Le travail en laboratoire est soutenu par la Nederlandse Organisatie voor Onderzoek Wetenschappelijk (NWO) (917.10.372) pour RMM. JD est affilié au programme FP7 de l&#39;UE BrainTrain ( <a href="http://www.brain-train.nl">www.brain-train.nl</a> ). Nous remercions Pieter Laurens-Baljon et Sabine Schmitz (tous deux CNCR, VU University Amsterdam) pour des images de formes d&#39;onde FO array multiélectrodes et les cultures neuronales utilisées dans la séquence vidéo.

<ol>
	<li>Katz, L. C., Shatz, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synaptic+activity+and+the+construction+of+cortical+circuits.">Synaptic activity and the construction of cortical circuits.</a> Science. 274, 1133-1138 (1996).</li><li>Khazipov, R., Luhmann, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+patterns+of+electrical+activity+in+the+developing+cerebral+cortex+of+humans+and+rodents.">Early patterns of electrical activity in the developing cerebral cortex of humans and rodents.</a> Trends in Neurosciences. 29, 414-418 (2006).</li><li>Spitzer, N. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrical+activity+in+early+neuronal+development.">Electrical activity in early neuronal development.</a> Nature. 444, 707-712 (2006).</li><li>Adelsberger, H., Garaschuk, O., Konnerth, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cortical+calcium+waves+in+resting+newborn+mice.">Cortical calcium waves in resting newborn mice.</a> Nat. Neurosci. 8, 988-990 (2005).</li><li>Garaschuk, O., Linn, J., Eilers, J., Konnerth, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-scale+oscillatory+calcium+waves+in+the+immature+cortex.">Large-scale oscillatory calcium waves in the immature cortex.</a> Nat. Neurosci. 3, 452-459 (2000).</li><li>Lamblin, . <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electroencephalography+of+the+premature+and+term+newborn.+Maturational+aspects+and+glossary.">Electroencephalography of the premature and term newborn. Maturational aspects and glossary.</a> Neurophysiol. Clin. 29, 123-219 (1999).</li><li>Rakic, P., Komuro, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+receptor/channel+activity+in+neuronal+cell+migration.">The role of receptor/channel activity in neuronal cell migration.</a> J. Neurobiol. 26, 299-315 (1995).</li><li>Spitzer, N. C., Root, C. M., Borodinsky, L. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orchestrating+neuronal+differentiation:+patterns+of+Ca2++spikes+specify+transmitter+choice.">Orchestrating neuronal differentiation: patterns of Ca2+ spikes specify transmitter choice.</a> Trends. Neurosci. 27, 415-421 (2004).</li><li>Canto, C. B., Wouterlood, F. G., Witter, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+does+the+anatomical+organization+of+the+entorhinal+cortex+tell+us.">What does the anatomical organization of the entorhinal cortex tell us.</a> Neural. Plast. , 381243-381243 (2008).</li><li>Bureau, I., Shepherd, G. M., 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=Precise+development+of+functional+and+anatomical+columns+in+the+neocortex.">Precise development of functional and anatomical columns in the neocortex.</a> Neuron. 42, 789-801 (2004).</li><li>Ikegaya, Y., Le Bon-Jego, M., Yuste, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-scale+imaging+of+cortical+network+activity+with+calcium+indicators.">Large-scale imaging of cortical network activity with calcium indicators.</a> Neuroscience research. 52, 132-138 (2005).</li></ol>

LaVision Biotec GmbH (Bielefeld, Allemagne) a parrainé les frais de soumission de cet article manuscrit.

Les méthodes que nous démontrons ici montrent protocoles appropriés pour l&#39;imagerie calcique de la dynamique du réseau à partir de cellules identifiables dans le développement de réseaux corticaux et hippocampiques chez la souris et aussi dans le cerveau du rat. Ces méthodes fournissent une résolution spatiale optimale pour visualiser un réseau local de cellules soma simultanément pour mesurer l&#39;activité supraliminaire. La résolution temporelle de l&#39;activité du réseau peut varier, selon le cadre de l&#39;acquisition des paramètres caméra CCD, pour optimiser le signal: les mesures de bruit de longue durée des événements supraliminaire, on trouve généralement dans le système nerveux en développement. Ces protocoles ne sont pas limités à des réseaux de l&#39;hippocampe et du cortex, mais aussi marquer les cellules à travers le système nerveux en développement. La limitation de cette méthode est que l&#39;activité supraliminaire ne peut être enregistrée.

