Ce travail a été financé par le Centre pour les technologies de la communication neuronale (CNCT), un Centre de ressources P41 financée par l&#39;Institut national d&#39;imagerie biomédicale et de bio-ingénierie (NIBIB, P41 EB002030) et soutenu par le National Institutes of Health (NIH). Les auteurs tiennent à remercier Rio Vetter des Technologies NeuroNexus pour le développement de techniques chirurgicales, et Paras Patel, de l&#39;Université du Michigan pour la compilation de la liste du matériel utilisé lors d&#39;interventions chirurgicales.

1. Pré-implantaire Procédures (commune) <ol><li> Rasage sommet de la tête de l&#39;animal à partir entre les yeux pour bien derrière les oreilles. Utilisez une tondeuse électrique coiffeur pour se raser la tête. Frotter la tête la première avec de l&#39;alcool isopropylique, puis bétadine (répéter 3x). Appliquer un lubrifiant oculaire. </li><li> Monter l&#39;animal dans les bars oreille stéréotaxiques. Diriger la pointe fixe de la barre de l&#39;oreille droite stéréotaxique dans le conduit auditif de l&#39;oreille droite de l&#39;animal en se déplaçant latéralement les têtes contre le canal. Un soin extrême doit être pris pour assurer que chaque embout-bar est correctement positionné dans le conduit auditif. Ensuite, appuyez sur la barre de l&#39;oreille gauche desserré dans le conduit auditif et appliquer une légère pression vers l&#39;intérieur. Saisissez le nez de l&#39;animal et il se tortillent en arrière fermement. Si l&#39;animal est correctement monté la tête se sentent monté de façon rigide. </li></ol> 2. Chirurgie pré-implantatoire (commune) <ol><li> Avec une paire de ciseaux fins, couper deux circ moitiéles médianes des vers l &#39;extérieur, enlever partiellement le cuir chevelu </li><li> Gratter et enlever le tissu conjonctif du périoste qui adhère à l&#39;os. Grattant avec un bord émoussé comme le dos d&#39;une lame de scalpel ou la pointe d&#39;un coton-tige stérile minimiser les saignements parce que la capillaires seront écrasés plutôt que de couper en douceur. Saignements osseux de contrôle utilisant de la cire d&#39;os ou d&#39;un fer à cautériser. </li><li> Désinfecter et nettoyer la surface de l&#39;os à l&#39;aide de peroxyde d&#39;hydrogène. Sécher l&#39;os pour faire les sutures crâniennes plus clairement visible. Le Bregma et les points lambda doit être noté et utilisé pour niveler la tête. L&#39;emplacement de la craniotomie et l&#39;implant d&#39;électrode doit être mesurée par rapport à Bregma et peut être temporairement marquée avec un stylo ou en perçant superficiellement dans la surface. L&#39;emplacement craniotomie dépendra des objectifs expérimentaux de l&#39;étude (c.-à-moteur, des expériences sensorielles) 1. </li><li> Percer trous de vis dans l&#39;os et placer le sol et la stabilisation séquipages. Toujours utiliser de l&#39;acier inoxydable ou des vis en titane. Bijoutier Small vis (par exemple # 2-56, 00-80 ou #) avec autant de threads par pouce que possible est souhaitable. </li></ol> 3. Procédures de silicium électrode implant <ol><li> Percer la craniotomie après l&#39;implantation vis. Percez quatre marques pilotes peu profonds pour les coins de la craniotomie. Utilisation de marques pilotes comme un guide percer le périmètre de la craniotomie. Retirez le centre de masse de l&#39;os qui n&#39;a pas été foré à l&#39;aide d&#39;une paire de pinces robustes. Le bord de la craniotomie ouverte peut être nécessaire de nettoyer avec d&#39;autres forages. Pièces minces d&#39;os peut être découpé avec une paire de microrongeurs. Planifiez votre chirurgie avec soin pour éviter les principaux vaisseaux sanguins tels que le sinus longitudinal, qui peuvent apparaître dans les 0,5 mm de la suture médiane longitudinale 1. La ponction du sinus sagittal peut provoquer des saignements importants. Dure-mère exposée devrait être maintenu hydraté avec aCSF ou une solution saline. </li><li> À percer la dure-mèrevous aurez besoin à la mode un petit crochet à l&#39;aide d&#39;une aiguille hypodermique stérile de petit calibre (par exemple, &lt;jauge 28). Prenez le biseau de l&#39;aiguille et appuyer à plat contre une surface dure (comme la partie plate d&#39;un scalpel) basculant légèrement pour former un coude à 90 degrés au point. Utilisation ce crochet de capture à la surface de la dure-mère, et tirer vers le haut depuis la surface du cerveau. La dure-mère peut être coupé avec des ciseaux ou micro peut être déchiré par des mouvements latéraux du crochet-mère. Prenez soin d&#39;éviter les vaisseaux sanguins sur la surface du cerveau lors de l&#39;utilisation du crochet-mère. Vous devriez remarquer CSF fuite quand mère est réséqué et une différence de couleur de la surface de la dure-mère. </li><li> Fixez soigneusement le fil de terre de l&#39;électrode de silicium autour de la base de la vis de terre, et de tact en place avec du ciment dentaire. Les électrodes de silicium doivent être placés avec soin afin que les fils électrodes câbles sont arqués au cours de la craniotomie. </li><li> Implants sera placé en utilisant un moteur linéaire actionneur placed sur un appareil de stéréotaxie. À fixer l&#39;électrode au dispositif d&#39;insertion, de polyéthylène glycol (PEG) est chauffé avec un fer à souder et appliqué à l&#39;insertion de tige et l&#39;électrode d&#39;enregistrement. </li><li> Avec l&#39;électrode fixée, manuellement abaisser la pointe de l&#39;électrode à l&#39;emplacement souhaité stéréotaxique sur la surface du cerveau. </li><li> Utilisation de l&#39;interface logicielle à l&#39;actionneur linéaire, déplacer l&#39;électrode dans la profondeur désirée dans le tissu cérébral. </li><li> Fixez l&#39;électrode d&#39;enregistrement dans le cerveau en attachant PEG à partir d&#39;une vis à côté de la câble de l&#39;électrode. Vous pouvez maintenant supprimer l&#39;électrode de l&#39;appareil d&#39;insertion par l&#39;ajout de sérum physiologique pour dissoudre le PEG lié. Soulever le dispositif d&#39;insertion loin de la craniotomie et répéter pour chaque électrode. </li><li> Couvrir la craniotomie exposée avec Gelfoam imbibé solution saline. Un polymère de silicone est ensuite utilisée pour couvrir le câble de l&#39;électrode et le protéger de l&#39;acrylique dentaire. Placez le connecteur dans la finaleemplacement, puis appliquer acrylique dentaire pour faire une coiffe robuste. </li></ol> 4. MicroECoG procédures d&#39;implantation des électrodes <ol><li> L&#39;implantation de l&#39;électrode microECoG impliquera une craniotomie légèrement plus grand. Pour un dispositif 5 x 5 mm, une craniotomie 6 x 6 mm doit être faite. Avant de percer la craniotomie, à séchage UV acrylique dentaire est appliqué à la périphérie du site craniotomie alors qu&#39;il est encore sec et ne risque pas de toucher la mère ou pie. </li><li> Une perceuse chirurgicale stérile est utilisé avec une fraise n ° 107 de percer hors de la surface de l&#39;os dans la forme générale de la craniotomie. Le plus petit N ° 106 bavure peut alors être utilisé pour percer le reste de l&#39;os vers le bas pour une couche mince et transparente. Rongeurs sera alors en mesure de soulever le morceau restant de l&#39;os. Le microECoG peut être implanté par voie péridurale ou sous-durale. Encore une fois, gardez la dure-mère bien hydraté avec le LCR artificiel ou Saline. </li><li> Afin d&#39;implanter le microECoG, placez un bras stéréotaxique sur l&#39;OPEcrâne n, et fixer l&#39;électrode sur le bras de l&#39;aide de ruban stérile. L&#39;électrode peut maintenant être abaissée dans la craniotomie. Assurez-vous que les sites d&#39;électrodes sont orientés vers le bas et sera en contact avec la dure-mère ou surface piale. Si maintenu humide, l&#39;électrode doit glisser sur le tissu et restera en place. </li><li> Le fil de terre est reliée à la vis de terre par enroulement autour d&#39;au moins trois fois sur et sous elle-même. La vis de terre peut être n&#39;importe quel vis qui a été en contact avec la dure-mère. Le fil de référence est également lié à la vis de référence de la même manière. </li><li> De petits morceaux de Gelfoam imbibé solution saline doit être placé autour de l&#39;électrode où il ya pia-mère ou exposés. Une petite quantité de solution saline Gelfoam imbibé devrait également couvrir la partie supérieure de l&#39;électrode à couche mince. Acrylique durcissable aux UV dentaire peut être appliquée à la partie supérieure de la Gelfoam et peut être utilisé pour créer un capuchon de tête stables. Le acrylique est appliquée directement sur la couche mince câble Covering jusqu&#39;à ce que le connecteur est atteinte. Soyez prudent de ne pas couvrir au-delà du fond de la protection du connecteur. </li><li> Alternativement, l&#39;implantation de la microECoG en 4.3 peut être immédiatement suivie par l&#39;implantation d&#39;une matrice de microélectrodes de silicium (étapes 3.2-3.6) par de petits trous qui sont fabriqués dans le substrat microECoG. Cela permet pour l&#39;enregistrement simultané de deux unités simples à différentes profondeurs le long avec des enregistrements de haute résolution sur le terrain de la surface du cerveau environnant. </li></ol> 5. Récupération post-opératoire <ol><li> Après que le ciment a complètement durci, suturer la peau étroitement autour de la tête-de plafonnement et d&#39;enlever l&#39;animal de la cadre de stéréotaxie. </li><li> Appliquer la poudre antiseptique ou une pommade antibiotique copieusement autour de la plaie. S&#39;il ya un saignement des oreilles, placer une partie bien aux antibiotiques dans le canal auditif. </li><li> Gardez l&#39;animal au chaud que les barbituriques empêcher l&#39;animal de maintenir sa chaleur corporelle. Maison each implantés chroniquement animal dans une cage séparée. Il prend habituellement de quatre à sept jours pour l&#39;animal de se remettre complètement de la chirurgie. </li></ol> 6. Les résultats représentatifs Une chirurgie réussie de silicium électrode implant aura l&#39;enregistrement des sites avec des impédances de mesure entre 500kohm-2MOhm, et en couches minces électrodes entre 10kOhm-50kOhm (à 1kHz). Le signal neuronal peut être vérifiée immédiatement après la chirurgie ainsi. Vous devriez être capable de voir des pointes sur les électrodes implantées et voir les oscillations d&#39;ondes lentes sur l&#39;électrode de surface du film mince (Figure 1). <img src="/files/ftp_upload/3565/3565fig1.jpg" alt="Figure 1" /> Figure 1. Les résultats représentatifs de l&#39;activité seule unité, et les oscillations ECOG. A) à large bande de données à partir de 6 canaux simultanément enregistrées d&#39;une électrode de silicium chronique implanté dans le néocortex. Notez que les pointes peuvent souvent être vus à travers les sites d&#39;enregistrement. b) EOscillations CoG de 6 canaux d&#39;un 16-canal à film mince à groupement d&#39;électrodes uECoG sur la surface du cerveau. La moyenne de tous les signaux 16 ont été retirés de chaque trace (référencement moyenne commune), et une 500 Hz filtre numérique passe-bas a été appliquée.

