Questo lavoro è stato sostenuto dalla prova UC Discovery di concessione Concept e dal NIH (R00 EB007241). Gli autori desiderano inoltre ringraziare Jacqueline Hubbard per la sua assistenza in questo esperimento.

1. Preparazione chirurgica <ol><li> Femmina CD 1 topi di età compresa tra 6-8 settimane sono state utilizzate nei nostri esperimenti. </li><li> Anestetizzare il mouse con una iniezione intraperitoneale di una combinazione di chetamina e xilazina (80 mg / kg ketamine/10 mg / kg xilazina). Posizionare il mouse su un tappetino omeotermi per garantire una temperatura ottimale del corpo a ~ 37 ° C. Monitorare costantemente il livello di anestesia testando riflessi dell&#39;animale (ad esempio, pizzicando piedi con una pinza smussati) e iniettare più l&#39;anestesia in caso di necessità. </li><li> Lubrificare entrambi gli occhi con un unguento lacrima artificiale. Rimuovere i peli sul cuoio capelluto con un rasoio e rimuovere i capelli residui usa il 70% di preparazione tamponi di alcol. Applicare uno strato sottile di crema di rimozione dei capelli Nair sul cuoio capelluto e attendere 2 minuti per esso abbia effetto. Pulire delicatamente via i capelli Nair e rimanente utilizzando tamponi di cotone inumiditi salina e pastiglie di preparazione alcol. Cuoio capelluto dovrebbe ora essere completamente glabro. </li><li> Disinfezione cuoio capelluto con un bastone betadine tampone e pulire con 70% etanolo preparazione pastiglie. </li><li> Avvolgete l&#39;animale in teli chirurgici per garantire una temperatura ottimale del corpo di ~ 37 ° C e montare l&#39;animale su un telaio stereotassico per immobilizzare il cranio. Battere leggermente il cranio per garantirne la stabilità. Un elenco di materiali utilizzati sono fornite nella Tabella 1. </li></ol> 2. Diluito-cranio Preparazione finestra corticale <ol><li> Avviare l&#39;incisione nel punto mediano tra gli occhi. Continua caudalmente al punto linea mediana tra le orecchie. Parte la pelle con una pinza. </li><li> Individuare l&#39;area deve essere diluito con un microscopio da dissezione e rimuovere delicatamente la fascia con una pinzetta. Asciugare il cranio con tamponi di cotone sterili prima di creare la finestra corticale assottigliata. Nei nostri esperimenti, abbiamo creato un 4 × 4 mm diluito cranica finestra ~ 1 mm posteriormente e lateralmente al bregma. </li><li> Cominci a diventare calvo cranio con un rotondo fresa in carburo di dimensioni punta 0,75 millimetri in un trapano a mano chirurgica utilizzando la luce onl travolgente movimentoy. Non applicare una pressione diretta sul cranio. Interrompere il fresaggio ogni 20-30 secondi per rimuovere la polvere osseo con soluzione salina sterile e tamponi di cotone e per evitare surriscaldamento del cranio. La soluzione salina aiuterà anche a dissipare il calore in tutto il cranio. </li><li> Una volta che lo strato esterno di osso compatto viene completamente rimosso lo strato centrale dell&#39;osso spugnoso dovrebbe essere visibile. Ci può essere qualche leggero sanguinamento da vasi sanguigni sono più evidenti nello strato osso spugnoso. Passare a una fresa pietra verde e continua che si esercita con cautela come strato spugnoso è più delicata. La fresa pietra verde sarà rimuovere il materiale meno osso creando uniformità in tutta la finestra del cranio. Interrompere il fresaggio di tanto in tanto per rimuovere la polvere delle ossa e per raffreddare il cranio. </li><li> Infine, quando il cranio è diventato più trasparente e vascolarizzazione del cervello è ora visibile, iniziare la lucidatura del cranio con una fresa di lucidatura. Ciò consentirà una più precisa assottigliamento mentre lisciandosi il cranio. Controllare magrezza del skull picchiettando delicatamente su di esso con una pinza. Arrestare lucidatura quando il cranio diventa leggermente flessibile. </li><li> La finestra diluito cranica dovrebbe essere completamente liscia e riflettente e pronto per l&#39;imaging (Figura 1). A causa della natura dei tessuti altamente diffondenti del cervello, il cranio deve essere diluito ad almeno 55 micron di profondità di penetrazione ottimale. Un elenco di materiali utilizzati sono fornite nella Tabella 1. </li></ol> 3. Tomografia a coerenza ottica Imaging <ol><li> Dopo l&#39;intervento chirurgico è completa, controllare la frequenza respiratoria dell&#39;animale e riflessi di garantire adeguato livello di anestesia e somministrare l&#39;anestesia supplementari, se necessario. Rimuovere animale dal telaio stereotassico, tenere animale avvolto in teli chirurgici, e degli animali il trasporto alla stazione di imaging. </li><li> Prima di controllare i segni di imaging per i riflessi e applicare ulteriori lacrima artificiale se necessario. Animale montare sul telaio stereotassico per fissare il cranio. </li><li> Luogo animale inOttobre fotocamera e la posizione TSCW sotto il fascio ottico (Figura 2). Una vista in sezione trasversale del cranio e cervello può ora essere visualizzati (Figura 3). </li><li> L&#39;acquisizione dei dati può iniziare un tempo area di interesse si trova. Per scopi di imaging, usiamo specchi galvanometrica per ottenere una finestra di imaging con una larghezza di 4,0 mm. Una profondità di 2 mm di imaging è stato ottenuto con 6 mW di potenza incidente e un punto focale 1 mm sotto il cranio assottigliato. Ogni sezione trasversale costituita da 2.048 scansioni assiali con un tasso di acquisizione di 0,14 sec per immagine. </li><li> Scansioni volumetriche del cervello può anche essere ottenuta raccogliendo una serie di 2D immagini trasversali mediante due serie di specchi per Galvo xy scansione con il primo specchio galvo scansione del fascio nella direzione sagittale e il secondo specchio di scansione galvanometrica nel coronale direzione. </li></ol>