functional calcium imaging in developing cortical networks

Un motif caractéristique de l&#39;activité dans le développement du système nerveux est spontanée, l&#39;activité du réseau synchronisé. L&#39;activité synchronisée a été observée dans la moelle intacte, le tronc cérébral épinière, la rétine, le cortex et dissocié les préparatifs de la culture neuronale. Pendant les périodes d&#39;activité spontanée, les neurones à dépolariser incendie unique ou salves de potentiels d&#39;action, l&#39;activation des canaux ioniques nombreuses. Dépolarisation active les canaux calciques voltage-dépendants sur les dendrites et les épines qui interviennent dans l&#39;influx de calcium. Hautement synchronisée activité électrique a été mesurée à partir de réseaux neuronaux locaux en utilisant des électrodes sur le terrain. Cette technique permet des taux élevés de l&#39;échantillonnage temporel, mais faible résolution spatiale due à intégrer lecture des neurones multiples en une seule électrode. Résolution cellule unique de l&#39;activité neuronale est possible en utilisant de patch-clamp électrophysiologie sur des neurones de tir unique pour mesurer l&#39;activité. Cependant, la capacité à mesurer à partir d&#39;un réseau est limité au nombre de neurones patché simultaneously, et est généralement seulement un ou deux neurones. L&#39;utilisation de calcium-dépendante colorants indicateurs fluorescents a permis à la mesure de l&#39;activité synchronisée à travers un réseau de cellules. Cette technique donne à la fois haute résolution spatiale et temporelle suffisante d&#39;échantillonnage pour enregistrer l&#39;activité spontanée du réseau de développement. Une caractéristique clé du nouveau-formant des réseaux corticaux et hippocampiques au cours du développement postnatal de pré-et le début est spontanée, synchronisée activité neuronale (Katz et Shatz, 1996; Khaziphov &amp; Luhmann, 2006). Cette activité de réseau en corrélation est considérée comme essentielle pour la génération de circuits fonctionnels dans le système nerveux en développement (Spitzer, 2006). Dans les deux primates et le cerveau de rongeurs, début électrique et les ondes du réseau de calcium sont observées avant et après la naissance in vivo et in vitro (Adelsberger et al, 2005;. Garaschuk et al, 2000;.. Lamblin et al, 1999). Ces schémas d&#39;activité précoce, qui sont connus pour le contrôle de plusieursprocessus de développement, y compris la différenciation, synaptogenèse et la plasticité neuronale (Rakic ​​&amp; Komuro, 1995;. Spitzer et al, 2004) sont d&#39;une importance critique pour le développement et la maturation correcte des circuits corticaux. Dans cette vidéo, parbleu, nous démontrons les méthodes utilisées pour l&#39;activité spontanée d&#39;image dans le développement de réseaux corticaux. Calcium indicateurs sensibles, tels que Fura 2-AM diffuse ester travers la membrane cellulaire où l&#39;activité estérase intracellulaire clive le PM esters de quitter le formulaire de cellules imperméants du colorant indicateur. La forme de l&#39;indicateur a imperméants groupes acides carboxyliques qui sont capables de détecter et ensuite lier les ions de calcium intracellulaire .. La fluorescence du colorant sensible au calcium est transitoirement modifié lors de la liaison au calcium. Les techniques d&#39;imagerie simple ou multi-photons sont utilisés pour mesurer le changement de photons émis par le colorant, et indiquent ainsi une altération de calcium intracellulaire. En outre, ces calcium-dindicateurs ependent peut être combiné avec d&#39;autres marqueurs fluorescents pour enquêter sur les types de cellules au sein du réseau actif.

Watch this Scientific Journal Video about Functional Calcium Imaging in Developing Cortical Networks at JoVE.com

Functional Calcium Imaging in Developing Cortical Networks

L&#39;activité spontanée de développer des réseaux neuronaux peuvent être mesurées en utilisant AM-ester formes de colorants indicateurs sensibles au calcium. Modifications du calcium intracellulaire, indiquant l&#39;activation neuronale, sont détectés comme des changements transitoires de la fluorescence indicateur avec un ou deux photons d&#39;imagerie. Ce protocole peut être adapté pour une gamme de stade de développement qui dépendent des réseaux neuronaux<em&gt; In vitro</em&gt;.

