Implication of GluR2 subunit of AMPA receptor in RGS14(414)-mediated memory enhancement

Ongoing quest for finding treatment against memory loss seen in aging and in many neurological and neurodegenerative diseases, so far has been unsuccessful and memory enhancers are seen as a potential remedy against this brain dysfunction. Recently, we showed that gene corresponding to a protein called regulator of G-protein signaling 14 of 414 amino acids (RGS14414) is a robust memory enhancer (Lopez-Aranda et al. 2009: Science). RGS14414-treatment in area V2 of visual cortex caused memory enhancement to such extent that it converted short-term object recognition memory (ORM) of 45min into long lasting long-term memory that could be traced even after many months. Now, through targeting of multiple receptors and molecules known to be involved in memory processing, we found that GluR2 subunit of AMPA receptor might be key to memory enhancement in RGS-animals. RGS14-animals showed a progressive increase in GluR2 protein expression while processing an object information which reached to highest level after 60min of object exposure, a time period required for conversion of short-term ORM into long-term memory in our laboratory set up. Normal rats could retain an object information in brain for 45min (short-term) and not for 60min. However, RGS-treated rats are able to retain the same information for 24h or longer (long-term). Therefore, highest expression of GluR2 subunit seen at 60min suggests that this protein might be key in memory enhancement and conversion to long-term memory in RGS-animals. In addition, we will also discuss the implication of Hebbian plasticity and interaction of brain circuits in memory enhancement.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This work was supported by project BFU2013-43458-R from MINECO, P12-CTS-1694 from JA

Mixed Elements in the Boundary Theory

The development of (static and dynamics)programs with constant and linear elements has shown good behaviour. It seems so natural to combine both advantages so that the results will not be affected by local distortions. This paper will be dedicated to presenting the reserch of mixed elements and the way to solve the over-determination that appears in some cases. Although all the study has been done with the potential theory, its application to elastic problems is straightforward

Spectroscopic characterisation of the stellar content of ultra diffuse galaxies

Understanding the peculiar properties of Ultra Diffuse Galaxies (UDGs) via spectroscopic analysis is a challenging task requiring very deep observations and exquisite data reduction. In this work we perform one of the most complete characterisations of the stellar component of UDGs to date using deep optical spectroscopic data from OSIRIS at GTC. We measure radial and rotation velocities, star formation histories (SFH) and mean population parameters, such as ages and metallicities, for a sample of five UDG candidates in the Coma cluster. From the radial velocities, we confirm the Coma membership of these galaxies. We find that their rotation properties, if detected at all, are compatible with dwarf-like galaxies. The SFHs of the UDG are dominated by old (~ 7 Gyr), metal-poor ([M/H] ~ -1.1) and alpha-enhanced ([Mg/Fe] ~ 0.4) populations followed by a smooth or episodic decline which halted ~ 2 Gyr ago, possibly a sign of cluster-induced quenching. We find no obvious correlation between individual SFH shapes and any UDG morphological properties. The recovered stellar properties for UDGs are similar to those found for DDO44, a local UDG analogue resolved into stars. We conclude that the UDGs in our sample are extended dwarfs whose properties are likely the outcome of both internal processes, such as bursty SFHs and/or high-spin haloes, as well as environmental effects within the Coma cluster.Comment: Accepted for publication in MNRA

New insights into peripheral nerve regeneration : The role of secretomes

Acord transformatiu CRUE-CSICNeurons of the peripheral nervous system retain the intrinsic capability of regenerate their axons after injury, by triggering a complex activation response. This genetic switch is dependent of signals from the injured axon. Schwann cells (SCs) in the distal stump of an injured nerve also play an active role in the local regulation of axonal programs, by using cell-to-cell contacts but also secreted signals, the so-called secretome. Secretome contains all the proteins (cytokines, growth factors and others) secreted by the cell and includes extracellular vesicles. The released vesicles can transport signaling proteins and both coding and regulatory RNAs, thus facilitating multilevel communication. It is nowadays clear that secretome of SCs is fundamental to both orchestrate Wallerian degeneration and to sustain axonal regeneration. Therefore, the use of secretome has emerged as an alternative to cell therapy in the field of tissue regeneration. In fact, separate components of SC secretome have been extensively used in experimental models to enhance peripheral nerve regeneration after injury. However, the most used secretome in neural therapies has been the one derived from mesenchymal (MSC) or other derived stem cells. In fact, the effects of cell therapy with MSCs have been mainly associated with the secretion of bioactive molecules and extracellular vesicles, which constitute their secretome. In this review, we first describe the role of SC and macrophage secretomes on Wallerian degeneration and axonal regeneration after peripheral nerve injury. Then, we review the different works reported in the literature that have used secretomes of SCs or MSCs in the treatment of peripheral nerve injuries in experimental models, to highlight the use of secretomes as a promising cell-free therapeutic approach, that reduces some of the risks associated with the use of cells, such as tumor formation or rejection

