Diese Arbeit wurde vom Center for Neural Kommunikationstechnologie (CNCT), eine P41 Resource Center des National Institute of Biomedical Imaging and Bioengineering (NIBIB, P41 EB002030) gefördert und unterstützt durch die National Institutes of Health (NIH) finanziert. Die Autoren möchten Rio Vetter von NeuroNexus Technologies für die Entwicklung der chirurgischen Techniken zu danken, und Paras Patel von der University of Michigan für die Erstellung der Liste der Geräte bei Operationen verwendet.

1. Pre-Implantationen (Allgemein) <ol><li> Rasieren Sie den oberen Teil den Kopf des Tieres aus zwischen die Augen zu und hinter den Ohren. Benutzen Sie elektrische Barbier Clippers, um den Kopf rasieren. Schrubben mit dem Kopf voran mit Isopropylalkohol, dann Betadin (3x wiederholen). Bewerben Auge Schmiermittel. </li><li> Montieren Sie das Tier im stereotaktischen Ohr Bars. Richten Sie die feste Spitze des rechten Ohres stereotaktischen bar in den Gehörgang des Tieres rechten Ohr durch Bewegen des Kopfes seitlich gegen den Kanal. Besondere Vorsicht ist nötig, um sicherzustellen, dass jedes Ohr-bar Spitze richtig im Gehörgang positioniert werden. Als nächstes drücken Sie den gelockerten linken Ohr bar in den Gehörgang und mit leichtem Druck nach innen. Fassen der Nase des Tieres und wackeln hin und her fest. Wenn das Tier richtig montiert ist der Kopf fühlt sich starr montiert. </li></ol> 2. Pre-Implantation Chirurgie (Allgemein) <ol><li> Mit einer feinen Schere, schnitt zwei halbe circles von der Mittellinie nach außen, teilweise Entfernen der Kopfhaut </li><li> Kratzen und entfernen Sie das Periost Bindegewebe, das bis auf die Knochen haftet. Schaben mit einem stumpfen Kante wie der Rücken eines Skalpellklinge oder der Spitze eines sterilen Wattestäbchen wird Blutungen zu minimieren, weil die Kapillaren werden gequetscht und nicht geschnitten werden reibungslos. Control-Knochen mit Knochen Blutungen Wachs oder eine Kauterisieren Eisen. </li><li> Desinfizieren und Reinigen der Knochenoberfläche mit Wasserstoffperoxid. Trocknen Sie die Knochen, die Schädelnähte besser sichtbar zu machen. Bregma und Lambda-Punkte sind zu beachten und werden verwendet, um die Kopfhöhe. Der Standort für Kraniotomie und Elektrode Implantat sollte in Bezug auf Bregma gemessen werden und kann vorübergehend mit einem Stift oder durch Bohren flach in die Oberfläche geprägt werden. Die Kraniotomie Standort wird von den experimentellen Ziele der Studie (dh motorische, sensorische Experimente) 1 abhängen. </li><li> Bohren Sie Schraublöcher in den Knochen und setzen Sie den Boden und die Stabilisierung sBesatzungen. Verwenden Sie immer aus Edelstahl oder Titan-Schrauben. Kleine Juwelier-Schrauben (zB # 2-56 oder # 00 bis 80) mit so vielen Fäden pro Zoll wie möglich sind wünschenswert. </li></ol> 3. Siliziumelektrode Implantationen <ol><li> Bohren Sie das Kraniotomie nach der Implantation Schrauben. Bohren Sie vier flachen Pilot Mark für die Ecken der Kraniotomie. Mit Pilot Mark als ein Führer bohren Sie die Perimeter der Kraniotomie. Entfernen Sie die mittlere Masse von Knochen, die nicht gebohrt wurde mit einem Paar robuste Zange. Der Rand der Kraniotomie müssen möglicherweise mit weiteren Bohrungen gereinigt werden. Dünne Knochen kann mit einem Paar von microrongeurs abgeschnitten. Planen Sie Ihre Operation sorgfältig zu großen Blutgefäßen wie der Sinus sagittalis, die innerhalb von 0,5 mm von der Mittellinie in Längsrichtung Naht 1 erscheinen können, zu vermeiden. Punktion des Sinus sagittalis kann dazu führen, umfangreiche Blutungen. Freigelegte Dura sollte gehalten hydratisiert mit aCSF oder Saline werden. </li><li> Zum Durchstoßen der Dura materSie benötigen, um Mode einen kleinen Haken mit einer sterilen Injektionsnadel von kleinen Messgerät (zB &lt;28 Gauge). Nehmen Sie die Abschrägung der Nadel und drücken Sie sie flach gegen eine feste Unterlage (zB dem flachen Teil eines Skalpells) leicht kippen, um eine 90 Grad Kurve an dem Punkt zu bilden. Verwenden Sie diese Haken, um die Oberfläche der Dura zu fangen, und nach oben