Imagerie fonctionnelle en calcium développement des réseaux corticaux

A hallmark pattern of activity in developing nervous systems is spontaneous, synchronized network activity. Synchronized activity has been observed in ...

functional-calcium-imaging-in-developing-cortical-networks

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Neuroscience

38.8K vues.  VU University, Amsterdam. L'activité spontanée de développer des réseaux neuronaux peuvent être mesurées en utilisant AM-ester formes de colorants indicateurs sensibles au calcium. Modifications du calcium intracellulaire, indiquant l'activation neuronale, sont détectés comme des changements transitoires de la fluorescence indicateur avec un ou deux photons d'imagerie. Ce protocole peut être adapté pour une gamme de stade de développement qui dépendent des réseaux neuronau...

Vidéo: Functional Calcium Imaging in Developing Cortical Networks

Functional Mapping with Simultaneous MEG and EEG

We use magnetoencephalography (MEG) and electroencephalography (EEG) to locate and determine the temporal evolution in brain areas involved in the processing of simple sensory stimuli. We will use somatosensory stimuli to locate the hand somatosensory areas, auditory stimuli to locate the auditory cortices, visual stimuli in four quadrants of the visual field to locate the early visual areas. These type of experiments are used for functional mapping in epileptic and brain tumor patients to locate eloquent cortices. In basic neuroscience similar experimental protocols are used to study the orchestration of cortical activity. The acquisition protocol includes quality assurance procedures, subject preparation for the combined MEG/EEG study, and acquisition of evoked-response data with somatosensory, auditory, and visual stimuli. We also demonstrate analysis of the data using the equivalent current dipole model and cortically-constrained minimum-norm estimates. Anatomical MRI data are employed in the analysis for visualization and for deriving boundaries of tissue boundaries for forward modeling and cortical location and orientation constraints for the minimum-norm estimates.

We use magnetoencephalography (MEG) and electroencephalography (EEG) to map brain areas involved in the processing of simple sensory stimuli.

Cartographie fonctionnelle avec MEG et EEG simultanée

We use magnetoencephalography (MEG) and electroencephalography (EEG) to locate and determine the temporal evolution in brain areas involved in the ...

Recherche

Neurosciences

Time-lapse Live Imaging of Clonally Related Neural Progenitor Cells in the Developing Zebrafish Forebrain

Precise patterns of division, migration and differentiation of neural progenitor cells are crucial for proper brain development and function1,2. To understand the behavior of neural progenitor cells in the complex in vivo environment, time-lapse live imaging of neural progenitor cells in an intact brain is critically required. In this video, we exploit the unique features of zebrafish embryos to visualize the development of forebrain neural progenitor cells in vivo. We use electroporation to genetically and sparsely label individual neural progenitor cells. Briefly, DNA constructs coding for fluorescent markers were injected into the forebrain ventricle of 22 hours post fertilization (hpf) zebrafish embryos and electric pulses were delivered immediately. Six hours later, the electroporated zebrafish embryos were mounted with low melting point agarose in glass bottom culture dishes. Fluorescently labeled neural progenitor cells were then imaged for 36hours with fixed intervals under a confocal microscope using water dipping objective lens. The present method provides a way to gain insights into the in vivo development of forebrain neural progenitor cells and can be applied to other parts of the central nervous system of the zebrafish embryo.

The present video demonstrates a method which takes advantage of the combination of electroporation and confocal microscopy to perform live imaging on individual neural progenitor cells in the developing zebrafish forebrain. In vivo analysis of the development of forebrain neural progenitor cells at a clonal level can be achieved in this way.

Imagerie time-lapse en direct de relation clonale cellules progénitrices neurales dans le cerveau antérieur développement Zebrafish

Precise patterns of division, migration and differentiation of neural progenitor cells are crucial for proper brain development and function1,2. To ...

In vivo Neuronal Calcium Imaging in C. elegans

The nematode worm C. elegans is an ideal model organism for relatively simple, low cost neuronal imaging in vivo. Its small transparent body and simple, well-characterized nervous system allows identification and fluorescence imaging of any neuron within the intact animal. Simple immobilization techniques with minimal impact on the animal's physiology allow extended time-lapse imaging. The development of genetically-encoded calcium sensitive fluorophores such as cameleon 1 and GCaMP 2 allow in vivo imaging of neuronal calcium relating both cell physiology and neuronal activity. Numerous transgenic strains expressing these fluorophores in specific neurons are readily available or can be constructed using well-established techniques. Here, we describe detailed procedures for measuring calcium dynamics within a single neuron in vivo using both GCaMP and cameleon. We discuss advantages and disadvantages of both as well as various methods of sample preparation (animal immobilization) and image analysis. Finally, we present results from two experiments: 1) Using GCaMP to measure the sensory response of a specific neuron to an external electrical field and 2) Using cameleon to measure the physiological calcium response of a neuron to traumatic laser damage. Calcium imaging techniques such as these are used extensively in C. elegans and have been extended to measurements in freely moving animals, multiple neurons simultaneously and comparison across genetic backgrounds. C. elegans presents a robust and flexible system for in vivo neuronal imaging with advantages over other model systems in technical simplicity and cost.

