Gain Modulation by Corticostriatal and Thalamostriatal Input Signals during Reward-Conditioned Behavior.

The cortex and thalamus send excitatory projections to the striatum, but little is known about how these inputs, either individually or collectively, regulate striatal dynamics during behavior. The lateral striatum receives overlapping input from the secondary motor cortex (M2), an area involved in licking, and the parafascicular thalamic nucleus (PF). Using neural recordings, together with optogenetic terminal inhibition, we examine the contribution of M2 and PF projections on medium spiny projection neuron (MSN) activity as mice performed an anticipatory licking task. Each input has a similar contribution to striatal activity. By comparing how suppressing single or multiple projections altered striatal activity, we find that cortical and thalamic input signals modulate MSN gain and that this effect is more pronounced in a temporally specific period of the task following the cue presentation. These results demonstrate that cortical and thalamic inputs synergistically regulate striatal output during reward-conditioned behavior

Integración de la educación ambiental en el currículo a nivel de aula. El caso de la experiencia ecocentros

Trece centros educativos de infantil y primaria de la región extremeña participaron en un proyecto de investigación educativa (Ecocentros) basado en las experiencias conocidas como ecoauditorías escolares. En esta investigación se pretende conocer cómo se desarrolló la integración de la educación ambiental en el aula teniendo en cuenta para ello las acciones que se llevaron a cabo, y que figuraban en la memoria interna elaborada por el profesorado de los centros participantes a lo largo de dos cursos consecutivos. El qué se incorpora al currículo y cómo se hace, es esencial para comprender en qué medida esta experiencia contribuye a llevar a cabo los objetivos de la educación ambiental para el desarrollo sostenible

Morphologic and functional correlates of synaptic pathology in the cathepsin D knockout mouse model of congenital neuronal ceroid lipofuscinosis

Mutations in the cathepsin D (CTSD) gene cause an aggressive neurodegenerative disease (congenital neuronal ceroid lipofuscinosis) that leads to early death. Recent evidence suggests that presynaptic abnormalities play a major role in the pathogenesis of CTSD deficiencies. To identify the early events that lead to synaptic alterations, we investigated synaptic ultrastructure and function in pre-symptomatic CTSD knock-out (Ctsd(−/−)) mice. Electron microscopy revealed that there were significantly greater numbers of readily releasable synaptic vesicles present in Ctsd(−/−) mice than in wild-type control mice as early as postnatal day 16. The size of this synaptic vesicle pool continued to increase with disease progression in the hippocampus and thalamus of the Ctsd(−/−) mice. Electrophysiology revealed a markedly decreased frequency of miniature excitatory postsynaptic currents (EPSCs) with no effect on pair-pulse modulation of the evoked EPSPs in the hippocampus of Ctsd(−/−) mice. The reduced miniature EPSC frequency was observed before the appearance of epilepsy or any morphological sign of synaptic degeneration. Taken together, the data indicate that CTSD is required for normal synaptic function, and that a failure in synaptic trafficking or recycling may be an early and important pathological mechanism in Ctsd(−/−) mice; these presynaptic abnormalities may initiate synaptic degeneration in advance of subsequent neuronal loss

Caracteres preimaginales y aspectos bionómicos de Gyriosomus luczotii Laporte, 1840 (Coleoptera, Tenebrionidae)

