Questo lavoro è stato supportato da sovvenzioni della Samsung Science and Technology Foundation (Project Number SSTF-BA1801-10).

<ol>
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A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Cre-dependent+GCaMP3+reporter+mouse+for+neuronal+imaging+in+vivo.">A Cre-dependent GCaMP3 reporter mouse for neuronal imaging in vivo.</a> Journal of Neuroscience. 32 (9), 3131-3141 (2012).</li><li>Mittmann, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-photon+calcium+imaging+of+evoked+activity+from+L5+somatosensory+neurons+in+vivo.">Two-photon calcium imaging of evoked activity from L5 somatosensory neurons in vivo.</a> Nature Neuroscience. 14 (8), 1089-1093 (2011).</li><li>Huber, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+dynamic+representations+in+the+motor+cortex+during+sensorimotor+learning.">Multiple dynamic representations in the motor cortex during sensorimotor learning.</a> Nature. 484 (7395), 473-478 (2012).</li><li>Grewe, B. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+ensemble+dynamics+underlying+a+long-term+associative+memory.">Neural ensemble dynamics underlying a long-term associative memory.</a> Nature. 543 (7647), 670-675 (2017).</li><li>Cai, D. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+shared+neural+ensemble+links+distinct+contextual+memories+encoded+close+in+time.">A shared neural ensemble links distinct contextual memories encoded close in time.</a> Nature. 534 (7605), 115-118 (2016).</li><li>Lin, M. Z., Schnitzer, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetically+encoded+indicators+of+neuronal+activity.">Genetically encoded indicators of neuronal activity.</a> Nature Neuroscience. 19 (9), 1142-1153 (2016).</li><li>Zhang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Miniscope+GRIN+Lens+System+for+Calcium+Imaging+of+Neuronal+Activity+from+Deep+Brain+Structures+in+Behaving+Animals.">Miniscope GRIN Lens System for Calcium Imaging of Neuronal Activity from Deep Brain Structures in Behaving Animals.</a> Current Protocols in Neuroscience. 86 (1), 56 (2019).</li><li>Jacob, A. 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K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Miniaturized+integration+of+a+fluorescence+microscope.">Miniaturized integration of a fluorescence microscope.</a> Nature Methods. 8 (10), 871-878 (2011).</li><li>Xiong, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Precise+Cerebral+Vascular+Atlas+in+Stereotaxic+Coordinates+of+Whole+Mouse+Brain.">Precise Cerebral Vascular Atlas in Stereotaxic Coordinates of Whole Mouse Brain.</a> Frontiers in Neuroanatomy. 11, 128 (2017).</li><li>Mukamel, E. A., Nimmerjahn, A., Schnitzer, M. 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Le abili tecniche chirurgiche sono essenziali per ottenere un'imaging ottico di calcio in vivo di successo con microscopia miniaturica a testa in regioni cerebrali più profonde come l'amigdala come abbiamo descritto qui. Pertanto, sebbene questo protocollo fornisca una linea guida per processi chirurgici ottimizzati di attacco della piastra di base e impianto dell'obiettivo GRIN, potrebbero essere necessari ulteriori processi di ottimizzazione per i passaggi critici. Come accennato nella sezione del protocollo, le coord...

