Using DREADD to Examine the Role of Infralimbic Gq-coupled Receptors in Fear Acquisition

Post-Traumatic Stress Disorder (PTSD) can develop after a person experiences a very traumatic event that produces a strong and long-lasting aversive memory. During any given year, approximately 8 million adults will suffer from PTSD. Existing treatments often fail to achieve a full extinction of the traumatic fear the patients re-experience. Consequently, how the brain processes and modulates fear memories continues to be an active area of research. The excitability of the infralimbic cortex (IL), a sub-region of the medial prefrontal cortex, is important for fear extinction. Previous studies done in our lab found that Gq-coupled receptors located in this region of the brain, specifically muscarinic and mGluR5 receptors play a critical role in the consolidation of extinction memory. However, their effect on the acquisition of fear is still unknown. Thus, the main purpose of this research is to determine whether the activation of Gq-coupled receptors in IL prior to the learning of fear affects fear memory. We hypothesized that stimulation of these receptors during fear conditioning would decrease acquired fear. To test this, we utilized a pharmacogenetic approach in the form of Designer Receptors Exclusively Activated by Designer Drugs (DREADD), which allow for controlled manipulation of the desired area in the brain using the selective agonist CNO. Adult male Sprague Dawley rats were surgically infused with a virus, which expressed a Gq-coupled DREADD. Three weeks later, the rats will be injected with CNO one hour prior to behavioral training and sacrificed for immunohistochemistry to examine neuronal activity

Least Change Secant Update Methods for Nonlinear Complementarity Problem

In this work, we introduce a family of Least Change Secant Update Methods for solving Nonlinear Complementarity Problems based on its reformulation as a nonsmooth system using the one-parametric class of nonlinear complementarity functions introduced by Kanzow and Kleinmichel -- We prove local and superlinear convergence for the algorithms -- Some numerical experiments show a good performance of this algorith

Rational approximations in Analytic QCD

We consider the ``modified Minimal Analytic'' (mMA) coupling that involves an infrared cut to the standard MA coupling. The mMA coupling is a Stieltjes function and, as a consequence, the paradiagonal Pade approximants converge to the coupling in the entire $Q^2$-plane except on the time-like semiaxis below the cut. The equivalence between the narrow width approximation of the discontinuity function of the coupling, on the one hand, and this Pade (rational) approximation of the coupling, on the other hand, is shown. We approximate the analytic analogs of the higher powers of mMA coupling by rational functions in such a way that the singularity region is respected by the approximants.Several comparisons, for real and complex arguments $Q^2$, between the exact and approximate expressions are made and the speed of convergence is discussed. Motivated by the success of these approximants, an improvement of the mMA coupling is suggested, and possible uses in the reproduction of experimental data are discussed.Comment: 12 pages,9 figures (6 double figures); figs.6-8 corrected due to a programming error; analysis extended to two IR cutoffs; Introduction rewritten; to appear in J.Phys.

Miositis osificante progresiva: ultraestructura, bioquímica e histoquímica de músculo macroscópicamente sano

Se estudió un caso de miositis osificante progresiva en una niña de 13 años, a la cual se le tomó una muestra de músculo gastronecmio lateral, aparentemente no afectado, en el curso de una intervención quirúrgica ortopédica. La muestra se procesó mediante métodos histológicos, histoquímicos, bioquímicos, inmunocitoquímicos y ultraestructurales. Se encontró un predominio de fibras musculares tipo I (83%) con alta capacidad oxidativa y baja capacidad glicolítica. Las fibras del tipo II eran pequeñas (área promedio 2.084 Um2 ) y mostraron otros signos de atrofia al examen ultraestructural. La densidad capilar fue relativamente alta, (573) siendo normal el índice capilar/fibra (1,76). Sin embargo, algunos capilares se mostraron engrosados y con la luz ocluida, con la tinción de amilasa-PAS, lo cual fue corroborado con la microscopía electrónica, donde se vio la membrana basal engrosada, e inclusive algunos capilares totalmente degenerados. No se encontró reacción de inmunofluorescencia con las globulinas anti-IgG ni anti-IgM en los cortes de músculo. El espacio intersticial se encontró agrandado. Se concluye que no hay evidencias de la participación de un mecanismo autoinmune en la miositis osificante progresiva, que existe un daño capilar y alteración de las fibras musculares, aún en el músculo que no manifiesta a simple vista proceso de osificación.During an orthopedic operation a sample of the apparently normal lateral gastronecmius muscle was taken from a 13 year old female patient affected by myositis ossificans progressiva. The muscle sample was analyzed by light, electron and fluorescence microscopy, and some enzymes were assayed. Muscle fibers were classified by the adenosintriphosphatase reaction. The percentage of type I fiber was high (83%). Atrophy was found in type II fibers as shown by small mean area (2.084 Um2 ) and some ultrastructural features as infoldings of the sarcolemma. Capillary density was high (573 capillaries/mm2 ), and capillaries per fiber index was normal (1.76), as were oxidative enzymes. However many capillaries were occluded, with thick basal membrane and abnormal endothelial cells and pericytes. No immunofluorescence was found with anti IgG or anti IgM in the muscle fibers. Intersticial spaces in the cross section of the muscle were enlarged. In conclusion, no evidence of autoimmune involvement was found in myositis ossificans progressiva, but alteracions of capillaries and muscle fibers were found in a muscle apparently not affected yet by the ossification process

