<ol><li> Anesthetize Mäuse mit Isofluran (4% für die Induktion, 1.5-2% für Chirurgie) mit IACUC genehmigten Verfahren. Es ist wichtig, dass Schwanz und / oder Zehen drückt verwendet werden, um sicherzustellen, das Tier vollständig betäubt. </li><li> Mit einem Nagetier Trimmer, rasieren die Haare aus dem Nacken bis zu den Augen. </li><li> Platzieren Sie die Maus in einem stereotaktischen Rahmen, über eine Operation Wasser re-zirkulierende Decke. Für eine sichere Befestigung des Kopfes mit Ohr Bars. </li><li> Bewerben Augensalbe, um das Tier das Auge vor dem Austrocknen zu verhindern. </li><li> Verwalten, subkutan, Dexamethason (0,2 mg / Kg) und Carprofen (5 mg / kg) zu verhindern, Schwellung des Gehirns und / oder eine entzündliche Reaktion, bzw.. </li><li> Vor Beginn der Operation zu sterilisieren operativen Bereich durch Abwischen der Haut mit drei wechselnden Seitenhiebe von 70% Alkohol und betadine. </li><li> Alle chirurgischen Instrumente wurden bereits sterilisiert mit einer Glasperle Sterilisator. Mit einer Schere, die mit Ethanol sterilisiert wurden, entfernen Sie die Haut über der Oberseite des Schädels, beginnend mit einem horizontalen Schnitt entlang der Unterseite des Kopfes, durch zwei Schnitte in der rostralen Richtung und erreichte fast die Augenlider, dann zwei schräge Schnitte folgten dass an der Mittellinie zusammen. </li><li> Ein Tropfen Lidocain + Adrenalin-Lösung ist an dieser Stelle auf die Knochenhaut angewendet starke Blutungen oder Schmerzen zu vermeiden. Mit einem Skalpell, Einfahren der Knochenhaut an den Rändern des Schädels. Auch leicht zurücknehmen die Muskulatur der Rückseite des Halses. </li><li> Vorsichtig kratzen die gesamte freiliegende Fläche des Schädels mit dem Skalpell auf eine trockene Oberfläche zu schaffen. Dies ist sehr wichtig, da es ermöglichen wird der Kleber besser haften, wenn später angewendet. </li><li> Sobald ein bildgebendes Ort gewählt worden ist, ist man bereit, die kraniale Fenster zu erstellen. Zuerst sanft &quot;draw&quot; einen Kreis von etwa 4 mm im Durchmesser mit der pneumatischen Dentalbohrers. </li><li> Nach einem leichten Bohren, gelten Lidocain + Adrenalin-Lösung wieder auf der Kopfoberfläche. Stoppen Sie die Bohrungen, wenn eine sehr dünne Schicht von Knochen übrig bleibt. Indem Sie sanft auf die Mitte der Kraniotomie zu spüren, wie er nachgibt, kann man in der Regel wissen, dass dieses Stadium erreicht ist. </li><li> Unter einem Tropfen Kochsalzlösung und unter Ausnutzung der Knochenbälkchen - die schwammartige Struktur des Knochens - Abheben der Kraniotomie aus dem Schädel mit sehr dünnen Spitze Pinzette. Die Saline ist wichtig, da es hilft, heben Sie den Schädel und Vorbeugung von Blutungen der Dura. </li><li> Bewerben Gelfoam, die zuvor in Kochsalzlösung an die Dura mater, um kleine Blutungen, die gelegentlich auftritt, wenn der Schädel entfernt Stop eingelegt. </li><li> Nach dem Trocknen der Dura mater Oberfläche und gewährleisten, dass es keine Blutung, legen Sie ihn vorsichtig ein steriles 5 mm Deckglas auf der Dura mater. (Hinweis: andere Gruppen auch einen Tropfen mit niedrigem Schmelzpunkt Agarose (1,2%) über die Laufzeit und legte das Deckglas auf dem Agar). </li><li> Einen Tropfen Cyanacrylat-Klebstoff auf der gegenüberliegenden Hemisphäre auf dem Schädel. Mit Hilfe einer Nadel, sanft die Kleber auf der ganzen Fenster, während man aufpassen, nicht unter das Glas gelegt. Kleben Sie können nun in eine dünne Schicht über die gesamte Oberfläche des Schädels angewandt werden. </li><li> Sobald der Leim getrocknet ist, mischen zahnärztliche Acryl und wenden sie in der Kopfoberfläche, in denen auch ein kleiner Rand des Deckglases, um es zu sichern. </li><li> Nach Sicherung der Deckglas, machen Sie eine kleine, gut um das Fenster mit zahnärztlichen Acryl. Auch einbetten Titan bar in der zahnärztlichen Acryl. Diese Bar wird später verwendet, um die Maus sicher zu befestigen auf die Bühne des Mikroskops für die Bildgebung werden. Es ist wichtig, um sicherzustellen, dass die Bar-Ebene ist, so dass es parallel mit dem Schädel-Fenster ist. Platzierung ein Stück Papier unter die Stange kann damit die Messlatte für Niveau bleiben, während die Acryl härtet. </li><li> Die zahnärztliche Acryl erlaubt ist, zu heilen (verhärten) für 10 Minuten, in welcher Zeit die Titan-bar ist fixiert. Legen Sie das Tier in einen warmen Käfig, bis es sich erholt. </li><li> Nach Erwachen aus der Narkose, kann das Tier noch am selben Tag abgebildet werden. </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>

