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Spinal inhibitory interneurons could contribute to amyotrophic lateral sclerosis (ALS) pathology, but their excitability has never been directly measured. We studied the excitability and morphology of glycinergic interneurons in early postnatal transgenic mice (SOD1Few studies in amyotrophic lateral sclerosis (ALS) measure effects of the disease on inhibitory interneurons synapsing onto motoneurons (MNs). However, inhibitory interneurons could contribute to dysfunction, particularly if altered before MN neuropathology, and establish a long-term imbalance of inhibition / excitation. We directly assessed excitability and morphology of glycinergic (GlyT2 expressing) ventral lumbar interneurons from SOD1G93AGlyT2eGFP (SOD1) and wildtype GlyT2eGFP (WT) mice on postnatal days 6-10. Patch clamp revealed dampened excitability in SOD1 interneurons, including depolarized persistent inward currents (PICs), increased voltage and current threshold for firing action potentials, along with a marginal decrease in afterhyperpolarization (AHP) duration. Primary neurites of ventral SOD1 inhibitory interneurons were larger in volume and surface area than WT. GlyT2 interneurons were then divided into 3 subgroups based on location: (1) interneurons within 100 μm of the ventral white matter, where Renshaw cells (RCs) are located, (2) interneurons interspersed with MNs in lamina IX, and (3) interneurons in the intermediate ventral area including laminae VII and VIII. Ventral interneurons in the RC area were the most profoundly affected, exhibiting more depolarized PICs and larger primary neurites. Interneurons in lamina IX had depolarized PIC onset. In lamina VII-VIII, interneurons were least affected. In summary, inhibitory interneurons show very early region-specific perturbations poised to impact excitatory / inhibitory balance of MNs, modify motor output, and provide early biomarkers of ALS. Therapeutics like riluzole which universally reduce CNS excitability could exacerbate the inhibitory dysfunction described here. Abstract figure legend SOD1 glycinergic interneurons in the ventral horn show altered morphology and excitability, including depolarization of PICs, depolarized threshold, shorter AHPs, smaller somata and larger primary neurites. Ventrally located interneurons are the most prominently affected. This article is protected by copyright. All rights reserved.

Although they share the common function of controlling muscle fiber contraction, spinal motoneurons display a remarkable diversity. Alpha-motoneurons are the "final common pathway", which relay all the information from spinal and supraspinal centers and allow the organism to interact with the outside world by controlling the contraction of muscle fibers in the muscles. On the other hand, gamma-motoneurons are specialized motoneurons that do not generate force and instead specifically innervate muscle fibers inside muscle spindles, which are proprioceptive organs embedded in the muscles. Beta-motoneurons are hybrid motoneurons that innervate both extrafusal and intrafusal muscle fibers. Even among alpha-motoneurons, there exists an exquisite diversity in terms of motoneuron electrical and molecular properties, physiological and structural properties of their neuromuscular junctions, and molecular and contractile properties of the innervated muscle fibers. This diversity, across species, across muscles, and across muscle fibers in a given muscle, underlie the vast repertoire of movements that one individual can perform.

Spinal alpha-motoneurons are classified in several types depending on the contractile properties of the innervated muscle fibers. This diversity is further displayed in different levels of vulnerability of distinct motor units to neurodegenerative diseases such as Amyotrophic Lateral Sclerosis (ALS). We summarize recent data suggesting that, contrary to the excitotoxicity hypothesis, the most vulnerable motor units are hypoexcitable and experience a reduction in their firing prior to symptoms onset in ALS. We suggest that a dysregulation of activity-dependent transcriptional programs in these motoneurons alter crucial cellular functions such as mitochondrial biogenesis, autophagy, axonal sprouting capability and re-innervation of neuromuscular junctions.

Spinal alpha-motoneurons are classified in several types depending on the contractile properties of the innervated muscle fibers. This diversity is further displayed in different levels of vulnerability of distinct motor units to neurodegenerative diseases such as Amyotrophic Lateral Sclerosis (ALS). We summarize recent data suggesting that, contrary to the excitotoxicity hypothesis, the most vulnerable motor units are hypoexcitable and experience a reduction in their firing prior to symptoms onset in ALS. We suggest that a dysregulation of activity-dependent transcriptional programs in these motoneurons alter crucial cellular functions such as mitochondrial biogenesis, autophagy, axonal sprouting capability and re-innervation of neuromuscular junctions.