Microbial iron management mechanisms in extremely acidic environments: comparative genomics evidence for diversity and versatility

<p>Abstract</p> <p>Background</p> <p>Iron is an essential nutrient but can be toxic at high intracellular concentrations and organisms have evolved tightly regulated mechanisms for iron uptake and homeostasis. Information on iron management mechanisms is available for organisms living at circumneutral pH. However, very little is known about how acidophilic bacteria, especially those used for industrial copper bioleaching, cope with environmental iron loads that can be 10¹⁸times the concentration found in pH neutral environments. This study was motivated by the need to fill this lacuna in knowledge. An understanding of how microorganisms thrive in acidic ecosystems with high iron loads requires a comprehensive investigation of the strategies to acquire iron and to coordinate this acquisition with utilization, storage and oxidation of iron through metal responsive regulation. <it>In silico </it>prediction of iron management genes and Fur regulation was carried out for three Acidithiobacilli: <it>Acidithiobacillus ferrooxidans </it>(iron and sulfur oxidizer) <it>A. thiooxidans </it>and <it>A. caldus </it>(sulfur oxidizers) that can live between pH 1 and pH 5 and for three strict iron oxidizers of the <it>Leptospirillum </it>genus that live at pH 1 or below.</p> <p>Results</p> <p>Acidithiobacilli have predicted FeoB-like Fe(II) and Nramp-like Fe(II)-Mn(II) transporters. They also have 14 different TonB dependent ferri-siderophore transporters of diverse siderophore affinity, although they do not produce classical siderophores. Instead they have predicted novel mechanisms for dicitrate synthesis and possibly also for phosphate-chelation mediated iron uptake. It is hypothesized that the unexpectedly large number and diversity of Fe(III)-uptake systems confers versatility to this group of acidophiles, especially in higher pH environments (pH 4–5) where soluble iron may not be abundant. In contrast, Leptospirilla have only a FtrI-Fet3P-like permease and three TonB dependent ferri-dicitrate siderophore systems. This paucity of iron uptake systems could reflect their obligatory occupation of extremely low pH environments where high concentrations of soluble iron may always be available and were oxidized sulfur species might not compromise iron speciation dynamics. Presence of bacterioferritin in the Acidithiobacilli, polyphosphate accumulation functions and variants of FieF-like diffusion facilitators in both Acidithiobacilli and Leptospirilla, indicate that they may remove or store iron under conditions of variable availability. In addition, the Fe(II)-oxidizing capacity of both <it>A. ferrooxidans </it>and Leptospirilla could itself be a way to evade iron stress imposed by readily available Fe(II) ions at low pH. Fur regulatory sites have been predicted for a number of gene clusters including iron related and non-iron related functions in both the Acidithiobacilli and Leptospirilla, laying the foundation for the future discovery of iron regulated and iron-phosphate coordinated regulatory control circuits.</p> <p>Conclusion</p> <p><it>In silico </it>analyses of the genomes of acidophilic bacteria are beginning to tease apart the mechanisms that mediate iron uptake and homeostasis in low pH environments. Initial models pinpoint significant differences in abundance and diversity of iron management mechanisms between Leptospirilla and Acidithiobacilli, and begin to reveal how these two groups respond to iron cycling and iron fluctuations in naturally acidic environments and in industrial operations. Niche partitions and ecological successions between acidophilic microorganisms may be partially explained by these observed differences. Models derived from these analyses pave the way for improved hypothesis testing and well directed experimental investigation. In addition, aspects of these models should challenge investigators to evaluate alternative iron management strategies in non-acidophilic model organisms.</p

