Ci piace riconoscere il National Institutes of Health e il National Institute of Neurological Disorders and Stroke per il finanziamento (R01NS079691).

<ol>
	<li>National Center for Health Statistics. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Health, United States, 2015: With Special Feature on Racial and Ethnic Health Disparities. , (2016).</li><li>Benjamin, E. 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=Heart+disease+and+stroke+statistics-2017+update:+a+report+from+the+American+Heart+Association.">Heart disease and stroke statistics-2017 update: a report from the American Heart Association.</a> Circulation. 135 (10), 229 (2017).</li><li>Rosamond, 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=Heart+Disease+and+Stroke+Statistics-2007+update:+a+report+from+the+American+Heart+Association+Statistics+Committee+and+Stroke+Statistics+Subcommittee.">Heart Disease and Stroke Statistics-2007 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee.</a> Circulation. 115 (5), 69 (2017).</li><li>Ovbiagele, 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=Forecasting+the+future+of+stroke+in+the+united+states:+A+policy+statement+from+the+American+heart+association+and+American+stroke+association.">Forecasting the future of stroke in the united states: A policy statement from the American heart association and American stroke association.</a> Stroke. 44 (8), 2361-2375 (2013).</li><li>Carmichael, S. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Themes+and+strategies+for+studying+the+biology+of+stroke+recovery+in+the+poststroke+epoch.">Themes and strategies for studying the biology of stroke recovery in the poststroke epoch.</a> Stroke. 39 (4), (2008).</li><li>Carmichael, S. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rodent+models+of+focal+stroke:+size,+mechanism,+and+purpose.">Rodent models of focal stroke: size, mechanism, and purpose.</a> NeuroRx: the journal of the American Society for Experimental NeuroTherapeutics. 2 (3), (2005).</li><li>Qin, 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=An+adaptive+role+for+BDNF+Val66Met+polymorphism+in+motor+recovery+in+chronic+stroke.">An adaptive role for BDNF Val66Met polymorphism in motor recovery in chronic stroke.</a> Journal of Neuroscience. 34 (7), 2493-2502 (2014).</li><li>Fluri, F., Schuhmann, M. K., Kleinshnitz, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+ischemic+stroke+and+their+application+in+clinical+research.">Animal models of ischemic stroke and their application in clinical research.</a> Drug Design, Development and Therapy. 9, 3445-3454 (2015).</li><li>Talley Watts, L., Zheng, W., Garling, R. J., Frohlich, V. C., Lechleiter, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rose+Bengal+Photothrombosis+by+Confocal+Optical+Imaging+In+Vivo:+A+Model+of+Single+Vessel+Stroke.">Rose Bengal Photothrombosis by Confocal Optical Imaging In Vivo: A Model of Single Vessel Stroke.</a> Journal of Visualized Experiments. (100), e52794 (2015).</li><li>Tuladhar, A., Payne, S. L., Scoichet, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Harnessing+the+potential+of+biomaterials+for+brain+repair+after+stroke.">Harnessing the potential of biomaterials for brain repair after stroke.</a> Frontiers. 5, 14 (2018).</li><li>Nih, L. R., Sideris, E., Carmicahel, S. T., Segura, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Injection+of+microporous+annealing+particle+(MAP)+hydrogels+in+the+stoke+cavity+reduces+gliosis+and+inflammation+and+promotes+NPC+migration+to+the+lesion.">Injection of microporous annealing particle (MAP) hydrogels in the stoke cavity reduces gliosis and inflammation and promotes NPC migration to the lesion.</a> Advance Materials. 29 (32), (2017).</li><li>Nih, L. R., Gojgini, S., Carmichael, S. T., Segura, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Duel-function+injectable+angiogenic+biomaterial+for+the+repair+of+brain+tissue+following+stroke.">Duel-function injectable angiogenic biomaterial for the repair of brain tissue following stroke.</a> Nature Materials. 17, 642-651 (2018).</li><li>Cook, 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=Hydrogel-delivered+brain-derived+neurotrophic+factor+promotes+tissue+repair+and+recovery+after+stroke.">Hydrogel-delivered brain-derived neurotrophic factor promotes tissue repair and recovery after stroke.</a> Journal of Cerebral Blood Flow &amp; Metabolism. 37, 1030-1045 (2017).</li><li>Lam, J., Lowry, W. E., Carmichael, S. T., Segura, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delivery+of+iPS-NPCs+to+the+stroke+cavity+within+a+hyaluronic+acid+matrix+promotes+the+differentiation+of+transplanted+cells.">Delivery of iPS-NPCs to the stroke cavity within a hyaluronic acid matrix promotes the differentiation of transplanted cells.</a> Advance Functional Materials. 24, 7053-7062 (2015).</li><li>Nih, L. R., 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=Engineered+HA+hydrogel+for+stem+cell+transplantation+in+the+brain:+Biocompatibility+data+using+a+design+of+experiment+approach.">Engineered HA hydrogel for stem cell transplantation in the brain: Biocompatibility data using a design of experiment approach.</a> Data in Brief. 10, 202-209 (2016).</li><li>Carmichael, S. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+3+Rs+of+Stroke+Biology:+Radial,+Relayed,+and+Regenerative.">The 3 Rs of Stroke Biology: Radial, Relayed, and Regenerative.</a> Neurotherapeutics. 13, 348-359 (2016).</li><li>Caicco, M. J., Cooke, M. J., Wang, Y., Tuladhar, A., Morshead, C. M., Shoichet, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+hydrogel+composite+system+for+sustained+epi-cortical+delivery+of+Cyclosporin+A+to+the+brain+for+treatment+of+stroke.">A hydrogel composite system for sustained epi-cortical delivery of Cyclosporin A to the brain for treatment of stroke.