El genoma d'un blat ancestral de més de 3.000 anys

La investigadora del Centre de Recerca en Agrigenòmica (CRAG) Laura R. Botigué ha realitzat un estudi en col·laboració amb investigadors britànics, en què s'ha seqüenciat per primera vegada el genoma d'una mostra de blat de fa més de 3.000 anys. La recerca ha aportat valuosa informació sobre aquest cereal, que va ser el més popular en l'antic Egipte, i la seva domesticació.La investigadora del Centro de Investigación en Agrigenómica (CRAG) Laura R. Botigué ha realizado un estudio en colaboración con investigadores británicos, en el que se ha secuenciado por primera vez el genoma de una muestra de trigo de hace más de 3.000 años. La investigación ha aportado valiosa información sobre este cereal, que fue el más popular en el antiguo Egipto, y su domesticación.The researcher from the Centre for Research in Agricultural Genomics (CRAG) Laura R. Botigué has conducted a study in collaboration with British researchers in which the genome of a wheat sample from more than 3,000 years ago has been sequenced for the first time. This research has provided valuable information about this cereal, which was the most popular in ancient Egypt, and its domestication

Involucrant a l'alumnat de primària en una pràctica científica autèntica : el taller Plantes Mutants

En els últims anys ha anat creixen el nombre d'iniciatives que estableixen col·laboracions entre alumnat i científics professionals. El present article, ofereix un exemple de taller d'aquest tipus que involucra a alumnat de 5è i 6è de primària en Pràctiques Científiques anàlogues a les dels científics del CRAG. Aquest taller permet als alumnes consolidar coneixements sobre les plantes i construir una primera idea de mutació. A més a més, la participació en aquest taller permet a l'alumnat desenvolupar una visió més positiva i propera de la ciència real així com despertar el seu interès per la recerca científica y la feina dels investigadors.In the last years, the number of collaborative work initiatives between children and professional researchers has been increasing. This article offers an example of a workshop that involves 9 to 12-year-old children in "real" scientific practices similar to what professional researchers do at CRAG. This workshop aims to help the students to consolidate their knowledge on plant biology and to build a first idea of genetic mutations. Furthermore, the workshop has a positive impact on the student's perceptions about science, helping them in developing a more accurate view of scientific research and in growing their interest towards it

Clozapine and haloperidol differently suppress the MK-801-increased glutamatergic and serotonergic transmission in the medial prefrontal cortex of the rat

The administration of noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonists such as phencyclidine and ketamine has been shown to increase the extracellular concentration of glutamate and serotonin (5-HT) in the medial prefrontal cortex (mPFC). In the present work, we used in vivo microdialysis to examine the effects of the more potent noncompetitive NMDA receptor antagonist, MK-801, on the efflux of glutamate and 5-HT in the mPFC, and whether the MK-801-induced changes in the cortical efflux of both transmitters could be blocked by clozapine and haloperidol given systemically or intra-mPFC. The systemic, but not the local administration of MK-801, induced an increased efflux of 5-HT and glutamate, which suggests that the NMDA receptors responsible for these effects are located outside the mPFC, possibly in GABAergic neurons that tonically inhibit glutamatergic inputs to the mPFC. The MK-801-induced increases of extracellular glutamate and 5-HT were dependent on nerve impulse and the activation of mPFC AMPA/kainate receptors as they were blocked by tetrodotoxin and NBQX, respectively. Clozapine and haloperidol blocked the MK-801-induced increase in glutamate, whereas only clozapine was able to block the increased efflux of 5-HT. The local effects of clozapine and haloperidol paralleled those observed after systemic administration, which emphasizes the relevance of the mPFC as a site of action of these antipsychotic drugs in offsetting the neurochemical effects of MK-801. The ability of clozapine to block excessive cortical 5-HT efflux elicited by MK-801 might be related to the superior efficacy of this drug in treating negative/cognitive symptoms of schizophrenia.This work was supported by the Spanish Ministry of Education and Science Grants SAF 2004-05525 and SAF 2003-04930 and by the Generalitat de Catalunya (SGR2005/00758 and SGR2005/00826). XL-G, ZB, and MA-B were recipients of predoctoral fellowships from the Consejo Superior de Investigaciones Científicas (CSIC), Spanish Ministry of Education and Science, and Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), respectively.Peer reviewe

