<ol><li> Anesthetize souris avec l&#39;isoflurane (4% pour l&#39;induction, de 1,5-2% pour la chirurgie) à l&#39;aide du IACUC procédures approuvées. Il est important que la queue et / ou pincées orteils sont utilisées afin de s&#39;assurer que l&#39;animal est complètement sous sédation. </li><li> L&#39;utilisation d&#39;un coupe-rongeurs, raser les poils du dos de la nuque jusqu&#39;aux yeux. </li><li> Placez la souris dans un cadre stéréotaxique, au cours d&#39;une chirurgie de l&#39;eau de recirculation couverture. De fixer solidement la tête avec des barres de l&#39;oreille. </li><li> Appliquer une pommade oculaire, afin d&#39;empêcher l&#39;œil de l&#39;animal de se dessécher. </li><li> Administrer, par voie sous cutanée, la dexaméthasone (0,2 mg / kg) et carprofène (5 mg / kg) pour éviter le gonflement du cerveau et / ou une réponse inflammatoire, respectivement. </li><li> Avant de commencer la chirurgie, la stérilisation de la zone d&#39;exploitation en essuyant la peau avec trois coups en alternance de l&#39;alcool 70% et la bétadine. </li><li> Tous les instruments chirurgicaux ont été pré-stérilisés à l&#39;aide d&#39;un stérilisateur à billes de verre. Avec des ciseaux qui ont été stérilisés avec de l&#39;éthanol, enlever la peau sur le dessus du crâne, à commencer par une coupe horizontale tout le long de la base de la tête, suivie de deux coupes dans la direction rostrale, atteignant presque les paupières, puis deux coupes obliques qui convergent vers la ligne médiane. </li><li> Une goutte de solution de lidocaïne + adrénaline est appliquée à ce point sur le périoste pour éviter un saignement excessif ou la douleur. Avec un scalpel, rétracter le périoste sur les bords du crâne. En outre, la légère rétraction des muscles de l&#39;arrière du cou. </li><li> Gratter délicatement toute la surface exposée du crâne avec le scalpel pour créer une surface sèche. Ceci est très important, car elle permettra à la colle de mieux adhérer lorsqu&#39;il est appliqué plus tard. </li><li> Une fois un site d&#39;imagerie a été choisi, on est prêt à créer la fenêtre crânienne. D&#39;abord, doucement &quot;dessiner&quot; un cercle d&#39;environ 4 mm de diamètre avec la perceuse pneumatique dentaire. </li><li> Après une légère forages, appliquer la solution de lidocaïne + adrénaline à nouveau sur la surface du crâne. Arrêter le forage lorsque une très fine couche d&#39;os est à gauche. En poussant doucement sur le centre de la craniotomie à sentir combien il cède la place, on peut généralement savoir que ce stade est atteint. </li><li> En vertu d&#39;une goutte de sérum physiologique et en prenant avantage des travées osseuses - la structure spongieuse de l&#39;os - déloger la craniotomie du crâne avec une pince pointe très fine. La solution saline est important, car il aidera à soulever le crâne et prévenir les saignements de la mère. </li><li> Appliquer Gelfoam qui a été préalablement trempées dans une solution saline pour la dure-mère d&#39;arrêter un saignement qui se produit occasionnellement de petits lorsque le crâne est enlevée. </li><li> Après séchage de la surface de la dure-mère et en assurant qu&#39;il n&#39;ya pas de saignement, en douceur jeter stériles de 5 mm lamelle de verre sur le dessus de la dure-mère. (Remarque: d&#39;autres groupes également placer une goutte de faible point de fusion d&#39;agarose (1,2%) au cours de la durée et de mettre la lamelle sur le dessus de l&#39;agar-agar). </li><li> Appliquez une goutte de colle à base de cyanoacrylate-à l&#39;hémisphère opposé sur le crâne. Avec l&#39;aide d&#39;une aiguille, appliquer doucement la colle tout autour de la fenêtre tout en faisant attention de ne pas la mettre sous verre. La colle peut maintenant être appliqué en couche mince sur toute la surface du crâne. </li><li> Une fois la colle séchée, mélange acrylique dentaire et l&#39;appliquer sur toute la surface du crâne, qui couvre également une jante petite partie de la lamelle, de le sécuriser. </li><li> Après avoir sécurisé la lamelle, faites un petit puits autour de la fenêtre à l&#39;acrylique dentaire. Aussi, intégrer une barre de titane à l&#39;acrylique dentaire. Cette barre sera ensuite utilisé pour attacher la souris en toute sécurité sur la scène du microscope pour l&#39;imagerie. Il est important de s&#39;assurer que la barre est de niveau, de sorte qu&#39;il est parallèle à la fenêtre crânienne. Placer un morceau de papier sous la barre peut permettre à la barre pour rester au niveau alors que les acryliques se durcit. </li><li> L&#39;acrylique dentaire est permis de guérir (durcir) pendant 10 minutes, moment où la barre de titane est fixé en place. Placez l&#39;animal dans une cage au chaud jusqu&#39;à ce qu&#39;elle récupère. </li><li> Après récupération de l&#39;anesthésie, l&#39;animal peut être imagée le même jour. </li></ol>

