669 research outputs found
Pituitary adenylate cyclase-activating polypeptide (PACAP) inhibits the slow afterhyperpolarizing current sI AHP in CA1 pyramidal neurons by activation multiple signaling pathways
The slow afterhyperpolarizing current (sIAHP ) is a calcium-dependent potassium current that underlies the late phase of spike frequency adaptation in hippocampal and neocortical neurons. sIAHP is a well-known target of modulation by several neurotransmitters acting via the cyclic AMP (cAMP) and protein kinase A (PKA)-dependent pathway. The neuropeptide pituitary adenylate cyclase activating peptide (PACAP) and its receptors are present in the hippocampal formation. In this study we have investigated the effect of PACAP on the sIAHP and the signal transduction pathway used to modulate intrinsic excitability of hippocampal pyramidal neurons. We show that PACAP inhibits the sIAHP , resulting in a decrease of spike frequency adaptation, in rat CA1 pyramidal cells. The suppression of sIAHP by PACAP is mediated by PAC1 and VPAC1 receptors. Inhibition of PKA reduced the effect of PACAP on sIAHP , suggesting that PACAP exerts part of its inhibitory effect on sIAHP by increasing camp and activating PKA. The suppression of sIAHP by PACAP was also strongly hindered by the inhibition of p38 MAP kinase (p38 MAPK). Concomitant inhibition of PKA and p38 MAPK indicates that these two kinases act in a sequential manner in the same pathway leading to the suppression of sIAHP . Conversely, protein kinase C is not part of the signal transduction pathway used by PACAP to inhibit sIAHP in CA1 neurons. Our results show that PACAP enhances the excitability of CA1 pyramidal neurons by inhibiting the sIAHP through the activation of multiple signaling pathways, most prominently cAMP/PKA and p38 MAPK. Our findings disclose a novel modulatory action of p38 MAPK on intrinsic excitability and the sIAHP , underscoring the role of this current as a neuromodulatory hub regulated by multiple protein kinases in cortical neurons. © 2013 Wiley Periodicals, Inc
The toxicity and intraspecific variability of Alexandrium andersonii Balech
The toxicity of Alexandrium andersonii Balech is unclear and its intraspecific variability has yet to be
studied. To address these gaps in our knowledge, in the present work five strains of A. andersonii from
four different localities were characterized. The results showed that despite genetic homogeneity in the
5.8-ITS (internal transcribed spacer) and large subunit (LSU) regions and similar growth rates, strains
originating from different locations varied with respect to cell size, the ratios of certain pigments, and
their growth patterns. Cultures of the strains grown at 20 8C were analyzed for toxicity using four
different methodologies. The two officially established methods, mouse bioassay and high-performance
liquid chromatography with fluorescence detection (HPLC-FLD) and post-column reaction analysis of
PSP toxins, failed to show the toxicity of any strain. Strains grown at 14 8C were also negative for PSP
toxins by HPLC-FLD. However, strains grown at 20 8C exhibited both a response characteristic of the
presence of toxin-inhibiting voltage-gated sodium channels, as demonstrated in a neuroblastoma neuro-
2a cell-based assay, as well as hemolytic activity in a sheep red blood cell assay
Especies promisorias para el ecoturismo en “Campo Aventura Roca Madre”, Toluviejo-Sucre, Colombia
RESUMEN
Objetivo. Determinar las especies de flora y fauna más importantes para el desarrollo del ecoturismo, en una localidad del departamento de Sucre, Colombia. Materiales y métodos. Se hizo un listado de las especies de flora y fauna observadas en el sendero ecológico de un centro de ecoturismo en Toluviejo, Sucre y se calculó su abundancia, importancia económica, estado de conservación y adaptaciones, que fueron evaluadas mediante un índice de importancia potencial para el ecoturismo, que suma los valores que se asignan a las variables consideradas de interés. Resultados. Se detectaron 18 especies promisorias de fauna, de 91 especies observadas y 16 especies vegetales de 53 observadas. Los animales de mayor potencial ecoturístico resultantes, fueron: Dendrobates truncatus y Saguinus oedipus, especies endémicas de Colombia, seguidas por Basiliscus basiliscus, Atta sp., Morpho peleides, Lycorea halia y Ara ararauna; todas estas con una alta abundancia y fácil detección. Dentro de las plantas, Anacardium excelsum obtuvo el mayor índice de importancia, como resultado de su endemismo y sus adaptaciones. Las especies Piper auritum, Matayba escrobiculata, Tabernaemontana cymosa y la comúnmente conocida como jazmín de monte, fueron fácilmente detectables y abundantes, además Brownea ariza y Tabebuia rosea resultaron las más representativas por la belleza de sus flores. Conclusiones. Se determinaron las especies que pueden ser de interés para los ecoturistas y esto hace posible mejorar el producto que se oferta a partir de profundizar en su conocimiento.