</a> Journal of Controlled Release. 166 (3), 197-202 (2013).</li><li>Moshayedi, P., 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=Systematic+optimization+of+an+engineered+hydrogel+allows+for+selective+control+of+human+neural+stem+cell+survival+and+differentiation+after+transplantation+in+the+stroke+brain.">Systematic optimization of an engineered hydrogel allows for selective control of human neural stem cell survival and differentiation after transplantation in the stroke brain.</a> Biomaterials. 105, 145-155 (2016).</li><li>Lu, H., 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=Hemodynamic+effects+of+intraoperative+anesthetics+administration+in+photothrombotic+stroke+model:+a+study+using+laser+speckle+imaging.">Hemodynamic effects of intraoperative anesthetics administration in photothrombotic stroke model: a study using laser speckle imaging.</a> BMC Neuroscience. 18 (10), (2017).</li><li>Wiersma, A. M., Winship, I. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+Photothrombotic+Stroke+in+the+Sensorimotor+Cortex+of+Rats+and+Preparation+of+Tissue+for+Analysis+of+Stroke+Volume+and+Topographical+Cortical+Localization+of+Ischemic+Infarct.">Induction of Photothrombotic Stroke in the Sensorimotor Cortex of Rats and Preparation of Tissue for Analysis of Stroke Volume and Topographical Cortical Localization of Ischemic Infarct.</a> Bio-protocol. 8 (10), (2018).</li><li>Liang, H., 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=Region-specific+and+activity-dependent+regulation+of+SVZ+neurogenesis+and+recovery+after+stroke.">Region-specific and activity-dependent regulation of SVZ neurogenesis and recovery after stroke.</a> PNAS. 116 (27), 13621-13630 (2019).</li><li>Payne, S. L., Anandakumaran, P. N., Varga, B. V., Morshead, C. M., Nagy, A., Shoichet, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+maturation+of+human+iPSC-derived+neuroepithelial+cells+influences+transplant+survival+in+the+stroke-injured+rat+brain.">In vitro maturation of human iPSC-derived neuroepithelial cells influences transplant survival in the stroke-injured rat brain.</a> Tissue Engineering Part A. 24, 351-360 (2018).</li><li>Lee, I. H., 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=Delayed+epidural+transplantation+of+human+induced+pluripotent+stem+cell-derived+neural+progenitors+enhances+functional+recovery+after+stroke.">Delayed epidural transplantation of human induced pluripotent stem cell-derived neural progenitors enhances functional recovery after stroke.</a> Science Reports. 7, 1943 (2017).</li><li>Somaa, F. 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=Peptide-based+scaffolds+support+human+cortical+progenitor+graft+integration+to+reduce+atrophy+and+promote+functional+repair+in+a+model+of+stroke.">Peptide-based scaffolds support human cortical progenitor graft integration to reduce atrophy and promote functional repair in a model of stroke.</a> Cell Reports. 20, 1964-1977 (2017).</li><li>Griffin, D. R., Weaver, W. M., Scumpia, P., Di Carlo, D., Segura, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accelerated+wound+healing+by+injectable+microporous+gel+scaffolds+assembled+from+annealed+building+blocks.">Accelerated wound healing by injectable microporous gel scaffolds assembled from annealed building blocks.</a> Nature Materials. 14 (7), 737-744 (2016).</li><li>Sideris, E. Y., Aaron, C. J., Carmichael, S. T., Segura, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hyaluronic+acid+particle+hydrogels+decrease+cerebral+atrophy+and+promote+pro-reparative+astrocyte/axonal+infiltration+in+the+core+after+ischemic+stroke.">Hyaluronic acid particle hydrogels decrease cerebral atrophy and promote pro-reparative astrocyte/axonal infiltration in the core after ischemic stroke.</a> bioRxiv. , (2019).</li><li>Yu, H., 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=Combinated+Transplantation+of+Neural+Stem+Cells+and+Collagen+Type+I+Promote+Functional+Recovery+After+Cerebral+Ischemia+in+Rats.">Combinated Transplantation of Neural Stem Cells and Collagen Type I Promote Functional Recovery After Cerebral Ischemia in Rats.</a> The Anatomical Record. 293 (5), 911-917 (2010).</li><li>Jin, 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=Transplantation+of+Human+Neural+Precursor+Cells+in+Matrigel+Scaffolding+Improves+Outcome+from+Focal+Cerebral+Ischemia+after+Delayed+Postischemic+Treatment+in+Rats.">Transplantation of Human Neural Precursor Cells in Matrigel Scaffolding Improves Outcome from Focal Cerebral Ischemia after Delayed Postischemic Treatment in Rats.</a> Journal of Cerebral Blood Flow &amp; Metabolism. 30 (3), 534-544 (2009).</li><li>Gelderblom, M., 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=Temporal+and+spatial+dynamics+of+cerebral+immune+cell+accumulation+in+stroke.">Temporal and spatial dynamics of cerebral immune cell accumulation in stroke.</a> Stroke. 40 (5), 1849-1857 (2009).</li><li>Wei, L., Erinjeri, J. P., Rovainen, C. M., Woolsey, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collateral+growth+and+angiogenesis+around+cortical+stroke.">Collateral growth and angiogenesis around cortical stroke.</a> Stroke. 32 (9), 2179-2184 (2001).</li><li>Zhang, R., 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=Activated+Neural+Stem+Cells+Contribute+to+Stroke-Induced+Neurogenesis+and+Neuroblast+Migration+toward+the+Infarct+Boundary+in+Adult+Rats.">Activated Neural Stem Cells Contribute to Stroke-Induced Neurogenesis and Neuroblast Migration toward the Infarct Boundary in Adult Rats.</a> Journal of Cerebral Blood Flow &amp; Metabolism. 24 (4), 441-448 (2004).</li></ol>