von der Hirnoberfläche. Die Dura schneiden kann mittels Micro Schere werden oder zerrissen mit seitlichen Bewegungen der Dura Haken werden. Achten Sie auf die Blutgefäße auf der Oberfläche des Gehirns zu vermeiden, wenn Sie die Dura Haken. Sie sollten bemerken CSF entweicht, wenn Dura reseziert und ein Unterschied in der Farbe von der Oberfläche der Dura. </li><li> Sorgfältig Verbinden Sie den Erdungsleiter des Silizium-Elektrode um die Basis der Erdungsschraube, und Taktgefühl an Ort und Stelle mit Zahnzement. Die Silizium-Elektroden sollten sorgfältig so platziert werden, dass die Elektroden-Kabel führt über die Kraniotomie sind gewölbt. </li><li> Implantate platziert unter Verwendung eines linearen Stellantrieb PLA werdenCed auf einem stereotaktischen Vorrichtung. Um die Elektrode an der Einführungsvorrichtung zu befestigen, wird Polyethylenglycol (PEG) mit einem Lötkolben erhitzt und auf Einsetzstange und der Aufzeichnungselektrode. </li><li> Mit der Elektrode befestigt, manuell regeln die Spitze der Elektrode auf die gewünschte stereotaktischen Stelle auf der Oberfläche des Gehirns. </li><li> Mit der Software-Schnittstelle zu den Linearantrieb, bewegen Sie die Elektrode in die gewünschte Tiefe innerhalb des Hirngewebes. </li><li> Sichern der Aufnahme Elektrode in das Gehirn durch Anbringen PEG von einer benachbarten Schraube des Elektrodenkabels. Jetzt können Sie die Elektrode aus der Einschubvorrichtung durch Zugabe von Kochsalzlösung, um die PEG gebunden aufzulösen. Heben Sie das Gerät vor Einsetzen der Kraniotomie und wiederholen Sie für jede Elektrode. </li><li> Decken Sie die ausgesetzt Kraniotomie mit Kochsalzlösung getränkte Gelfoam. Ein Silikon-Polymer wird dann verwendet, um das Elektrodenkabel decken und schützen es vor der zahnärztlichen Acryl. Positionieren Sie den Stecker in der letztenStandort, dann wenden Sie Dentalacryl, um eine robuste Kopfbedeckungsgegenstand machen. </li></ol> 4. MicroECoG Elektroden-Implantationen <ol><li> Die Implantation der microECoG Elektrode beinhalten einen geringfügig größeren Kraniotomie. Für eine 5 x 5 mm Einrichtung, muss eine 6 x 6 mm Kraniotomie werden. Vor dem Bohren des Kraniotomie, ist UV-härtende Dentalacryl an die Peripherie der Kraniotomie Stelle aufgebracht, während es noch trocken und nicht in Gefahr, Berühren der Dura oder Pia. </li><li> Sterile, chirurgische Bohrer mit einem # 107 Grat zum Bohren von der Oberfläche des Knochens in der allgemeinen Form der Kraniotomie. Je kleiner Nr. 106 Grat kann dann verwendet, um zu bohren, den Rest des Knochens bis zu einer dünnen transparenten Schicht werden. Rongeure wird dann in der Lage, heben Sie die verbleibenden Stück Knochen. Die microECoG können epidural oder subdural implantiert werden. Auch hier halten die Dura gut hydriert mit künstlichem CSF oder Saline. </li><li> Um die microECoG implantieren, platzieren Sie einen stereotaktischen Arm über die OPEn Schädel, und sichern Sie die Elektrode auf den Arm mit sterilen Band. Die Elektrode kann nun nach unten in die Kraniotomie gesenkt werden. Sicherstellen, dass die Elektrode Standorte sind nach unten gerichtet und werden den Kontakt mit der Dura oder Pia-Oberfläche. Wenn feucht gehalten, sollte die Elektrode auf das Gewebe gleiten und damit es nicht verrutschen. </li><li> Die Erdung wird mit der Erdungsschraube durch Umschlingung mindestens dreimal über und unter sich verbunden sind. Der Boden Schraube kann eine Schraube, die in Kontakt mit der Dura gekommen ist sein. Die erste Draht kann auch auf die Referenz-Förderschnecken in der gleichen Weise verbunden werden. </li><li> Kleine Stücke von Kochsalzlösung getränkt Gelfoam sollte die Elektrode umgibt platziert werden, wo es Dura oder Pia ausgesetzt. Eine kleine Menge Kochsalzlösung getränkte Gelfoam sollten auch die Spitze der Dünnschicht-Elektrode. UV-härtende Dentalacryl kann auf der Oberseite des Gelfoam angewendet werden und kann verwendet werden, um eine stabile Kopfkappe zu erstellen. Die Acrylsäure ist direkt mit dem dünnen Film aufgebracht Kabel Covering, bis der Verbinder erreicht