Etape 1 Sacrifice du rat selon des protocoles établis. Enlever le cerveau du crâne et de le rincer dans de la glace froide DEPC traitées eau Milli Q pour enlever toute trace de sang de surface. Etape 2 Placer sur une plaque de métal froid. Couper le cerveau bi-moitié dans l&#39;hémisphère droit et gauche. <img src="/files/ftp_upload/old/269_2008_7_19_3/269_Figure-01.png" alt="269_Figure-01" width="474" height="224" /> Figure 1. Les positions de coupe de la vue médiale de l&#39;hémisphère rat Étape 3 Recueillir le bulbe olfactif à droite après la première coupe. Flash geler l&#39;échantillon dans l&#39;azote liquide et conserver à -80 ° C. <img src="/files/ftp_upload/old/269_2008_7_19_4/269_Figure-02.png" alt="269_Figure-02" width="564" height="145" /> Figure 2. Dissection bulbe olfactif Etape 4 Recueillir le droit cortex frontal après la deuxième coupe, en utilisant une lame et une Dumont n ° 5 forceps. Flash geler l&#39;échantillon dans l&#39;azote liquide et conserver à -80 ° C. <img src="/files/ftp_upload/old/269_2008_7_19_5/269_Figure-03.png" alt="269_Figure-03" width="566" height="220" /> Figure 3. Frontale du cortex de dissection Etape 5 Recueillir le striatum (noyau caudé) juste après la troisième coupe à l&#39;aide de deux pinces No.5 Dumont. Flash geler l&#39;échantillon dans l&#39;azote liquide et conserver à -80 ° C. <img src="/files/ftp_upload/old/269_2008_7_19_6/269_Figure-04.png" alt="269_Figure-04" width="555" height="208" /> Figure 4. Striatum (noyau caudé) la dissection Etape 6 Pour recueillir l&#39;hippocampe, placez la face ventrale du cerveau et puis retirez du mésencéphale pour exposer l&#39;hippocampe. Disséquer l&#39;hippocampe du cortex en utilisant deux pinces Dumont n ° 5. Flash geler l&#39;échantillon dans l&#39;azote liquide et conserver à -80 ° C. <img src="/files/ftp_upload/old/269_2008_7_19_7/269_Figure-05.png" alt="269_Figure-05" width="559" height="191" /> Figure 5. Dissection Hippocampus

<ol>
	<li>Palkovits, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Maps and guide to micro-dissection of the rat brain. , (c.1988).</li><li>Swanson, L. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Brain maps: structure of the rat brain. 3rd revised edition. , (2004).</li></ol>

Les animaux ont été traités selon le protocole pour l&#39;utilisation des animaux dans la recherche approuvée par le Comité sur l&#39;utilisation d&#39;animaux vivants dans l&#39;enseignement et la recherche (CULATR) à l&#39;Université de Hong Kong et selon le National Institutes of Health des lignes directrices pour l&#39;utilisation des animaux.

Différentes régions du cerveau associée aux différentes maladies neurodégénératives. Par exemple, le cortex frontal et le striatum se rapportent à la maladie de Parkinson alors hippocampe concerne la maladie d&#39;Alzheimer. Précis de micro-dissection du cerveau nous permet de détecter les changements ARNm et la protéine dans la région de malades avec plus de précision.

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micro-dissection of rat brain for rna or protein extraction from specific brain region

Micro-dissection du cerveau de rat dans différentes régions est extrêmement important pour l&#39;étude de différentes maladies neurodégénératives. Cette vidéo montre des micro-dissection des quatre régions du cerveau majeurs comprennent bulbe olfactif, le cortex frontal, le striatum et l&#39;hippocampe dans les tissus de cerveau de rat frais. Conseils utiles pour un retrait rapide des régions respectives afin d&#39;éviter la dégradation de l&#39;ARN et des protéines du tissu sont donnés.