<ol>
	<li>Paxinos, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Rat Brain in Stereotaxic Coordinates. , (2007).</li><li>Fujisawa, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavior-dependent+short-term+assembly+dynamics+in+the+medial+prefrontal+cortex.">Behavior-dependent short-term assembly dynamics in the medial prefrontal cortex.</a> Nat. Neurosci. 11 (7), 823-833 (2008).</li><li>Merrill, D. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrical+stimulation+of+excitable+tissue:+design+of+efficacious+and+safe+protocols.">Electrical stimulation of excitable tissue: design of efficacious and safe protocols.</a> J. Neurosci. Methods. 141, 171-171 (2005).</li><li>Gage, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Naive+coadaptive+cortical+control.">Naive coadaptive cortical control.</a> J. Neural Eng. 2, 52-52 (2005).</li><li>Marzullo, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+Closed-Loop+Neural+Interface+Technology+in+a+Rat+Model:+Combining+Motor+Cortex+Operant+Conditioning+With+Visual+Cortex+Microstimulation.">Development of Closed-Loop Neural Interface Technology in a Rat Model: Combining Motor Cortex Operant Conditioning With Visual Cortex Microstimulation.</a> IEEE Trans. Neur. Sys. and Rehab. Eng. 18 (2), 117-126 (2010).</li><li>Maynard, E. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Utah+intracortical+electrode+array:+a+recording+structure+for+potential+brain-computer+interfaces.">The Utah intracortical electrode array: a recording structure for potential brain-computer interfaces.</a> Electroencephalogr. Clin. Neurophysiol. 102, 228-239 (1997).</li><li>Kipke, D. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silicon-substrate+intracortical+microelectrode+arrays+for+long-term+recording+of+neuronal+spike+activity+in+cerebral+cortex.">Silicon-substrate intracortical microelectrode arrays for long-term recording of neuronal spike activity in cerebral cortex.</a> IEEE Trans. Neural Syst. Rehab. Eng. 11 (2), 151-155 (2003).</li><li>Vetter, R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chronic+neural+recording+using+silicon-substrate+microelectrode+arrays+implanted+in+cerebral+cortex.">Chronic neural recording using silicon-substrate microelectrode arrays implanted in cerebral cortex.</a> IEEE Trans. Biomed. Eng. 51 (6), 896-904 (2004).</li></ol>