Il calcio è un secondo messaggero onnipresente, che gioca un ruolo cruciale in quasi tutte le funzioni cellulari8. Nei neuroni, il potenziale d'azione di cottura e l'input sinaptico causano un rapido cambiamento del libero intracellulare [Ca2+]9,10. Pertanto, tracciare i transitori di calcio offre l'opportunità di monitorare l'attività neuronale. I GECI sono potenti strumenti che consentono il monitoraggio [Ca2+] in popolazioni cellulari definite e compartimenti intracellulari11,12. Tra molti tipi diversi di indicatore di calcio a base proteica, GCaMP, una sonda Ca2+ basata su una singola molecola GFP13, è il GECI più ottimizzato e quindi ampiamente utilizzato. Attraverso più cicli di ingegneria, è stato sviluppato un certo numero di varianti di GCaMP12,14,15,16. Usiamo uno dei GCAMP sviluppati di recente, GCaMP7b, in questo protocollo16. I sensori GCaMP hanno notevolmente contribuito allo studio delle funzioni del circuito neurale in una serie di organismi modello come l'imaging dei transitori Ca2+ durante losviluppo 17,l'imaging in vivo in uno specifico strato corticale18,la misurazione della dinamica del circuito nell'apprendimento delle attività motorie19 e l'imaging dell'attività dell'insieme cellulare correlata alla memoria della paura associativa nell'ippocampo e nell'amigdala20,21.
L'imaging ottico dei GECI presenta diversivantaggi 22. La codifica genetica consente ai GECI di essere espressi stabilmente per un periodo di tempo a lungo termine in un sottoinsieme specifico di cellule definite dal profilo genetico o da modelli specifici di connettività anatomica. L'imaging ottico consente il monitoraggio cronico simultaneo in vivo di centinaia o migliaia di neuroni negli animali vivi. Sono stati sviluppati alcuni sistemi di imaging ottico per l'imaging in vivo e l'analisi di GECI all'interno del cervello di topi che si comportano liberamente con microscopi miniaturizzati a fluorescenzaa testa 21,23,24,25. Nonostante la tecnica di imaging ottico in vivo basata su GECI, lente GRIN e un microscopio in miniatura a testa sia un potente strumento per studiare il legame tra attività e comportamento del circuito neurale, l'applicazione di questa tecnologia all'amigdala è stata difficile a causa di diversi problemi tecnici legati al targeting dell'obiettivo GRIN alle cellule che esprimono GECI nell'amigdala senza causare artefatti di movimento che riducono gravemente la qualità dell'acquisizione di immagini e trovano cellule che esprimono GECI. Questo protocollo mira a fornire una linea guida utile per le procedure chirurgiche di attacco della piastra di base e impianto dell'obiettivo GRIN che sono passaggi critici per l'imaging ottico di calcio in vivo di successo nell'amigdala. Sebbene questo protocollo si rivolge all'amigdala, la maggior parte delle procedure descritte qui sono comunemente applicabili ad altre regioni cerebrali più profonde. Sebbene questo protocollo sia basato su un particolare sistema (ad esempio, Inscopix), lo stesso scopo può essere facilmente raggiunto con altri sistemi alternativi.