<ol>
	<li>Bizheva, K., Unterhuber, A., Hermann, B., Povazay, B., Sattmann, H., Drexler, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+ex+vivo+and+in+vitro+brain+morphology+in+animal+models+with+ultrahigh+resolution+optical+coherence+tomography.">Imaging ex vivo and in vitro brain morphology in animal models with ultrahigh resolution optical coherence tomography.</a> Journal of Biomedical Optics. 9, 719-724 (2004).</li><li>Fujimoto, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+coherence+tomography+for+ultrahigh+resolution+in+vivo+imaging.">Optical coherence tomography for ultrahigh resolution in vivo imaging.</a> Nature Biotechnology. 21, 1361-1367 (2003).</li><li>Wantanabe, H., Rajagopalan, U. M., Nakamichi, Y., Igarashi, K. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensitivity+advantage+of+swept+source+and+fourier+domain+optical+coherence+tomography.">Sensitivity advantage of swept source and fourier domain optical coherence tomography.</a> Optics Express. 11, 2183-2189 (2003).</li><li>Leitgeb, R. A., Drexler, W., Unterhuber, A., Hermann, B., Bajraszewski, T., Le, T., Stingl, A., Fercher, A. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrahigh+resolution+fourier+domain+optical+coherence+tomography.">Ultrahigh resolution fourier domain optical coherence tomography.</a> Optics Express. 12, 2156-2165 (2004).</li><li>Drew, P. J., Shih, A. Y., Driscoll, J. D., Knutsen, P. M., Blinder, P., Davalos, D., Akassoglou, K., Tsai, P. 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H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GPU+accelerated+real-time+multi-functional+spectral-domain+optical+coherence+tomography+system+at+1300nm.">GPU accelerated real-time multi-functional spectral-domain optical coherence tomography system at 1300nm.</a> Optics Express. 20, 14797-14813 (2012).</li><li>Aguirre, A. D., Chen, Y., Fujimoto, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Depth-resolved+imaging+of+functional+activation+in+the+rat+cerebral+cortex+using+optical+coherence+tomography.">Depth-resolved imaging of functional activation in the rat cerebral cortex using optical coherence tomography.</a> Opt. Lett. 31, 3459-3461 (2006).</li><li>Chen, Y., Aguirre, A. D., Ruvinskaya, L., Devor, A., Boas, D. A., Fujimoto, J. 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Nessun conflitto di interessi dichiarati.