Gli autori dichiarano che TS è uno dei fondatori di Tempo Therapeutics, che cerca di commercializzare idrogel MAP.

Qui dimostriamo un modello di ictus permanente facilmente riproducibile, minimamente invasivo e descriviamo come iniettare un biomateriale nell'infarto cinque giorni dopo l'ictus. L'uso del colorante fototrombotico Rose Bengal e di un laser collimato a 520 nm collegato al dispositivo stereotassico ci dà la possibilità di posizionare il tratto sulla corteccia motoria del mouse con maggiore precisione. Cinque giorni dopo l'ictus, la posizione dell'infarto è visibile a occhio al centro dell'irradiazione, 2,0 mm medio-lat...

L'ictus è la principale causa di disabilità e la quinta causa di morte negli Stati Uniti1. Circa l'87% di tutti gli ictus sono ischemici, mentre la maggior parte del restante 13% sono emorragici2. Un ictus ischemico è definito come il blocco del flusso sanguigno in un'arteria al tessuto circostante. Questa occlusione si traduce in privazione di ossigeno e successiva necrosi che spesso porta a disabilità permanente nei pazienti sopravvissuti. Mentre c'è stata una diminuzione del tasso di mortalitàdell'ictus 3, la sua prevalenza dovrebbe aumentare a 3,4 milioni di persone entro il 20304. Questo aumento dei sopravvissuti disabili e il conseguente onere economico ha portato a una spinta per la ricerca sull'ictus che si concentra sui meccanismi di riparazione neurale. Dopo l'ictus c'è un periodo infiammatorio che porta alla formazione di una cicatrice che impedisce alla regione necrotica di espandersi. La regione che circonda il nucleo necrotico è definita "peri-infarto" e vi è una forte evidenza che la plasticità in questa regione, che include l'aumento dell'angiogenesi, della neurogenesi e della germinazione assonale, è direttamente collegata al recupero osservato nei modelli animali e umani5. Poiché non esistono modelli in vitro in grado di replicare correttamente le complesse interazioni successive all'ictus, i modelli animali sono essenziali per la ricerca sull'ictus.
Esistono diversi modelli in vivo che possono essere utilizzati per produrre ictus ischemico. Uno dei modelli più comuni utilizzati nei topi è l'occlusione dell'arteria cerebrale media, o MCAo, attraverso l'occlusione distale o prossimale (tramite filamento intra-arterioso). Il modello prossimale, noto anche come filamento MCAo (fMCAo), in genere si traduce in grandi ictus ischemici che comprendono ovunque dal 5% al 50% dell'emisfero cerebrale, a seconda del numero di fattori6. In questi modelli, una sutura o un filamento viene avanzato dall'arteria carotide interna alla base dell'arteria cerebrale media (MCA) e mantenuto in posizione per un determinato periodo di tempo. Questo metodo per l'occlusione, che può essere reso temporaneo o permanente, produce un infarto centrato nello striato e può o meno coinvolgere la corteccia sovrastante6. La dimensione del tratto risultante è altamente variabile e sono necessarie tecniche di imaging, come il doppler laser, per confermare l'efficacia della procedura in ciascun topo. L'occlusione del filamento intra-arterioso o intra-luminale che dura più di 30 minuti produce ictus all'estremità più ampia dell'intervallo di dimensioni. Alcuni ricercatori si sono concentrati su tempi di occlusione del filamento più brevi, che richiedono una sostanziale attenzione sperimentale e la convalida del laboratorio7. I modelli di filamento MCAo nei topi seguono fasi simili di morte cellulare, progressione ischemica e formazione di una regione peri-infartuale come osservato nei casi di ictus umano; tuttavia, gli ictus più grandi assomigliano più da vicino allo stato di malattia degli infarti cerebrali maligni, che sono meno comuni, meno curabili ictus umani6. Nel frattempo, l'occlusione MCA distale richiede un intervento chirurgico e una craniectomia più coinvolti. In questo modello, la parte distale dell'MCA che corre lungo la superficie del cervello è direttamente occlusa con una cravatta di sutura o cauterizzazione. In alcune varianti della tecnica, le arterie carotidi sono unilateralmente occluse unilateralmente o transitoriamente-bilateralmente. Un vantaggio dell'MCAo distale è che produce una corsa a base corticale di dimensioni inferiori rispetto al modello di filamento. Tuttavia, il modello distale produce un output comportamentale più povero a causa della traselezione dell'arteria carotide esterna (ECA), che è anche una preoccupazione con fMCAo6.
Un modello di corsa alternativo che è noto per essere meno invasivo è il modello fototrombotico (PT). Il modello PT si traduce in una posizione ben definita di ischemia ed è associato ad un alto tasso di sopravvivenza8. La tecnica si basa su un colorante fotosensibile iniettato per via intraperitoneale che consente la foto-ossidazione intravascolare semplicemente irradiando il tessuto desiderato con una luce o un laser9. Dopo l'eccitazione, si formano radicali di ossigeno che causano danni endoteliali, che attivano l'aggregazione piastrinica e la formazione di coaguli nell'area irradiata8,9. Lo stretto controllo sulla dimensione e la posizione della corsa, nonché l'elevata riproducibilità del modello PT, lo rendono ideale per lo studio dei biomateriali. Mentre la precisione è resa possibile utilizzando un laser e coordinate stereotassiche, ci sono alcuni svantaggi che possono rendere questo modello meno ideale per pochi studi. A differenza del modello fMCAo, il modello di corsa PT non può essere riperfuso. Pertanto, i materiali per studiare gli agenti neuroprotettivi specifici per i danni a seguito di riperfusione o i meccanismi successivi alla riperfusione non sarebbero utili qui8. Inoltre, a causa dell'insulto microvascolare del modello PT, si vede una penombra ischemica relativamente piccola. Invece, si verifica edema vasogenico locale, che è insolito per l'ictus umano, rendendo questo modello indesiderabile per gli studi farmacologici preclinici focalizzati sull'area peri-infartuale6,8.
L'obiettivo generale delle strategie dei biomateriali nell'ictus è quello di fornire agenti bioattivi o di agire come una matrice extracellulare surrogata per la crescita del tessuto cerebrale. Una strategia che esploreremo utilizzando i nostri metodi è quella di fornire idrogel direttamente nel nucleo dell'ictus, al contrario del tessuto peri-infartuale in cui vengono somministrate molte terapie cellulari attuali10. Il razionale di questo approccio è che la consegna nel tessuto necrotico trovato nel nucleo eviterà di interrompere il tessuto sano circostante o di recuperare. Supponiamo che la diffusione di qualsiasi agente attivo incluso nel biomateriale sarà in grado di raggiungere il peri-infarto dal nucleo, soprattutto perché troviamo che la consegna di biomateriali idrogel riduce lo spessore della cicatrice gliale11. Questo è importante poiché la regione del peri-infarto ha dimostrato di mostrare neuroplasticità dopo l'ictus, rendendola un bersaglio attraente. Inoltre, la consegna di una matrice surrogata al nucleo dell'ictus può essere caricata con12 angiogenici o13 fattori neurogeni per guidare la formazione di nuovo tessuto, così come le cellule per la consegna14. La consegna cellulare è notevolmente migliorata utilizzando una matrice perché protegge le cellule dalle dure forze di iniezione e dall'ambiente locale presente durante il parto, oltre a incoraggiare la differenziazione e l'attecchimento15.
Questi biomateriali terapeutici iniettabili hanno rilevanza clinica nelle applicazioni dell'ictus, in quanto attualmente non esistono terapie mediche che stimolino il recupero neuronale dopo l'ictus. I circuiti neurali sottostanti coinvolti nel recupero si trovano nel tessuto cerebrale adiacente al nucleodell'ictus 16, mentre il nucleo dell'ictus stesso è privo di tessuto neurale vitale. Prevediamo che la consegna di un biomateriale nel nucleo dell'ictus necrotico ha il potenziale per stimolare il tessuto adiacente verso processi rigenerativi attraverso una serie di meccanismi precedentemente menzionati, tra cui il rilascio di depositi di fattori dicrescita 13,la stimolazione della crescita del tessuto e la promozione del recuperodellosviluppo del tessuto cerebrale11, 12,l'alterazione delle risposte immunitarie17e la consegna di terapie derivate da cellule staminali14, 18. Tuttavia, per studiare efficacemente la possibilità di queste applicazioni, è necessario un metodo coerente e riproducibile per indurre l'ictus e iniettare biomateriali. Il modello di corsa PT utilizza tecniche che offrono un controllo preciso sull'orientamento e sulla posizione del tratto. Un laser collegato al dispositivo stereotassico guida gli orientamenti e le pompe collegate ai dispositivi stereotassica controllano la velocità di iniezione del materiale senza la necessità di ulteriori forme di imaging. Pertanto, abbiamo scelto di descrivere i metodi per eseguire un colpo PT nelle cortecce motorie dei topi e per iniettare biomateriali nel nucleo dell'ictus. Qui, utilizziamo idrogel di particelle ricotte microporose (MAP) come biomateriale per iniezione senza cellule aggiunte o fattori di crescita. Inoltre, spieghiamo come recuperare con successo il cervello con biomateriale intatto e discutiamo i saggi di immunochimica utilizzati per analizzare l'esito dell'ictus con e senza iniezione di biomateriali.