<ol>
	<li>Svoboda, K., Denk, W., Kleinfeld, D., Tank, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=+In+vivo+dendritic+calcium+dynamics+in+neocortical+pyramidal+neurons."> In vivo dendritic calcium dynamics in neocortical pyramidal neurons.</a> Nature. 85, 161-165 (1997).</li><li>Lendvai, B., Stern, E. A., Chen, B., Svoboda, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experience-dependent+plasticity+of+dendritic+spines+in+the+developing+rat+barrel+cortex+in+vivo.">Experience-dependent plasticity of dendritic spines in the developing rat barrel cortex in vivo.</a> Nature. 404, 876-881 (2000).</li><li>Trachtenberg, J. T., Chen, B., Knott, G. W., Feng, G., Sanes, J. R., Welker, E., Svoboda, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+in+vivo+imaging+of+experience-dependent+synaptic+plasticity+in+adult+cortex.">Long-term in vivo imaging of experience-dependent synaptic plasticity in adult cortex.</a> Nature. 420, 788-794 (2002).</li><li>Portera-Cailliau, C., Weimer, R. M., DePaola, V., Caroni, P., Svoboda, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diverse+modes+of+axon+elaboration+in+the+developing+neocortex.">Diverse modes of axon elaboration in the developing neocortex.</a> PLoS Biol. 3, (2005).</li><li>Holtmaat, A., Wilbrecht, L., Knott, G. W., Welker, E., Svoboda, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experience-dependent+and+cell-type-specific+spine+growth+in+the+neocortex.">Experience-dependent and cell-type-specific spine growth in the neocortex.</a> Nature. 441, 979-983 (2006).</li></ol>

Comme nous l&#39;avons montré dans la vidéo et dans les figures complémentaires, la préparation fenêtre crânienne, combinées avec l&#39;utilisation de microscopie à deux photons, est un outil très puissant pour étudier in vivo la structure et la fonction du néocortex. La technique requiert une formation rigoureuse pour se familiariser avec l&#39;anatomie pertinentes et les procédures chirurgicales fines et les compétences que requiert cette préparation. Seuls les chirurgies vierges peuvent être utilisés pour l&#39;imagerie c...

Barres de titane sont fabriquées sur mesure

a craniotomy surgery procedure for chronic brain imaging

Les techniques d&#39;imagerie sont de plus en plus important dans le fonctionnement du cerveau étude. Parmi eux, microscopie à deux photons laser à balayage a émergé comme une méthode extrêmement utile, car elle permet l&#39;étude du cerveau vivre intacte. Avec une préparation appropriée, cette technique permet l&#39;observation de la même zone corticale chronique, de quelques minutes à plusieurs mois. Dans cette vidéo, nous montrons une préparation pour l&#39;imagerie in vivo chroniques du cerveau en utilisant microscopie à deux photons. Cette technique a été initialement mis au point par le Dr Karel Svoboda, qui est maintenant un Howard Hughes Medical Institute à Janelia ferme. Les préparatifs comme celui illustré ici peut être utilisé pour l&#39;imagerie de la structure du néocortex (par exemple, la dynamique dendritiques et axonales), pour enregistrer l&#39;activité neuronale en utilisant des colorants sensibles au calcium, à l&#39;image dynamique du flux sanguin cortical, ou pour les études d&#39;imagerie optique intrinsèque. Imagerie profonde du néocortex est possible avec optimale chirurgies fenêtre crânienne. D&#39;exploitation dans les conditions les plus stériles possibles pour éviter les infections, avec l&#39;aide d&#39;un soin extrême de ne pas endommager la dure-mère pendant la chirurgie, entraînera réussie et durable de verre recouverte de fenêtres crâniennes.