Imaging con OCT e assottigliato-teschio è un romanzo neuro-imaging tecnica che è solo stato recentemente studiato 15, 16. Nei nostri esperimenti, abbiamo dimostrato la fattibilità di SD-OCT immagini attraverso un TSCW in un modello di topo in vivo. Dai risultati ottenuti, il cranio è assottigliata a circa 55 micron e la profondità di penetrazione è ottenuta a circa 1 mm con risoluzione di immagine di 8 um e 20 um in direzione assiale e laterale, rispettivamente. Nel profilo di intensità di seg...

Dalla sua introduzione nei primi anni del 1990, ottobre è stato ampiamente utilizzato per l&#39;imaging biologico della struttura dei tessuti e la funzione 2. Ottobre genera immagini in sezione trasversale misurando il tempo di ritardo dell&#39;eco di 4 luce riflessa mediante l&#39;attuazione di bassa coerenza con sorgente di luce a fibre ottiche 2,4 interferometro di Michelson. SD-OCT, noto anche come dominio di Fourier ottobre (FD-OCT), è stato introdotto nel 1995 5 e offre una modalità di imaging superiore rispetto alla tradizionale dominio del tempo OCT (TD-OCT). In SD-ottobre, il braccio di riferimento viene mantenuto fermo con conseguente alta velocità e ad altissima risoluzione di acquisizione dell&#39;immagine 6-9. Attualmente, i modelli TSCW sono stati ampiamente utilizzati in applicazioni per brain imaging in vivo di due fotoni microscopia in luogo di una craniotomia tradizionale. Questi TSCW sono stati utilizzati in concomitanza con un piatto cranio personalizzato o un foglio di copertura in vetro 10-13 per fornire ulteriori imaging stabilità. Nei nostri studi, abbiamo osservato che gli accessori come questi non sono necessari per l&#39;imaging ottobre quando un TSCW viene utilizzato. Pertanto, la mancanza di una piastra cranio o vetrini di vetro consente una più ampia gamma di dimensioni di imaging finestra in quanto potrebbero interferire con il fascio ottico e modificare immagini ottobre A assottigliata-cranio preparazione ha dimostrato di essere vantaggioso in studi di imaging del cervello utilizzando due fotoni microscopia 10-13. Nei nostri esperimenti, ci avvaliamo di un sistema SD-OCT per l&#39;immagine del corteccia in vivo attraverso un TSCW. La nostra misura SD-OCT installazione di imaging contiene una, la banda larga a bassa coerenza sorgente luminosa costituita da due diodi superluminescenti (SLD) centrato a 1295 nm con una larghezza di banda di 97 nm con un conseguente risoluzione assiale e laterale di 8 micron e 20 micron, rispettivamente 14 . Con il nostro dispositivo di imaging ottico, prevediamo che l&#39;imaging attraverso un TSCW ha un grande potenziale per individuare e visualizzare le strutture e le funzioni in otessuti del cervello ptically denso.