<table>
	<tbody>
		<tr>
			<td>10% Normal Goat Serum</td>
			<td>VWR</td>
			<td>100504-028</td>
			<td>For blocking buffer</td>
		</tr>
		<tr>
			<td>2-ply alcohol pre pad, Sterile, Medium</td>
			<td>Medline</td>
			<td>MDS090735</td>
			<td></td>
		</tr>
		<tr>
			<td>25uL Hamilton Syringe 702RN, no needle</td>
			<td>Fishcer Scientific</td>
			<td>14824663</td>
			<td>Syringes used to inject biomaterials</td>
		</tr>
		<tr>
			<td>25uL Positive displacement pipette</td>
			<td>Gilson</td>
			<td>M-25</td>
			<td></td>
		</tr>
		<tr>
			<td>2x Beam Expander, 400-650nm</td>
			<td>Thorlabs</td>
			<td>GBE02-A</td>
			<td>Laser beam expander</td>
		</tr>
		<tr>
			<td>Adjustable Stage Platform</td>
			<td>Kopf Instruments</td>
			<td>901</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Glucose Transporter GLUT1 antibody, rabbit</td>
			<td>Abcam</td>
			<td>ab113435</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Iba1 Antibody, goat</td>
			<td>abcam</td>
			<td>ab5076</td>
			<td></td>
		</tr>
		<tr>
			<td>BD Vacutainer Safety-Lok Blood Collection Sets. 25G, 12&#34;</td>
			<td>Medsupply</td>
			<td>367294</td>
			<td>For perfusions</td>
		</tr>
		<tr>
			<td>BKF12- Matte Black Aluminum Foil</td>
			<td>Thorlabs</td>
			<td>BKF12</td>
			<td>To cover anything that is reflective when using laser.</td>
		</tr>
		<tr>
			<td>Bone Iris Mini Scissors - 3-1/2&#34;</td>
			<td>Sklar surgical instruments</td>
			<td>64-2035</td>
			<td></td>
		</tr>
		<tr>
			<td>C57BL/6 Mice</td>
			<td>Jackson Laboratory</td>
			<td>000664</td>
			<td>8-12 weeks of age</td>
		</tr>
		<tr>
			<td>Cage Assembly Rob</td>
			<td>Thorlabs</td>
			<td>ER3-P4</td>
			<td>3&#34; Long, diameter 6mm, 4 pack - for attaching laser to sterotax</td>
		</tr>
		<tr>
			<td>Carbon Steel Burrs -0.5mm Diameter</td>
			<td>Fine Science Tools</td>
			<td>19007-05</td>
			<td>For creating burr hole</td>
		</tr>
		<tr>
			<td>Chromium(III) potassium sulfate dodecahydrate</td>
			<td>VWR</td>
			<td>EM1.01036.0250</td>
			<td></td>
		</tr>
		<tr>
			<td>Compact Controller for pigtailed lasers</td>
			<td>Thorlabs</td>
			<td>CLD1010LP</td>
			<td></td>
		</tr>
		<tr>
			<td>Cotton Swabs</td>
			<td>VWR</td>
			<td>89031-288</td>
			<td></td>
		</tr>
		<tr>
			<td>CP 25 pipette tips</td>
			<td>Gilson</td>
			<td>F148012</td>
			<td></td>
		</tr>
		<tr>
			<td>Donkey anti-goat IgG H&#38;L (488)</td>
			<td>abcam</td>
			<td>ab150129</td>
			<td></td>
		</tr>
		<tr>
			<td>Donkey Anti-rabbit IgG H&#38;L (647)</td>
			<td>abcam</td>
			<td>ab150075</td>
			<td></td>
		</tr>
		<tr>
			<td>Donkey Anti-rat IgG H&#38;L (555)</td>
			<td>abcam</td>
			<td>ab150154</td>
			<td></td>
		</tr>
		<tr>
			<td>EMS DPX Mountant</td>
			<td>Elecron Microscopy Sciences</td>
			<td>13512</td>
			<td>Mounting solution for slides</td>
		</tr>
		<tr>
			<td>EMS Gelatin Powder Type A 300 Bloom</td>
			<td>Electron Microscopy Sciences</td>
			<td>16564</td>
			<td>For gelatin coating slides</td>
		</tr>
		<tr>
			<td>EMS Paraformaldehyde, Granular</td>
			<td>VWR</td>
			<td>100504-162</td>
			<td>For making 45 PFA</td>
		</tr>
		<tr>
			<td>ESD Worstation kit</td>
			<td>Elmstat</td>
			<td>WSKK5324SB</td>
			<td>Need for setting up the laser</td>
		</tr>
		<tr>
			<td>Fiber Bench Wall Plate, unthreaded</td>
			<td>Thorlabs</td>
			<td>HCA3</td>
			<td>Need for connecting laser to Kopf shaft</td>
		</tr>
		<tr>
			<td>FiberPort</td>
			<td>Thorlabs</td>
			<td>PAF-X-5-A</td>
			<td>FC/APC&#38; APC, f=4.6mm, 350-700nm, diameter 0.75mm</td>
		</tr>
		<tr>
			<td>Fine Scissors - straight/sharp-blunt/10cm</td>
			<td>Fine Science Tools</td>
			<td>14028-10</td>
			<td></td>
		</tr>
		<tr>
			<td>GFAP Antibody, rat</td>
			<td>Thermo Fisher Scientific</td>
			<td>13-0300</td>
			<td></td>
		</tr>
		<tr>
			<td>Heating Plate</td>
			<td>Kopf Instruments</td>
			<td>HP-4M</td>
			<td></td>
		</tr>
		<tr>
			<td>ImmEdge Hydrophobic Barrier Pen</td>
			<td>Vector Laboratories</td>
			<td>H-4000</td>
			<td>For staining slides</td>
		</tr>
		<tr>
			<td>IMPAC 6-Integrated Multi Patient Anesthesia Center</td>
			<td>VetEquip</td>
			<td>901808</td>
			<td></td>
		</tr>
		<tr>
			<td>Iodine Prep Pads</td>
			<td>Medx Supple</td>
			<td>MED MDS093917H</td>
			<td></td>
		</tr>
		<tr>
			<td>Jewlers Forceps #5</td>
			<td>GFS chemicals</td>
			<td>46085</td>
			<td></td>
		</tr>
		<tr>
			<td>Laser Safety Glasses</td>
			<td>Thorlabs</td>