Se describe la morfología y microestructura coriónica del huevo y la morfología del primer estadio larvario de Gyriosomus luczotii Laporte, 1840 (Coleoptera, Tenebrionidae, Nycteliini). También se exponen antecedentes bionómicos y distribucionales de la especie. Para la obtención de huevos y larvas, se recolectaron parejas en el terreno que fueron mantenidas en cajas de cria hasta la ovoposición y posterior eclosión. La estructura y ornamentación del exocorion del huevo y características morfológicas externas de la larva fueron analizadas mediante microscopía electrónica de barrido. Los resultados muestran que los huevos de G. luczotii presentan un micropilo redondeado y exocorion liso, con células hexagonales sin aeropilos. Las larvas de G. luczotii presentan características morfológicas adaptativas para la vida edáfica del tipo Pedobionta: cápsula cefálica con gran cantidad de sensillas, patas protorácicas de función cavadora, y pigopodio bien desarrollado. Se analiza la importancia de algunos caracteres morfológicos de la larva de primer estadio como criterio de diagnóstico específico y se establece que las diferencias interespecíficas referidas a las sensillas frontales, la forma del clípeo y el margen anterior del labro tienen valor taxonómico y probablemente filogenético. Palabras clave: Tenebrionidae, Gyriosomus, Morfología, Estadios preimaginales, Desierto costero, Chile.Preimaginal characters and bionomical aspects of Gyriosomus luczotii Laporte, 1840 (Coleoptera, Tenebrionidae) We describe the morphology and microstructure of the egg chorion, and the morphology of the first instar larva of Gyriosomus luczotii Laporte, 1840 (Coleoptera, Tenebrionidae, Nycteliini). Bionomical and distributional data on this species are also provided. To obtain eggs and larvae, couples were collected in the field and kept in rearing cages until oviposture and ecclosion. The structure and adornment of the egg exochorion, and the exterior morphological features of larvae were examined with electron scanning microscopy. The eggs of G. luczotii showed a rounded micropyle and a smooth exochorion, composed of hexagonal cells without aeropyles. The larvae of G. luczotii showed morphological characteristics suited for an edaphic life similar to that of Pedobionta: digging prothoracic legs, cephalic capsule with abundant sensilla, and well–developed pygopodium. We analysed the importance of larval morphology as an element for specific diagnosis and found that interspecific differences regarding frontal sensilla, clypeus shape, and anterior part of labrum, had a taxonomic value and possibly a phylogenetic value. Key words: Tenebrionidae, Gyriosomus, Morphology, Preimaginal stages, Coastal desert, Chile.Se describe la morfología y microestructura coriónica del huevo y la morfología del primer estadio larvario de Gyriosomus luczotii Laporte, 1840 (Coleoptera, Tenebrionidae, Nycteliini). También se exponen antecedentes bionómicos y distribucionales de la especie. Para la obtención de huevos y larvas, se recolectaron parejas en el terreno que fueron mantenidas en cajas de cria hasta la ovoposición y posterior eclosión. La estructura y ornamentación del exocorion del huevo y características morfológicas externas de la larva fueron analizadas mediante microscopía electrónica de barrido. Los resultados muestran que los huevos de G. luczotii presentan un micropilo redondeado y exocorion liso, con células hexagonales sin aeropilos. Las larvas de G. luczotii presentan características morfológicas adaptativas para la vida edáfica del tipo Pedobionta: cápsula cefálica con gran cantidad de sensillas, patas protorácicas de función cavadora, y pigopodio bien desarrollado. Se analiza la importancia de algunos caracteres morfológicos de la larva de primer estadio como criterio de diagnóstico específico y se establece que las diferencias interespecíficas referidas a las sensillas frontales, la forma del clípeo y el margen anterior del labro tienen valor taxonómico y probablemente filogenético. Palabras clave: Tenebrionidae, Gyriosomus, Morfología, Estadios preimaginales, Desierto costero, Chile

Notas sobre a biologia de Centrolabrus caeruleus Azevedo, 1999 (Teleostei: Labridae)

Centrolabrus caeruleus is a recently described littoral fish whose biology is poorly known, despite the fact that it is very abundant in the Azores. This paper presents general information about the age and growth, food and reproduction of this species. Males grow to larger sizes than females, and there are sexual differences in colour and behaviour. Preliminary von Bertalanffy growth curves are given for both sexes, based on modal analysis of the monthly length-frequency distributions. The length-weight relationship is also given. Food is dominated by small phytal invertebrates. Reproduction occurs mainly between March and June. Young of the year are seen from July on. Territorial males build algal nests where females spawn. Details of nest building, and of the courtship and spawning behaviours are given

Composition and distribution of the Orthoptera assemblage (Insecta) in an arid basin in North-Central Chile