<table border="1"><tbody><tr><td> Materiale </td><td> Azienda </td><td> Numero di catalogo </td><td> Commenti </td></tr><tr><td> Ketamina </td><td> Phoenix Pharmaceuticals </td><td> 57319-542-02 </td><td></td></tr><tr><td> Xylazina </td><td> Akorn, Inc. </td><td> 139-236 </td><td></td></tr><tr><td> Artificial Tears Unguento </td><td> Rugby </td><td> 0536-6550-91 </td><td></td></tr><tr><td> Nair </td><td> Church &amp; Dwight Co., Inc. </td><td> 4010130 </td><td></td></tr><tr><td> Alcool sterile Prep Pad </td><td> Kendall Healthcare </td><td> 6818 </td><td></td></tr><tr><td> Cotone Tipped Applicatori </td><td> FISHERBRAND </td><td> 23-400-115 </td><td></td></tr><tr><td> Betadine Soluzione Swabstick </td><td> Purdue Prodotti &lt;/ Td&gt; <td> 67618-153-01 </td><td></td></tr><tr><td> Soluzione salina, 0,9% </td><td> Phoenix Pharmaceuticals </td><td> 57319-555-08 </td><td></td></tr><tr><td> Stereotassica Telaio </td><td> Stoelting </td><td></td><td></td></tr><tr><td> Trapano a mano ad alta velocità chirurgica </td><td> Foredom </td><td></td><td> 38.000 rpm </td></tr><tr><td> Carbide rotonda Bur </td><td> Stoelting </td><td></td><td> 0,75 millimetri </td></tr><tr><td> Dura-verdi Pietre </td><td> Shofu </td><td></td><td> Shank: HP Forma: BA1 </td></tr><tr><td> CompoMaster grossa &amp; CompoMaster Lucidatore </td><td> Shofu </td><td></td><td> Forma: Mini-Pt. </td></tr><tr><td> SpaceDrapes </td><td> Braintree Scientific, Inc. </td><td></td><td></td></tr></tbody></table>

thinned-skull cortical window technique for in vivo optical coherence tomography imaging

Tomografia a coerenza ottica (OCT) è una tecnica di imaging biomedico ad alta risoluzione spazio-temporale. Con il suo approccio mini-invasivo ottobre è stato ampiamente utilizzato in oftalmologia, dermatologia, gastroenterologia e 1-3. Utilizzando una finestra assottigliata cranio-corticale (TSCW), ci avvaliamo di spectral-domain OCT (SD-OCT) modalità come strumento per l&#39;immagine della corteccia in vivo. Comunemente, un aperto-cranio è stato utilizzato per neuro-imaging in quanto fornisce una maggiore versatilità, tuttavia, un approccio TSCW è meno invasiva ed è un mezzo efficace per l&#39;imaging lungo termine in studi neuropatologia. Qui, presentiamo un metodo per creare un TSCW in un modello di topo per l&#39;imaging in vivo ottobre della corteccia cerebrale.

Dopo aver creato una finestra assottigliata sulla corteccia cerebrale vascolarizzazione dovrebbe essere ora evidenziare visivamente (Figura 1) e consentirà una profondità di imaging profondo (fino a 1 mm). La corteccia destra viene diluito a circa 55 micron, rispetto ad un teschio normale misurato a 140 micron (Figura 1) e fornisce maggiore chiarezza ottica. Ulteriori diradamento a 10-15 micron è possibile 11 Non occorre tuttavia che l&#39;uso di vetrini in vetro e piastre...

Watch this Scientific Journal Video about Thinned-skull Cortical Window Technique for In Vivo Optical Coherence Tomography Imaging at JoVE.com

Thinned-skull Cortical Window Technique for In Vivo Optical Coherence Tomography Imaging

Vi presentiamo un metodo per creare un assottigliata-teschio finestra corticale (TSCW) in un modello di topo per<em&gt; In vivo</em&gt; Ottobre immagini della corteccia cerebrale.

Diluito-cranio Tecnica finestra corticale per<em&gt; In Vivo</em&gt; Tomografia a coerenza ottica Imaging

Optical coherence tomography (OCT) is a biomedical imaging technique  with high spatial-temporal resolution. With its minimally invasive approach OCT  has ...

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Neuroscience

Thinned-skull Cortical Window Technique for In Vivo Optical Coherence Tomography Imaging

15.1K Views.  University of California, Riverside. Vi presentiamo un metodo per creare un assottigliata-teschio finestra corticale (TSCW) in un modello di topo per In vivo Ottobre immagini della corteccia cerebrale.