In vivo Neuronal Calcium Imaging in C. elegans

With its small transparent body, well-documented neuroanatomy and a host of amenable genetic techniques and reagents, C. elegans makes an ideal model organism for in vivo neuronal imaging using relatively simple, low-cost techniques. Here we describe single neuron imaging within intact adult animals using genetically encoded fluorescent calcium indicators.

En imagerie calcique in vivo des neurones en C. elegans

The nematode worm C. elegans is an ideal model organism  for relatively simple, low cost neuronal imaging in vivo. Its small transparent body and simple, ...

Fast Micro-iontophoresis of Glutamate and GABA: A Useful Tool to Investigate Synaptic Integration

One of the fundamental interests in neuroscience is to understand the integration of excitatory and inhibitory inputs along the very complex structure of the dendritic tree, which eventually leads to neuronal output of action potentials at the axon. The influence of diverse spatial and temporal parameters of specific synaptic input on neuronal output is currently under investigation, e.g. the distance-dependent attenuation of dendritic inputs, the location-dependent interaction of spatially segregated inputs, the influence of GABAergig inhibition on excitatory integration, linear and non-linear integration modes, and many more.
With fast micro-iontophoresis of glutamate and GABA it is possible to precisely investigate the spatial and temporal integration of glutamatergic excitation and GABAergic inhibition. Critical technical requirements are either a triggered fluorescent lamp, light-emitting diode (LED), or a two-photon scanning microscope to visualize dendritic branches without introducing significant photo-damage of the tissue. Furthermore, it is very important to have a micro-iontophoresis amplifier that allows for fast capacitance compensation of high resistance pipettes. Another crucial point is that no transmitter is involuntarily released by the pipette during the experiment.
Once established, this technique will give reliable and reproducible signals with a high neurotransmitter and location specificity. Compared to glutamate and GABA uncaging, fast iontophoresis allows using both transmitters at the same time but at very distant locations without limitation to the field of view. There are also advantages compared to focal electrical stimulation of axons: with micro-iontophoresis the location of the input site is definitely known and it is sure that only the neurotransmitter of interest is released. However it has to be considered that with micro-iontophoresis only the postsynapse is activated and presynaptic aspects of neurotransmitter release are not resolved. In this article we demonstrate how to set up micro-iontophoresis in brain slice experiments.

In this article we introduce fast micro-iontophoresis of neurotransmitters as a technique to investigate integration of postsynaptic signals with high spatial and temporal precision.

Rapide Micro-iontophorèse de glutamate et le GABA: un outil utile d&#39;étudier l&#39;intégration synaptique

One of the fundamental interests in neuroscience is to understand the integration of excitatory and inhibitory inputs along the very complex structure of ...

Live Imaging of Mitosis in the Developing Mouse Embryonic Cortex

Although of short duration, mitosis is a complex and dynamic multi-step process fundamental for development of organs including the brain. In the developing cerebral cortex, abnormal mitosis of neural progenitors can cause defects in brain size and function. Hence, there is a critical need for tools to understand the mechanisms of neural progenitor mitosis. Cortical development in rodents is an outstanding model for studying this process. Neural progenitor mitosis is commonly examined in fixed brain sections. This protocol will describe in detail an approach for live imaging of mitosis in ex vivo embryonic brain slices. We will describe the critical steps for this procedure, which include: brain extraction, brain embedding, vibratome sectioning of brain slices, staining and culturing of slices, and time-lapse imaging. We will then demonstrate and describe in detail how to perform post-acquisition analysis of mitosis. We include representative results from this assay using the vital dye Syto11, transgenic mice (histone H2B-EGFP and centrin-EGFP), and in utero electroporation (mCherry-&#945;-tubulin). We will discuss how this procedure can be best optimized and how it can be modified for study of genetic regulation of mitosis. Live imaging of mitosis in brain slices is a flexible approach to assess the impact of age, anatomy, and genetic perturbation in a controlled environment, and to generate a large amount of data with high temporal and spatial resolution. Hence this protocol will complement existing tools for analysis of neural progenitor mitosis.