Watch this Scientific Journal Video about Micro-dissection of Rat Brain for RNA or Protein Extraction from Specific Brain Region at JoVE.com

Micro-dissection of Rat Brain for RNA or Protein Extraction from Specific Brain Region

Micro-dissection du cerveau de rat pour l&#39;ARN ou de l&#39;extraction de protéines à partir région spécifique du cerveau

Micro-dissection of rat brain into various regions is extremely important for the study of different neurodegenerative diseases. This video demonstrates ...

micro-dissection-rat-brain-for-rna-or-protein-extraction-from

Research

JoVE Journal

Biology

52.5K vues.  The University of Hong Kong - HKU. Micro-dissection du cerveau de rat dans différentes régions est extrêmement important pour l'étude de différentes maladies neurodégénératives. Cette vidéo montre des micro-dissection des quatre régions du cerveau majeurs comprennent bulbe olfactif, le cortex frontal, le striatum et l'hippocampe dans les tissus de cerveau de rat frais. Conseils utiles pour un retrait rapide des régions respectives afin d'éviter la dégradation de l'ARN et des pr...

Vidéo: Micro-dissection of Rat Brain for RNA or Protein Extraction from Specific Brain Region

Application of Light-cured Dental Adhesive Resin for Mounting Electrodes or Microdialysis Probes in Chronic Experiments

In chronic recording experiments, self-curing dental acrylic resins have been used as a mounting base of electrodes or microdialysis-probes. Since these acrylics do not bond to the bone, screws have been used as anchors. However, in small experimental animals like finches or mouse, their craniums are very fragile and can not successfully hold the anchors. In this report, we propose a new application of light-curing dental resins for mounting base of electrodes or microdialysis probes in chronic experiments. This material allows direct bonding to the cranium. Therefore, anchor screws are not required and surgical field can be reduced considerably. Past experiences show that the bonding effect maintains more than 2 months. Conventional resin's window of time when the materials are pliable and workable is a few minutes. However, the window of working time for these dental adhesives is significantly wider and adjustable.

In this report, we propose a new application of light-curing dental resins for mounting base of electrodes or microdialysis probes in chronic experiments. This material allows direct bonding to the cranium.

Application de résine photopolymérisable adhésif dentaire pour les électrodes de montage ou des sondes de microdialyse dans les expériences chroniques

In chronic recording experiments, self-curing dental acrylic resins have been used as a mounting base of electrodes or microdialysis-probes. Since these ...

Recherche

Biologie

RNA Extraction from Neuroprecursor Cells Using the Bio-Rad Total RNA Kit

Extraction d&#39;ARN à partir de cellules Neuroprecursor Utiliser le Bio-Rad ARN total Kit

Batch Immunostaining for Large-Scale Protein Detection in the Whole Monkey Brain

Immunohistochemistry (IHC) is one of the most widely used laboratory techniques for the detection of target proteins in situ. Questions concerning the expression pattern of a target protein across the entire brain are relatively easy to answer when using IHC in small brains, such as those of rodents. However, answering the same questions in large and convoluted brains, such as those of primates presents a number of challenges. Here we present a systematic approach for immunodetection of target proteins in an adult monkey brain. This approach relies on the tissue embedding and sectioning methodology of NeuroScience Associates (NSA) as well as tools developed specifically for batch-staining of free-floating sections. It results in uniform staining of a set of sections which, at a particular interval, represents the entire brain. The resulting stained sections can be subjected to a wide variety of analytical procedures in order to measure protein levels, the population of neurons expressing a certain protein.

Large-scale immunodetection of target proteins across the entire primate brain is possible by employing novel tissue embedding and sectioning methods combined with the use of creative apparatus for batch staining of multiple free-floating sections at a given time.

Immunocoloration lots pour la détection de protéines à grande échelle dans le cerveau du singe entier

Immunohistochemistry (IHC) is one of the most widely used laboratory techniques for the detection of target proteins in situ. Questions concerning the ...

Preparation of Rat Brain Aggregate Cultures for Neuron and Glia Development Studies

An in vitro system that recapitulates the development and differentiation of progenitors into mature neurons and glia in the central nervous system (CNS) would provide a powerful platform for neuroscientists to investigate axo-glial interactions, properties and differentiation of multipotent progenitors, and progression of oligodendroglial lineage cells at the cellular and molecular level.  We describe here a CNS aggregate culture system from embryonic rat forebrains, which can be maintained in a serum-free medium up to 3-4 weeks and is used in our laboratory as a model to study neuron-glia interaction and CNS myelination.  This video clip will demonstrate how to isolate and grow these CNS aggregate cultures from E16 rat brain.  Furthermore, from the same brain dissection, highly enriched regular dissociated neuronal cultures can be readily obtained and used for various studies on CNS neurons or used for co-cultures with other cells. 