A Mainly Circum-Mediterranean Origin for West Eurasian and North African mtDNAs in Puerto Rico with Strong Contributions from the Canary Islands and West Africa

Maternal lineages of West Eurasian and North African origin account for 11.5% of total mitochondrial ancestry in Puerto Rico. Historical sources suggest that this ancestry arrived mostly from European migrations that took place during the four centuries of the Spanish colonization of Puerto Rico. This study analyzed 101 mitochondrial control region sequences and diagnostic coding region variants from a sample set randomly and systematically selected using a census-based sampling frame to be representative of the Puerto Rican population, with the goal of defining West Eurasian-North African maternal clades and estimating their possible geographical origin. Median-joining haplotype networks were constructed using HVR-I and –II sequences from various reference populations in search of shared haplotypes. A posterior probability analysis was performed to estimate the percentage of possible origins across wide geographic regions for the entire sample set and for the most common haplogroups on the island. Principal component analyses were conducted to place the Puerto Rican mtDNA set within the variation present amongst all reference populations. Our study shows that up to 38% of West Eurasian and North African mitochondrial ancestry in Puerto Rico most likely migrated from the Canary Islands. However, most of those haplotypes had previously migrated to the Canary Islands from elsewhere, and there are substantial contributions from various populations across the circum-Mediterranean region and from West African populations related to the modern Wolof and Serer peoples from Senegal and the nomad Fulani who extend up to Cameroon. In conclusion, the West Eurasian mitochondrial ancestry in Puerto Ricans is geographically diverse. However, haplotype diversity seems to be low and frequencies have been shaped by population bottlenecks, migration waves, and random genetic drift. Consequently, approximately 47% of mtDNAs of West Eurasian and North African ancestry in Puerto Rico probably arrived early in its colonial history

Seed regeneration in native forests of Nothofagus antarctica under silvopastoral use in Southern Patagonia, Argentina

The aim of the present study was to evaluate the effect of silvopastoral use in two pure stands of Nothofagus antarctica (ñire, ñirre) growing at two site qualities on the regeneration cycle from production and quality of seeds, and the establishment and mortality of seedling in Southern Patagonia (Argentina). To evaluate seed production four traps were distributed to capture the spatial variation of each stand during seven years (2004-2010). Also, seed viability and germination were evaluated. In each site, permanent sampling plots were used to measure seedling establishment and mortality. Seed production in stands under silvopastoral use varied from 1 to 40 million seeds ha-1, with no differences compared to seed production in surrounding primary forests of the same site quality. Stands under silvopastoral use showed that seed quality varied among sites being higher in the lower site quality. However, there was no difference in seed quality between silvopastoral use and primary forests stands. Seedling establishment was improved in the stands under silvopastoral use compared to primary forests, but mortality rate was high (or total) in all situations. We concluded that silvopastoral use of the studied stands did not modify substantially seed regeneration compared to primary forests.Los objetivos de este estudio fueron: i) evaluar la regeneración, desde el punto de vista de su producción y calidad de semillas, así como también de la instalación y supervivencia de plántulas, de dos rodales puros de Nothofagus antarctica (ñire, ñirre) bajo uso silvopastoril en distintas calidades de sitio en Patagonia Sur (51º S, Argentina); ii) comparar estos aspectos de la regeneración de ñire entre rodales bajo uso silvopastoril y bosque primario en similares condiciones geográficas y temporales. Para evaluar la producción de semillas, se usaron cuatro trampas de captura distribuidas espacialmente en cada sitio durante siete años (2004- 2010), determinándose además tamaño, viabilidad y germinación. En cada sitio, se instalaron parcelas permanentes de muestreo para cuantificar la incorporación y supervivencia de plántulas. La producción de semillas en los rodales bajo uso silvopastoril varió desde 1 a 40 millones por hectárea, sin diferenciarse de la producción en bosques primarios aledaños de igual calidad de sitio. En los rodales bajo uso silvopastoril la calidad de las semillas varió entre clases de sitio algunos años, siendo mayor en el sitio de calidad inferior. Sin embargo, en general, no se encontraron diferencias entre bosques primarios y con uso silvopastoril. La instalación de plántulas se vio favorecida en los rodales con uso silvopastoril respecto a bosques primarios, no obstante, la supervivencia fue muy baja o nula en todas las situaciones. Se concluyó que en las situaciones estudiadas el uso silvopastoril de los bosques de ñire no modificó sustancialmente su regeneración por semillas respecto a bosques primarios.Fil: Bahamonde, Héctor A.. Instituto Nacional de Tecnologia Agropecuaria; Argentina; Universidad Nacional de la Patagonia Austral; Argentina;Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina; Instituto Nacional de Tecnologia Agropecuaria; Argentina; Universidad Nacional de la Patagonia Austral; Argentina;Fil: Monelos, Lucas H.. Universidad Nacional de la Patagonia Austral; Argentina;Fil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Revising the diversity within the Dwarf Dog-faced Bat, Molossops temminckii (Chiroptera, Molossidae), with the revalidation of the endangered Molossops griseiventer