ist. Achten Sie darauf, über die Unterseite des Steckers Mütze bedecken. </li><li> Alternativ kann die Implantation der microECoG in 4,3 sofort durch die Implantation eines Silizium-Mikroelektroden-Anordnung (Schritte 3,2-3,6) durch kleine Löcher, die in der microECoG Substrat hergestellt werden, gefolgt werden. Dies ermöglicht eine gleichzeitige Aufnahme beider einzelne Einheiten in verschiedenen Tiefen mit hoher Auflösung Field Recordings aus der umgebenden Oberfläche des Gehirns. </li></ol> 5. Postoperativen Erholung <ol><li> Nachdem der Zement völlig ausgehärtet ist, nähen die Haut eng um den Kopf ab und legen Sie das Tier von der stereotaktischen Rahmen. </li><li> Bewerben antiseptischen Pulver oder antibiotische Salbe reichlich um die Wunde herum. Wenn es eine Blutung aus den Ohren, legen Sie einige Antibiotika gut in den Gehörgang. </li><li> Halten Sie das Tier warm wie Barbiturate, das Tier daran hindern, die Aufrechterhaltung ihrer Körperwärme. Haus EACh chronisch implantierten Tier in einem separaten Käfig. Es dauert in der Regel vier bis sieben Tage für das Tier, wieder ganz gesund aus der Chirurgie. </li></ol> 6. Repräsentative Ergebnisse Eine erfolgreiche Siliziumelektrode Implantat-Chirurgie wird eine Aufnahmefunktion Standorte mit Impedanzen messen zwischen 500kOhm-2MOhm, und Dünnfilm-Elektroden, zwischen 10kOhm-50kOhm (bei 1 kHz). Das neuronale Signal kann sofort nach der Operation kontrolliert sowie werden. Sie sollten in der Lage, Spikes auf die implantierten Elektroden zu sehen und sehen, langsame Welle Schwingungen auf der Oberfläche Dünnschicht-Elektrode (Abbildung 1). <img src="/files/ftp_upload/3565/3565fig1.jpg" alt="1" /> Abbildung 1. Repräsentative Ergebnisse der einzelnen Einheit Aktivität und ECoG Schwingungen. A) Wide-Band-Daten von 6 Kanäle gleichzeitig aufgezeichnet von einer chronischen Silizium-Elektrode in der Großhirnrinde implantiert. Beachten Sie, dass Spitzen oft in Aufnahmestellen gesehen werden. b) ECoG Schwingungen von 6 Kanälen eines 16-Kanal-Dünnschicht-uECoG Elektrodenanordnung auf der Oberfläche des Gehirns. Der Mittelwert aller 16 Signale wurden von jeder Spur (gemeinsamen Mittelwert Referenzierung) entfernt und ein 500 Hz digitalen Tiefpaßfilter angelegt.

<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 ist Teil-Eigentümer des NeuroNexus Technologies.

Es gibt eine zunehmende Interesse an der Nutzung intrakortikale Oberfläche und Mehrkanal-Aufnahme-Schnittstellen für die Erforschung von Hirnfunktionen 2, die Bereitstellung Mikrostimulation 3 oder Steuersignale für neuroprothetische Systeme 4,5. Die Methoden in diesem Video zeigen, wie skizziert, um chronische und durchdringenden Oberflächenelektrode Systeme implantieren. Während andere Silizium chronischen Elektrodensysteme 6 existieren, haben wir über die Implantation planaren Elektroden von 7,8 NeuroNexus Technologies entwickelt konzentriert. Techniken zur Implantation anderer Elektrodensysteme variieren beträchtlich. Der chirurgischen Schritte beschrieben, kann die Montage des Tieres in den stereotaktischen Ohr Bars der schwierigste und wichtigste Schritt bei der Bestimmung der Genauigkeit der Platzierung der implantierten Elektroden zu sein. Ist äußerste Vorsicht geboten, deshalb müssen davon ausgehen, dass jedes Ohr-bar Spitze richtig im Gehörgang positioniert. Nach Assurance, dass das Ohr-bar Spitze in den Gehörgang des Tieres rechte Ohr ist, lassen Sie den Hals des Tieres mit der rechten Hand, während Sie Ihren linken Daumen und Zeigefinger an den Kopf zu stützen und üben Sie Druck des Kopfes gegen die Ohr-bar Spitze fortsetzen. Mit der rechten Hand, drücken Sie die linke Ohr gelockert bar in den Gehörgang und mit leichtem Druck nach innen. Verschieben Sie die linke Seite der den Kopf des Tieres nach unten und vorne und überall, bis Sie das linke Ohr-bar Spitze Slip in den Gehörgang fühlen kann. Mit der rechten Hand, weiterhin Druck auf dem linken Ohr bar gelten. Lassen Sie den Kopf des Tieres und mit Ihrer linken Hand jetzt frei, ziehen Sie die Stellschraube des linken Ohres bar.