Wie wir in der Video-und in den ergänzenden Angaben, die kraniale Fenster Vorbereitung, mit dem Einsatz von Zwei-Photonen-Mikroskopie in Kombination gezeigt haben, ist ein sehr mächtiges Werkzeug, um in vivo die Struktur und Funktion des Neokortex zu studieren. Die Technik erfordert hartes Training, um sich mit der Anatomie und der feine chirurgische Eingriffe und Fähigkeiten, die diese Vorbereitung erfordert. Nur makellose Operationen können für chronische Bildgebung verwendet werden. Wenn die Dura stark oder durchbohrt manipuliert wi...

a craniotomy surgery procedure for chronic brain imaging

Bildgebende Verfahren gewinnen zunehmend an Bedeutung in der Studie Gehirnfunktion. Unter ihnen hat Zwei-Photonen-Laser-Scanning-Mikroskopie als eine äußerst nützliche Methode, weil damit das Studium der lebenden intakten Gehirn ermöglicht. Bei entsprechender Vorbereitung, ermöglicht diese Technik die Beobachtung der gleichen kortikalen Bereich chronisch, von Minuten bis zu Monaten. In diesem Video zeigen wir eine Vorbereitung für chronische in-vivo-Bildgebung des Gehirns mittels Zwei-Photonen-Mikroskopie. Diese Technik wurde ursprünglich Pionierarbeit von Dr. Karel Svoboda, der jetzt ein Howard Hughes Medical Institute Investigator an Janelia Farm. Die Vorbereitungen wie das hier gezeigte können für die Bildgebung des Neokortex Struktur (z. B. dendritischen und axonalen Dynamik), verwendet werden, um neuronale Aktivität Datensatz mit Calcium-sensitiven Farbstoffen, zu Bild kortikalen Durchblutung Dynamik, oder intrinsische optische Bildgebung. Deep Imaging des Neocortex ist mit optimalen kranialen Fenster Operationen möglich. Unter dem meisten sterilen Bedingungen möglich, Infektionen zu vermeiden, zusammen mit mit äußerster Vorsicht, nicht zu beschädigen die Dura mater während der Operation wird in erfolgreiche und dauerhafte Glas überdachten kranialen Fenster führen.

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

Dieses Video-und Protokoll zu demonstrieren, wie man ein Glas überdachten kranialen Fenster in Nagetieren zu implantieren. Diese Zubereitungen können bei chronischen in vivo Zwei-Photonen-Imaging des Neokortex über Zeitskalen von Monaten verwendet werden. Es kann auch für andere Arten der Bildgebung, darunter optische Eigensicherheit Signal Bildgebung verwendet werden.

Ein Kraniotomie Chirurgie Verfahren für chronische Brain Imaging

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 Aufrufe.  University of California, Los Angeles. Dieses Video-und Protokoll zu demonstrieren, wie man ein Glas überdachten kranialen Fenster in Nagetieren zu implantieren. Diese Zubereitungen können bei chronischen in vivo Zwei-Photonen-Imaging des Neokortex über Zeitskalen von Monaten verwendet werden. Es kann auch für andere Arten der Bildgebung, darunter optische Eigensicherheit Signal Bildgebung verwendet werden.

Serie: 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.

Anwendung von Licht-gehärteten Dental Adhesive Resin für Montage-Elektroden oder Mikrodialysesonden in Chronic Experimente

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

Forschung

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-Array für chronische 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. ...

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-Array für chronische 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 ...

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.

Murine Renal Transplantation

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.

Live-Imaging der Zebrafisch embryonalen Gehirn durch konfokale Mikroskopie

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.

Erstellen MR Imaging Kinderspiel - Pediatric Neuroimaging-Protokoll, Richtlinien und Verfahren

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.

Biolumineszenz-Bildgebung von HO-1 Hochregulation in der 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 ...

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.

Kartierung der Nachwirkungen der Theta Burst Stimulation auf das menschliche Gehör Cortex mit 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 ...

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.

Isolierung von humanen Hepatozyten durch eine Zwei-Schritt-Verfahren Collagenase 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.

Blutprobenentnahme aus der laterale Schwanzvene der Ratte

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