<table><tbody><tr><td>26G needle</td><td>BD</td><td>302002</td><td>Surgery</td></tr><tr><td>AAV1-Syn-GCaMP7b-WPRE</td><td>Addgene</td><td>104493-AAV1</td><td>Surgery</td></tr><tr><td>AAV2/1-CaMKii&amp;alpha;-GFP</td><td>custom made</td><td></td><td>Surgery</td></tr><tr><td>Acrylic-Dental cement (Ortho-jet Acrylic Pink)</td><td>Lang</td><td>1334-pink</td><td>Surgery &amp;amp; Baseplate Attachment</td></tr><tr><td>Air flow manipulator</td><td>Neurotar</td><td>NTR000253-04</td><td>Baseplate Attachment</td></tr><tr><td>Amoxicillin</td><td>SIGMA</td><td>A8523-5G</td><td>Surgery</td></tr><tr><td>Baseplate</td><td>INSCOPIX</td><td>1050-002192</td><td>Baseplate Attachment</td></tr><tr><td>Baseplate cover</td><td>INSCOPIX</td><td>1050-002193</td><td>Baseplate Attachment</td></tr><tr><td>Behavioral apparatus (chamber)</td><td>Coulbourn Instrument</td><td>Testcage</td><td>Behavior test</td></tr><tr><td>Behavioral apparatus (software)</td><td>Coulbourn Instrument</td><td>Freeze Frame</td><td>Behavior test</td></tr><tr><td>Carbon cage</td><td>Neurotar</td><td>180mm x 70mm</td><td>Baseplate Attachment</td></tr><tr><td>Carprofen</td><td>SIGMA</td><td>PHR1452-1G</td><td>Surgery</td></tr><tr><td>Data processing software</td><td>INSCOPIX</td><td>INSCOPIX Data Processing Software</td><td>Baseplate Attachment &amp;amp; Behavior test</td></tr><tr><td>Dexamethasone</td><td>SIGMA</td><td>D1756-500MG</td><td>Surgery</td></tr><tr><td>Drill</td><td>Seyang</td><td>marathon-4</td><td>Surgery</td></tr><tr><td>Drill bur</td><td>ELA</td><td>US1/2, Shank104</td><td>Surgery</td></tr><tr><td>Glass needle</td><td>WPI</td><td>PG10165-4</td><td>Surgery</td></tr><tr><td>GRIN lens (INSCOPIX Proview Lens Probe)</td><td>INSCOPIX</td><td>1050-002208</td><td>Surgery</td></tr><tr><td>Hamilton Syringe</td><td>Hamilton</td><td>84875</td><td>Surgery</td></tr><tr><td>Head plate</td><td>Neurotar</td><td>Model 5</td><td>Surgery</td></tr><tr><td>Hex-key</td><td>INSCOPIX</td><td>1050-004195</td><td>Baseplate Attachment</td></tr><tr><td>Laptop computer</td><td>Samsung</td><td>NT950XBV</td><td>Surgery &amp;amp; Baseplate Attachment</td></tr><tr><td>Lens holder, Stereotaxic rod (INSCOPIX proview implant kit)</td><td>INSCOPIX</td><td>1050-004223</td><td>Surgery</td></tr><tr><td>Microscope gripper</td><td>INSCOPIX</td><td>1050-002199</td><td>Baseplate Attachment</td></tr><tr><td>Microscope, DAQ software, hardware</td><td>INSCOPIX</td><td>nVista 3.0</td><td>Baseplate Attachment &amp;amp; Behavior test</td></tr><tr><td>Mobile homecage</td><td>Neurotar</td><td>MHC V5</td><td>Baseplate Attachment</td></tr><tr><td>Moterized arm</td><td>Neurostar</td><td>Customized</td><td>Surgery</td></tr><tr><td>Moterized arm software</td><td>Neurostar</td><td>Customized</td><td>Surgery</td></tr><tr><td>NI board</td><td>National instrument</td><td></td><td>Behavior test</td></tr><tr><td>Removable epoxy bond</td><td>WPI</td><td>Kwik-Cast</td><td>Surgery</td></tr><tr><td>Resin cement (Super-bond)</td><td>Sun medical</td><td>Super bond C&amp;amp;B</td><td>Surgery</td></tr><tr><td>Skull screw</td><td>Stoelting</td><td>51457</td><td>Surgery</td></tr><tr><td>Stereotaxic electrode holder</td><td>ASI</td><td>EH-600</td><td>Surgery</td></tr><tr><td>Stereotaxic frame</td><td>Stoelting</td><td>51600</td><td>Surgery</td></tr><tr><td>Stereotaxic manipulator</td><td>Stoelting</td><td>51600</td><td>Baseplate Attachment</td></tr></tbody></table>

successful in vivo calcium imaging with a head-mount miniaturized microscope in the amygdala of freely behaving mouse

Il monitoraggio in tempo reale in vivo delle attività neuronali negli animali che si muovono liberamente è uno degli approcci chiave per collegare l'attività neuronale al comportamento. A tal fine, è stata sviluppata e applicata con successo a molte strutture cerebrali1,2,3,4,5,6una tecnica di imaging in vivo che rileva i transitori di calcio nei neuroni utilizzando indicatori di calcio geneticamente codificati (GECI), un microscopio a fluorescenza miniaturizzata e una lente indice di rifrazione gradiente (GRIN). Questa tecnica di imaging è particolarmente potente perché consente l'imaging simultaneo cronico di popolazioni cellulari geneticamente definite per un periodo di lungo periodo fino a diverse settimane. Sebbene utile, questa tecnica di imaging non è stata facilmente applicata alle strutture cerebrali che si trovano in profondità nel cervello come l'amigdala, una struttura cerebrale essenziale per l'elaborazione emotiva e la memoria della pauraassociativa 7. Ci sono diversi fattori che rendono difficile l'applicazione della tecnica di imaging all'amigdala. Ad esempio, gli artefatti del movimento di solito si verificano più frequentemente durante l'imaging condotto nelle regioni cerebrali più profonde perché un microscopio a testa impiantato in profondità nel cervello è relativamente instabile. Un altro problema è che il ventricolo laterale è posizionato vicino alla lente GRIN impiantata e il suo movimento durante la respirazione può causare artefatti di movimento altamente irregolari che non possono essere facilmente corretti, il che rende difficile formare una vista di imaging stabile. Inoltre, poiché le cellule nell'amigdala sono solitamente silenziose in uno stato di riposo o anestetizzato, è difficile trovare e mettere a fuoco le cellule bersaglio che esprimono GECI nell'amigdala durante la procedura di base per l'imaging successivo. Questo protocollo fornisce una linea guida utile su come indirizzare in modo efficiente le cellule che esprimono GECI nell'amigdala con microscopio miniaturizzato a testa per un'imaging di calcio in vivo di successo in una regione cerebrale così profonda. Si noti che questo protocollo si basa su un particolare sistema (ad esempio, Inscopix) ma non limitato ad esso.