Watch this Scientific Journal Video about A Craniotomy Surgery Procedure for Chronic Brain Imaging at JoVE.com

A Craniotomy Surgery Procedure for Chronic Brain Imaging

Cette vidéo et le protocole de montrer comment implanter une verrière fenêtre crânienne chez les rongeurs. Ces préparations peuvent être utilisées pour les maladies chroniques in vivo à deux photons imagerie du néocortex des échelles de temps de plusieurs mois. Il peut également être utilisé pour d&#39;autres types d&#39;imagerie, y compris l&#39;imagerie signal optique intrinsèque.

Une procédure de chirurgie Craniotomie pour l&#39;imagerie cérébrale chronique

Imaging techniques are becoming increasingly important in the study brain function. Among them, two-photon laser scanning microscopy has emerged as an ...

a-craniotomy-surgery-procedure-for-chronic-brain-imaging

Research

JoVE Journal

Biology

63.7K vues.  University of California, Los Angeles. Cette vidéo et le protocole de montrer comment implanter une verrière fenêtre crânienne chez les rongeurs. Ces préparations peuvent être utilisées pour les maladies chroniques in vivo à deux photons imagerie du néocortex des échelles de temps de plusieurs mois. Il peut également être utilisé pour d'autres types d'imagerie, y compris l'imagerie signal optique intrinsèque.

Vidéo: A Craniotomy Surgery Procedure for Chronic Brain Imaging

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

Micro-drive Array for Chronic in vivo Recording: Drive Fabrication

Chronic recording of large populations of neurons is a valuable technique for studying the function of neuronal circuits in awake behaving rats. Lightweight recording devices carrying a high density array of tetrodes allow for the simultaneous monitoring of the activity of tens to hundreds of individual neurons. Here we describe a protocol for the fabrication of a micro-drive array with twenty one independently movable micro-drives. This device has been used successfully to record from hippocampal and cortical neurons in our lab. We show how to prepare a custom designed, 3-D printed plastic base that will hold the micro-drives. We demonstrate how to construct the individual micro-drives and how to assemble the complete micro-drive array. Further preparation of the drive array for surgical implantation, such as the fabrication of tetrodes, loading of tetrodes into the drive array and gold-plating, is covered in a subsequent video article.

Micro-drive Array for Chronic in vivo Recording: Drive Fabrication

In this protocol we demonstrate how to fabricate a micro-drive array for chronic electrophysiological recordings in rats.

Micro-drive tableau pour les maladies chroniques In vivo Enregistrement: Disque de fabrication

Chronic recording of large populations of neurons is a valuable technique for studying the function of neuronal circuits in awake behaving rats. ...

Micro-drive Array for Chronic in vivo Recording: Tetrode Assembly

The tetrode, a bundle of four electrodes, has proven to be a valuable tool for the simultaneous recording of multiple neurons in-vivo.  The differential amplitude of action potential signatures over the channels of a tetrode allows for the isolation of single-unit activity from multi-unit signals.  The ability to precisely control the stereotaxic location and depth of the tetrode is critical for studying coordinated neural activity across brain regions.  In combination with a micro-drive array, it is possible to achieve precise placement and stable control of many tetrodes over the course of days to weeks.  In this protocol, we demonstrate how to fabricate and condition tetrodes using basic tools and materials, install the tetrodes into a multi-drive tetrode array for chronic in-vivo recording in the rat, make ground wire connections to the micro-drive array, and attach a protective cone onto the micro-drive array in order to protect the tetrodes from physical contact with the environment.



Micro-drive Array for Chronic in vivo Recording: Tetrode Assembly

In this protocol we demonstrate how to fabricate and condition tetrodes for use with a micro-drive array, which was designed for chronic electrophysiological recordings in rats. In addition, we illustrate the final stages of micro-drive array construction, which includes installing ground wires and a protective cone.

Micro-drive tableau pour les maladies chroniques In vivo Enregistrement: Assemblée Tétrode

The tetrode, a bundle of four electrodes, has proven to be a valuable tool for the simultaneous recording of multiple neurons in-vivo.  The differential ...