DRK est en partie propriétaire de Technologies NeuroNexus.

Il ya un intérêt croissant pour l&#39;utilisation et la surface intracorticales interfaces d&#39;enregistrement multicanaux pour la recherche 2 le fonctionnement du cerveau, fournissant microstimulation 3, ou des signaux de contrôle pour les systèmes de neuroprothèses 4,5. Les méthodes décrites dans cette vidéo montrent comment implanter chroniques systèmes d&#39;électrodes de pénétration et de surface. Alors que d&#39;autres systèmes de silicium d&#39;électrodes chroniques existent 6, nous nous sommes concentrés sur l&#39;implantation d&#39;électrodes planes développées par NeuroNexus Technologies 7,8. Techniques pour l&#39;implantation de systèmes d&#39;électrodes en d&#39;autres varient considérablement. Parmi les étapes chirurgicales décrites, de montage de l&#39;animal dans les barres d&#39;oreilles stéréotaxiques peut être la plus difficile et la plus importante étape dans la détermination de la précision de placement des électrodes implantées. Un soin extrême doit être prise, par conséquent, à supposer que chaque embout-bar est correctement positionné dans le conduit auditif. Après Assurance que le sommet de l&#39;épi-bar est dans le conduit auditif de l&#39;oreille droite de l&#39;animal, relâchez le cou de l&#39;animal avec votre main droite pendant que votre pouce gauche et l&#39;index continuer à soutenir la tête et appliquer une pression de la tête contre le sommet de l&#39;épi-bar. Avec votre main droite, pousser la barre oreille gauche desserré dans le conduit auditif et appliquer une légère pression vers l&#39;intérieur. Déplacer le côté gauche de la tête de l&#39;animal vers le bas et vers l&#39;avant et tout autour de jusqu&#39;à ce que vous pouvez sentir le glissement pointe l&#39;oreille gauche-bar dans le conduit auditif. Avec votre main droite, continuer à faire pression sur la barre de l&#39;oreille gauche. Relâchez la tête de l&#39;animal et, avec votre main gauche maintenant libre, serrer la vis de réglage de la barre de l&#39;oreille gauche.