Climatic variability and decline of Atlantic Iberian Nephrops fisheries
PresentationNephrops landings and landings per unit effort from the mixed bottom trawl fishery in the northwest Spain have a marked downward trend since the earliest 90s. Since 2006, a recovery plan has been developed but improvement signs have not been detected up to now, and the fishery shows currently a depleted state. Multiple environmental-related causal mechanisms may interact in this decline other than fishing pressure. Climatic variability of the region was characterized using series (1950-2010) of teleconnection patterns (North Atlantic Oscillation index, Eastern Atlantic index, Scandinavian index and Poleward index). Fishery Nephrops data and climatic series were jointly analyzed. The aim was to indentify relationships between the Nephrops dynamics and the environmental system, and the mechanisms that could have an influence on the biological fluctuation
Finding answers in lipid profile in COVID-19 patients
Introduction: A small percentage of patients will develop a severe form of COVID-19 caused by SARS-CoV-2 infection. Thus, it is important to predict the potential outcomes identifying early markers of poor prognosis. In this context, we evaluated the association of SARS-CoV-2 infection with lipid abnormalities and their role in prognosis. Methods: Single-center, retrospective, observational study of COVID-19 patients admitted from March to October 2020. Clinical and laboratory data, comorbidities, and treatments for COVID-19 were evaluated. Main outcomes including intensive care unit (ICU) admission and mortality were analyzed with a multivariable Cox proportional hazards regression model. Results: We selected 1489 from a total of 2038 consecutive patients with confirmed COVID-19, who had a complete lipid profile before ICU admission. During the follow-up performed in 1109 patients, we observed a decrease in T-c, HDL-c, and LDL-c in 28.6%, 42.9%, and 30.4% of patients, respectively, and an increase in TG in 76.8%. The decrease of both T-c and HDL- c was correlated with a decrease in albumin levels (r = 0.39 and r = 0.37, respectively). Kaplan–Meier survival curves found an increased ICU admission in patients with lower T-c (HR 0.55, CI 0.36–0.86), HDL-c (HR 0.61, CI 0.45–0.84), and LDL-c (HR 0.85, CI 0.74–0.97). Higher values of T-c (HR 0.45, CI 0.36–0.57), HDL-c (HR 0.66, CI 0.54–0.81), and LDL-c (HR 0.86, CI 0.78–0.94) showed a protective effect on mortality. Conclusions: Abnormalities in lipid profile are a frequent complication of SARS-CoV-2 infection and might be related to morbidity and mortalityThis work was supported by the following grants: Proyectos
de Investigación en Salud (FIS) PI16-02091 and PI19-00584 (funded
by Instituto de Salud Carlos III), TIRONET2-CM, B2017/BMD-3724
(funded by Comunidad de Madrid) and cofinanced by FEDER funds to
M.M
ANALYSIS OF UNCERTAINTY IN THE STANDARIZATION OF CPUE INDEXES
Catch per unit effort (CPUE) indices are considered as one of
the main information sources used in fish stock assessment
models (Zou et al., 2019). There are many ways for the
standardization of these indices:
• Generalized lineal models (GLMs)
• Generalized additive models (GAMs)
• Geostatistical models.
To evaluate the accuracy and uncertainty associated with
CPUE indices derived from datasets with different spatial
information.
• How? With the standardization of CPUE indices using
geostatistical models in different sampling scenarios,
comparing them with GLMs and GAMs models
- …