Az embrionális GAD formák szerepe a fejlődő szagló-rendszerben = Role of Embryonic GAD Forms in the Developing Olfactory System

Mindkét GAD gén kifejeződik a 10 napos egér embrió szagló plakódjában. Az expresszió a későbbiekben a szaglóhámban marad meg. Két részlegesen átfedő GABAerg sejtpopulációt azonosítottunk a fejlődő frontonazális nyúlványban: ezek a vándorló LHRH+/GAD65+eGAD+ sejtcsoport és az un. "migratory mass" (MM), amely GAD67+(eGAD)/OMP+ sejteket tartalmaz. A GAD65 jelenlétét először sikerült azonosítanunk a vándorló LHRH+ sejtekben. A GAD65 expresszió 1 hónapos korig folytatódik a már nem vándorló LHRH tartalmú idegsejt populációban is. A felnőtt GAD67 gyakorlatilag nem mutatható ki a frontonazális nyúlványban. Ebben a struktúrában a GAD67 génről alternetív "splicing" mechanizmussal képződő embrionális GAD a fő GAD fehérjeforma. A GAD65 hiányos egérben az LHRH neuronok vándorlása a GABAA receptor gátlásához hasonló módon zavart: a vándorlás sebessége fokozódott és iránya az előagyban megváltozott. A GAD67 hiánya nem befolyásolta jelentősen az LHRH+ sejtek vándorlását. Ennek valószínű magyarázata az, hogy a GAD67 KO egerekben az embrionális GAD mennyisége megnövekedett. | 1) Both GAD genes are expressed in the mouse embryo as early as E10 in the olfactory placode. The expression later is maintained in the olfactory epithelium (OE). 2) We have found that, except for the OE, there are two partially overlapping GABAergic lineages in the developing frontonasal process: the migratory LHRH+/GAD65+/eGAD+ and the migratory mass (MM), which is: GAD67+(eGAD)+/OMP+. The identification of GAD65 in the migratory LHRH+ cells is a novel result. 3) GAD65 expression in the LHRH lineage continues in the post-migratory LHRH+ neurons until the first month postnatally. 4) The adult GAD67 is barely expressed in the frontonasal process, instead, the alternatively spliced embryonic GAD is the predominant GAD derived from the GAD67 gene. 5) The absence of GAD65 in GAD65 KO mice impared the migration of LHRH+ cells in a way similar to the effect of GABA- A-R inhibitors, namely, enhanced speed of migration and change in direction of migration in the forebrain part of the migratory route. 6) The absence of GAD67 in GAD67 KO mice is not so pronounced, probably due to up-regulation of embryonic GAD

Hibakorrekciós algoritmusok a koordináta méréstechnikában = Error correction algorithms in coordinate measuring technique

A projekt keretében kidolgozásra került egy mérési eljárás, amely alkalmas mérő- és megmunkálógépek mozgó elemeinek térbeli helyzetének és orientációjának meghatározására. A mérés eredményeként azok a transzformációs mátrix jelennek meg, amely a testnek a referencia koordináta rendszerhez viszonyított helyzetét határozzák meg. A továbbiakban ezeket az értékeket használjuk fel a korrekciós vektorok meghatározására. Közbenső mátrixok rotációs részének meghatározásához kvaternió interpolációt, a transzlációciós vektor kiszámításánál spline interpolációt alkalmaztunk. A mérési eljárás hibáit részletesen elemeztük egy koordináta asztal esetében. | In the framework of the project a new measurement system was developed, which is capable to determine the position and orientation of measuring or production machine's carriages simultaneously. The results are given int he form of transformation matrices reprezenting the position and orientation of the body relative to the reference coordinate system. Later these values are used to calculate the correction vectors. For the determination of the rotational part of the intermediate matrices quaternion interpolation was used, while in case of the translational portion spline interpolation was applied. The possible errors of the measuring system were analysed in case of a 2D coordinate table

The small molecule Mek1/2 inhibitor U0126 disrupts the chordamesoderm to notochord transition in zebrafish

<p>Abstract</p> <p>Background</p> <p>Key molecules involved in notochord differentiation and function have been identified through genetic analysis in zebrafish and mice, but MEK1 and 2 have so far not been implicated in this process due to early lethality (<it>Mek1-/-</it>) and functional redundancy (<it>Mek2-/-</it>) in the knockout animals.</p> <p>Results</p> <p>Here, we reveal a potential role for Mek1/2 during notochord development by using the small molecule Mek1/2 inhibitor U0126 which blocks phosphorylation of the Mek1/2 target gene Erk1/2 <it>in vivo</it>. Applying the inhibitor from early gastrulation until the 18-somite stage produces a specific and consistent phenotype with lack of dark pigmentation, shorter tail and an abnormal, undulated notochord. Using morphological analysis, in situ hybridization, immunhistochemistry, TUNEL staining and electron microscopy, we demonstrate that in treated embryos the chordamesoderm to notochord transition is disrupted and identify disorganization in the medial layer of the perinotochordal basement mebrane as the probable cause of the undulations and bulges in the notochord. We also examined and excluded FGF as the upstream signal during this process.</p> <p>Conclusion</p> <p>Using the small chemical U0126, we have established a novel link between MAPK-signaling and notochord differentiation. Our phenotypic analysis suggests a potential connection between the MAPK-pathway, the COPI-mediated intracellular transport and/or the copper-dependent posttranslational regulatory processes during notochord differentiation.</p