The genus Molossops includes two monotypic species of insectivore bats distributed in South America: Molossops neglectus and Molossops temminckii. Both can be differentiated, based on sizes, M. temminckii being smaller (forearm less than 33 mm). Despite being monotypic, at least two additional subspecies have been described for M. temminckii, of which M. temminckii griseiventer from the inter-Andean Valley of the Magdalena River in Colombia might represent a valid taxon. To test the taxonomic status of M. t. griseiventer, we reviewed specimens of M. temminckii from cis- and trans-Andean localities in Colombia. We used Cytochrome-b and Cytochrome Oxidase I comparisons to test the phylogenetic position of cis- and trans-Andean samples and compared qualitative morphology, morphometric and bioacoustics. Our results show that M. t. griseiventer is differentiated from cis-Andean specimens, providing further evidence of its validity at the species level. Furthermore, M. temminckii (sensu stricto) is also distributed in Colombia, but both M. griseiventer and M. temminckii are allopatric, with the Andes acting as a barrier. The specific identity of the specimens from the Caribbean Region of Colombia needs a new evaluation, but our results clearly show that the diversity of Molossops is underestimated

Early Universe Constraints on Time Variation of Fundamental Constants

We study the time variation of fundamental constants in the early Universe. Using data from primordial light nuclei abundances, CMB and the 2dFGRS power spectrum, we put constraints on the time variation of the fine structure constant $\alpha$, and the Higgs vacuum expectation value $$without assuming any theoretical framework. A variation in$$ leads to a variation in the electron mass, among other effects. Along the same line, we study the variation of $\alpha$ and the electron mass $m_e$. In a purely phenomenological fashion, we derive a relationship between both variations.Comment: 18 pages, 12 figures, accepted for publication in Physical Review

The Effects of Pharmacogenetic Activation or Inhibition of the Infralimbic Cortex on Fear Conditioning

Post-Traumatic Stress Disorder (PTSD) can develop after experiencing a very traumatic event which produces a profound and lasting aversive memory in the affected person. Annually, about 8 million people suffer from PTSD. Current treatments are not optimal in achieving a full extinction of the traumatic fear the patients reexperience. Therefore, how the brain processes and modulates fear memories continue to be an active area of research. The excitability of the infralimbic cortex (IL), a sub-region of the medial prefrontal cortex (mPFC), is important for fear extinction, but the effects of IL on fear conditioning have not been extensively studied. Pharmacogenetic approaches, such as Designer Receptors Exclusively Activated by Designer Drugs (DREADD), currently allow for specific and controlled manipulation of different areas of the brain to study their respective functions. The main purpose of this research is to determine whether the excitability of IL affects fear conditioning. We hypothesized that activation of IL during fear conditioning would decrease the acquired fear. To test this, adult male Sprague Dawley rats were surgically infused with a virus that expressed a stimulatory DREADD. Three weeks later, the rats were exposed to fear conditioning, and sacrificed for immunohistochemistry to examine neuronal activity. Preliminary results show that activation of the DREADD receptor increased labeling of c-Fos, and pErk, which indicates increased neuronal activity. This suggests that stimulating the DREADD receptors is activating that brain structure. Next, we will examine whether activation of IL during fear conditioning will decrease acquired fear levels