Task- and Time-Dependent Memory Enhancement by Dehydroepiandosterone in Day-Old Chicks

We have previously reported the presence of dehydroepiandosterone (DHEA) in the dayold- chick brain, and a role for it in enhanced memory formation. Here we confirm that intracerebral injections of DHEA 5 min before training on the weak passive avoidance task enhanced recall 24 hours after training. Recall per se on an appetitive visual categorization task was not altered by administration of DHEA 5 min before training. However administration of DHEA 5 min before limited or very limited training on a visual categorization task (20 or 10 pecks only) appeared to enhance consolidation of this task at test 24 h after training; reducing the latency and total time taken to complete the test (60 pecks), while not detrimentally altering accuracy. Moreover, DHEA is unlikely to induce this effect via possible anxiolytic effects because it did not alter behavior in the open field test. We also examined diffusion of DHEA throughout the brain at various stages following intracerebral injection

Vasorelaxant Effect of a Baccharis trimera Infusion on Precontracted Rat Aortic Rings

Baccharis trimera (Less.) DC is a South American plant that in folk medicine is considered to produce reduction in blood pressure. One aspect of this putative effect is the vasorelaxation. The aim of this work was to evaluate the ability of a B. trimera extract to relax rat aortic rings precontracted with noradrenaline. As the infusion is the usual way of intake of this plant, an infusion of B. trimera was prepared using 100g of the plant (leaves) boiled in water, frozen and lyophilized. Working solutions were prepared using different concentrations of the dried extract diluted in Krebs Henseleit solution. It was proved that the infusion relaxed the aortic rings in a dose dependent manner 100 minutes after adding the extract to the bath. Considering as 100% the maximum contraction achieved with noradrenaline, a relaxation of 101.1±2.3% was observed with the highest dose of the infusion used in these experiments (0.32mg/mL). While in control rings relaxation was 12.9±2.4%. In aortic rings denuded from endothelium the percentage of vasoralaxation did not show statistically significant differences when compared to intact rings. These data support the hypothesis of a vasorelaxant effect of this plant and constitutes the first approach to the scientific basis of a potential antihypertensive effect

Quid: observatorio de medios

El informe está estructurado en seis partes. En la primera, “Transparencia y derecho a la información en Jalisco”, se presenta un artículo que sintetiza cómo fue que en diciembre de 2011, el Congreso y el Gobierno del Jalisco se organizaron para aprobar la “Ley de Información Pública de Jalisco y sus Municipios”, como un intercambio de favores entre estos poderes. En la segunda parte, "Medios de comunicación y periodismo en Jalisco", se presentan trabajos sobre los cambios en la prensa local, los medios de comunicación y los juegos panamericanos, las condiciones laborales de los periodistas en Guadalajara, y la prensa roja. En la tercer parte, "Economía política de los medios de comunicación y las industrias culturales en Jalisco" se incluyen trabajos sobre la industria de la música, la propaganda disfrazada de periodismo, y los medios públicos. En la cuarta parte, "Medios de comunicación y telecomunicaciones", se abordan los temas de la lucha por las telecomunicaciones en México, y la televisión abierta como una herramienta política para construir estrategias gubernamentales. En la quinta parte, "Producción de investigación académica del observatorio de medios", se presenta un análisis de contenido de cinco periódicos mexicanos con respecto al tema del medio ambiente. La sexta parte es una semblanza del periodista Víctor Wario Romo.ITESO, A.C

Forgetting of long-term memory requires activation of NMDA receptors, L-type voltage-dependent Ca(2+) channels, and calcineurin

In the past decades, the cellular and molecular mechanisms underlying memory consolidation, reconsolidation, and extinction have been well characterized. However, the neurobiological underpinnings of forgetting processes remain to be elucidated. Here we used behavioral, pharmacological and electrophysiological approaches to explore mechanisms controlling forgetting. We found that post-acquisition chronic inhibition of the N-methyl-D-aspartate receptor (NMDAR), L-type voltage-dependent Ca2+ channel (LVDCC), and protein phosphatase calcineurin (CaN), maintains long-term object location memory that otherwise would have been forgotten. We further show that NMDAR activation is necessary to induce forgetting of object recognition memory. Studying the role of NMDAR activation in the decay of the early phase of long-term potentiation (E-LTP) in the hippocampus, we found that ifenprodil infused 30min after LTP induction in vivo blocks the decay of CA1-evoked postsynaptic plasticity, suggesting that GluN2B-containing NMDARs activation are critical to promote LTP decay. Taken together, these findings indicate that a well-regulated forgetting process, initiated by Ca2+ influx through LVDCCs and GluN2B-NMDARs followed by CaN activation, controls the maintenance of hippocampal LTP and long-term memories over time