<table border="1"><tbody><tr><td> Équipement </td><td> Entreprise </td><td> Numéro de catalogue </td><td> Commentaires </td></tr><tr><td> Vis osseuse - # 2-56 x 3/16, Phillips à tête cylindrique, 18-8 S / S </td><td> BoltDepot </td><td> 7650 </td><td></td></tr><tr><td> Vis osseuse - # 2-56 x 1/8, phillips à tête cylindrique, 18-8 S / S </td><td> BoltDepot </td><td> 9617 </td><td></td></tr><tr><td> Oxygen Tank Grand - K Taille </td><td> Gaz cryogéniques </td><td> OXKME </td><td></td></tr><tr><td> Oxygen Tank Petit - E Taille </td><td> Gaz cryogéniques </td><td> OXYE-AL </td><td></td></tr><tr><td> Vannas-Tübingen Ciseaux printemps - 2,5 mm de lame, angle </td><td> Outils belle science </td><td> 15002-08 </td><td></td></tr><tr><td> Dumont n ° 5 Pince, Teflon </td><td> Outils belle science </td><td> 11626-11 </td><td></td></tr><tr><td> Dumont n ° 5 Pince, Dumostar </td><td> Outils belle science </td><td> 11295-10 </td><td></td></tr><tr><td> Étudiant Vannas Ciseaux printemps </td><td> Outils belle science </td><td> 91500-09 </td><td></td></tr><tr><td> Adson Pince </td><td> Outils belle science </td><td> 11006-12 </td><td></td></tr><tr><td> Friendman-Pearson Ronqeur, courbé </td><td> Outils belle science </td><td> 16221-14 </td><td></td></tr><tr><td> Ciseaux Iris - ToughCut </td><td> Outils belle science </td><td> 14058-11 </td><td></td></tr><tr><td> Vannas-Tübingen Ciseaux Spring - Lame 5mm, Droit </td><td> Fine des sciences Outils </td><td> 15003-08 </td><td></td></tr><tr><td> Manche de bistouri </td><td> Outils belle science </td><td> 10003-12 </td><td></td></tr><tr><td> Boîte de stérilisation en plastique </td><td> Outils belle science </td><td> 20810-02 </td><td></td></tr><tr><td> Inoxydable règle en acier </td><td> Outils belle science </td><td> 30086-15 </td><td></td></tr><tr><td> Probe &amp; Spatule - 14cm Straight </td><td> Outils belle science </td><td> 10090-13 </td><td></td></tr><tr><td> Hémostatique droite </td><td> Outils belle science </td><td> 13002-10 </td><td></td></tr><tr><td> Hémostatique courbé </td><td> Outils belle science </td><td> 13003-10 </td><td></td></tr><tr valign="bottom"><td> Micro Drill StaBavures en acier inless - 0.7mm </td><td> Outils belle science </td><td> 19008-07 </td><td> Pack de 10 </td></tr><tr valign="bottom"><td> Micro bavures foreuse en acier inoxydable - 0,5 mm </td><td> Outils belle science </td><td> 19007-05 </td><td> Pack de 10 </td></tr><tr valign="bottom"><td> Vis à os auto-taraudeuses - 1.17mm (diam) - 4.7mm (longueur) </td><td> Outils belle science </td><td> 19010-00 </td><td> 100/Pack </td></tr><tr valign="bottom"><td> Artificial Tears </td><td> Pêcheur </td><td> NC9860842 </td><td> Chaque </td></tr><tr valign="bottom"><td> Betadine </td><td> Pêcheur </td><td> 19-066452 </td><td> Bouteille </td></tr><tr valign="bottom"><td> Filtres à charbon F-AIR </td><td> Pêcheur </td><td> NC9112250 </td><td> Boîte </td></tr><tr valign="bottom"><td> Coton applicateur à pointe, non stérile </td> &lt;services td Matériel&gt; </td><td> 1104 </td><td> 10Pack/Case </td></tr><tr valign="bottom"><td> Gaze 2 &quot;x 2&quot; </td><td> Services du matériel </td><td> 1630 </td><td> 25Pack/Case </td></tr><tr valign="bottom"><td> Pointe de l&#39;aiguille, 23 GA x 1 &quot; </td><td> Services du matériel </td><td> 39412 </td><td> Vendu par cas </td></tr><tr valign="bottom"><td> Pointe de l&#39;aiguille, 27 x GA 1.25 &quot; </td><td> Services du matériel </td><td> 25251 </td><td></td></tr><tr valign="bottom"><td> Pointe de l&#39;aiguille, 30 x GA 0.5 &quot; </td><td> Services du matériel </td><td> 22023 </td><td> 10Box/Case </td></tr><tr valign="bottom"><td> Pommade, 0,6 g Triple Antibiotic </td><td> Services du matériel </td><td> 2528 </td><td></td></tr><tr valign="bottom"><td> Pochette, Auto Seal stérilisation griffoir<html> s, 3,5 &quot;x 8&quot; </td><td> Services du matériel </td><td> 1023 </td><td> 10Box/Case </td></tr><tr valign="bottom"><td> Sonneries Solution 1000ml </td><td> Services du matériel </td><td> 5263 </td><td> 12Bag/Case </td></tr><tr valign="bottom"><td> Lame de bistouri stérile jetable N ° 15 </td><td> Services du matériel </td><td> 1975 </td><td> 3Box/Case </td></tr><tr valign="bottom"><td> Suture, Nylon w/P-3 aiguille, 5-0, 18po. </td><td> Services du matériel </td><td> 4618 </td><td> 12/boîte </td></tr><tr valign="bottom"><td> Thibaude, jetable 23 &quot;x 36&quot; </td><td> Services du matériel </td><td> 2545 </td><td> 15Pack/Case </td></tr><tr valign="bottom"><td> Lubrifiant, Jelly chirurgical stérile </td><td> Services du matériel </td><td> 2538 </td><td> 12Box/Case </td></tr>&quot;&gt; <td> Résorbable Gel Moussant 2cmx6cmx7mm </td><td> Services du matériel </td><td> 3107 </td><td></td></tr><tr valign="bottom"><td> Six Jeu de tournevis Piece Set-vis </td><td> Jewelers nationale fournitures </td><td> ETSCR98001 </td><td></td></tr><tr valign="bottom"><td> Kwik Sil adhésif </td><td> WPI </td><td> KWIK-SIL </td><td></td></tr><tr valign="bottom"><td> Kwik Sil Tubes </td><td> WPI </td><td> 600009 </td><td></td></tr><tr valign="top"><td> Électrodes de silicium chroniques de 16 à 64 sites </td><td> Technologies NeuroNexus </td><td> Varie sur la conception de la sonde </td><td></td></tr><tr valign="top"><td> Chroniques minces électrodes de surface du film (microECoG) de 16 à 32 sites </td><td> Technologies NeuroNexus </td><td> Varie sur la conception de la sonde </td><td>&nbsp;
 </td>
 </tr>
 </tbody>
</table>

surgical implantation of chronic neural electrodes for recording single unit activity and electrocorticographic signals

Le succès à long terme des enregistrements électrophysiologiques dépend souvent de la qualité de la chirurgie d&#39;implantation. Ici, nous fournir des informations utiles pour les chirurgiens qui apprennent le processus d&#39;implantation de systèmes d&#39;électrodes. Nous démontrons la procédure d&#39;implantation à la fois une pénétration et une électrode de surface. Le processus chirurgical est décrit à partir de début à la fin, y compris des descriptions détaillées de chaque étape tout au long de la procédure. Il convient également de noter que ce guide est axé vers la vidéo des procédures menées dans des modèles de rongeurs et d&#39;autres modèles de petits animaux. Les modifications des procédures décrites sont réalisables pour d&#39;autres modèles animaux.

Watch this Scientific Journal Video about Surgical Implantation of Chronic Neural Electrodes for Recording Single Unit Activity and Electrocorticographic Signals at JoVE.com

Surgical Implantation of Chronic Neural Electrodes for Recording Single Unit Activity and Electrocorticographic Signals

Nous fournir des informations utiles pour les chirurgiens qui apprennent le processus d&#39;implantation d&#39;électrodes d&#39;enregistrement chroniques neural. Techniques de systèmes d&#39;électrodes à la fois pénétrantes et de surface sont décrits dans un modèle animal rongeur.