Summary Efference copies are neural replicas of motor outputs used to anticipate the sensory consequences of a self-generated motor action or to coordinate neural networks involved in distinct motor behaviors. 1 An established example of this motor-to-motor coupling is the efference copy of the propulsive motor command, which supplements classical visuo-vestibular reflexes to ensure gaze stabilization during amphibian larval locomotion. 2 Such feedforward replica of spinal pattern-generating circuits produces a spino-extraocular motor coupled activity that evokes eye movements, spatiotemporally coordinated to tail undulation independently of any sensory signal. 3 , 4 Exploiting the developmental stages of the frog, 1 studies in metamorphing Xenopus demonstrated the persistence of this spino-extraocular motor command in adults and its developmental adaptation to tetrapodal locomotion. 5 , 6 Here, we demonstrate for the first time the existence of a comparable locomotor-to-ocular motor coupling in the mouse. In neonates, ex vivo nerve recordings of brainstem-spinal cord preparations reveal a spino-extraocular motor coupled activity similar to the one described in Xenopus. In adult mice, trans-synaptic rabies virus injections in lateral rectus eye muscle label cervical spinal cord neurons closely connected to abducens motor neurons. Finally, treadmill-elicited locomotion in decerebrated preparations 7 evokes rhythmic eye movements in synchrony with the limb gait pattern. Overall, our data are evidence for the conservation of locomotor-induced eye movements in vertebrate lineages. Thus, in mammals as in amphibians, CPG-efference copy feedforward signals might interact with sensory feedback to ensure efficient gaze control during locomotion.

SummaryEfference copies are neural replicas of motor outputs used to anticipate the sensory consequences of a self-generated motor action or to coordinate neural networks involved in distinct motor behaviors1. An established example of this motor-to-motor coupling is the efference copy of the propulsive motor command that supplements classical visuo-vestibular reflexes to ensure gaze stabilization during amphibian larval locomotion2. Such feedforward replica from spinal pattern-generating circuits produces a spino-extraocular motor coupled activity that evokes eye movements, spatio-temporally coordinated to tail undulation independently of any sensory signal3,4. Exploiting the evolutionary-development characteristic of the frog1, studies in metamorphing Xenopus demonstrated the persistence of this spino-extraocular motor command in adults, and its developmental adaptation to tetrapodal locomotion5,6. Here, we demonstrate for the first time the existence of a comparable locomotor-to-ocular motor coupling in the mouse. In neonates, ex vivo nerve recordings from brainstem-spinal cord preparation reveals a spino-extraocular motor coupled activity similar to the one described in Xenopus. In adult mice, trans-synaptic rabies injection in lateral rectus eye muscle labels cervical spinal cord neurons projecting directly to abducens motor neurons. Finally, treadmill-elicited locomotion in decerebrated preparations7 evokes rhythmic eye movements in synchrony with the limb gait pattern. Overall, our data are evidence for the conservation of locomotor-induced eye movements in higher tetrapods. Thus, in mammals as in amphibians, during locomotion CPG-efference copy feedforward signals might interact with sensory feedback to ensure efficient gaze control.HighlightsSpino-extraocular motor coupling is evidenced from newborn mice ex vivo preparationsAdult decerebrated mice exhibit conjugated rhythmic eye movements during treadmill locomotionLocomotor-induced oculomotor activity occurs in absence of visuo-vestibular inputsConserved CPG-based efference copy signal in vertebrates with common features.eTOC blurbWe report a functional coupling between spinal locomotor and oculomotor networks in the mouse, similar to the one previously described in Amphibians. This is the first evidence for the direct contribution of locomotor networks to gaze control in mammals, suggesting a conservation of the spino-extraocular coupling in higher tetrapods during sustained locomotion.

Esta propuesta se enmarca en el departamento de Arauca en Colombia y está orientada a la creación de una empresa denominada SERVIAGRO E&M MAQUINARIA AGRÍCOLA S.A.S empresa prestadora de servicios de alquiler de maquinaria agrícola, dirigida a todos los agricultores que requieran el servicio de maquinaria agrícola en el departamento. This proposal is framed in the department of Arauca in Colombia and is aimed at the creation of a company called SERVIAGRO E&M MAQUINARIA AGRÍCOLA SAS, a provider of agricultural machinery rental services, aimed at all farmers who require the service of agricultural machinery in the Department. http://www.ustadistancia.edu.co/?page_id=3956 Especialización

