: II - mapping a protoplanetary disc with stable structures at 0.15 au

The HOYS citizen science project conducts long term, multifilter, high cadence monitoring of large YSO samples with a wide variety of professional and amateur telescopes. We present the analysis of the light curve of V1490 Cyg in the Pelican Nebula. We show that colour terms in the diverse photometric data can be calibrated out to achieve a median photometric accuracy of 0.02 mag in broadband filters, allowing detailed investigations into a variety of variability amplitudes over timescales from hours to several years. Using Gaia DR2 we estimate the distance to the Pelican Nebula to be 870 +70 −55 pc. V1490 Cyg is a quasi-periodic dipper with a period of 31.447 ± 0.011 d. The obscuring dust has homogeneous properties, and grains larger than those typical in the ISM. Larger variability on short timescales is observed in U and Rc−Hα, with U-amplitudes reaching 3 mag on timescales of hours, indicating the source is accreting. The Hα equivalent width and NIR/MIR colours place V1490 Cyg between CTTS/WTTS and transition disk objects. The material responsible for the dipping is located in a warped inner disk, about 0.15 AU from the star. This mass reservoir can be filled and emptied on time scales shorter than the period at a rate of up to 10−10 M�/yr, consistent with low levels of accretion in other T Tauri stars. Most likely the warp at this separation from the star is induced by a protoplanet in the inner accretion disk. However, we cannot fully rule out the possibility of an AA Tau-like warp, or occultations by the Hill sphere around a forming planet

Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions

At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark-gluon plasma (QGP)(1). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed(2-6). Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions(7), is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton-proton (pp) collisions(8,9), but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton-proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p-Pb collision results(10,11), indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb-Pb collisions, where a QGP is formed.Peer reviewe

ϒ production in p–Pb collisions at √sNN=8.16 TeV

ϒ production in p–Pb interactions is studied at the centre-of-mass energy per nucleon–nucleon collision √sNN = 8.16 TeV with the ALICE detector at the CERN LHC. The measurement is performed reconstructing bottomonium resonances via their dimuon decay channel, in the centre-of-mass rapidity intervals 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, down to zero transverse momentum. In this work, results on the ϒ(1S) production cross section as a function of rapidity and transverse momentum are presented. The corresponding nuclear modification factor shows a suppression of the ϒ(1S) yields with respect to pp collisions, both at forward and backward rapidity. This suppression is stronger in the low transverse momentum region and shows no significant dependence on the centrality of the interactions. Furthermore, the ϒ(2S) nuclear modification factor is evaluated, suggesting a suppression similar to that of the ϒ(1S). A first measurement of the ϒ(3S) has also been performed. Finally, results are compared with previous ALICE measurements in p–Pb collisions at √sNN = 5.02 TeV and with theoretical calculations.publishedVersio