Video: Thinned-skull Cortical Window Technique for In Vivo Optical Coherence Tomography Imaging

A Thin-skull Window Technique for Chronic Two-photon In vivo Imaging of Murine Microglia in Models of Neuroinflammation

Traditionally in neuroscience, in vivo two photon imaging of the murine central nervous system has either involved the use of open-skull1,2 or thinned-skull 3 preparations. While the open-skull technique is very versatile, it is not optimal for studying microglia because it is invasive and can cause microglial activation. Even though the thinned-skull approach is minimally invasive, the repeated re-thinning of skull required for chronic imaging increases the risks of tissue injury and microglial activation and allows for a limited number of imaging sessions. Here we present a chronic thin-skull window method for monitoring murine microglia in vivo over an extended period of time using two-photon microscopy. We demonstrate how to prepare a stable, accessible, thinned-skull cortical window (TSCW) with an apposed glass coverslip that remains translucent over the course of three weeks of intermittent observation. This TSCW preparation is far more immunologically inert with respect to microglial activation than open craniotomy or repeated skull thinning and allows an arbitrary number of imaging sessions during a time period of weeks. We prepare TSCW in CX3CR1 GFP/+ mice 4 to visualize microglia with enhanced green fluorescent protein to &le;150 &mu;m beneath the pial surface. We also show that this preparation can be used in conjunction with stereotactic brain injections of the HIV-1 neurotoxic protein Tat, adjacent to the TSCW, which is capable of inducing durable microgliosis. Therefore, this method is extremely useful for examining changes in microglial morphology and motility over time in the living brain in models of HIV Associated Neurocognitive Disorder (HAND) and other neurodegenerative diseases with a neuroinflammatory component.

A Thin-skull Window Technique for Chronic Two-photon In vivo Imaging of Murine Microglia in Models of Neuroinflammation

We describe a method for repeatedly visualizing murine microglia and circulating monocytes in vivo over hours, days or weeks using transcranial two-photon microscopy. We demonstrate how to prepare a thinned-skull window that allows intermittent observation of quiescent microglia that can be activated by adjacent stereotactic injection of the HIV-1 regulatory protein Tat.

Un sottile cranio Tecnica Finestra per cronica a due fotoni In vivo</emImaging> della microglia nei modelli murini di neuroinfiammazione

Traditionally in neuroscience, in vivo two photon imaging of the murine central nervous system has either involved the use of open-skull1,2 or ...

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Neuroscienze

Chronic Imaging of Mouse Visual Cortex Using a Thinned-skull Preparation

In vivo imaging using two-photon laser scanning microscopy (2PLSM) allows the study of living cells and neuronal processes in the intact brain. The technique presented here allows the imaging of the same area of the brain at several time points (chronic imaging) with microscopic resolution allowing the tracking of dendritic spines which are the small structures that represent the majority of postsynaptic excitatory sites in the CNS. The ability to clearly resolve fine cortical structures over several time points has many advantages, specifically in the study of brain plasticity in which morphological changes at synapses and circuit remodeling may help explain underlying mechanisms. In this video and supplementary material, we show a protocol for chronic in vivo imaging of the intact brain using a thinned-skull preparation. The thinned-skull preparation is a minimally invasive approach, which avoids potential damage to the dura and/or cortex, thus reducing the onset of an inflammatory response. When this protocol is performed correctly, it is possible to clearly monitor changes in dendritic spine characteristics in the intact brain over a prolonged period of time.

In this video and supplemental material, we show a protocol for chronic in vivo imaging of the intact brain using a thinned-skull preparation.

Imaging cronica di mouse corteccia visiva Utilizzando un Assottigliato-teschio di preparazione

In vivo imaging using two-photon laser scanning microscopy (2PLSM) allows the study of living cells and neuronal processes in the intact brain. The ...