A protocols for an embryonic rat brain aggregate culture system is described. Multipotent progenitors in the aggregates can develop and differentiate into neurons, astrocytes and oligodendrocytes.

Préparation des cultures de cerveau de rat d&#39;agrégation pour Neuron et études sur le développement Glia

An in vitro system that recapitulates the development and differentiation of progenitors into mature neurons and glia in the central nervous system (CNS) ...

Obtaining High Quality RNA from Single Cell Populations in Human Postmortem Brain Tissue

We proposed to investigate the gray matter reduction in the superior temporal gyrus seen in schizophrenia patients, by interrogating gene expression profiles of pyramidal neurons in layer III. It is well known that the cerebral cortex is an exceptionally heterogeneous structure comprising diverse regions, layers and cell types, each of which is characterized by distinct cellular and molecular compositions and therefore differential gene expression profiles. To circumvent the confounding effects of tissue heterogeneity, we used laser-capture microdissection (LCM) in order to isolate our specific cell-type i.e pyramidal neurons.
Approximately 500 pyramidal neurons stained with the Histogene staining solution were captured using the Arcturus XT LCM system. RNA was then isolated from captured cells and underwent two rounds of T7-based linear amplification using Arcturus/Molecular Devices kits. The Experion LabChip (Bio-Rad) gel and electropherogram indicated good quality a(m)RNA, with a transcript length extending past 600nt required for microarrays. The amount of mRNA obtained averaged 51&mu;g, with acceptable mean sample purity as indicated by the A260/280 ratio, of 2.5. Gene expression was profiled using the Human X3P GeneChip probe array from Affymetrix.

We describe a process using laser-capture microdissection to isolate and extract RNA from a homogeneous cell population, pyramidal neurons, in layer III of the superior temporal gyrus in postmortem human brains. We subsequently linearly amplify (T7-based) mRNA, and hybridize the sample to the Affymetrix human X3P microarray.

Obtention d&#39;ARN de haute qualité provenant des populations cellule unique de tissus post-mortem du cerveau de l&#39;homme

We proposed to investigate the gray matter reduction in the superior temporal gyrus seen in schizophrenia patients, by interrogating gene expression ...

Engineering Cell-permeable Protein

The protein transduction technique enables the direct delivery of biologically active material into mammalian cells [for review see 1,2]. For this one can make use of the translocating ability of so-called cell penetrating peptides (CPPs), also designated as protein transduction domains (PTDs). The TAT-CPP derived from the human immunodeficiency virus type 1 (HIV-1) Tat (trans-activator of transcription) protein has been widely used. The positively charged TAT promotes cell permeability thereby overcoming the barriers of the cellular membrane by endocytosis or/and direct membrane penetration2. In combination with a nuclear localization signal (NLS) fusion proteins are able to enter the nucleus exhibiting functionality. Our video presentation demonstrates, as an exemplification for the engineering of cell-permeable proteins, the construction, production and application of a cell-permeable version of the DNA-modifying enzyme Cre.
Cre is a site-specific recombinase that is able to recognize and recombine 34 base pair loxP sites in mammalian cells in vitro and in vivo. Therefore the Cre/loxP system is widely used to conditionally induce mutations in the genome of living cells3,4. The delivery of active Cre recombinase to cells, however, represents a limitation.
We describe the pSESAME vector system, which allows a direct insertion of the gene-of-interest and provides a platform to rapidly clone different domains and tags used within the vector in a convenient and standardized manner. Rearranging of the different tags has been shown to modify the biochemical properties of the fusion proteins providing a possibility to achieve higher yield and better solubility. We demonstrate how to express and purify recombinant cell-permeant proteins in and from E. coli. The functionality of the recombinant Cre protein is finally validated in cell culture by assessing its intracellular recombinase activity.

Protein transduction enables the direct delivery of biologically active proteins into cells. In contrast to conventional methods such as DNA transfection or viral transduction this non-invasive paradigm allows highly efficient cellular manipulation in a titratable manner circumventing cellular toxicity and the risk of oncogenic transformation by permanent genetic modification.