L&#39;implantation chirurgicale d&#39;électrodes neurales chroniques pour l&#39;enregistrement d&#39;activité Unité unique et Signaux Electrocorticographic

The success of long-term electrophysiological recordings often depends on the quality of the implantation surgery.  Here we provide useful information for ...

surgical-implantation-chronic-neural-electrodes-for-recording-single

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Neuroscience

47.1K vues.  University of Michigan. Nous fournir des informations utiles pour les chirurgiens qui apprennent le processus d'implantation d'électrodes d'enregistrement chroniques neural. Techniques de systèmes d'électrodes à la fois pénétrantes et de surface sont décrits dans un modèle animal rongeur.

Vidéo: Surgical Implantation of Chronic Neural Electrodes for Recording Single Unit Activity and Electrocorticographic Signals

Recording Human Electrocorticographic (ECoG) Signals for Neuroscientific Research and Real-time Functional Cortical Mapping

Neuroimaging studies of human cognitive, sensory, and motor processes are usually based on noninvasive techniques such as electroencephalography (EEG), magnetoencephalography or functional magnetic-resonance imaging. These techniques have either inherently low temporal or low spatial resolution, and suffer from low signal-to-noise ratio and/or poor high-frequency sensitivity. Thus, they are suboptimal for exploring the short-lived spatio-temporal dynamics of many of the underlying brain processes. In contrast, the invasive technique of electrocorticography (ECoG) provides brain signals that have an exceptionally high signal-to-noise ratio, less susceptibility to artifacts than EEG, and a high spatial and temporal resolution (i.e., &lt;1 cm/&lt;1 millisecond, respectively). ECoG involves measurement of electrical brain signals using electrodes that are implanted subdurally on the surface of the brain. Recent studies have shown that ECoG amplitudes in certain frequency bands carry substantial information about task-related activity, such as motor execution and planning1, auditory processing2 and visual-spatial attention3. Most of this information is captured in the high gamma range (around 70-110 Hz). Thus, gamma activity has been proposed as a robust and general indicator of local cortical function1-5. ECoG can also reveal functional connectivity and resolve finer task-related spatial-temporal dynamics, thereby advancing our understanding of large-scale cortical processes. It has especially proven useful for advancing brain-computer interfacing (BCI) technology for decoding a user's intentions to enhance or improve communication6 and control7. Nevertheless, human ECoG data are often hard to obtain because of the risks and limitations of the invasive procedures involved, and the need to record within the constraints of clinical settings. Still, clinical monitoring to localize epileptic foci offers a unique and valuable opportunity to collect human ECoG data. We describe our methods for collecting recording ECoG, and demonstrate how to use these signals for important real-time applications such as clinical mapping and brain-computer interfacing. Our example uses the BCI2000 software platform8,9 and the SIGFRIED10 method, an application for real-time mapping of brain functions. This procedure yields information that clinicians can subsequently use to guide the complex and laborious process of functional mapping by electrical stimulation.
Prerequisites and Planning:
Patients with drug-resistant partial epilepsy may be candidates for resective surgery of an epileptic focus to minimize the frequency of seizures. Prior to resection, the patients undergo monitoring using subdural electrodes for two purposes: first, to localize the epileptic focus, and second, to identify nearby critical brain areas (i.e., eloquent cortex) where resection could result in long-term functional deficits. To implant electrodes, a craniotomy is performed to open the skull. Then, electrode grids and/or strips are placed on the cortex, usually beneath the dura. A typical grid has a set of 8 x 8 platinum-iridium electrodes of 4 mm diameter (2.3 mm exposed surface) embedded in silicon with an inter-electrode distance of 1cm. A strip typically contains 4 or 6 such electrodes in a single line. The locations for these grids/strips are planned by a team of neurologists and neurosurgeons, and are based on previous EEG monitoring, on a structural MRI of the patient's brain, and on relevant factors of the patient's history. Continuous recording over a period of 5-12 days serves to localize epileptic foci, and electrical stimulation via the implanted electrodes allows clinicians to map eloquent cortex. At the end of the monitoring period, explantation of the electrodes and therapeutic resection are performed together in one procedure.
In addition to its primary clinical purpose, invasive monitoring also provides a unique opportunity to acquire human ECoG data for neuroscientific research. The decision to include a prospective patient in the research is based on the planned location of their electrodes, on the patient's performance scores on neuropsychological assessments, and on their informed consent, which is predicated on their understanding that participation in research is optional and is not related to their treatment. As with all research involving human subjects, the research protocol must be approved by the hospital's institutional review board. The decision to perform individual experimental tasks is made day-by-day, and is contingent on the patient's endurance and willingness to participate. Some or all of the experiments may be prevented by problems with the clinical state of the patient, such as post-operative facial swelling, temporary aphasia, frequent seizures, post-ictal fatigue and confusion, and more general pain or discomfort.
At the Epilepsy Monitoring Unit at Albany Medical Center in Albany, New York, clinical monitoring is implemented around the clock using a 192-channel Nihon-Kohden Neurofax monitoring system. Research recordings are made in collaboration with the Wadsworth Center of the New York State Department of Health in Albany. Signals from the ECoG electrodes are fed simultaneously to the research and the clinical systems via splitter connectors. To ensure that the clinical and research systems do not interfere with each other, the two systems typically use separate grounds. In fact, an epidural strip of electrodes is sometimes implanted to provide a ground for the clinical system. Whether research or clinical recording system, the grounding electrode is chosen to be distant from the predicted epileptic focus and from cortical areas of interest for the research. Our research system consists of eight synchronized 16-channel g.USBamp amplifier/digitizer units (g.tec, Graz, Austria). These were chosen because they are safety-rated and FDA-approved for invasive recordings, they have a very low noise-floor in the high-frequency range in which the signals of interest are found, and they come with an SDK that allows them to be integrated with custom-written research software. In order to capture the high-gamma signal accurately, we acquire signals at 1200Hz sampling rate-considerably higher than that of the typical EEG experiment or that of many clinical monitoring systems. A built-in low-pass filter automatically prevents aliasing of signals higher than the digitizer can capture. The patient's eye gaze is tracked using a monitor with a built-in Tobii T-60 eye-tracking system (Tobii Tech., Stockholm, Sweden). Additional accessories such as joystick, bluetooth Wiimote (Nintendo Co.), data-glove (5th Dimension Technologies), keyboard, microphone, headphones, or video camera are connected depending on the requirements of the particular experiment.
Data collection, stimulus presentation, synchronization with the different input/output accessories, and real-time analysis and visualization are accomplished using our BCI2000 software8,9. BCI2000 is a freely available general-purpose software system for real-time biosignal data acquisition, processing and feedback. It includes an array of pre-built modules that can be flexibly configured for many different purposes, and that can be extended by researchers' own code in C++, MATLAB or Python. BCI2000 consists of four modules that communicate with each other via a network-capable protocol: a Source module that handles the acquisition of brain signals from one of 19 different hardware systems from different manufacturers; a Signal Processing module that extracts relevant ECoG features and translates them into output signals; an Application module that delivers stimuli and feedback to the subject; and the Operator module that provides a graphical interface to the investigator.
A number of different experiments may be conducted with any given patient. The priority of experiments will be determined by the location of the particular patient's electrodes. However, we usually begin our experimentation using the SIGFRIED (SIGnal modeling For Realtime Identification and Event Detection) mapping method, which detects and displays significant task-related activity in real time. The resulting functional map allows us to further tailor subsequent experimental protocols and may also prove as a useful starting point for traditional mapping by electrocortical stimulation (ECS).
Although ECS mapping remains the gold standard for predicting the clinical outcome of resection, the process of ECS mapping is time consuming and also has other problems, such as after-discharges or seizures. Thus, a passive functional mapping technique may prove valuable in providing an initial estimate of the locus of eloquent cortex, which may then be confirmed and refined by ECS. The results from our passive SIGFRIED mapping technique have been shown to exhibit substantial concurrence with the results derived using ECS mapping10.
The protocol described in this paper establishes a general methodology for gathering human ECoG data, before proceeding to illustrate how experiments can be initiated using the BCI2000 software platform. Finally, as a specific example, we describe how to perform passive functional mapping using the BCI2000-based SIGFRIED system.