"Mutants plants" workshop protocol : didactic guide for researchers and instructors to conduct a science workshop with groups of school students aged 10 to 14

The "Mutant Plants" workshop pursues the dual aim of promoting scientific vocations and publicizing the importance of Plant Science to meet current and future societal challenges.This workshop was designed jointly by the Centre for Research in Agricultural Genomics (CRAG) and the Research Centre for Scientific and Mathematical Education (CRECIM) from the Autonomous University of Barcelona (UAB), thanks to the financial support of the Spanish Foundation for Science and Technology (FCT-16-10825) and the Severo Ochoa program of Excellence Centres (SEV-2015-0533), both from the Spanish Ministry of Economy, Industry and Competitiveness

Àgora - Trobada d'escoles i científiques sobre alimentació

El programa 100tíficas ha conseguido convocar a más de 200 científicas que han compartido su experiencia en la carrera del ámbito científico y tecnológico con alumnos y alumnas de 100 escuelas de Cataluña en el marco del Día Internacional de la Mujer y la Niña en la Ciencia (11 de febrero, 2021). A causa de la pandemia, este año esta actividad se ha realizado de manera virtual. Ahora, tenemos la oportunidad de que algunas de estas mujeres compartan su experiencia personal de manera presencial con alumnos y alumnas de escuelas de Barcelona. En este caso, la actividad se centrará en científicas que han realizado trabajos de investigación en alimentación. Esta actividad quiere dar visibilidad a las mujeres del mundo científico y tecnológico y, a la vez, impulsar las vocaciones científico-técnicas de las niñas.Peer reviewe

Implicació dels sistemes glutamatèrgic i GABAèrgic en la mort per excitotoxicitat en cultius de cèl·lules granulars de cerebel. Alteracions d'aquests sistemes pel contaminant orgànic persistent dieldrín.