Ingénierie cellulaire perméable protéines

The protein transduction technique enables the direct delivery of biologically active material into mammalian cells [for review see 1,2]. For this one can ...

Toxin Induction and Protein Extraction from Fusarium spp. Cultures for Proteomic Studies

Fusaria are filamentous fungi able to produce different toxins. Fusarium mycotoxins such as deoxynivalenol, nivalenol, T2, zearelenone, fusaric acid, moniliformin, etc... have adverse effects on both human and animal health and some are considered as pathogenicity factors. Proteomic studies showed to be effective for deciphering toxin production mechanisms (Taylor et al., 2008) as well as for identifying potential pathogenic factors (Paper et al., 2007, Houterman et al., 2007) in Fusaria. It becomes therefore fundamental to establish reliable methods for comparing between proteomic studies in order to rely on true differences found in protein expression among experiments, strains and laboratories. The procedure that will be described should contribute to an increased level of standardization of proteomic procedures by two ways. The filmed protocol is used to increase the level of details that can be described precisely. Moreover, the availability of standardized procedures to process biological replicates should guarantee a higher robustness of data, taking into account also the human factor within the technical reproducibility of the extraction procedure.
The protocol described requires 16 days for its completion: fourteen days for cultures and two days for protein extraction (figure 1). 
Briefly, Fusarium strains are grown on solid media for 4 days; they are then manually fragmented and transferred into a modified toxin inducing media (Jiao et al., 2008) for 10 days. Mycelium is collected by filtration through a Miracloth layer. Grinding is performed in a cold chamber. Different operators performed extraction replicates (n=3) in order to take into account the bias due to technical variations (figure 2). Extraction was based on a SDS/DTT buffer as described in Taylor et al. (2008) with slight modifications. Total protein extraction required a precipitation process of the proteins using Aceton/TCA/DTT buffer overnight and Acetone /DTT washing (figure 3a,3b). Proteins were finally resolubilized in the protein-labelling buffer and quantified. Results of the extraction were visualized on a 1D gel (Figure 4, SDS-PAGE), before proceeding to 2D gels (IEF/SDS-PAGE). The same procedure can be applied for proteomic analyses on other growing media and other filamentous fungi (Miles et al., 2007).

Toxin Induction and Protein Extraction from Fusarium spp. Cultures for Proteomic Studies

Protein extraction for proteomic analyses in fungal species requires high levels of standardization to be accomplished according with the minimum information about a proteomic experiment (MIAPE) guidelines. We present a video-protocol that includes a procedure for minimizing experimental bias during toxin induction and protein extraction from Fusarium spp.

L&#39;induction ou à toxines et d&#39;extraction de protéines à partir Fusarium Spp. Cultures pour les études protéomiques

Fusaria are filamentous fungi able to produce different toxins. Fusarium mycotoxins such as deoxynivalenol, nivalenol, T2, zearelenone, fusaric acid, ...

Purification of Transcripts and Metabolites from Drosophila Heads

For the last decade, we have tried to understand the molecular and cellular mechanisms of neuronal degeneration using Drosophila as a model organism. Although fruit flies provide obvious experimental advantages, research on neurodegenerative diseases has mostly relied on traditional techniques, including genetic interaction, histology, immunofluorescence, and protein biochemistry. These techniques are effective for mechanistic, hypothesis-driven studies, which lead to a detailed understanding of the role of single genes in well-defined biological problems. However, neurodegenerative diseases are highly complex and affect multiple cellular organelles and processes over time. The advent of new technologies and the omics age provides a unique opportunity to understand the global cellular perturbations underlying complex diseases. Flexible model organisms such as Drosophila are ideal for adapting these new technologies because of their strong annotation and high tractability. One challenge with these small animals, though, is the purification of enough informational molecules (DNA, mRNA, protein, metabolites) from highly relevant tissues such as fly brains. Other challenges consist of collecting large numbers of flies for experimental replicates (critical for statistical robustness) and developing consistent procedures for the purification of high-quality biological material. Here, we describe the procedures for collecting thousands of fly heads and the extraction of transcripts and metabolites to understand how global changes in gene expression and metabolism contribute to neurodegenerative diseases. These procedures are easily scalable and can be applied to the study of proteomic and epigenomic contributions to disease.