Recording Human Electrocorticographic ECoG Signals for Neuroscientific Research and Real-time Functional Cortical Mapping

We present a method for collecting electrocorticographic signals for research purposes from humans who are undergoing invasive epilepsy monitoring. We show how to use the BCI2000 software platform for data collection, signal processing and stimulus presentation. Specifically, we demonstrate SIGFRIED, a BCI2000-based tool for real-time functional brain mapping.

Enregistrement de l&#39;homme (Electrocorticographic ECoG) Signaux pour la recherche neuroscientifique et en temps réel la cartographie fonctionnelle corticale

Neuroimaging studies of human cognitive, sensory, and motor processes are usually based on noninvasive techniques such as electroencephalography (EEG), ...

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Neurosciences

Optical Recording of Suprathreshold Neural Activity with Single-cell and Single-spike Resolution

Signaling of information in the vertebrate central nervous system is often carried by populations of neurons rather than individual neurons. Also propagation of suprathreshold spiking activity involves populations of neurons. Empirical studies addressing cortical function directly thus require recordings from populations of neurons with high resolution. Here we describe an optical method and a deconvolution algorithm to record neural activity from up to 100 neurons with single-cell and single-spike resolution. This method relies on detection of the transient increases in intracellular somatic calcium concentration associated with suprathreshold electrical spikes (action potentials) in cortical neurons. High temporal resolution of the optical recordings is achieved by a fast random-access scanning technique using acousto-optical deflectors (AODs)1. Two-photon excitation of the calcium-sensitive dye results in high spatial resolution in opaque brain tissue2. Reconstruction of spikes from the fluorescence calcium recordings is achieved by a maximum-likelihood method. Simultaneous electrophysiological and optical recordings indicate that our method reliably detects spikes (&gt;97% spike detection efficiency), has a low rate of false positive spike detection (&lt; 0.003 spikes/sec), and a high temporal precision (about 3 msec) 3. This optical method of spike detection can be used to record neural activity in vitro and in anesthetized animals in vivo3,4.

Understanding the function of the vertebrate central nervous system requires recordings from many neurons because cortical function arises on the level of populations of neurons. Here we describe an optical method to record suprathreshold neural activity with single-cell and single-spike resolution, dithered random-access scanning. This method records somatic fluorescence calcium signals from up to 100 neurons with high temporal resolution. A maximum-likelihood algorithm deconvolves the underlying suprathreshold neural activity from the somatic fluorescence calcium signals. This method reliably detects spikes with high detection efficiency and a low rate of false positives and can be used to study neural populations in vitro and in vivo.

D&#39;enregistrement optique de l&#39;activité neuronale supraliminaire avec une résolution à cellule unique et un seul pic

Signaling of information in the vertebrate central nervous system is often carried by populations of neurons rather than individual neurons. Also ...

Multi-unit Recording Methods to Characterize Neural Activity in the Locust (Schistocerca Americana) Olfactory Circuits

Detection and interpretation of olfactory cues are critical for the survival of many organisms. Remarkably, species across phyla have strikingly similar olfactory systems suggesting that the biological approach to chemical sensing has been optimized over evolutionary time1. In the insect olfactory system, odorants are transduced by olfactory receptor neurons (ORN) in the antenna, which convert chemical stimuli into trains of action potentials. Sensory input from the ORNs is then relayed to the antennal lobe (AL; a structure analogous to the vertebrate olfactory bulb). In the AL, neural representations for odors take the form of spatiotemporal firing patterns distributed across ensembles of principal neurons (PNs; also referred to as projection neurons)2,3. The AL output is subsequently processed by Kenyon cells (KCs) in the downstream mushroom body (MB), a structure associated with olfactory memory and learning4,5. Here, we present electrophysiological recording techniques to monitor odor-evoked neural responses in these olfactory circuits.
First, we present a single sensillum recording method to study odor-evoked responses at the level of populations of ORNs6,7. We discuss the use of saline filled sharpened glass pipettes as electrodes to extracellularly monitor ORN responses. Next, we present a method to extracellularly monitor PN responses using a commercial 16-channel electrode3. A similar approach using a custom-made 8-channel twisted wire tetrode is demonstrated for Kenyon cell recordings8. We provide details of our experimental setup and present representative recording traces for each of these techniques.