			<td>LG10B</td>
			<td>Amber Lenses, 35% Visible light (googles versions available too)</td>
		</tr>
		<tr>
			<td>M27-1084 Powerful LED Dual Goose-neck</td>
			<td>United Scope</td>
			<td>LED-11C</td>
			<td></td>
		</tr>
		<tr>
			<td>Medical USP Grade Oxygen</td>
			<td>Airgas</td>
			<td>OX USP250</td>
			<td></td>
		</tr>
		<tr>
			<td>Miltex Adson Dressing Forceps, Disecting-grade</td>
			<td>Intefra Miltex</td>
			<td>V96-118</td>
			<td></td>
		</tr>
		<tr>
			<td>Mini Cord/Cordless Small Animal Trimmer</td>
			<td>Harvard aparatus</td>
			<td>72-6110</td>
			<td></td>
		</tr>
		<tr>
			<td>Mini-pump variable flow</td>
			<td>Thomas Scientific</td>
			<td>70730-064</td>
			<td>Pump for perfusions</td>
		</tr>
		<tr>
			<td>Mouse Brain Matrices, Coronal Slices, 1mm</td>
			<td>Kent Scientific</td>
			<td>RBMA-200c</td>
			<td>For TTC slices</td>
		</tr>
		<tr>
			<td>Mouse Gas Anethesia Head Holder</td>
			<td>Kopf Instruments</td>
			<td>923-B</td>
			<td></td>
		</tr>
		<tr>
			<td>Nanojet Control Box</td>
			<td>Chemyx</td>
			<td>10050</td>
			<td></td>
		</tr>
		<tr>
			<td>Nanojet pump header</td>
			<td>Chemxy</td>
			<td>10051</td>
			<td>Attach to stereotaxic device for injecting biomaterial</td>
		</tr>
		<tr>
			<td>Needle RN 30G PT STY 3, 0.5 inch</td>
			<td>Fishcer Scientific</td>
			<td>NC9459562</td>
			<td></td>
		</tr>
		<tr>
			<td>Non-rupture ear bars 60&#186;</td>
			<td>Kopf Instruments</td>
			<td>922</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS buffer pH 7.4</td>
			<td>VWR</td>
			<td>97062 338</td>
			<td></td>
		</tr>
		<tr>
			<td>Pigtaled laser 520 nm, 100mW, 5G Pin</td>
			<td>Thorlabs</td>
			<td>LP520-MF100</td>
			<td></td>
		</tr>
		<tr>
			<td>Positive charge glass slides</td>
			<td>Hareta</td>
			<td>AHS90-WH</td>
			<td></td>
		</tr>
		<tr>
			<td>Power engergy meter</td>
			<td>Thorlabs</td>
			<td>PM100D</td>
			<td>Used to measure your mW laser output</td>
		</tr>
		<tr>
			<td>Puralube Vet Ointment</td>
			<td>Dr. Foster Smith</td>
			<td>9N-76855</td>
			<td></td>
		</tr>
		<tr>
			<td>Rectal Probe Mouse</td>
			<td>kopf Instruments</td>
			<td>Ret-3-ISO</td>
			<td></td>
		</tr>
		<tr>
			<td>Rose Bengal Dye 95%</td>
			<td>Sigma-Aldrich</td>
			<td>330000-5G</td>
			<td></td>
		</tr>
		<tr>
			<td>Shaft Modified 8-32 threaded hole 1/2&#34; depth</td>
			<td>Kopf Instruments</td>
			<td>1770-02</td>
			<td>For connecting laser to sterotaxic device</td>
		</tr>
		<tr>
			<td>Slim photodiode power sensor</td>
			<td>Thorlabs</td>
			<td>S130VC</td>
			<td>Used with power energy meter</td>
		</tr>
		<tr>
			<td>SM1-Threaed 30 mm Cage Plate 0.35&#34; thick 2 Retaining</td>
			<td>Thorlabs</td>
			<td>CP02</td>
			<td>For connecting laser expander</td>
		</tr>
		<tr>
			<td>Sol-M U-100 Insuline syringe with 1/2 unit markings 0.5 mL</td>
			<td>VWR</td>
			<td>10002-726</td>
			<td>To inject rose bengal</td>
		</tr>
		<tr>
			<td>StainTray Slide Staining System</td>
			<td>Simport Scientific</td>
			<td>M920-2</td>
			<td>For staining slides</td>
		</tr>
		<tr>
			<td>Sterotaxic device</td>
			<td>Kopf Instruments</td>
			<td>940</td>
			<td>Small Animal Stereotaxic Instrument</td>
		</tr>
		<tr>
			<td>Student Adson Forceps -1x2 teeth</td>
			<td>Fine Science Tools</td>
			<td>91127-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Student Fine Forceps - straight/broad Shanks</td>
			<td>Fine Science Tools</td>
			<td>91113-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Temperature Controller</td>
			<td>Kopf Instruments</td>
			<td>TCAT-2LV</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue-Tek OCT compound</td>
			<td>VWR</td>
			<td>25608-930</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>VWR</td>
			<td>97063-864</td>
			<td></td>
		</tr>
		<tr>
			<td>Upper Bracket Clamp</td>
			<td>Kopf Instruments</td>
			<td>1770-c</td>
			<td>For connecting laser to sterotaxic device</td>
		</tr>
		<tr>
			<td>Vetbond Tissue Adhessive 3mL</td>
			<td>Santa Cruz Biotechnology</td>
			<td>sc-361931</td>
			<td></td>
		</tr>
		<tr>
			<td>Vogue Professional My Manicurist</td>
			<td>Bargin Source</td>
			<td>6400</td>
			<td>For Burrs</td>
		</tr>
		<tr>
			<td>VWR Bead Sterilizers</td>
			<td>VWR</td>
			<td>75999-328</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue Tek OCT compound</td>
			<td>Sakura</td>
			<td>4583</td>
			<td>For tissue embeding</td>
		</tr>
	</tbody>
</table>