A Polished and Reinforced Thinned-skull Window for Long-term Imaging of the Mouse Brain

In vivo imaging of cortical function requires optical access to the brain without disruption of the intracranial environment. We present a method to form a polished and reinforced thinned skull (PoRTS) window in the mouse skull that spans several millimeters in diameter and is stable for months. The skull is thinned to 10 to 15 &mu;m in thickness with a hand held drill to achieve optical clarity, and is then overlaid with cyanoacrylate glue and a cover glass to: 1) provide rigidity, 2) inhibit bone regrowth and 3) reduce light scattering from irregularities on the bone surface. Since the skull is not breached, any inflammation that could affect the process being studied is greatly reduced. Imaging depths of up to 250 &mu;m below the cortical surface can be achieved using two-photon laser scanning microscopy. This window is well suited to study cerebral blood flow and cellular function in both anesthetized and awake preparations. It further offers the opportunity to manipulate cell activity using optogenetics or to disrupt blood flow in targeted vessels by irradiation of circulating photosensitizers.

We present a method to form an imaging window in the mouse skull that spans millimeters and is stable for months without inflammation of the brain. This method is well suited for longitudinal studies of blood flow, cellular dynamics, and cell/vascular structure using two-photon microscopy.

Un lucido e rinforzato Assottigliato cranio-Window a lungo termine Imaging del cervello di topo

In vivo imaging of cortical function requires optical access to the brain without disruption of the intracranial environment. We present a method to form ...

In Vivo Two-photon Imaging Of Experience-dependent Molecular Changes In Cortical Neurons

The brain's ability to change in response to experience is essential for healthy brain function, and abnormalities in this process contribute to a variety of brain disorders1,2. To better understand the mechanisms by which brain circuits react to an animal's experience requires the ability to monitor the experience-dependent molecular changes in a given set of neurons, over a prolonged period of time, in the live animal. While experience and associated neural activity is known to trigger gene expression changes in neurons1,2, most of the methods to detect such changes do not allow repeated observation of the same neurons over multiple days or do not have sufficient resolution to observe individual neurons3,4. Here, we describe a method that combines in vivo two-photon microscopy with a genetically encoded fluorescent reporter to track experience-dependent gene expression changes in individual cortical neurons over the course of day-to-day experience. 
One of the well-established experience-dependent genes is Activity-regulated cytoskeletal associated protein (Arc)5,6. The transcription of Arc is rapidly and highly induced by intensified neuronal activity3, and its protein product regulates the endocytosis of glutamate receptors and long-term synaptic plasticity7. The expression of Arc has been widely used as a molecular marker to map neuronal circuits involved in specific behaviors3. In most of those studies, Arc expression was detected by in situ hybridization or immunohistochemistry in fixed brain sections. Although those methods revealed that the expression of Arc was localized to a subset of excitatory neurons after behavioral experience, how the cellular patterns of Arc expression might change with multiple episodes of repeated or distinctive experiences over days was not investigated. 
In vivo two-photon microscopy offers a powerful way to examine experience-dependent cellular changes in the living brain8,9. To enable the examination of Arc expression in live neurons by two-photon microscopy, we previously generated a knock-in mouse line in which a GFP reporter is placed under the control of the endogenous Arc promoter10. This protocol describes the surgical preparations and imaging procedures for tracking experience-dependent Arc-GFP expression patterns in neuronal ensembles in the live animal. In this method, chronic cranial windows were first implanted in Arc-GFP mice over the cortical regions of interest. Those animals were then repeatedly imaged by two-photon microscopy after desired behavioral paradigms over the course of several days. This method may be generally applicable to animals carrying other fluorescent reporters of experience-dependent molecular changes4.

In Vivo Two-photon Imaging Of Experience-dependent Molecular Changes In Cortical Neurons

Experience-dependent molecular changes in neurons are essential for the brain's ability to adapt in response to behavioral challenges. An in vivo two-photon imaging method is described here that allows the tracking of such molecular changes in individual cortical neurons through genetically encoded reporters.

In Vivo a due fotoni di imaging dei cambi molecolari esperienza-dipendenti nei neuroni corticali

The brain's ability to change in response to experience is essential for healthy brain function, and abnormalities in this process contribute to a variety ...