La cuenca del valle del río Elqui (Región de Coquimbo, Chile) es un importante foco de actividad agrofrutícola y turística dentro de la zona norte-centro de Chile cuyas condiciones climáticas se caracterizan por el aumento de la temperatura y la disminución de la precipitación. En el contexto del calentamiento global es esperable que la hoya hidrográfica del río Elqui experimente una tendencia ascendente en la aridez, alteraciones en la fenología de plantas y artrópodos y cambios en la riqueza y biodiversidad local de los ecosistemas. En este sentido, en el presente trabajo, mediante colectas manuales en sectores de secano y cultivo de las localidades de Marquesa, Diaguitas y Pisco Elqui en el valle de Elqui, se documentó la composición taxonómica y abundancia del ensamble de Orthoptera (Insecta) en la cuenca del valle del Elqui, se analizó la distribución espacial de las especies constituyentes del ensamble mediante SIG y se documentó la importancia de Orthoptera como potenciales plagas dentro de esta cuenca árida del norte-centro de Chile. Se capturó un total de 204 ejemplares, correspondientes a cuatro familias y seis especies, de las cuales cinco especies fueron capturadas en sectores de secano y cultivo. Acrididae fue la familia más abundante y diversa dentro de los sitios de estudio (65,2% del total capturado) y Trimerotropis ochraceipennis la especie más abundante dentro del sitio de estudio. Las familias Gryllidae, Ommexechidae y Tristiridae estuvieron representadas por una sola especie. La presencia de estas especies en los sectores de secano puede constituir un factor de riesgo para la agricultura, al considerarse potenciales focos irruptivos frente a determinadas condiciones climáticas, y además ocasionar daños en cultivos agrícolas, plantaciones y pastizales. La relación entre la microdistribución del ensamble de Orthoptera presente en el valle de Elqui y el índice NDVI mostró una clara preferencia por la vegetación densa y poco densa (NDVI = 0,1 - 0,49). El presente trabajo es una primera aproximación al estudio de los ortópteros considerados plagas potenciales para el valle del Elqui.The Elqui river basin (Coquimbo Region, Chile) is an important fruit-growing and tourist center in the North and Central area of Chile, where climate conditions are characterized by a rise in temperature and decrease in precipitation. Within the context of global warming, the hydrographical basin of the Elqui River is expected to show a rising trend toward aridity, as well as alterations in the phenology of plants and arthropods, and changes in the local biodiversity and richness of ecosystems. In this respect, this research analyzes the taxonomic composition, abundance and distribution of the assemblage of Orthoptera (Insecta) through hand-collecting in rangeland and farmland of the localities of Marquesa, Diaguitas, and Pisco Elqui in the Elqui valley. We documented the taxonomic composition and abundance of the Orthoptera assemblage (Insecta), and analyzed the spatial distribution of its component species by using SIG. We also documented the potential orthopterans have to become a plague in this arid watershed of North-Central Chile. A total of 204 specimens were captured, belonging to four families and six species, five of which were common to rangeland and farmland. Acrididae was the most abundant and varied family among the study sites (65.2% of the total captured) and Trimerotropis ochraceipennis the most abundant species. The families Gryllidae, Ommexechidae and Tristiridae were represented by only one species. The presence of these species in the rangeland can be a risk factor for agriculture, considering potential irruptive outbreaks under certain climate conditions, and can also cause damage to crops, plantations and grasslands. The relationship between microdistribution of the Orthoptera assemblage present in the Elqui valley and the NDVI index showed a clear preference for dense and not so dense vegetation (NDVI = 0.1 - 0.49). This is a first approach to the study of orthopterans which are considered potential plagues to the Elqui valley.Fil: Alfaro, Fermín M.. Universidad de La Serena (Chile)Fil: Pizarro-Araya, Jaime. Universidad de La Serena (Chile)Fil: Cepeda-Pizarro, Jorge. Universidad de La Serena (Chile)Fil: Bodini, Andrés. Centro de Estudios Avanzados en Zonas Áridas (La Serena, Chile

A new method for the estimation of variance matrix with prescribed zeros in nonlinear mixed effects models

We propose a new method for the Maximum Likelihood Estimator (MLE) of nonlinear mixed effects models when the variance matrix of Gaussian random effects has a prescribed pattern of zeros (PPZ). The method consists in coupling the recently developed Iterative Conditional Fitting (ICF) algorithm with the Expectation Maximization (EM) algorithm. It provides positive definite estimates for any sample size, and does not rely on any structural assumption on the PPZ. It can be easily adapted to many versions of EM.Comment: Accepted for publication in Statistics and Computin

Labile carbon in biological soil crusts in the Tabernas desert, SE Spain.

Decomposition processes are extremely important in biological soil crusts (BSCs). Although the effects of temperature and moisture on such processes have been widely studied, little is known about the influence of the readily metabolizable substrate (labile C) and how this substrate varies in different types of BSCs. In the present study, BSCs formed by cyanobacteria (CYANO) and by lichens (DIPLOS and LEPRA) were incubated at 25 °C (optimum temperature) and different moisture levels, for evaluation of the pool of labile C in the crust layers. Labile C was estimated as the sum of CO2-C emitted and the C extracted with hot water (80 °C) at the end of the incubation period. In all crusts, the relationship between emission and moisture fitted a quadratic model. For the different moisture contents, the sum of CO2-C emitted and C extracted with hot water converged to a constant value for each type of crust. This value, considered as the maximum content of labile C in the crust, was extremely high in DIPLOS, reaching up to 40% of the total organic C (TOC) initially present. In all crusts, and independently of the consumption of labile C, simple sugars (sucrose, glucose) remained at the end of the incubation period, which suggests that these sugars may play a protective role in BSCs. The presence of mannitol suggests that the fructose released during hydrolysis of sucrose was reduced to mannitol, thus enabling electron transport during moments of intense respiratory stress. The intense respiration in DIPLOS is partly due to the metabolism of polyphenols, which are possibly derived from the growth and death of free-living fungi that proliferate during incubation of the crusts. These results demonstrate that the metabolic processes in BSCs differ depending on the type of organisms that form the crusts and that there is a high risk of C loss from Diploschistes BSCs after heavy rainfall events.Peer reviewe