[cat] El glutamat i el GABA són, respectivament, el principal neurotransmissor excitador i inhibidor del sistema nerviós central. Un balanç incorrecte entre aquests dos sistemes de neurotransmissors pot conduir a estats patològics. L'excés de glutamat extracel·lular produeix neurotoxicitat per un mecanisme dependent de l'entrada de Ca2+ a través del receptor NMDA de glutamat. Aquest fenomen es coneix amb el nom d'excitotoxicitat. El paper del neurotransmissor GABA en el procés d'excitotoxicitat no és clar. Si bé alguns treballs descriuen que l'increment de la neurotransmissió GABAèrgica resulta protectora de l'excitotoxicitat, d'altres descriuen el cas contrari. L'exposició aguda al plaguicida organoclorat dieldrín produeix, en humans i en animals d'experimentació, síndrome d'hiperexcitabilitat, produint convulsions que poden arribar a causar la mort de l'organisme. Aquest efecte s'explica per l'acció antagonista del dieldrín en el receptor GABAA. Aquest plaguicida ja no s'utilitza en països desenvolupats. Tot i això, degut a l'elevada persistència i bioacumulació del dieldrín, i a què encara s'utilitza en països subdesenvolupats i que té una gran capacitat de viatjar llargues distàncies, a dia d'avui la població general de tot el món continua exposada a aquest plaguicida. Així, actualment, el dieldrín es considera un "contaminant orgànic persistent" (COP). Si bé es coneixen els efectes aguts de l'exposició a dieldrín, no estan clars quins efectes adversos sobre el sistema nerviós central podria produir l'exposició perllongada a baixes concentracions de dieldrín. En aquesta tesi es desenvolupa un model d'excitotoxicitat en cultius primaris de cèl·lules granulars de cerebel, basat en l'alliberament de glutamat endogen. En aquest model s'estudia la implicació del receptor GABAA i d'altres canals de clorur en la mort excitotòxica. Es descriu que l'entrada de clorur a través del receptor GABAA i de canals de clorur dependents d'àcid niflúmic incrementa l'excitotoxicitat. A més, s'estudien els efectes de concentracions subcitotòxiques de dieldrín sobre els sistemes GABAèrgic i glutamatèrgic en cultius de cèl·lules granulars de cerebel exposats durant períodes perllongats. Es descriu que el bloqueig parcial del receptor GABAA induït pel dieldrín, produeix una resposta compensatòria en els receptors NMDA de glutamat (disminució), de manera que quan s'exposen els cultius a l'estímul excitotòxic prèviament descrit, no es produeix excitotoxicitat. Els resultats obtinguts en aquesta tesi indiquen que el receptor GABAA és una diana preferencial de l'acció neurotòxica del plaguicida organoclorat dieldrín. Com a treball annex, es discuteix la utilització dels cultius primaris reagregats de cervell com a model in vitro en estudis de neurotoxicitat.[eng] "Implication of glutamatergic and GABAergic systems in the mechanism of excitotoxicity in cerebellar granule cell culture. Alterations of these systems by the Persistent Organic Pollutant dieldrin". TEXT: Glutamate and GABA are, respectively, the main excitatory and inhibitory neurotransmitters in the central nervous system. An imbalance between these systems might produce a pathological state. An excess of extracellular glutamate produces neurotoxicity by a mechanism dependent on a Ca2+ influx through the NMDA receptor. This phenomenon is known as excitotoxicity. The role of the GABA neurotransmitter in the excitotoxicity process in not clear. While, some authors describe that an increment in the GABAergic neurotransmission results in neuroprotection from the excitotoxicity, other authors describe the other way round. The acute exposure to the organochlorine pesticide dieldrin produces an hiperexcitability syndrome. This effect is due to the GABAA antagonist action of dieldrin. This pesticide is not longer used in developed countries. Nevertheless, nowadays people all over the world are exposed to this pesticide due to the utilization in developing countries, the high capacity of dieldrin to travel long distances and the high persistence and bioaccumulation of this compound. Actually, we now refer to dieldrin as a Persistent Organic Pollutant (POP). Although the effects of the acute exposure to dieldrin are well documented, there is a lack of information about the effects of chronic exposure to lower concentrations of this contaminant. In this thesis an excitotoxicity model based in the release of the endogenous glutamate is developed in primary cultures of cerebellar granule cells. With this model we study the implication of the GABAA receptor and other chloride channels in the excitotoxic mechanism. It is described that the chloride influx through the GABAA receptor and through niflumic acid sensitive chloride channels increases excitotoxicity. The effects of subcitotoxic concentrations of dieldrin on GABAergic and glutamatergic systems in primary cultures of cerebellar granule cells exposed for long periods are also studied. We describe that the partial block of the GABAA receptor produced by dieldrin, produces a compensatory response in the NMDA receptors (decrease). The decrease of the functional NMDA receptors makes the cultures insensitive to the excitotoxicity induced by released glutamate. The results obtained in this thesis indicate that the GABAA receptor is an important target when considering the neurotoxic effects of dieldrin

Excitotoxic death induced by released glutamate in depolarized primary cultures of mouse cerebellar granule cells is dependent on GABAA receptors and niflumic acid-sensitive chloride channels

Excitotoxic neuronal death has been linked to neurological and neurodegenerative diseases. Several studies have sought to clarify the involvement of Cl- channels in neuronal excitotoxicity using either N-methyl-D-aspartic acid (NMDA) or α-amino-3-hydroxy-5-methylisoxazole-4- propionate/kainic acid agonists. In this work we induced excitotoxic death in primary cultures of cerebellar granule cells by means of endogenously released glutamate. Excitotoxicity was provoked by exposure to high extracellular K + concentrations ([K+]o) for 5 min. Under these conditions, a Ca2+-dependent release of glutamate was evoked. When extracellular glutamate concentration rose to between 2 and μM, cell viability was significantly reduced by 30-40%. The NMDA receptor antagonists (MK-801 and D-2-amino-5-phosphonopentanoic acid) prevented cell death. Exposure to high [K+]o produced a 36Cl- influx which was significantly reduced by picrotoxinin. In addition, the GABAA receptor antagonists (bicuculline, picrotoxinin and SR 95531) protected cells from high [K+]o-triggered excitotoxicity and reduced extracellular glutamate concentration. The Cl- channel blockers niflumic acid and 5-nitro-2-(3-phenylpropylamino)benzoic acid also exerted a neuroprotective effect and reduced extracellular glutamate concentration, even though they did not reduce high [K+] o-induced 36Cl- influx. Primary cultures of cerebellar granule cells also contain a population of GABAergic neurons that released GABA in response to high [K+]o. Chronic treatment of primary cultures with kainic acid abolished GABA release and rendered granule cells insensitive to high [K+]o exposure, even though NMDA receptors were functional. Altogether, these results demonstrate that, under conditions of membrane depolarization, low micromolar concentrations of extracellular glutamate might induce an excitotoxic process through both NMDA and GABAA receptors and niflumic acid-sensitive CP channels.This work was supported by grants FIS 01/1318 (Ministry of Health), SAF 2003-04930 (Ministry of Science and Technology cofinanced with FEDER funds), 2001SGR00356 and 2001SGR00355 (CIRIT, Generalitat de Catalunya, Spain). Z.B. is in receipt of a predoctoral fellowship from the Spanish Ministry of Education. A. Maresma is acknowledged for her collaboration