Medios de comunicación y derecho a la información en Jalisco, 2019

Si 2018 fue el año de las confrontaciones políticas entre los candidatos por ocupar puestos de representación popular para el Congreso local, las alcaldías y el gobierno del estado, 2019 fue un año de cambios en la organización institucional del Poder Ejecutivo, pero también de inercias y conflictos en materia de política comunicativa. En esta edición, el Informe de Medios aborda, desde varias perspectivas, las confrontaciones entre el ejecutivo del estado y la prensa, las condiciones en las se aplicaron cambios en los medios públicos del estado, la representación mediática del feminicidio y la cobertura de los miles de casos de personas desaparecidas en Jalisco; la impunidad activa con la que operan los homicidas de periodistas y la violación a la libertad de prensa. Para finalizar, se integraron historias de personajes vinculados con la comunicación que lamentablemente fallecieron en 2019.ITESO, A.C

Molecular Constraints on Synaptic Tagging and Maintenance of Long-Term Potentiation: A Predictive Model

Protein synthesis-dependent, late long-term potentiation (LTP) and depression (LTD) at glutamatergic hippocampal synapses are well characterized examples of long-term synaptic plasticity. Persistent increased activity of the enzyme protein kinase M (PKM) is thought essential for maintaining LTP. Additional spatial and temporal features that govern LTP and LTD induction are embodied in the synaptic tagging and capture (STC) and cross capture hypotheses. Only synapses that have been "tagged" by an stimulus sufficient for LTP and learning can "capture" PKM. A model was developed to simulate the dynamics of key molecules required for LTP and LTD. The model concisely represents relationships between tagging, capture, LTD, and LTP maintenance. The model successfully simulated LTP maintained by persistent synaptic PKM, STC, LTD, and cross capture, and makes testable predictions concerning the dynamics of PKM. The maintenance of LTP, and consequently of at least some forms of long-term memory, is predicted to require continual positive feedback in which PKM enhances its own synthesis only at potentiated synapses. This feedback underlies bistability in the activity of PKM. Second, cross capture requires the induction of LTD to induce dendritic PKM synthesis, although this may require tagging of a nearby synapse for LTP. The model also simulates the effects of PKM inhibition, and makes additional predictions for the dynamics of CaM kinases. Experiments testing the above predictions would significantly advance the understanding of memory maintenance.Comment: v3. Minor text edits to reflect published versio

The regulatory role of long-term depression in juvenile and adult mouse ocular dominance plasticity

The study of experience-dependent ocular dominance (OD) plasticity has greatly contributed to the understanding of visual development. During the critical period, preventing input from one eye results in a significant impairment of vision, and loss of cortical responsivity via the deprived eye. Residual ocular dominance plasticity has recently been observed in adulthood. Accumulating evidence suggests that OD plasticity involves N-methyl-D-aspartate receptor (NMDAR)-dependent long-term depression (LTD). Here we report that the administration of a selective LTD antagonist prevented the ocular dominance shift during the critical period. The NMDAR co-agonist D-serine facilitated adult visual cortical LTD and the OD shift in short-term monocularly deprived (MD) adult mice. When combined with reverse suture, D-serine proved effective in restoring a contralaterally-dominated visual input pattern in long-term MD mice. This work suggests LTD as a key mechanism in both juvenile and adult ocular dominance plasticity, and D-serine as a potential therapeutic in human amblyopic subjects

Medios de comunicación y derecho a la información en Jalisco, 2016

Se rescata el acontecer mediático y las trasformaciones más relevantes en materia de derecho a la información entre 2015 y 2016. Este periodo arroja interesantes análisis con respecto a temas como los cambios del sistema de medios en Jalisco; la trasparencia y el acceso a la información, así como la configuración de quienes integran las instituciones que vigilan su aplicación; la transición a la televisión digital terrestre; los desaparecidos y la falta de acceso a la información, y el rostro de la prensa local a partir de sus capacidades financieras desde la perspectiva de su independencia editorial. Asimismo, se registraron hechos importantes que están marcando un parteaguas en el estado, como la alerta de violencia contra las mujeres en Jalisco, la iniciativa ciudadana #Ley3de3, las modificaciones al Premio Jalisco de Periodismo y las implicaciones del nuevo sistema penal para los medios y los periodistas. Cierra con un espacio para mantener viva la memoria de los profesionales de la comunicación que han participado en la construcción del acontecer informativo, cultural y de entretenimiento local

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years