Two-Photon in vivo Imaging of Dendritic Spines in the Mouse Cortex Using a Thinned-skull Preparation

In the mammalian cortex, neurons form extremely complicated networks and exchange information at synapses. Changes in synaptic strength, as well as addition/removal of synapses, occur in an experience-dependent manner, providing the structural foundation of neuronal plasticity. As postsynaptic components of the most excitatory synapses in the cortex, dendritic spines are considered to be a good proxy of synapses. Taking advantages of mouse genetics and fluorescent labeling techniques, individual neurons and their synaptic structures can be labeled in the intact brain. Here we introduce a transcranial imaging protocol using two-photon laser scanning microscopy to follow fluorescently labeled postsynaptic dendritic spines over time in vivo. This protocol utilizes a thinned-skull preparation, which keeps the skull intact and avoids inflammatory effects caused by exposure of the meninges and the cortex. Therefore, images can be acquired immediately after surgery is performed. The experimental procedure can be performed repetitively over various time intervals ranging from hours to years. The application of this preparation can also be expanded to investigate different cortical regions and layers, as well as other cell types, under physiological and pathological conditions.

Two-Photon in vivo Imaging of Dendritic Spines in the Mouse Cortex Using a Thinned-skull Preparation

Time-lapse imaging in the living animal provides valuable information on structural reorganization in the intact brain. Here, we introduce a thinned-skull preparation that allows transcranial imaging of fluorescently labeled synaptic structures in the living mouse cortex by two-photon microscopy.

Two-Photon<em&gt; In vivo</em&gt; Imaging di spine dendritiche nella corteccia mouse Uso un teschio Diluito-Preparazione

In the mammalian cortex, neurons form extremely complicated networks and exchange information at synapses. Changes in synaptic strength, as well as ...

Optical Coherence Tomography: Imaging Mouse Retinal Ganglion Cells In Vivo

Structural changes in the retina are common manifestations of ophthalmic diseases. Optical coherence tomography (OCT) enables their identification in vivo&#8212;rapidly, repetitively, and at a high resolution. This protocol describes OCT imaging in the mouse retina as a powerful tool to study optic neuropathies (OPN). The OCT system is an interferometry-based, non-invasive alternative to common post mortem histological assays. It provides a fast and accurate assessment of retinal thickness, allowing the possibility to track changes, such as retinal thinning or thickening. We present the imaging process and analysis with the example of the Opa1delTTAG mouse line. Three types of scans are proposed, with two quantification methods: standard and homemade calipers. The latter is best for use on the peripapillary retina during radial scans; being more precise, is preferable for analyzing thinner structures. All approaches described here are designed for retinal ganglion cells (RGC) but are easily adaptable to other cell populations. In conclusion, OCT is efficient in mouse model phenotyping and has the potential to be used for the reliable evaluation of therapeutic interventions.

Optical Coherence Tomography: Imaging Mouse Retinal Ganglion Cells In Vivo

This manuscript describes a protocol for the in vivo imaging of the mouse retina with high-resolution spectral domain optical coherence tomography (SD-OCT). It focuses on retinal ganglion cells (RGC) in the peripapillary region, with several scanning and quantifying approaches described.

Tomografia a coerenza ottica: Imaging Mouse ganglionari cellule In Vivo

Structural changes in the retina are common manifestations of ophthalmic diseases. Optical coherence tomography (OCT) enables their identification in ...

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 Due-fotone Imaging dei neuroni corticali in topi neonatali

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 ...

Retinal Vascular Reactivity as Assessed by Optical Coherence Tomography Angiography

The vascular supply to the retina has been shown to dynamically adapt through vasoconstriction and vasodilation to accommodate the metabolic demands of the retina. This process, referred to as retinal vascular reactivity (RVR), is mediated by neurovascular coupling, which is impaired very early in retinal vascular diseases such as diabetic retinopathy. Therefore, a clinically feasible method of assessing vascular function may be of significant interest in both research and clinical settings. Recently, in vivo imaging of the retinal vasculature at the capillary level has been made possible by the FDA approval of optical coherence tomography angiography (OCTA), a noninvasive, minimal risk and dyeless angiography method with capillary level resolution. Concurrently, physiological and pathological changes in RVR have been shown by several investigators. The method shown in this manuscript is designed to investigate RVR using OCTA with no need for alterations to the clinical imaging procedures or device. It demonstrates real time imaging of the retina and retinal vasculature during exposure to hypercapnic or hyperoxic conditions. The exam is easily performed with two personnel in under 30 min with minimal subject discomfort or risk. This method is adaptable to other ophthalmic imaging devices and the applications may vary based on the composition of the gas mixture and patient population. A strength of this method is that it allows for an investigation of retinal vascular function at the capillary level in human subjects in vivo. Limitations of this method are largely those of OCTA and other retinal imaging methods including imaging artifacts and a restricted dynamic range. The results obtained from the method are OCT and OCTA images of the retina. These images are amenable to any analysis that is possible on commercially available OCT or OCTA devices. The general method, however, can be adapted to any form of ophthalmic imaging.