Long-term exposure to dieldrin reduces γ-aminobutyric acid type A and N-methyl-D-aspartate receptor function in primary cultures of mouse cerebellar granule cells

The organochlorine pesticide dieldrin is a persistent organic pollutant that accumulates in the fatty tissue of living organisms. In mammals, it antagonizes the GABAA receptor, producing convulsions after acute exposure. Although accumulation in human brain has been reported, little is known about the effects of long-term exposure to dieldrin in the nervous system. Homeostatic control of the balance between excitation and inhibition has been reported when neuronal activity is chronically altered. We hypothesized that noncytotoxic concentrations of dieldrin could decrease glutamatergic neurotransmission as a consequence of a prolonged reduction in GABAA receptor function. Long-term exposure of primary cerebellar granule cell cultures to 3 μM dieldrin reduced the GABAA receptor function to 55% of control, as measured by the GABA-induced 36Cl− uptake. This exposure produced a significant reduction (∼35%) of the NMDA-induced increase in [Ca2+]i and of the [3H]MK-801 binding, which was not accompanied by a reduction in the NMDA receptor subunit NR1, as determined by Western blot. Consistent with the decreased NMDA receptor function, dieldrin-treated cultures were insensitive to an excitotoxic stimulus induced by exposure to high potassium. In summary, we report that the chronic reduction of GABAA receptor function induced by dieldrin decreases the number of functional NMDA receptors, which may be attributable to a mechanism of synaptic scaling. These effects could underlie neural mechanisms involved in cognitive impairment produced by low-level exposure to dieldrin.Funded by: FEDER funds. Grant Numbers: SAF 2003-4930, FIS PI061212, CB06/02/0024, 2005/SGR/00826.Peer Reviewe

Involucrant a l'alumnat de primària en una pràctica científica autèntica : el taller Plantes Mutants

En els últims anys ha anat creixen el nombre d'iniciatives que estableixen col·laboracions entre alumnat i científics professionals. El present article, ofereix un exemple de taller d'aquest tipus que involucra a alumnat de 5è i 6è de primària en Pràctiques Científiques anàlogues a les dels científics del CRAG. Aquest taller permet als alumnes consolidar coneixements sobre les plantes i construir una primera idea de mutació. A més a més, la participació en aquest taller permet a l'alumnat desenvolupar una visió més positiva i propera de la ciència real així com despertar el seu interès per la recerca científica y la feina dels investigadors.In the last years, the number of collaborative work initiatives between children and professional researchers has been increasing. This article offers an example of a workshop that involves 9 to 12-year-old children in "real" scientific practices similar to what professional researchers do at CRAG. This workshop aims to help the students to consolidate their knowledge on plant biology and to build a first idea of genetic mutations. Furthermore, the workshop has a positive impact on the student's perceptions about science, helping them in developing a more accurate view of scientific research and in growing their interest towards it

Effects of 3α-amino-5α-pregnan-20-one on GABAA receptor: Synthesis, activity and cytotoxicity

The 3α-hydroxy function has been considered essential for the biological activity of neurosteroids at the GABAA receptor. It was found that 3α-amino-5α-pregnan-20-one (3) increased the binding of [3H]flunitrazepam at the GABAA receptor in the primary culture of cortical neurons. This derivative did not display cytotoxicity at relevant neuroactive concentrations, and its structure enabled us to gain further insight into possible functional group modifications in position 3α. Various synthetic methods were investigated in search for the most suitable synthetic approach