Neural progenitor mitosis is a critical parameter of neurogenesis. Much of our understanding of neural progenitor mitosis is based on analysis of fixed tissue. Live imaging in embryonic brain slices is a versatile technique to assess mitosis with high temporal and spatial resolution in a controlled environment.

Imagerie en direct de la mitose dans les développement Cortex souris embryonnaires

Although of short duration, mitosis is a complex and dynamic multi-step process fundamental for development of organs including the brain. In the ...

In Vivo Functional Brain Imaging Approach Based on Bioluminescent Calcium Indicator GFP-aequorin

Functional in vivo imaging has become a powerful approach to study the function and physiology of brain cells and structures of interest. Recently a new method of Ca2+-imaging using the bioluminescent reporter GFP-aequorin (GA) has been developed. This new technique relies on the fusion of the GFP and aequorin genes, producing a molecule capable of binding calcium and&#160;&#8212; with the addition of its cofactor coelenterazine &#8212; emitting bright light that can be monitored through a photon collector. Transgenic lines carrying the GFP-aequorin gene have been generated for both mice and Drosophila. In Drosophila, the GFP-aequorin gene has been placed under the control of the GAL4/UAS binary expression system allowing for targeted expression and imaging within the brain. This method has subsequently been shown to be capable of detecting both inward Ca2+-transients and Ca2+-released from inner stores. Most importantly it allows for a greater duration in continuous recording, imaging at greater depths within the brain, and recording at high temporal resolutions (up to 8.3 msec). Here we present the basic method for using bioluminescent imaging to record and analyze Ca2+-activity within the mushroom bodies, a structure central to learning and memory in the fly brain.

In Vivo Functional Brain Imaging Approach Based on Bioluminescent Calcium Indicator GFP-aequorin

Here we present a novel Ca2+-imaging approach using a bioluminescent reporter. This approach uses a fused construct GFP-aequorin which binds to Ca2+ and emits light, eliminating the need for light excitation. Significantly this method permits long continuous imaging, access to deep brain structures and high temporal resolution.

In Vivo cérébrale fonctionnelle approche d&#39;imagerie à base de calcium Bioluminescent Indicateur GFP-aequorine

Functional in vivo imaging has become a powerful approach to study the function and physiology of brain cells and structures of interest. Recently a new ...

Simultaneous Recordings of Cortical Local Field Potentials, Electrocardiogram, Electromyogram, and Breathing Rhythm from a Freely Moving Rat

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls body functions and internal organ rhythms when animals are exposed to emotional challenges and changes in their living environments. In general experiments, signals from different organs, such as the brain and the heart, are recorded by independent recording systems that require multiple recording devices and different procedures for processing the data files. This study describes a new method that can simultaneously monitor electrical biosignals, including tens of local field potentials in multiple brain regions, electrocardiograms that represent the cardiac rhythm, electromyograms that represent awake/sleep-related muscle contraction, and breathing signals, in a freely moving rat. The recording configuration of this method is based on a conventional micro-drive array for cortical local field potential recordings in which tens of electrodes are accommodated, and the signals obtained from these electrodes are integrated into a single electrical board mounted on the animal's head. Here, this recording system was improved so that signals from the peripheral organs are also transferred to an electrical interface board. In a single surgery, electrodes are first separately implanted into the appropriate body parts and the target brain areas. The open ends of all of these electrodes are then soldered to individual channels of the electrical board above the animal's head so that all of the signals can be integrated into the single electrical board. Connecting this board to a recording device allows for the collection of all of the signals into a single device, which reduces experimental costs and simplifies data processing, because all data can be handled in the same data file. This technique will aid the understanding of the neurophysiological correlates of the associations between central and peripheral organs.

This study introduces a method for the simultaneous recording of local field potentials in the brain, electrocardiograms, electromyograms, and breathing signals of a freely moving rat. This technique, which reduces experimental costs and simplifies data analysis, will contribute to the understanding of the interactions between the brain and peripheral organs.

Enregistrements simultanés des potentiels corticaux champ Local, électrocardiogramme, électromyogramme et respiration rythmique d’un Rat librement mobile

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls ...