Convalida dell'impianto dell'obiettivo GRIN Prima di attaccare cronicamente la base al cervello cementando, l'impianto dell'obiettivo GRIN deve essere convalidato. Negli animali con impianto di lenti di successo, sia GCaMP che esprimono cellule e vasi sanguigni sono stati chiaramente osservati all'interno di un intervallo piana focale determinato dalla distanza tra lente oggettiva del microscopio e lente GRIN impiantata (Figura 2A e B). ...

Watch this Scientific Journal Video about Successful In vivo Calcium Imaging with a Head-Mount Miniaturized Microscope in the Amygdala of Freely Behaving Mouse at JoVE.com

Successful In vivo Calcium Imaging with a Head-Mount Miniaturized Microscope in the Amygdala of Freely Behaving Mouse

L'imaging microendoscopico in vivo del calcio è uno strumento inestimabile che consente il monitoraggio in tempo reale delle attività neuronali negli animali che si comportano liberamente. Tuttavia, l'applicazione di questa tecnica all'amigdala è stata difficile. Questo protocollo mira a fornire una linea guida utile per indirizzare con successo le cellule di amigdala con un microscopio miniaturizzato nei topi.

Imaging di calcio in vivo di successo con un microscopio miniaturizzato head-mount nell'amigdala del topo che si comporta liberamente

In vivo real-time monitoring of neuronal activities in freely moving animals is one of key approaches to link neuronal activity to behavior. For this ...

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Neuroscience

12.0K Views.  Korea Advanced Institute of Science and Technology (KAIST). L'imaging microendoscopico in vivo del calcio è uno strumento inestimabile che consente il monitoraggio in tempo reale delle attività neuronali negli animali che si comportano liberamente. Tuttavia, l'applicazione di questa tecnica all'amigdala è stata difficile. Questo protocollo mira a fornire una linea guida utile per indirizzare con successo le cellule di amigdala con un microscopio miniaturizzato nei topi.

Video: Successful In vivo Calcium Imaging with a Head-Mount Miniaturized Microscope in the Amygdala of Freely Behaving Mouse

Two-photon Calcium Imaging in Mice Navigating a Virtual Reality Environment

In recent years, two-photon imaging has become an invaluable tool in neuroscience, as it allows for chronic measurement of the activity of genetically identified cells during behavior1-6. Here we describe methods to perform two-photon imaging in mouse cortex while the animal navigates a virtual reality environment. We focus on the aspects of the experimental procedures that are key to imaging in a behaving animal in a brightly lit virtual environment. The key problems that arise in this experimental setup that we here address are: minimizing brain motion related artifacts, minimizing light leak from the virtual reality projection system, and minimizing laser induced tissue damage. We also provide sample software to control the virtual reality environment and to do pupil tracking. With these procedures and resources it should be possible to convert a conventional two-photon microscope for use in behaving mice.

Here we describe the experimental procedures involved in two-photon imaging of mouse cortex during behavior in a virtual reality environment.

Due fotoni Imaging di calcio in topi Navigazione una realtà ambiente virtuale

In recent years, two-photon imaging has become an invaluable tool in neuroscience, as it allows for chronic measurement of the activity of genetically ...

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Comportamento

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 Imaging del calcio nell'oliva inferiore del topo

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 ...