Murine Renal Transplantation Procedure

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell et al over 30 years ago (1) and refined by Zhang et al years later (2), few people in the world have mastered this procedure. In our laboratory we have successfully performed 1200 orthotopic kidney transplantations with &gt; 90% survival rate. The key points for success include stringent control of reperfusion injury, bleeding and thrombosis, both during the procedure and post-transplantation, and use of 10-0 instead of 11-0 suture for anastomoses.
Post-operative care and treatment of the recipient is extremely important to transplant success and evaluation. All renal graft recipients receive antibiotics in the form of an injection of penicillin immediately post-transplant and sulfatrim in the drinking water continually. Overall animal health is evaluated daily and whole blood creatinine analyses are performed routinely with a portable I-STAT machine to assess graft function.

Renal transplantation in mice is a technically challenging procedure that requires careful post-operative care and treatment for success.

Murin procédure transplantation rénale

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell ...

Live Imaging of the Zebrafish Embryonic Brain by Confocal Microscopy

In this video, we demonstrate the method our lab has developed to analyze the cell shape changes and rearrangements required to bend and fold the developing zebrafish brain (Gutzman et al, 2008). Such analysis affords a new understanding of the underlying cell biology required for development of the 3D structure of the vertebrate brain, and significantly increases our ability to study neural tube morphogenesis. The embryonic zebrafish brain is shaped beginning at 18 hours post fertilization (hpf) as the ventricles within the neuroepithelium inflate. By 24 hpf, the initial steps of neural tube morphogenesis are complete. Using the method described here, embryos at the one cell stage are injected with mRNA encoding membrane-targeted green fluorescent protein (memGFP). After injection and incubation, the embryo, now between 18 and 24 hpf, is mounted, inverted, in agarose and imaged by confocal microscopy. Notably, the zebrafish embryo is transparent making it an ideal system for fluorescent imaging. While our analyses have focused on the midbrain-hindbrain boundary and the hindbrain, this method could be extended for analysis of any region in the zebrafish to a depth of 
80-100 &mu;m.

In this video, we demonstrate a method by which to analyze the developing vertebrate brain in live zebrafish embryos at single cell resolution by confocal microscopy. This includes the method by which we inject the single-cell zebrafish embryo and subsequently mount and image the developing brain.

En direct l&#39;imagerie du cerveau de poisson zèbre embryonnaires par microscopie confocale

In this video, we demonstrate the method our lab has developed to analyze the cell shape changes and rearrangements required to bend and fold the ...

Making MR Imaging Child's Play - Pediatric Neuroimaging Protocol, Guidelines and Procedure

Within the last decade there has been an increase in the use of structural and functional magnetic resonance imaging (fMRI) to investigate the neural basis of human perception, cognition and behavior 1, 2. Moreover, this non-invasive imaging method has grown into a tool for clinicians and researchers to explore typical and atypical brain development. Although advances in neuroimaging tools and techniques are apparent, (f)MRI in young pediatric populations remains relatively infrequent 2. Practical as well as technical challenges when imaging children present clinicians and research teams with a unique set of problems 3, 2. To name just a few, the child participants are challenged by a need for motivation, alertness and cooperation. Anxiety may be an additional factor to be addressed. Researchers or clinicians need to consider time constraints, movement restriction, scanner background noise and unfamiliarity with the MR scanner environment2,4-10. A progressive use of functional and structural neuroimaging in younger age groups, however, could further add to our understanding of brain development. As an example, several research groups are currently working towards early detection of developmental disorders, potentially even before children present associated behavioral characteristics e.g.11. Various strategies and techniques have been reported as a means to ensure comfort and cooperation of young children during neuroimaging sessions. Play therapy 12, behavioral approaches 13, 14,15, 16-18 and simulation 19, the use of mock scanner areas 20,21, basic relaxation 22 and a combination of these techniques 23 have all been shown to improve the participant's compliance and thus MRI data quality. Even more importantly, these strategies have proven to increase the comfort of families and children involved 12. One of the main advances of such techniques for the clinical practice is the possibility of avoiding sedation or general anesthesia (GA) as a way to manage children's compliance during MR imaging sessions 19,20. In the current video report, we present a pediatric neuroimaging protocol with guidelines and procedures that have proven to be successful to date in young children.

Making MR Imaging Child&#039;s Play - Pediatric Neuroimaging Protocol, Guidelines and Procedure

Despite an increase in the use of structural and functional magnetic resonance imaging (fMRI) in humans, the study of young pediatric populations remains a challenge. We present a hands-on, step-by-step video protocol including guidelines for clinicians and researchers intending to perform (f)MRI in young children.