This study demonstrates that, in a mouse model of ALS, excitatory synapses on spinal motoneurons are disrupted. Activation of the cAMP/PKA pathway reverts the functional and structural synaptic deficits and ameliorates disease markers by increasing motoneuron firing., Excessive excitation is hypothesized to cause motoneuron (MN) degeneration in amyotrophic lateral sclerosis (ALS), but actual proof of hyperexcitation in vivo is missing, and trials based on this concept have failed. We demonstrate, by in vivo single-MN electrophysiology, that, contrary to expectations, excitatory responses evoked by sensory and brainstem inputs are reduced in MNs of presymptomatic mutSOD1 mice. This impairment correlates with disrupted postsynaptic clustering of Homer1b, Shank, and AMPAR subunits. Synaptic restoration can be achieved by activation of the cAMP/PKA pathway, by either intracellular injection of cAMP or DREADD-Gs stimulation. Furthermore, we reveal, through independent control of signaling and excitability allowed by multiplexed DREADD/PSAM chemogenetics, that PKA-induced restoration of synapses triggers an excitation-dependent decrease in misfolded SOD1 burden and autophagy overload. In turn, increased MN excitability contributes to restoring synaptic structures. Thus, the decrease of excitation to MN is an early but reversible event in ALS. Failure of the postsynaptic site, rather than hyperexcitation, drives disease pathobiochemistry., Graphical Abstract

Although ALS is an adult-onset neurodegenerative disease, motoneuron electrical properties are already altered during embryonic development. Motoneurons must therefore exhibit a remarkable capacity for homeostatic regulation to maintain a normal motor output for most of the life of the patient. In the present paper, we demonstrate how maintaining homeostasis could come at a very high cost. We studied the excitability of spinal motoneurons from young adult SOD1(G93A) mice to end-stage. Initially homeostasis is highly successful in maintaining their overall excitability. This initial success, however, is achieved by pushing some cells far above the normal range of passive and active conductances. As the disease progresses, both passive and active conductances shrink below normal values in the surviving cells. This shrinkage may thus promote survival, implying the previously large values contribute to degeneration. These results support the hypothesis that motoneuronal homeostasis may be “hyper-vigilant” in ALS and a source of accumulating stress.Significance StatementDuring ALS, motoneurons exhibit a remarkable ability to maintain a normal motor output despite continuous alterations of their electrophysiological properties, up to the point when overt symptoms become apparent. We show that this homeostatic process can sometimes push motoneurons beyond the normal range, which may be causing long-lasting harm.

Appropriate scaling of motor output from mouse to humans is essential. The motoneurons that generate all motor output are, however, very different in rodents compared with humans, being smaller and much more excitable. In contrast, feline motoneurons are more similar to those in humans. These scaling differences need to be taken into account for the use of rodents for translational studies of motor output.

International audience; Hyperexcitability has been suggested to contribute to motoneuron degeneration in amyotrophic lateral sclerosis (ALS). If this is so, and given that the physiological type of a motor unit determines the relative susceptibility of its motoneuron in ALS, then one would expect the most vulnerable motoneurons to display the strongest hyperexcitability prior to their degeneration, whereas the less vulnerable should display a moderate hyperexcitability, if any. We tested this hypothesis in vivo in two unrelated ALS mouse models by correlating the electrical properties of motoneurons with their physiological types, identified based on their motor unit contractile properties. We found that, far from being hyperexcitable, the most vulnerable motoneurons become unable to fire repetitively despite the fact that their neuromuscular junctions were still functional. Disease markers confirm that this loss of function is an early sign of degeneration. Our results indicate that intrinsic hyperexcitability is unlikely to be the cause of motoneuron degeneration.

[EN] A rationalized design of the organic structure directing agents (OSDAs) allows the preparation of zeolites with specific framework topologies, crystal sizes and/or chemical compositions. In the last years, organic molecules containing aromatic rings in their structures have been described as efficient OSDAs for the synthesis of zeolites with different physico-chemical properties. The unique ability of these aromatic molecules to form rigid and bulky OSDAs by supramolecular self-assembling of two organic molecules, mainly through p–p interactions, has allowed the synthesis of zeolites with large void volumes, controlled chemical distribution and/or high external surface areas. Along the present review, I would like to highlight the recent achievements reported in the literature using aromatic self-assembled bulky dimers as OSDAs for the synthesis of zeolites., Financial support by the Spanish Government-MINECO through "Severo Ochoa" (SEV 2012-0267), Consolider Ingenio 2010-Multicat, MAT2012-37160 and, Intramural-201480I015 is acknowledged. The author especially acknowledges to Dr. Cristina Martinez and Prof. Avelino Corma for helpful discussions.