Multi-unit Recording Methods to Characterize Neural Activity in the Locust Schistocerca Americana Olfactory Circuits

We demonstrate variations of the extracellular multi-unit recording technique to characterize odor-evoked responses in the first three stages of the invertebrate olfactory pathway. These techniques can easily be adapted to examine ensemble activity in other neural systems as well.

Méthodes d&#39;enregistrement multi-unités pour caractériser l&#39;activité neuronale dans le Criquet (<em&gt; Schistocerca americana</em&gt; Circuits olfactifs)

Detection and interpretation of olfactory cues are critical for the survival  of many organisms. Remarkably, species across phyla have strikingly similar ...

A Method for Systematic Electrochemical and Electrophysiological Evaluation of Neural Recording Electrodes

New materials and designs for neural implants are typically tested separately, with a demonstration of performance but without reference to other implant characteristics.&#160;This precludes a rational selection of a particular implant as optimal for a particular application and the development of new materials based on the most critical performance parameters.&#160;This article develops a protocol for in vitro and in vivo testing of neural recording electrodes.&#160;Recommended parameters for electrochemical and electrophysiological testing are documented with the key steps and potential issues discussed.&#160;This method eliminates or reduces the impact of many systematic errors present in simpler in vivo testing paradigms, especially variations in electrode/neuron distance and between animal models.&#160;The result is a strong correlation between the critical in vitro and in vivo responses, such as impedance and signal-to-noise ratio.&#160;This protocol can easily be adapted to test other electrode materials and designs.&#160;The in vitro techniques can be expanded to any other nondestructive method to determine further important performance indicators.&#160;The principles used for the surgical approach in the auditory pathway can also be modified to other neural regions or tissue.

Different electrode coatings affect neural recording performance through changes to electrochemical, chemical and mechanical properties. Comparison of electrodes in vitro is relatively simple, however comparison of in vivo response is typically complicated by variations in electrode/neuron distance and between animals. This article provides a robust method to compare neural recording electrodes.

Une méthode pour électrochimique systématique et l&#39;évaluation électrophysiologique des neurones électrodes d&#39;enregistrement

New materials and designs for neural implants are typically tested separately, with a demonstration of performance but without reference to other implant ...

Extracellular Recording of Neuronal Activity Combined with Microiontophoretic Application of Neuroactive Substances in Awake Mice

Differences in the activity of neurotransmitters and neuromodulators, and consequently different neural responses, can be found between anesthetized and awake animals. Therefore, methods allowing the manipulation of synaptic systems in awake animals are required in order to determine the contribution of synaptic inputs to neuronal processing unaffected by anesthetics. Here, we present methodology for the construction of electrodes to simultaneously record extracellular neural activity and release multiple neuroactive substances at the vicinity of the recording sites in awake mice. By combining these procedures, we performed microiontophoretic injections of gabazine to selectively block GABAA receptors in neurons of the inferior colliculus of head-restrained mice. Gabazine successfully modified neural response properties such as the frequency response area and stimulus-specific adaptation. Thus, we demonstrate that our methods are suitable for recording single-unit activity and for dissecting the role of specific neurotransmitter receptors in auditory processing.
The main limitation of the described procedure is the relatively short recording time (~3 hr), which is determined by the level of habituation of the animal to the recording sessions. On the other hand, multiple recording sessions can be performed in the same animal. The advantage of this technique over other experimental procedures used to manipulate the level of neurotransmission or neuromodulation (such as systemic injections or the use of optogenetic models), is that the drug effect is confined to the local synaptic inputs to the target neuron. In addition, the custom-manufacture of electrodes allows adjustment of specific parameters according to the neural structure and type of neuron of interest (such as the tip resistance for improving the signal-to-noise ratio of the recordings).

We present methods for the construction of electrodes to simultaneously record extracellular neural activity and release multiple neuroactive substances at the vicinity of the recording sites in awake mice. This technique allows the detailed analysis of putative local synaptic inputs to the neuron of interest.

Extracellulaires enregistrement de l&#39;activité neuronale Combiné avec Microiontophoretic Application des substances neuroactifs chez la souris Awake

Differences in the activity of neurotransmitters and neuromodulators, and consequently different neural responses, can be found between anesthetized and ...

Fabrication of High Contact-Density, Flat-Interface Nerve Electrodes for Recording and Stimulation Applications

Many attempts have been made to manufacture multi-contact nerve cuff electrodes that are safe, robust and reliable for long term neuroprosthetic applications. This protocol describes a fabrication technique of a modified cylindrical nerve cuff electrode to meet these criteria. Minimum computer-aided design and manufacturing (CAD and CAM) skills are necessary to consistently produce cuffs with high precision (contact placement 0.51 &#177; 0.04 mm) and various cuff sizes. The precision in spatially distributing the contacts and the ability to retain a predefined geometry accomplished with this design are two criteria essential to optimize the cuff&#39;s interface for selective recording and stimulation. The presented design also maximizes the flexibility in the longitudinal direction while maintaining sufficient rigidity in the transverse direction to reshape the nerve by using materials with different elasticities. The expansion of the cuff&#39;s cross sectional area as a result of increasing the pressure inside the cuff was observed to be 25% at 67 mm Hg. This test demonstrates the flexibility of the cuff and its response to nerve swelling post-implant. The stability of the contacts&#39; interface and recording quality were also examined with contacts&#39; impedance and signal-to-noise ratio metrics from a chronically implanted cuff (7.5 months), and observed to be 2.55 &#177; 0.25 k&#8486; and 5.10 &#177; 0.81 dB respectively.

This article provides a detailed description on the fabrication process of a high contact-density flat interface nerve electrode (FINE). This electrode is optimized for recording and stimulating neural activity selectively within peripheral nerves.

Fabrication de haute Contactez-Density, Flat-Interface Electrodes nerveuses pour l&#39;enregistrement et de stimulation Applications

Many attempts have been made to manufacture multi-contact nerve cuff electrodes that are safe, robust and reliable for long term neuroprosthetic ...