Faire jouer IRM enfant - Protocole neuroimagerie pédiatrique, lignes directrices et la procédure

Within the last decade there has been an increase in the use of structural and functional magnetic resonance imaging (fMRI) to investigate the neural ...

Bioluminescence Imaging of Heme Oxygenase-1 Upregulation in the Gua Sha Procedure

Gua Sha is a traditional Chinese folk therapy that employs skin scraping to cause subcutaneous microvascular blood extravasation and bruises. The protocol for bioluminescent optical imaging of HO-1-luciferase transgenic mice reported in this manuscript provides a rapid in vivo assay of the upregulation of the heme oxygenase-1 (HO-1) gene expression in response to the Gua Sha procedure. HO-1 has long been known to provide cytoprotection against oxidative stress. The upregulation of HO-1, assessed by the bioluminescence output, is thought to represent an antioxidative response to circulating hemoglobin products released by Gua Sha. Gua Sha was administered by repeated strokes of a smooth spoon edge over lubricated skin on the back or other targeted body part of the transgenic mouse until petechiae (splinter hemorrhages) or ecchymosis (bruises) indicative of extravasation of blood from subcutaneous capillaries was observed. After Gua Sha, bioluminescence imaging sessions were carried out daily for several days to follow the dynamics of HO-1 expression in multiple internal organs.

Gua Sha, traditional Chinese therapeutic skin scraping, causes subcutaneous microvascular blood extravasation. We report a protocol of bioluminescence imaging of HO-1-luciferase transgenic mice to demonstrate that Gua Sha upregulates heme oxygenase-1 (HO-1) in multiple organs.

Imagerie par bioluminescence de l&#39;hème oxygénase-1 Régulation à la hausse dans la procédure de Gua Sha

Gua Sha is a traditional Chinese folk therapy that employs skin scraping to cause subcutaneous microvascular blood extravasation and bruises. The protocol ...

Mapping the After-effects of Theta Burst Stimulation on the Human Auditory Cortex with Functional Imaging

Auditory cortex pertains to the processing of sound, which is at the basis of speech or music-related processing1. However, despite considerable recent progress, the functional properties and lateralization of the human auditory cortex are far from being fully understood. Transcranial Magnetic Stimulation (TMS) is a non-invasive technique that can transiently or lastingly modulate cortical excitability via the application of localized magnetic field pulses, and represents a unique method of exploring plasticity and connectivity. It has only recently begun to be applied to understand auditory cortical function 2. 
An important issue in using TMS is that the physiological consequences of the stimulation are difficult to establish. Although many TMS studies make the implicit assumption that the area targeted by the coil is the area affected, this need not be the case, particularly for complex cognitive functions which depend on interactions across many brain regions 3. One solution to this problem is to combine TMS with functional Magnetic resonance imaging (fMRI). The idea here is that fMRI will provide an index of changes in brain activity associated with TMS. Thus, fMRI would give an independent means of assessing which areas are affected by TMS and how they are modulated 4. In addition, fMRI allows the assessment of functional connectivity, which represents a measure of the temporal coupling between distant regions. It can thus be useful not only to measure the net activity modulation induced by TMS in given locations, but also the degree to which the network properties are affected by TMS, via any observed changes in functional connectivity.
Different approaches exist to combine TMS and functional imaging according to the temporal order of the methods. Functional MRI can be applied before, during, after, or both before and after TMS. Recently, some studies interleaved TMS and fMRI in order to provide online mapping of the functional changes induced by TMS 5-7. However, this online combination has many technical problems, including the static artifacts resulting from the presence of the TMS coil in the scanner room, or the effects of TMS pulses on the process of MR image formation. But more importantly, the loud acoustic noise induced by TMS (increased compared with standard use because of the resonance of the scanner bore) and the increased TMS coil vibrations (caused by the strong mechanical forces due to the static magnetic field of the MR scanner) constitute a crucial problem when studying auditory processing. 
This is one reason why fMRI was carried out before and after TMS in the present study. Similar approaches have been used to target the motor cortex 8,9, premotor cortex 10, primary somatosensory cortex 11,12 and language-related areas 13, but so far no combined TMS-fMRI study has investigated the auditory cortex. The purpose of this article is to provide details concerning the protocol and considerations necessary to successfully combine these two neuroscientific tools to investigate auditory processing. 
Previously we showed that repetitive TMS (rTMS) at high and low frequencies (resp. 10 Hz and 1 Hz) applied over the auditory cortex modulated response time (RT) in a melody discrimination task 2. We also showed that RT modulation was correlated with functional connectivity in the auditory network assessed using fMRI: the higher the functional connectivity between left and right auditory cortices during task performance, the higher the facilitatory effect (i.e. decreased RT) observed with rTMS. However those findings were mainly correlational, as fMRI was performed before rTMS. Here, fMRI was carried out before and immediately after TMS to provide direct measures of the functional organization of the auditory cortex, and more specifically of the plastic reorganization of the auditory neural network occurring after the neural intervention provided by TMS. 
Combined fMRI and TMS applied over the auditory cortex should enable a better understanding of brain mechanisms of auditory processing, providing physiological information about functional effects of TMS. This knowledge could be useful for many cognitive neuroscience applications, as well as for optimizing therapeutic applications of TMS, particularly in auditory-related disorders.