injection of hydrogel biomaterial scaffolds to the brain after stroke

L'ictus è la principale causa di disabilità e la quinta causa di morte negli Stati Uniti. Circa l'87% di tutti gli ictus sono ictus ischemici e sono definiti come il blocco improvviso di un vaso che fornisce sangue al cervello. Entro pochi minuti dal blocco, le cellule iniziano a morire e provocano danni irreparabili ai tessuti. Gli attuali trattamenti terapeutici si concentrano sulla rimozione del coagulo o sulla lisi per consentire la riperfusione e prevenire danni cerebrali più gravi. Sebbene la plasticità cerebrale transitoria possa salvare parte del tessuto danneggiato nel tempo, frazioni significative di pazienti rimangono con deficit neurologici che non si risolveranno mai. C'è una mancanza di opzioni terapeutiche per trattare i deficit neurologici causati dall'ictus, sottolineando la necessità di sviluppare nuove strategie per trattare questa crescente popolazione di pazienti. I biomateriali iniettabili sono attualmente in fase di progettazione per migliorare la plasticità cerebrale e migliorare la riparazione endogena attraverso la somministrazione di agenti attivi o cellule staminali. Un metodo per testare questi approcci è quello di utilizzare un modello di colpo di roditore, iniettare il biomateriale nel nucleo dell'ictus e valutare la riparazione. Conoscere la posizione precisa del nucleo dell'ictus è fondamentale per il trattamento accurato dopo l'ictus, pertanto, un modello di ictus che si traduce in una posizione di ictus prevedibile è preferibile per evitare la necessità di imaging prima dell'iniezione. Il seguente protocollo tratterà come indurre un ictus fototrombotico, come iniettare un idrogel in modo controllato e preciso e come estrarre e criosezionare il cervello mantenendo intatto il biomateriale. Inoltre, evidenzieremo come questi stessi materiali idrogel possono essere utilizzati per la co-consegna di cellule staminali. Questo protocollo può essere generalizzato all'uso di altri biomateriali iniettabili nel nucleo dell'ictus.

Lo scopo di questo metodo era dimostrare come iniettare biomateriali nel cervello dopo l'ictus. Un modello fototrombotico con rose bengal e un laser a 520 nm è stato utilizzato per l'orientamento controllato della lesione del tratto sia in termini di dimensioni che di posizione. Cinque giorni dopo l'ictus l'infarto poteva essere visualizzato durante l'intervento chirurgico (Figura 1B) e mediante TTC e imaging di vetrini macchiati IHC (Figura 2). Un aumento del ...

Watch this Scientific Journal Video about Injection of Hydrogel Biomaterial Scaffolds to The Brain After Stroke at JoVE.com

Injection of Hydrogel Biomaterial Scaffolds to The Brain After Stroke

L'ictus è un problema globale con opzioni di trattamento minime e nessuna terapia clinica attuale per rigenerare il tessuto cerebrale perso. Qui descriviamo i metodi per creare un preciso colpo fototrombotico nella corteccia motoria dei roditori e la successiva iniezione di biomateriali idrogel per studiare i loro effetti sulla rigenerazione dei tessuti dopo l'ictus.

Iniezione di scaffold di idrogel Biomateriale al cervello dopo l'ictus

Stroke is the leading cause of disability and the fifth-leading cause of death in the United States. Approximately 87% of all strokes are ischemic strokes ...

injection-of-hydrogel-biomaterial-scaffolds-to-the-brain-after-stroke

Research

JoVE Journal

Biology

4.9K Views.  Duke University. L'ictus è un problema globale con opzioni di trattamento minime e nessuna terapia clinica attuale per rigenerare il tessuto cerebrale perso. Qui descriviamo i metodi per creare un preciso colpo fototrombotico nella corteccia motoria dei roditori e la successiva iniezione di biomateriali idrogel per studiare i loro effetti sulla rigenerazione dei tessuti dopo l'ictus.

Video: Injection of Hydrogel Biomaterial Scaffolds to The Brain After Stroke

Methods for Patch Clamp Capacitance Recordings from the Calyx

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal. Electrical recordings from the presynaptic terminal allow the measurement of action potentials, calcium channel currents, vesicle fusion (exocytosis) and subsequent membrane uptake (endocytosis). The fusion of vesicles containing neurotransmitter causes the vesicle membrane to be added to the cell membrane of the calyx. This increase in the amount of cell membrane is measured as an increase in capacitance. The subsequent reduction in capacitance indicates endocytosis, the process of membrane uptake or removal from the calyx membrane. Endocytosis, is necessary to maintain the structure of the calyx and it is also necessary to form vesicles that will be filled with neurotransmitter for future exocytosis events. Capacitance recordings at the calyx of Held have made it possible to directly and rapidly measure vesicular release and subsequent endocytosis in a mammalian CNS nerve terminal. In addition, the corresponding postsynaptic activity can be simultaneously measured by using paired recordings. Thus a complete picture of the presynaptic and postsynaptic electrical activity at a central nervous system synapse is achievable using this preparation. Here, the methods for slice preparation, morphological features for identification of calyces of Held, basic patch clamping techniques, and examples of capacitance recordings to measure exocytosis and endocytosis are presented.

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal.

Metodi per la registrazioni Morsetto capacità patch dal Calyx

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal. ...