Neuroscienze

Craniotomy Procedure for Visualizing Neuronal Activities in Hippocampus of Behaving Mice

Imaging neuronal activities at single-cell resolution in awake behaving animals is a very powerful approach for the investigation of neural circuit functions in systems neuroscience. However, high absorbance and scattering of light in mammalian tissue limit intravital imaging mostly to superficial brain regions, leaving deep-brain areas, such as the hippocampus, out of reach for optical microscopy. In this video, we show the preparation and implantation of the custom-made imaging window to enable chronic in vivo imaging of the dorsal hippocampal CA1 region in head-fixed behaving mice. The custom-made window is supplemented with an infusion cannula that allows targeted delivery of viral vectors and drugs to the imaging area. By combining this preparation with wide-field imaging, we performed a long-term recording of neuronal activity using a fluorescent calcium indicator from large subsets of neurons in behaving mice over several weeks. We also demonstrated the applicability of this preparation for voltage imaging with single-spike resolution. High-performance genetically encoded indicators of neuronal activity and scientific CMOS cameras allowed the recurrent visualization of subcellular morphological details of single neurons at high temporal resolution. We also discuss the advantages and potential limitations of the described method and its compatibility with other imaging techniques.

This article demonstrates the preparation of a custom-made imaging window supplemented with infusion cannula and its implantation onto the CA1 region of the hippocampus in mice.

Procedura craniotomia per la visualizzazione delle attività neuronali nell'ippocampo dei topi che si comportano

Imaging neuronal activities at single-cell resolution in awake behaving animals is a very powerful approach for the investigation of neural circuit ...

Implantation of a Cranial Window for Repeated In Vivo Imaging in Awake Mice

To fully understand the cellular physiology of neurons and glia in behaving animals, it is necessary to visualize their morphology and record their activity in vivo in behaving mice. This paper describes a method for the implantation of a chronic cranial window to allow for the longitudinal imaging of brain cells in awake, head-restrained mice. In combination with genetic strategies and viral injections, it is possible to label specific cells and regions of interest with structural or physiological markers. This protocol demonstrates how to combine viral injections to label neurons in the vicinity of GCaMP6-expressing astrocytes in the cortex for simultaneous imaging of both cells through a cranial window. Multiphoton imaging of the same cells can be performed for days, weeks, or months in awake, behaving animals. This approach provides researchers with a method for viewing cellular dynamics in real time and can be applied to answer a number of questions in neuroscience.

Implantation of a Cranial Window for Repeated In Vivo Imaging in Awake Mice

Presented here is a protocol for the implantation of a chronic cranial window for the longitudinal imaging of brain cells in awake, head-restrained mice.

Impianto di una finestra cranica per l'imaging ripetuto in vivo in topi svegli

To fully understand the cellular physiology of neurons and glia in behaving animals, it is necessary to visualize their morphology and record their ...

Stereotaxic Viral Injection and Gradient-Index Lens Implantation for Deep Brain In Vivo Calcium Imaging

A miniature fluorescence microscope (miniscope) is a potent tool for in vivo calcium imaging from freely behaving animals. It offers several advantages over conventional multi-photon calcium imaging systems: (1) compact; (2) light-weighted; (3) affordable; and (4) allows recording from freely behaving animals. This protocol describes brain surgeries for deep brain in vivo calcium imaging using a custom-developed miniscope recording system. The preparation procedure consists of three steps, including (1) stereotaxically injecting the virus at the desired brain region of a mouse brain to label a specific subgroup of neurons with genetically encoded calcium sensor; (2) implantation of gradient-index (GRIN) lens that can relay calcium image from deep brain region to the miniscope system; and (3) affixing the miniscope holder over the mouse skull where miniscope can be attached later. To perform in vivo calcium imaging, the miniscope is fastened onto the holder, and neuronal calcium images are collected along with simultaneous behavior recordings. The present surgery protocol is compatible with any commercial or custom-built single-photon and two-photon imaging systems for deep brain in vivo calcium imaging.

Stereotaxic Viral Injection and Gradient-Index Lens Implantation for Deep Brain In Vivo Calcium Imaging

Miniscope in vivo calcium imaging is a powerful technique to study neuronal dynamics and microcircuits in freely behaving mice. This protocol describes performing brain surgeries to achieve good in vivo calcium imaging using a miniscope.

Iniezione virale stereotassica e impianto di lenti con indice di gradiente per l'imaging del calcio in vivo nel cervello profondo

A miniature fluorescence microscope (miniscope) is a potent tool for in vivo calcium imaging from freely behaving animals. It offers several advantages ...