In amyotrophic lateral sclerosis (ALS), an adult onset disease in which there is progressive degeneration of motoneurones, it has been suggested that an intrinsic hyperexcitability of motoneurones (i.e. an increase in their firing rates), contributes to excitotoxicity and to disease onset. Here we show that there is no such intrinsic hyperexcitability in spinal motoneurones. Our studies were carried out in an adult mouse model of ALS with a mutated form of superoxide dismutase 1 around the time of the first muscle fibre denervations. We showed that the recruitment current, the voltage threshold for spiking and the frequency-intensity gain in the primary range are all unchanged in most spinal motoneurones, despite an increased input conductance. On its own, increased input conductance would decrease excitability, but the homeostasis for excitability is maintained due to an upregulation of a depolarizing current that is activated just below the spiking threshold. However, this homeostasis failed in a substantial fraction of motoneurones, which became hypoexcitable and unable to produce sustained firing in response to ramps of current. We found similar results both in lumbar motoneurones recorded in anaesthetized mice, and in sacrocaudal motoneurones recorded in vitro, indicating that the lack of hyperexcitability is not caused by anaesthetics. Our results suggest that, if excitotoxicity is indeed a mechanism leading to degeneration in ALS, it is not caused by the intrinsic electrical properties of motoneurones but by extrinsic factors such as excessive synaptic excitation.

In the last years, the preparation of small pore zeolites, especially those presenting large cavities in their structure, have received much attention because they have shown excellent application in catalysis (such as methanol-to-olefins or selective catalytic reduction of NOx) and gas separations. In the present review, we will focus on the diverse synthetic routes followed to direct the crystallization of small pore zeolites and, on the other hand, the most outstanding applications of those small pore microporous materials., This work has been supported by the Spanish Government through Consolider Ingenio 2010-Multicat, the "Severo Ochoa Program", MAT2012-37160 and MAT2012-31657 and by UPV through PAID-06-11 (n.1952). Manuel Moliner also acknowledges "Subprograma Ramon y Cajal" for the contract RYC-2011-08972.

Titanosilicate forms of expanded MWW-related material are synthesized starting from a pure silica precursor, ITQ-1. This procedure improves the current synthetic route of the expanded titanosilicate MWW material (Ti-YNU-1), which requires the use of a borosilicate MWW as precursor and, consequently, several postsynthetic acid treatments for removing boron atoms from the framework. The expanded Ti-MWW-related materials presented here show better activity than regular Ti-MWW in the selective epoxidation reaction of cyclohexene using H2O2 as oxidant., Financial support by the Spanish MINECO (MAT2012-37160, and Consolider Ingenio 2010-Multicat), Generalitat Valenciana by the PROMETEO program, and UPV through PAID-06-11 (no. 1952) is acknowledged. M.M. also acknowledges "Subprograma Ramon y Cajal" for the contract RYC-2011-08972.

[EN] Isomerization of sugars is used in a variety of industrially relevant processes and in glycolysis. Here, we show that hydrophobic zeolite beta with framework tin or titanium Lewis acid centers isomerizes sugars, e.g., glucose, via reaction pathways that are analogous to those of metalloenzymes. Specifically, experimental and theoretical investigations reveal that glucose partitions into the zeolite in the pyranose form, ring opens to the acyclic form in the presence of the Lewis acid center, isomerizes into the acyclic form of fructose, and finally ring closes to yield the furanose product. The zeolite catalysts provide processing advantages over metalloenzymes such as an ability to work at higher temperatures and in acidic conditions that allow for the isomerization reaction to be coupled with other important conversions., The work at Caltech and the University of Delaware was financially supported as part of the Catalysis Center for Energy Innovation, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award DE-SC0001004. M.M acknowledges the Fundacion Ramon Areces Postdoctoral Research Fellowship Program and the "Subprograma Ramon y Cajal" for Contract RYC-2011-08972 for financial support. R.B.D. acknowledges the Obra Social "la Caixa" for a graduate fellowship. A.P. acknowledges the Caltech Summer Undergraduate Research Fellowship program(SURF) for financial support. The computational studies for this work were supported by the U.S. Department of Energy under Contract DE-AC0206CH11357 and this material is based upon work supported as part of the Institute for Atom-efficient Chemical Transformations (IACT), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences. We gratefully acknowledge grants of computer time from the ANL Laboratory Computing Resource Center (LCRC), and the ANL Center for Nanoscale Materials. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Sciences of the U.S. Department of Energy under Contract DE-AC02-05CH11231.