Ricerca

Biologia

Intravitreous Injection for Establishing Ocular Diseases Model

Intravitreous injection is a widely used technique in visual sciences research. It can be used to establish animal models with ocular diseases or as direct application of local treatment. This video introduces how to use simple and inexpensive tools to finish the intravitreous injection procedure. Use of a 1 ml syringe, instead of a hemilton syringe, is used. Practical tips for how to make appropriate injection needles using glass pipettes with perfect tips, and how to easily connect the syringe needle with the glass pipette tightly together, are given.
To conduct a good intravitreous injection, there are three aspects to be observed: 1) injection site should not disrupt retina structure; 2) bleeding should be avoided to reduce the risk of infection; 3) lens should be untouched to avoid traumatic cataract. In brief, the most important point is to reduce the interruption of normal ocular structure. To avoid interruption of retina, the superior nasal region of rat eye was chosen. Also, the puncture point of the needle was at the par planar, which was about 1.5 mm from the limbal region of the rat eye. A small amount of vitreous is gently pushed out through the puncture hole to reduce the intraocular pressure before injection. With the 45&deg; injection angle, it is less likely to cause traumatic cataract in the rat eye, thus avoiding related complications and influence from lenticular factors. In this operation, there was no cutting of the conjunctiva and ocular muscle, no bleeding. With quick and minor injury, a successful intravitreous injection can be done in minutes. 
The injection set outlined in this particular protocol is specific for intravitreous injection. However, the methods and materials presented here can also be used for other injection procedures in drug delivery to the brain, spinal cord or other organs in small mammals.

Intravitreous injection is a widely used technique in visual sciences research for ocular diseases or as direct application of local treatment. This video demonstrated a protocol for intravitreous injection using a 1ml syringe with glass pipette. Useful tips about avoiding massive bleeding and lens damage are given.

Iniezione intravitreale per stabilire Modello malattie oculari

Intravitreous injection is a widely used technique in visual sciences research. It can be used to establish animal models with ocular diseases or as ...

Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation

Using microfabrication technologies is a prerequisite to create scaffolds of reproducible geometry and constant quality for three-dimensional cell cultivation. These technologies offer a wide spectrum of advantages not only for manufacturing but also for different applications. The size and shape of formed cell clusters can be influenced by the exact and reproducible architecture of the microfabricated scaffold and, therefore, the diffusion path length of nutrients and gases can be controlled.1 This is unquestionably a useful tool to prevent apoptosis and necrosis of cells due to an insufficient nutrient and gas supply or removal of cellular metabolites.
Our polymer chip, called CellChip, has the outer dimensions of 2 x 2 cm with a central microstructured area. This area is subdivided into an array of up to 1156 microcontainers with a typical dimension of 300 m edge length for the cubic design (cp- or cf-chip) or of 300 m diameter and depth for the round design (r-chip).2
So far, hot embossing or micro injection moulding (in combination with subsequent laborious machining of the parts) was used for the fabrication of the microstructured chips. Basically, micro injection moulding is one of the only polymer based replication techniques that, up to now, is capable for mass production of polymer microstructures.3 However, both techniques have certain unwanted limitations due to the processing of a viscous polymer melt with the generation of very thin walls or integrated through holes. In case of the CellChip, thin bottom layers are necessary to perforate the polymer and provide small pores of defined size to supply cells with culture medium e.g. by microfluidic perfusion of the containers.
In order to overcome these limitations and to reduce the manufacturing costs we have developed a new microtechnical approach on the basis of a down-scaled thermoforming process. For the manufacturing of highly porous and thin walled polymer chips, we use a combination of heavy ion irradiation, microthermoforming and track etching. In this so called "SMART" process (Substrate Modification And Replication by Thermoforming) thin polymer films are irradiated with energetic heavy projectiles of several hundred MeV introducing so-called "latent tracks" Subsequently, the film in a rubber elastic state is formed into three dimensional parts without modifying or annealing the tracks. After the forming process, selective chemical etching finally converts the tracks into cylindrical pores of adjustable diameter.

We present two processes for the microfabrication of porous polymer chips for three-dimensional cell cultivation. The first one is hot embossing combined with a solvent vapour welding process. The second one uses a recently developed microthermoforming process combined with ion track technology leading to a significant simplification of manufacture.

Microfabbricazione di chip di dimensioni Ponteggi per tridimensionale coltura cellulare

Using microfabrication technologies is a prerequisite to create scaffolds of reproducible geometry and constant quality for three-dimensional cell ...

Zebrafish Brain Ventricle Injection

Proper brain ventricle formation during embryonic brain development is required for normal brain function.  Brain ventricles are the highly conserved cavities within the brain that are filled with cerebrospinal fluid.  In zebrafish, after neural tube formation, the neuroepithelium undergoes a series of constrictions and folds while it fills with fluid resulting in brain ventricle formation.  In order to understand the process of ventricle formation, and the neuroepithelial shape changes that occur at the same time, we needed a way to visualize the ventricle space in comparison to the brain tissue.  However, the nature of transparent zebrafish embryos makes it difficult to differentiate the tissue from the ventricle space.  Therefore, we developed a brain ventricle injection technique where the ventricle space is filled with a fluorescent dye and imaged by brightfield and fluorescent microscopy.  The brightfield and the fluorescent images are then processed and superimposed in Photoshop.  This technique allows for visualization of the ventricle space with the fluorescent dye, in comparison to the shape of the neuroepithelium in the brightfield image.  Brain ventricle injection in zebrafish can be employed from 18 hours post fertilization through early larval stages.  We have used this technique extensively in our studies of brain ventricle formation and morphogenesis as well as in characterizing brain morphogenesis mutants (1-3).

After neural tube formation, the neuroepithelium constricts and folds while the tube fills with embryonic cerebrospinal fluid (eCSF) to form the embryonic brain ventricles. We developed this ventricle injection technique to better visualize the fluid filled space in contrast to the neuroepithelial shape in a live embryo.

Zebrafish Cervello iniezione ventricolo

Proper brain ventricle formation during embryonic brain development is required for normal brain function.  Brain ventricles are the highly conserved ...

The Gateway to the Brain: Dissecting the Primate Eye

The visual system in humans is considered the gateway to the world and plays a principal role in the plethora of sensory, perceptual and cognitive processes. It is therefore not surprising that quality of vision is tied to quality of life . Despite widespread clinical and basic research surrounding the causes of visual disorders, many forms of visual impairments, such as retinitis pigmentosa and macular degeneration, lack effective treatments. Non-human primates have the closest general features of eye development to that of humans. Not only do they have a similar vascular anatomy, but amongst other mammals, primates have the unique characteristic of having a region in the temporal retina specialized for high visual acuity, the fovea1. Here we describe a general technique for dissecting the primate retina to provide tissue for retinal histology, immunohistochemistry, laser capture microdissection, as well as light and electron microscopy. With the extended use of the non-human primate as a translational model, our hope is that improved understanding of the retina will provide insights into effective approaches towards attenuating or reversing the negative impact of visual disorders on the quality of life of affected individuals.