Simultaneous Imaging of Microglial Dynamics and Neuronal Activity in Awake Mice

Since brain functions are under the continuous influence of the signals derived from peripheral tissues, it is critical to elucidate how glial cells in the brain sense various biological conditions in the periphery and transmit the signals to neurons. Microglia, immune cells in the brain, are involved in synaptic development and plasticity. Therefore, the contribution of microglia to neural circuit construction in response to the internal state of the body should be tested critically by intravital imaging of the relationship between microglial dynamics and neuronal activity.
Here, we describe a technique for the simultaneous imaging of microglial dynamics and neuronal activity in awake mice. Adeno-associated virus encoding R-CaMP, a gene-encoded calcium indicator of red fluorescence protein, was injected into layer 2/3 of the primary visual cortex in CX3CR1-EGFP transgenic mice expressing EGFP in microglia. After viral injection, a cranial window was installed onto the brain surface of the injected region. In vivo two-photon imaging in awake mice 4 weeks after the surgery demonstrated that neural activity and microglial dynamics could be recorded simultaneously at the sub-second temporal resolution. This technique can uncover the coordination between microglial dynamics and neuronal activity, with the former responding to peripheral immunological states and the latter encoding the internal brain states.

Here, we describe a protocol combining adeno-associated virus injection with cranial window implantation for simultaneous imaging of microglial dynamics and neuronal activity in awake mice.

Imaging simultaneo delle dinamiche microgliali e dell'attività neuronale in topi svegli

Since brain functions are under the continuous influence of the signals derived from peripheral tissues, it is critical to elucidate how glial cells in ...

In Vivo Wide-Field and Two-Photon Calcium Imaging from a Mouse Using a Large Cranial Window

Wide-field calcium imaging from the mouse&#39;s neocortex allows one to observe cortex-wide neural activity related to various brain functions. On the other hand, two-photon imaging can resolve the activity of local neural circuits at the single-cell level. It is critical to make a large cranial window to perform multiple-scale analysis using both imaging techniques in the same mouse. To achieve this, one must remove a large section of the skull and cover the exposed cortical surface with transparent materials. Previously, glass skulls and polymer-based cranial windows have been developed for this purpose, but these materials are not easily fabricated. The present protocol describes a simple method for making a large cranial window consisting of commercially available polyvinylidene chloride (PVDC) wrapping film, a transparent silicone plug, and a cover glass. For imaging the dorsal surface of an entire hemisphere, the window size was approximately 6 x 3 mm2. Severe brain vibrations were not observed regardless of such a large window. Importantly, the condition of the brain surface did not deteriorate for more than one month. Wide-field imaging of a mouse expressing a genetically-encoded calcium indicator (GECI), GCaMP6f, specifically in astrocytes, revealed synchronized responses in a few millimeters. Two-photon imaging of the same mouse showed prominent calcium responses in individual astrocytes over several seconds. Furthermore, a thin layer of an adeno-associated virus was applied to the PVDC film and successfully expressed GECI in cortical neurons over the cranial window. This technique is reliable and cost-effective for making a large cranial window and facilitates the investigation of the neural and glial dynamics and their interactions during behavior at the macroscopic and microscopic levels.

In Vivo Wide-Field and Two-Photon Calcium Imaging from a Mouse Using a Large Cranial Window

The present protocol describes making a large (6 x 3 mm2) cranial window using food wrap, transparent silicone, and cover glass. This cranial window allows in vivo wide-field and two-photon calcium imaging experiments in the same mouse.

In vivo Imaging del calcio a campo largo e a due fotoni da un topo utilizzando una grande finestra cranica

Wide-field calcium imaging from the mouse&#39;s neocortex allows one to observe cortex-wide neural activity related to various brain functions. On the ...