In Vivo Two-photon Imaging of Cortical Neurons in Neonatal Mice

Two-photon imaging is a powerful tool for the in vivo analysis of neuronal circuits in the mammalian brain. However, a limited number of in vivo imaging methods exist for examining the brain tissue of live newborn mammals. Herein we summarize a protocol for imaging individual cortical neurons in living neonatal mice. This protocol includes the following two methodologies: (1) the Supernova system for sparse and bright labeling of cortical neurons in the developing brain, and (2) a surgical procedure for the fragile neonatal skull. This protocol allows the observation of temporal changes of individual cortical neurites during neonatal stages with a high signal-to-noise ratio. Labeled cell-specific gene silencing and knockout can also be achieved by combining the Supernova with RNA interference and CRISPR/Cas9 gene editing systems. This protocol can, thus, be used for analyzing the developmental dynamics of cortical neurons, molecular mechanisms that control the neuronal dynamics, and changes in neuronal dynamics in disease models.

In Vivo Two-photon Imaging of Cortical Neurons in Neonatal Mice

We present an in vivo two-photon imaging protocol for imaging the cerebral cortex of neonatal mice. This method is suitable for analyzing the developmental dynamics of cortical neurons, the molecular mechanisms that control the neuronal dynamics, and the changes in neuronal dynamics in disease models.

In Vivo Two-photon Imaging de neurones corticaux en souris néonatales

Two-photon imaging is a powerful tool for the in vivo analysis of neuronal circuits in the mammalian brain. However, a limited number of in vivo imaging ...

In vivo Calcium Imaging in Mouse Inferior Olive

Inferior olive (IO), a nucleus in the ventral medulla, is the only source of climbing fibers that form one of the two input pathways entering the cerebellum. IO has long been proposed to be crucial for motor control and its activity is currently considered to be at the center of many hypotheses of both motor and cognitive functions of the cerebellum. While its physiology and function have been relatively well studied on single-cell level in vitro, presently there are no reports on the organization of the IO network activity in living animals. This is largely due to the extremely challenging anatomical location of the IO, making it difficult to subject to conventional fluorescent imaging methods, where an optic path must be created through the entire brain located dorsally to the region of interest.
Here we describe an alternative method for obtaining state-of-the-art -level calcium imaging data from the IO network. The method takes advantage of the extreme ventral location of the IO and involves a surgical procedure for inserting a gradient-refractive index (GRIN) lens through the neck viscera to come into contact with the ventral surface of the calcium sensor GCaMP6s-expressing IO in anesthetized mice. A representative calcium imaging recording is shown to demonstrate the feasibility to record IO neuron activity after the surgery. While this is a non-survival surgery and the recordings must be conducted under anesthesia, it avoids damage to life-critical brainstem nuclei and allows conducting large variety of experiments investigating spatiotemporal activity patterns and input integration in the IO. This procedure with modifications could be used for recordings in other, adjacent regions of the ventral brainstem.

In vivo Calcium Imaging in Mouse Inferior Olive

We present a protocol to expose the brainstem of adult mouse from the ventral side. By using a gradient-refractive index lens with a miniature microscope, calcium imaging can be used to examine the activity of inferior olive neural somata in vivo.

In vivo Imagerie du calcium chez la souris Olive inférieure

Inferior olive (IO), a nucleus in the ventral medulla, is the only source of climbing fibers that form one of the two input pathways entering the ...

Reliable Acquisition of Electroencephalography Data during Simultaneous Electroencephalography and Functional MRI

Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), EEG-fMRI, combines the complementary properties of scalp EEG (good temporal resolution) and fMRI (good spatial resolution) to measure neuronal activity during an electrographic event, through hemodynamic responses known as blood-oxygen-level-dependent (BOLD) changes. It is a non-invasive research tool that is utilized in neuroscience research and is highly beneficial to the clinical community, especially for the management of neurological diseases, provided that proper equipment and protocols are administered during data acquisition. Although recording EEG-fMRI is apparently straightforward, the correct preparation, especially in placing and securing the electrodes, is not only important for safety but is also critical in ensuring the reliability and analyzability of the EEG data obtained. This is also the most experience-demanding part of the preparation. To address these issues, a straightforward protocol that ensures data quality was developed. This article provides a step-by-step guide for acquiring reliable EEG data during EEG-fMRI using this protocol that utilizes readily available medical products. The presented protocol can be adapted to different applications of EEG-fMRI in research and clinical settings, and may be beneficial to both inexperienced and expert operators.

This article provides a straightforward protocol for acquiring good quality electroencephalography (EEG) data during simultaneous EEG and functional magnetic resonance imaging by utilizing readily available medical products.

Acquisition fiable de données d’électroencéphalographie au cours de l’électroencéphalographie simultanée et de l’IRM fonctionnelle

Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), EEG-fMRI, combines the complementary properties of scalp EEG ...