The non-human primate is an important translational species for our understanding of development and aging. The anatomical organization of the primate retina may provide important insights into normal and pathological conditions in humans.

La Porta del Cervello: Dissezione l&#39;Occhio Primate

The visual system in humans is considered the  gateway  to the world and plays a principal role in the plethora of sensory, perceptual and cognitive ...

Intraperitoneal Injection into Adult Zebrafish

A convenient method for chemically treating zebrafish is to introduce the reagent into the tank water, where it will be taken up by the fish. However, this method makes it difficult to know how much reagent is absorbed or taken up per fish. Some experimental questions, particularly those related to metabolic studies, may be better addressed by delivering a defined quantity to each fish, based on weight. Here we present a method for intraperitoneal (IP) injection into adult zebrafish. Injection is into the abdominal cavity, posterior to the pelvic girdle. This procedure is adapted from veterinary methods used for larger fish. It is safe, as we have observed zero mortality. Additionally, we have seen bleeding at the injection site in only 5 out of 127 injections, and in each of those cases the bleeding was brief, lasting several seconds, and the quantity of blood lost was small. Success with this procedure requires gentle handling of the fish through several steps including fasting, weighing, anesthetizing, injection, and recovery. Precautions are required to minimize stress throughout the procedure. Our precautions include using a small injection volume and a 35G needle. We use Cortland salt solution as the vehicle, which is osmotically balanced for freshwater fish. Aeration of the gills is maintained during the injection procedure by first bringing the fish into a surgical plane of anesthesia, which allows slow operculum movements, and second, by holding the fish in a trough within a water-saturated sponge during the injection itself. We demonstrate the utility of IP injection by injecting glucose and monitoring the rise in blood glucose level and its subsequent return to normal. As stress is known to increase blood glucose in teleost fish, we compare blood glucose levels in vehicle-injected and non-injected adults and show that the procedure does not cause a significant rise in blood glucose.

We demonstrate intraperitoneal injection into adult zebrafish. We use a 10 &mu;l NanoFil microsyringe controlled by a Micro4 controller and UltraMicroPump III. This demonstration includes the use of cold water as an anesthetic.

Iniezione intraperitoneale in Zebrafish adulti

A convenient method for chemically treating zebrafish is to introduce the reagent into the tank water, where it will be taken up by the fish. However, ...

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

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

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

Mappatura delle postumi di Theta Burst stimolazione sulla corteccia uditiva umana con imaging funzionale

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

Intraductal Injection for Localized Drug Delivery to the Mouse Mammary Gland

Herein we describe a protocol to deliver various reagents to the mouse mammary gland via intraductal injections. Localized drug delivery and knock-down of genes within the mammary epithelium has been difficult to achieve due to the lack of appropriate targeting molecules that are independent of developmental stages such as pregnancy and lactation. Herein, we describe a technique for localized delivery of reagents to the mammary gland at any stage in adulthood via intraductal injection into the nipples of mice. The injections can be performed on live mice, under anesthesia, and allow for a non-invasive and localized drug delivery to the mammary gland. Furthermore, the injections can be repeated over several months without damaging the nipple. Vital dyes such as Evans Blue are very helpful to learn the technique. Upon intraductal injection of the blue dye, the entire ductal tree becomes visible to the eye. Furthermore, fluorescently labeled reagents also allow for visualization and distribution within the mammary gland. This technique is adaptable for a variety of compounds including siRNA, chemotherapeutic agents, and small molecules.

A protocol for the non-invasive intraductal delivery of aqueous reagents to the mouse mammary gland is described. The method takes advantage of localized injection into the nipples of mammary glands targeting mammary ducts specifically. This technique is adaptable for a variety of compounds including siRNA, chemotherapeutic agents and small molecules.

Iniezione intraduttale per Localizzato Drug Delivery per il mouse ghiandola mammaria

Herein we describe a protocol to deliver various reagents to the mouse mammary gland via intraductal injections. Localized drug delivery and knock-down of ...

Reconstitution of a Transmembrane Protein, the Voltage-gated Ion Channel, KvAP, into Giant Unilamellar Vesicles for Microscopy and Patch Clamp Studies

Giant Unilamellar Vesicles (GUVs) are a popular biomimetic system for studying membrane associated phenomena. However, commonly used protocols to grow GUVs must be modified in order to form GUVs containing functional transmembrane proteins. This article describes two dehydration-rehydration methods &#8212; electroformation and gel-assisted swelling &#8212; to form GUVs containing the voltage-gated potassium channel, KvAP. In both methods, a solution of protein-containing small unilamellar vesicles is partially dehydrated to form a stack of membranes, which is then allowed to swell in a rehydration buffer. For the electroformation method, the film is deposited on platinum electrodes so that an AC field can be applied during film rehydration. In contrast, the gel-assisted swelling method uses an agarose gel substrate to enhance film rehydration. Both methods can produce GUVs in low (e.g., 5 mM) and physiological (e.g., 100 mM) salt concentrations. The resulting GUVs are characterized via fluorescence microscopy, and the function of reconstituted channels measured using the inside-out patch-clamp configuration. While swelling in the presence of an alternating electric field (electroformation) gives a high yield of defect-free GUVs, the gel-assisted swelling method produces a more homogeneous protein distribution and requires no special equipment.

The reconstitution of the transmembrane protein, KvAP, into giant unilamellar vesicles (GUVs) is demonstrated for two dehydration-rehydration methods &#8212; electroformation, and gel-assisted swelling. In both methods, small unilamellar vesicles containing the protein are fused together to form GUVs that can then be studied by fluorescence microscopy and patch-clamp electrophysiology.

Ricostituzione di una proteina transmembrana, la tensione gated canali ionici, KvAP, in Giant unilamellari vescicole per la microscopia e Patch Clamp Studies

Giant Unilamellar Vesicles (GUVs) are a popular biomimetic system for studying membrane associated phenomena. However, commonly used protocols to grow ...

Sampling Blood from the Lateral Tail Vein of the Rat

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

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

Prelievo di sangue dalla vena della coda laterale del Topo

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