Subcellular Imaging of Neuronal Calcium Handling In Vivo

Calcium (Ca2+) imaging has been largely used to examine neuronal activity, but it is becoming increasingly clear that subcellular Ca2+ handling is a crucial component of intracellular signaling. The visualization of subcellular Ca2+ dynamics in vivo,&#160;where neurons can be studied in their native, intact circuitry, has proven technically challenging in complex nervous systems. The transparency and relatively simple nervous system of the nematode Caenorhabditis elegans enable the cell-specific expression and in vivo visualization of fluorescent tags and indicators. Among these are fluorescent indicators that have been modified for use in the cytoplasm as well as various subcellular compartments, such as the mitochondria. This protocol enables non-ratiometric Ca2+ imaging in vivo with a subcellular resolution that permits the analysis of Ca2+ dynamics down to the level of individual dendritic spines and mitochondria. Here, two available genetically encoded indicators with different Ca2+ affinities are used to demonstrate the use of this protocol for measuring relative Ca2+ levels within the cytoplasm or mitochondrial matrix in a single pair of excitatory interneurons (AVA). Together with the genetic manipulations and longitudinal observations possible in C. elegans, this imaging protocol may be useful for answering questions regarding how Ca2+ handling regulates neuronal function and plasticity.

Subcellular Imaging of Neuronal Calcium Handling In Vivo

The current methods describe a non-ratiometric approach for high-resolution, sub-compartmental calcium imaging in vivo in Caenorhabditis elegans using readily available genetically encoded calcium indicators.

Imaging subcellulare della manipolazione neuronale del calcio in vivo

Calcium (Ca2+) imaging has been largely used to examine neuronal activity, but it is becoming increasingly clear that subcellular Ca2+ handling is a ...

Imaging a due fotoni e calcio ad ampio campo nel collicolo superiore

Calcium Imaging in Mouse Superior Colliculus

The superior colliculus (SC), an evolutionarily conserved midbrain structure in all vertebrates, is the most sophisticated visual center before the emergence of the cerebral cortex. It receives direct inputs from ~30 types of retinal ganglion cells (RGCs), with each encoding a specific visual feature. It remains elusive whether the SC simply inherits retinal features or if additional and potentially de novo processing occurs in the SC. To reveal the neural coding of visual information in the SC, we provide here a detailed protocol to optically record visual responses with two complementary methods in awake mice. One method uses two-photon microscopy to image calcium activity at single-cell resolution without ablating the overlaying cortex, while the other uses wide-field microscopy to image the whole SC of a mutant mouse whose cortex is largely undeveloped. This protocol details these two methods, including animal preparation, viral injection, headplate implantation, plug implantation, data acquisition, and data analysis. The representative results show that the two-photon calcium imaging reveals visually evoked neuronal responses at single-cell resolution, and the wide-field calcium imaging reveals&#160;neural activity across the entire SC. By combining these two methods, one can reveal the neural coding in the SC at different scales, and such combination can also be applied to other brain regions.

Autore in primo piano: Svelare la codifica neurale e i meccanismi di elaborazione visiva nel collicolo superiore 

This protocol details the procedure for imaging calcium responses in the superior colliculus (SC) of awake mice, including imaging single-neuron activity with two-photon microscopy while leaving the cortex intact in wild-type mice, and imaging the entire SC with wide-field microscopy in partial-cortex mutant mice.

Imaging del calcio nel collicolo superiore del topo

The superior colliculus (SC), an evolutionarily conserved midbrain structure in all vertebrates, is the most sophisticated visual center before the ...

Imaging di calcio in vivo di successo con un microscopio miniaturizzato head-mount nell'amigdala del topo che si comporta liberamente

Riepilogo

Esplora Altri Video

Capitoli in questo video

Due fotoni Imaging di calcio in topi Navigazione una realtà ambiente virtuale

In vivo Imaging del calcio nell'oliva inferiore del topo

Procedura craniotomia per la visualizzazione delle attività neuronali nell'ippocampo dei topi che si comportano

Impianto di una finestra cranica per l'imaging ripetuto in vivo in topi svegli

Iniezione virale stereotassica e impianto di lenti con indice di gradiente per l'imaging del calcio in vivo nel cervello profondo

Imaging simultaneo delle dinamiche microgliali e dell'attività neuronale in topi svegli

In vivo Imaging del calcio a campo largo e a due fotoni da un topo utilizzando una grande finestra cranica

Imaging subcellulare della manipolazione neuronale del calcio in vivo

Imaging del calcio nel collicolo superiore del topo

Imaging del calcio nel collicolo superiore del topo