Auditory processing is the basis of speech and music-related processing. Transcranial Magnetic Stimulation (TMS) has been used successfully to study cognitive, sensory and motor systems but has rarely been applied to audition. Here we investigated TMS combined with functional Magnetic Resonance Imaging to understand the functional organization of auditory cortex.

Cartographie des séquelles de Theta Burst Stimulation sur le cortex auditif humain à l&#39;imagerie fonctionnelle

Auditory cortex pertains to the processing of sound, which is at the basis of speech or music-related processing1. However, despite considerable recent ...

Isolation of Human Hepatocytes by a Two-step Collagenase Perfusion Procedure

The liver, an organ with an exceptional regeneration capacity, carries out a wide range of functions, such as detoxification, metabolism and homeostasis. As such, hepatocytes are an important model for a large variety of research questions. In particular, the use of human hepatocytes is especially important in the fields of pharmacokinetics, toxicology, liver regeneration and translational research. Thus, this method presents a modified version of a two-step collagenase perfusion procedure to isolate hepatocytes as described by Seglen 1.
Previously, hepatocytes have been isolated by mechanical methods. However, enzymatic methods have been shown to be superior as hepatocytes retain their structural integrity and function after isolation. This method presented here adapts the method designed previously for rat livers to human liver pieces and results in a large yield of hepatocytes with a viability of 77&plusmn;10%. The main difference in this procedure is the process of cannulization of the blood vessels. Further, the method described here can also be applied to livers from other species with comparable liver or blood vessel sizes.

A modified two-step collagenase perfusion procedure for isolation of human hepatocytes is described. This method can also be applied to other mammalian livers. The isolated hepatocytes are available in high yield and viability, making them a suitable model for scientific research in areas such as liver regeneration, pharmacokinetics and toxicology.

Isolement des hépatocytes humains par un deux-étape collagénase procédure de perfusion

The liver, an organ with an exceptional regeneration capacity, carries out a wide range of functions, such as detoxification, metabolism and homeostasis. ...

Sampling Blood from the Lateral Tail Vein of the Rat

Blood samples are commonly obtained in many experimental contexts to measure targets of interest, including hormones, immune factors, growth factors, proteins, and glucose, yet the composition of the blood is dynamically regulated and easily perturbed. One factor that can change the blood composition is the stress response triggered by the sampling procedure, which can contribute to variability in the measures of interest. Here we describe a procedure for blood sampling from the lateral tail vein in the rat. This procedure offers significant advantages over other more commonly used techniques. It permits rapid sampling with minimal pain or invasiveness, without anesthesia or analgesia. Additionally, it can be used to obtain large volume samples (upwards of 1 ml in some rats), and it may be used repeatedly across experimental days. By minimizing the stress response and pain resulting from blood sampling, measures can more accurately reflect the true basal state of the animal, with minimal influence from the sampling procedure itself.

Blood samples are useful for assessing biomarkers of physiological states or disease in vivo. Here we describe the methodology to sample blood from the lateral tail vein in the rat. This method provides rapid samples with minimal pain and invasiveness.

L&#39;échantillonnage de sang de la veine caudale latérale de la Rat

Blood samples are commonly obtained in many experimental contexts to measure targets of interest, including hormones, immune factors, growth factors, ...