Purification of Transcripts and Metabolites from Drosophila Heads

We describe here the procedures for the extraction and purification of mRNA and metabolites from Drosophila heads. We are applying these techniques to better understand the cellular perturbations underlying neuronal degeneration. These methodologies can be easily scaled and adapted for other "omic" projects.

Purification des relevés de notes et de métabolites<em&gt; Drosophila</em&gt; Têtes

For the last decade, we have tried to understand the molecular and cellular mechanisms of neuronal degeneration using Drosophila as a model organism. ...

Investigating Protein-protein Interactions in Live Cells Using Bioluminescence Resonance Energy Transfer

Assays based on Bioluminescence Resonance Energy Transfer (BRET) provide a sensitive and reliable means to monitor protein-protein interactions in live cells. BRET is the non-radiative transfer of energy from a 'donor' luciferase enzyme to an 'acceptor' fluorescent protein. In the most common configuration of this assay, the donor is Renilla reniformis luciferase and the acceptor is Yellow Fluorescent Protein (YFP). Because the efficiency of energy transfer is strongly distance-dependent, observation of the BRET phenomenon requires that the donor and acceptor be in close proximity. To test for an interaction between two proteins of interest in cultured mammalian cells, one protein is expressed as a fusion with luciferase and the second as a fusion with YFP. An interaction between the two proteins of interest may bring the donor and acceptor sufficiently close for energy transfer to occur. Compared to other techniques for investigating protein-protein interactions, the BRET assay is sensitive, requires little hands-on time and few reagents, and is able to detect interactions which are weak, transient, or dependent on the biochemical environment found within a live cell. It is therefore an ideal approach for confirming putative interactions suggested by yeast two-hybrid or mass spectrometry proteomics studies, and in addition it is well-suited for mapping interacting regions, assessing the effect of post-translational modifications on protein-protein interactions, and evaluating the impact of mutations identified in patient DNA.

Interactions between proteins are fundamental to all cellular processes. Using Bioluminescence Resonance Energy Transfer, the interaction between a pair of proteins can be monitored in live cells and in real time. Furthermore, the effects of potentially pathogenic mutations can be assessed.

Étudier les interactions protéine-protéine dans les cellules vivantes en utilisant le transfert d&#39;énergie de résonance de bioluminescence

Assays based on Bioluminescence Resonance Energy Transfer (BRET) provide a sensitive and reliable means to monitor protein-protein interactions in live ...

Protein Isolation from the Developing Embryonic Mouse Heart Valve Region

Western blot analysis is a commonly employed technique for detecting and quantifying protein levels. However, for small tissue samples, this analysis method may not be sufficiently sensitive to detect a protein of interest. To overcome these difficulties, we examined protocols for obtaining protein from adult human cardiac valves and modified these protocols for the developing early embryonic mouse counterparts. In brief, the mouse embryonic aortic valve regions, including the aortic valve and surrounding aortic wall, are collected in the minimal possible volume of a Tris-based lysis buffer with protease inhibitors. If required based on the breeding strategy, embryos are genotyped prior to pooling four embryonic aortic valve regions for homogenization. After homogenization, an SDS-based sample buffer is used to denature the sample for running on an SDS-PAGE gel and subsequent western blot analysis. Although the protein concentration remains too low to quantify using spectrophotometric protein quantification assays and have sample remaining for subsequent analyses, this technique can be used to successfully detect and semi-quantify phosphorylated proteins via western blot from pooled samples of four embryonic day 13.5 mouse aortic valve regions, each of which yields approximately 1 &#956;g of protein. This technique will be of benefit for studying cell signaling pathway activation and protein expression levels during early embryonic mouse valve development.

The analysis of protein expression in young embryonic mouse valves has been hampered by the limited tissue available. This manuscript provides a protocol for preparing protein from developing embryonic mouse valve regions for western blot analysis.

Protein Isolation du développement embryonnaire Souris Coeur Région Valve

Western blot analysis is a commonly employed technique for detecting and quantifying protein levels. However, for small tissue samples, this analysis ...