Vibrational analysis and thermal behavior of salvia hispanica, nigella sativa and papaver somniferum seeds

Introduction: Salvia hispanica L., Nigella sativa L. and Papaver somniferum L. are involved in opiate-dependent behavior. It is known that the seeds of these three herbs contain high amounts of antioxidants, which are helpful in disease prevention, but further research is needed on some of their other phytochemical components (terpene alkaloids, benzoquinones and others), which are claimed to affect human opioid receptors. Methods: Seeds from the three afore mentioned plants have been studied by ATR-FTIR vibrational spectroscopy and thermo analytical techniques (TG/DTG, DTA and DSC). Results: The infrared spectrum has confirmed the presence of the ester carbonyl of terpenoid alkaloids (such as nigellamine) and the fully conjugated cyclic dione structure of quinones (e.g., thymoquinone). As regards the thermal stability of these seeds, small differences have been observed in their thermal profiles (endothermic effects at around 333C for chia, 268C for black cumin and 319C for poppy seeds), which can be ascribed to their different content in carbohydrates. Conclusions: The functional groups of the main active constituents and the thermal behavior of these three seeds have been elucidated

On the probable composition of ‘Jamaican stone’ aphrodisiac

A dangerous aphrodisiac, commonly known as ‘Jamaican stone’, banned by the U.S. Food and Drug Administration, has been studied by vibrational spectroscopy in order to solve the controversy on its composition. The results of the ATR-FTIR analysis revealed the presence of the a-pyrone ring, which is characteristic of bufadienolides from toad venom and bulbs of squill (Drimia maritima (L.) Stearn). This conclusion was reached after a comparative study with the spectra for phytochemicals derived from gambir and cat''s claw, two Uncaria species also preconized as aphrodisiacs and deemed as possible constituents of the ‘stone’. Owing to their physiologic similarities to digoxin, bufadienolides have been shown to produce a toxic profile similar to that of digoxin, although the lack one of the side chains found on digoxin should allow the use of hemodialysis to treat ‘Jamaican stone’ overdose

Role of RGS14(414) in object recognition memory and regulation of synaptic plasticity in perirhinal cortex

Participation of perirhinal and frontal cortices in processing of object recognition memory has long been recognized, however, recently our laboratory extended this to area V2 of visual cortex. We observed that RGS14414-mediated activation of area V2 neurons leads to an enormous increase in object recognition memory. This memory enhancement was of such extent that it converted short term memory of 45 minutes into long lasting long-term memory that could be traced even after many months. Here, we have tested the memory enhancer effect of RGS14414 in perirhinal cortex, an area intimately involved in processing of object memory. A relationship of behavioral performance of RGS14414-treated rats with electrophysiological synaptic plasticity was investigated. Stimulation of perirhinal cortex with RGS14414 produced an equally robust increase in object recognition memory as was observed in area V2. Further, we found that RGS14414-mediated activation of perirhinal cortex, (i) blocked the depotentiation induced by 1Hz stimulation during 10min; (ii) blocked the LTP induced by 20Hz stimulation while showed no effect at 100Hz stimulation; and (iii) reduced the LTD induced by the application of 20µM carbachol, a cholinergic receptor agonist, during 10min, however no effect was observed at a higher concentration (50µM). Furthermore, we also observed that phosphorylated isoforms of AMPA receptor 1 and 2 (iGluR1 & iGluR2) were significantly reduced. Thus, our results indicate that iGluRs reflects the level of synaptic plasticity (LTP and LTD) observed in RGS-animals but lack this correlation with enhanced memory behavior. This work was supported by projects from MINECO, Junta de Andalucía y NIH.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Maestras mezcaleras

ITESO, A.C