This article describes a method for measuring retinal vasculature reactivity in vivo with human subjects using a gas breathing provocation technique to deliver vasoactive stimuli while acquiring retinal images.

Reattività vascolare retinica valutata dall'angiografia ottica sulla tomografia a coezione

The vascular supply to the retina has been shown to dynamically adapt through vasoconstriction and vasodilation to accommodate the metabolic demands of ...

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 ...

Imaging multimodale basato su OCT di occhi di donatori umani per la ricerca sull'AMD

Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration

A progression sequence for age-related macular degeneration (AMD) learned from optical coherence tomography (OCT)-based multimodal (MMI) clinical imaging could add prognostic value to laboratory findings. In this work, ex vivo OCT and MMI were applied to human donor eyes prior to retinal tissue sectioning. The eyes were recovered from non-diabetic white donors aged &#8805;80 years old, with a death-to-preservation time (DtoP) of &#8804;6 h. The globes were recovered on-site, scored with an 18 mm trephine to facilitate cornea removal, and immersed in buffered 4% paraformaldehyde. Color fundus images were acquired after anterior segment removal with a dissecting scope and an SLR camera using trans-, epi-, and flash illumination at three magnifications. The globes were placed in a buffer within a custom-designed chamber with a 60 diopter lens. They were imaged with spectral domain OCT (30&#176; macula cube, 30 &#181;m spacing, averaging = 25), near-infrared reflectance, 488 nm autofluorescence, and 787 nm autofluorescence. The AMD eyes showed a change in the retinal pigment epithelium (RPE), with drusen or subretinal drusenoid deposits (SDDs), with or without neovascularization, and without evidence of other causes. Between June 2016 and September 2017, 94 right eyes and 90 left eyes were recovered (DtoP: 3.9 &plusmn; 1.0 h). Of the 184 eyes, 40.2% had AMD, including early intermediate (22.8%), atrophic (7.6%), and neovascular (9.8%) AMD, and 39.7% had unremarkable maculas. Drusen, SDDs, hyper-reflective foci, atrophy, and fibrovascular scars were identified using OCT. Artifacts included tissue opacification, detachments (bacillary, retinal, RPE, choroidal), foveal cystic change, an undulating RPE, and mechanical damage. To guide the cryo-sectioning, OCT volumes were used to find the fovea and optic nerve head landmarks and specific pathologies. The ex vivo volumes were registered with the in vivo volumes by selecting the reference function for eye tracking. The ex vivo visibility of the pathology seen in vivo depends on the preservation quality. Within 16 months, 75 rapid DtoP donor eyes at all stages of AMD were recovered and staged using clinical MMI methods.

Autore in primo piano: Imaging multimodale ex vivo basato su OCT di occhi di donatori umani per la ricerca sulla degenerazione maculare legata all'età  

Laboratory assays can leverage prognostic value from the longitudinal optical coherence tomography (OCT)-based multimodal imaging of age-related macular degeneration (AMD). Human donor eyes with and without AMD are imaged using OCT, color, near-infrared reflectance scanning laser ophthalmoscopy, and autofluorescence at two excitation wavelengths prior to tissue sectioning.

Ex Vivo Imaging multimodale basato su OCT di occhi di donatori umani per la ricerca sulla degenerazione maculare legata all'età

A progression sequence for age-related macular degeneration (AMD) learned from optical coherence tomography (OCT)-based multimodal (MMI) clinical imaging ...