Implantation of Chronic Silicon Probes and Recording of Hippocampal Place Cells in an Enriched Treadmill Apparatus

An important requisite for understanding brain function is the identification of behavior and cell activity correlates. Silicon probes are advanced electrodes for large-scale electrophysiological recording of neuronal activity, but the procedures for their chronic implantation are still underdeveloped. The activity of hippocampal place cells is known to correlate with an animal&#39;s position in the environment, but the underlying mechanisms are still unclear. To investigate place cells, here we describe a set of techniques which range from the fabrication of devices for chronic silicon probe implants to the monitoring of place field activity in a cue-enriched treadmill apparatus. A micro-drive and a hat are built by fitting and fastening together 3D-printed plastic parts. A silicon probe is mounted on the micro-drive, cleaned, and coated with dye. A first surgery is performed to fix the hat on the skull of a mouse. Small landmarks are fabricated and attached to the belt of a treadmill. The mouse is trained to run head-fixed on the treadmill. A second surgery is performed to implant the silicon probe in the hippocampus, following which broadband electrophysiological signals are recorded. Finally, the silicon probe is recovered and cleaned for reuse. The analysis of place cell activity in the treadmill reveals a diversity of place field mechanisms, outlining the benefit of the approach.

We describe the diverse steps to implant chronic silicon probes and to record place cells in mice that are running head-fixed on a cue-enriched treadmill apparatus.

Implantation des sondes de silicium chronique et enregistrement des cellules hippocampiques Place dans un appareil de tapis roulant enrichi

An important requisite for understanding brain function is the identification of behavior and cell activity correlates. Silicon probes are advanced ...

Chronic Implantation of Whole-cortical Electrocorticographic Array in the Common Marmoset

Electrocorticography (ECoG) allows the monitoring of electrical field potentials from the cerebral cortex with high spatiotemporal resolution. Recent development of thin, flexible ECoG electrodes has enabled conduction of stable recordings of large-scale cortical activity. We have developed a whole-cortical ECoG array for the common marmoset. The array continuously covers almost the entire lateral surface of cortical hemisphere, from the occipital pole to the temporal and frontal poles, and it captures whole-cortical neural activity in one shot. This protocol describes a chronic implantation procedure of the array in the epidural space of the marmoset brain. Marmosets have two advantages regarding ECoG recordings, one being the homologous organization of anatomical structures in humans and macaques, including frontal, parietal, and temporal complexes. The other advantage is that the marmoset brain is lissencephalic and contains a large number of complexes, which are more difficult to access in macaques with ECoG, that are exposed to the brain surface.These features allow direct access to most cortical areas beneath the surface of the brain. This system provides an opportunity to investigate global cortical information processing with high resolutions at a sub-millisecond order in time and millimeter order in space.

We have developed a whole-cortical electrocorticographic array for the common marmoset that continuously covers almost the entire lateral surface of cortex, from the occipital pole to the temporal and frontal poles. This protocol describes a chronic implantation procedure of the array in the epidural space of the marmoset brain.

Implantation chronique d’ensemble-corticale Electrocorticographic tableau dans l’ouistiti commun

Electrocorticography (ECoG) allows the monitoring of electrical field potentials from the cerebral cortex with high spatiotemporal resolution. Recent ...

Wide-field Single-photon Optical Recording in Brain Slices Using Voltage-sensitive Dye

Wide-field single photon voltage-sensitive dye (VSD) imaging of brain slice preparations is a useful tool to assess the functional connectivity in neural circuits. Due to the fractional change in the light signal, it has been difficult to use this method as a quantitative assay. This article describes special optics and slice handling systems, which render this technique stable and reliable. The present article demonstrates the slice handling, staining, and recording of the VSD-stained hippocampal slices in detail. The system maintains physiological conditions for a long time, with good staining, and prevents mechanical movements of the slice during the recordings. Moreover, it enables staining of slices with a small amount of the dye. The optics achieve high numerical aperture at low magnification, which allows recording of the VSD signal at the maximum frame rate of 10 kHz, with 100 pixel x 100-pixel spatial resolution. Due to the high frame rate and spatial resolution, this technique allows application of the post-recording filters that provide sufficient signal-to-noise ratio to assess the changes in neural circuits.

We introduce a reproducible and stable optical recording method for brain slices using voltage-sensitive dye. The article describes voltage-sensitive dye staining and recording of optical signals using conventional hippocampal slice preparations.

Enregistrement optique à grand champ à un seul photon dans des tranches de cerveau à l'aide de teinture sensible à la tension

Wide-field single photon voltage-sensitive dye (VSD) imaging of brain slice preparations is a useful tool to assess the functional connectivity in neural ...

Preparation of Peripheral Nerve Stimulation Electrodes for Chronic Implantation in Rats

Peripheral nerve cuff electrodes have long been used in the neurosciences and related fields for stimulation of, for example, vagus or sciatic nerves. Several recent studies have demonstrated the effectiveness of chronic VNS in enhancing central nervous system plasticity to improve motor rehabilitation, extinction learning, and sensory discrimination. Construction of chronically implantable devices for use in such studies is challenging due to rats&#8217; small size, and typical protocols require extensive training of personnel and time-consuming microfabrication methods. Alternatively, commercially available implantable cuff electrodes can be purchased at a significantly higher cost. In this protocol, we present a simple, low-cost method for construction of small, chronically implantable peripheral nerve cuff electrodes for use in rats. We validate the short and long-term reliability of our cuff electrodes by demonstrating that VNS in ketamine/xylazine anesthetized rats produces decreases in breathing rate consistent with activation of the Hering-Breuer reflex, both at the time of implantation and up to 10 weeks after device implantation. We further demonstrate the suitability of the cuff electrodes for use in chronic stimulation studies by pairing VNS with skilled lever press performance to induce motor cortical map plasticity.

Existing approaches for constructing chronically implantable peripheral nerve cuff electrodes for use in small rodents often require specialized equipment and/or highly trained personnel. In this protocol we demonstrate a simple, low-cost approach for fabricating chronically implantable cuff electrodes, and demonstrate their effectiveness for vagus nerve stimulation (VNS) in rats.

Préparation d’électrodes de stimulation nerveuse périphérique pour l’implantation chronique chez les rats

Peripheral nerve cuff electrodes have long been used in the neurosciences and related fields for stimulation of, for example, vagus or sciatic nerves. ...