Functional analysis of the Drosophila embryonic germ cell transcriptome by RNA interference

In Drosophila melanogaster, primordial germ cells are specified at the posterior pole of the very early embryo. This process is regulated by the posterior localized germ plasm that contains a large number of RNAs of maternal origin. Transcription in the primordial germ cells is actively down-regulated until germ cell fate is established. Bulk expression of the zygotic genes commences concomitantly with the degradation of the maternal transcripts. Thus, during embryogenesis, maternally provided and zygotically transcribed mRNAs determine germ cell development collectively. In an effort to identify novel genes involved in the regulation of germ cell behavior, we carried out a large-scale RNAi screen targeting both maternal and zygotic components of the embryonic germ line transcriptome. We identified 48 genes necessary for distinct stages in germ cell development. We found pebble and fascetto to be essential for germ cell migration and germ cell division, respectively. Our data uncover a previously unanticipated role of mei-P26 in maintenance of embryonic germ cell fate. We also performed systematic co-RNAi experiments, through which we found a low rate of functional redundancy among homologous gene pairs. As our data indicate a high degree of evolutionary conservation in genetic regulation of germ cell development, they are likely to provide valuable insights into the biology of the germ line in general

What have we learned from two-pore potassium channels? Their molecular configuration and function in the human heart

Two-pore domain potassium channels (K2P) control excitability, stabilize the resting membrane potential below firing threshold, and accelerate repolarisation in different cells. Until now, fifteen different genes for the six K2P channel subfamily were cloned. The pore-forming part is translated from two genes and they are built up from a dimer of two two-unit transmembrane domains functioning with a wide spectrum of physiological profiles. K2P ion channels were discovered in the last two decades and gave novel opportunity to recognize the complex molecular mechanism of the potassium ion flux, and may lead to the design of individual drug targeting in the future. In this review, we summarise the structure, function, channelopathies and pharmacological silhouette of the two-pore potassium channels in the human tissues. In addition, we present the computer model of the partially reconstructed wild type K2P1/TWIK1 lacking the intracellular C and N terminal loop

Mapping Fluorescence Enhancement of Plasmonic Nanorod Coupled Dye Molecules

Plasmonically enhanced fluorescence is a widely studied and applied phenomenon, however only a comparative theoretical and experimental analyses of coupled fluorophores and plasmonic nanoresonators makes it possible to uncover, how this phenomenon can be controlled. A numerical optimization method was applied to design configurations that are capable of resulting in an enhancement of excitation and emission, moreover of both phenomena simultaneously in coupled Cy5 dye molecule and gold nanorod systems. Parametric sensitivity studies revealed, how the fluorescence enhancement depends on the molecule's location, distance and orientation. Coupled systems designed for simultaneous improvement exhibited the highest (intermediate directional) total fluorescence enhancement, which is accompanied by intermediate sensitivity to the molecule's parameters, except the location and orientation sensitivity at the excitation wavelength. Gold nanorods with a geometry corresponding to the predicted optimal configurations were synthesized, and DNA strands were used to control the Cy5 dye molecule distance from the nanorod surface via hybridization of the Cy5-labelled oligonucleotide. State-of-the-art dSTORM microscopy was used to accomplish a proof-of-concept experimental demonstration of the theoretically predicted (directional) total fluorescence enhancement. The measured fluorescence enhancement was in good agreement with theoretical predictions, thus providing a complete kit to design and prepare coupled nanosystems exhibiting plasmonically enhanced fluorescence.Comment: 15 pages, 7 figure

Reduction of intracellular oxidative stress with copper incorporated layered double hydroxide

Biocompatible Cu(II)-doped layered double hydroxide (CMA) nanoparticles were developed to combat reactive oxygen species. The 2-dimensional nanozymes showed both superoxide dismutase and catalase-like activity in chemical assays, while proved as..

Input-Output Features of Anatomically Identified CA3 Neurons during Hippocampal Sharp Wave/Ripple Oscillation In Vitro.

Hippocampal sharp waves and the associated ripple oscillations (SWRs) are implicated in memory processes. These network events emerge intrinsically in the CA3 network. To understand cellular interactions that generate SWRs, we detected first spiking activity followed by recording of synaptic currents in distinct types of anatomically identified CA3 neurons during SWRs that occurred spontaneously in mouse hippocampal slices. We observed that the vast majority of interneurons fired during SWRs, whereas only a small portion of pyramidal cells was found to spike. There were substantial differences in the firing behavior among interneuron groups; parvalbumin-expressing basket cells were one of the most active GABAergic cells during SWRs, whereas ivy cells were silent. Analysis of the synaptic currents during SWRs uncovered that the dominant synaptic input to the pyramidal cell was inhibitory, whereas spiking interneurons received larger synaptic excitation than inhibition. The discharge of all interneurons was primarily determined by the magnitude and the timing of synaptic excitation. Strikingly, we observed that the temporal structure of synaptic excitation and inhibition during SWRs significantly differed between parvalbumin-containing basket cells, axoaxonic cells, and type 1 cannabinoid receptor (CB1)-expressing basket cells, which might explain their distinct recruitment to these synchronous events. Our data support the hypothesis that the active current sources restricted to the stratum pyramidale during SWRs originate from the synaptic output of parvalbumin-expressing basket cells. Thus, in addition to gamma oscillation, these GABAergic cells play a central role in SWR generation