Classical studies of the mammalian neuromuscular system have shown an impressive adaptation match between the intrinsic properties of motoneurons and the contractile properties of their motor units. In these studies, the rate at which motoneurons start to fire repetitively corresponds to the rate at which individual twitches start to sum, and the firing rate increases linearly with the amount of excitation (“primary range”) up to the point where the motor unit develops its maximal force. This allows for the gradation of the force produced by a motor unit by rate modulation. In adult mouse motoneurons, however, we recently described a regime of firing (“subprimary range”) that appears at lower excitation than what is required for the primary range, a finding that might challenge the classical conception. To investigate the force production of mouse motor units, we simultaneously recorded, for the first time, the motoneuron discharge elicited by intracellular ramps of current and the force developed by its motor unit. We showed that the motor unit developed nearly its maximal force during the subprimary range. This was found to be the case regardless of the input resistance of the motoneuron, the contraction speed, or the tetanic force of the motor unit. Our work suggests that force modulation in small mammals mainly relies on the number of motor units that are recruited rather than on rate modulation of individual motor units.

[EN] The present invention relates to a process for the direct synthesis of a material with a CHA zeolite structure in the silicoaluminate form thereof containing copper atoms, which comprises at least the following steps: (i) Preparation of a mixture which contains at least one water source, one copper source, one polyamine, one source of Y tetravalent element, one source of X trivalent element, the tetraethylammonium cation as the only OSDA and one source of alkaline or alkaline earth (A) cations, and wherein the synthesis mixture has the following molar composition: YO 2 : a X 2 O 3 : b OSDA : c A : d H 2 O : e Cu : f polyamine (ii) Crystallization of the mixture obtained in (i) in a reactor; (iii) Recovery of the crystalline material obtained in (ii)., [ES] Síntesis directa de Cu-CHA mediante la combinación de un complejo de Cu y tetraetilamonio, y aplicaciones en catálisis. La presente invención se refiere a un proceso para la síntesis directa de un material con estructura zeolítica CHA en su forma silicoaluminato conteniendo átomos de cobre que puede comprender, al menos, los siguientes pasos: (i) Preparación de una mezcla que contenga, al menos, una fuente de agua, una fuente de cobre, una poliamina, una fuente de elemento tetravalente Y, una fuente de elemento trivalente X, el catión tetraetilamonio como único ADEO y una fuente de cationes alcalinos o alcalinotérreos (A), y donde la mezcla de síntesis tiene la siguiente composición molar: YO2: a X2O3: b ADEO: c A: d H2O: e Cu: f Poliamina. (ii) Cristalización de la mezcla obtenida en (i) en un reactor. (iii) Recuperación del material cristalino obtenido en (ii)., Consejo Superior de Investigaciones Científicas (España), Universidad Politécnica de Valencia, A1 Solicitud de patente con informe sobre el estado de la técnica

Does the afterhyperpolarization current control the gain and discharge variability of motoneurones according to the same law? We investigated this issue in lumbar motoneurones of anaesthetized cats. Using dynamic clamp, we measured the conductance, time constant and driving force of the AHP current in a sample of motoneurones and studied how the gain was correlated to these quantities. To study the action of the AHP on the discharge variability and to compare it to its action on the gain, we injected an artificial AHP-like current in motoneurones. This increased the natural AHP. In three motoneurones, we abolished most of the natural AHP with the calcium chelator BAPTA to investigate the condition where the discharge was essentially controlled by the artificial AHP. Our results demonstrate that both the gain and the coefficient of variation of the firing rate are inversely proportional to the magnitude and to the time constant of the artificial AHP conductance. This indicates that the AHP exerts the same control over the gain and the variability. This mechanism ensures that the variability of the discharge is modulated with the gain. This guarantees a great regularity of the discharge when the motoneurone is in a low excitability state and hence good control of the force produced.

Metal-containing zeolites, especially Sn-Beta, perform as very efficient heterogeneous catalysts in the selective oxidation of levoglucosenone, which is considered as a platform chemical for the production of highly-valuable chemicals, towards the synthesis of the optically pure gamma-lactone(S)-gamma-hydroxymethyl-alpha,beta-butenolide (HBO) using H2O2 as an oxidizing agent. Using Sn-Beta as a catalyst, yields up to 75% of (S)-gamma-hydroxymethyl-alpha,beta-butenolide are achieved in a "one-pot" cascade reaction. When Sn-Beta is combined with an acid resin, such as Amberlyst-15, the "two-step" process allows yields up to 90%., This work has been supported by the Spanish Government MINECO through Consolider Ingenio 2010-Multicat and MAT2012-37160, and by UPV through PAID-06-11 (n.1952). Manuel Moliner also acknowledges "Subprograma Ramon y Cajal" for contract RYC-2011-08972. ITQ thanks the "Program Severo Ochoa" for financial support.