<table border="1"><tbody><tr><td> Ausrüstung </td><td> Firma </td><td> Katalog-Nummer </td><td> Kommentare </td></tr><tr><td> Bone Screw - # 2-56 x 3/16, Phillips Linsenkopf, 18-8 S / S </td><td> BoltDepot </td><td> 7650 </td><td></td></tr><tr><td> Bone Screw - # 2-56 x 1/8, Phillips Linsenkopf, 18-8 S / S </td><td> BoltDepot </td><td> 9617 </td><td></td></tr><tr><td> Große Oxygen Tank - Größe K </td><td> Kryogenen Gasen </td><td> OXKME </td><td></td></tr><tr><td> Kleine Oxygen Tank - Größe E </td><td> Kryogenen Gasen </td><td> OXYE-AL </td><td></td></tr><tr><td> Vannas-Tübingen Frühling Schere - 2,5-mm-Klinge, abgewinkelt </td><td> Fine Science Tools </td><td> 15002-08 </td><td></td></tr><tr><td> Dumont Nr. 5 Pinzetten, Teflon </td><td> Fine Science Tools </td><td> 11626-11 </td><td></td></tr><tr><td> Dumont Nr. 5 Pinzetten, Dumostar </td><td> Fine Science Tools </td><td> 11295-10 </td><td></td></tr><tr><td> Studentische Vannas Frühling Schere </td><td> Fine Science Tools </td><td> 91500-09 </td><td></td></tr><tr><td> Pinzetten Adson </td><td> Fine Science Tools </td><td> 11006-12 </td><td></td></tr><tr><td> Friendman-Pearson Ronqeur, gebogen </td><td> Fine Science Tools </td><td> 16221-14 </td><td></td></tr><tr><td> Iris Schere - ToughCut </td><td> Fine Science Tools </td><td> 14058-11 </td><td></td></tr><tr><td> Vannas-Tübingen Frühling Schere - 5mm Klinge, glatter </td><td> Fine Science Tools </td><td> 15003-08 </td><td></td></tr><tr><td> Skalpellgriff </td><td> Fine Science Tools </td><td> 10003-12 </td><td></td></tr><tr><td> Kunststoff-Box Sterilisation </td><td> Fine Science Tools </td><td> 20810-02 </td><td></td></tr><tr><td> Stainless Steel Ruler </td><td> Fine Science Tools </td><td> 30086-15 </td><td></td></tr><tr><td> Probe &amp; Spachtel - Straight 14cm </td><td> Fine Science Tools </td><td> 10090-13 </td><td></td></tr><tr><td> Gerade Hemostat </td><td> Fine Science Tools </td><td> 13002-10 </td><td></td></tr><tr><td> Hemostat Curved </td><td> Fine Science Tools </td><td> 13003-10 </td><td></td></tr><tr valign="bottom"><td> Mikro Bohr-Stainless Stahl Grate - 0.7mm </td><td> Fine Science Tools </td><td> 19008-07 </td><td> 10er-Pack </td></tr><tr valign="bottom"><td> Micro Drill Stainless Steel Grate - 0,5 mm </td><td> Fine Science Tools </td><td> 19007-05 </td><td> 10er-Pack </td></tr><tr valign="bottom"><td> Self-Knochenschrauben - 1,17 mm (Durchmesser) - 4,7 mm (Länge) </td><td> Fine Science Tools </td><td> 19010-00 </td><td> 100/Pack </td></tr><tr valign="bottom"><td> Künstliche Tränen </td><td> Fischer </td><td> NC9860842 </td><td> Jeder </td></tr><tr valign="bottom"><td> Betadine </td><td> Fischer </td><td> 19-066452 </td><td> Flasche </td></tr><tr valign="bottom"><td> F-Air Carbon-Filter </td><td> Fischer </td><td> NC9112250 </td><td> Kanister </td></tr><tr valign="bottom"><td> Applicator Wattestäbchen, unsteril </td> &lt;td&gt; Materiel Dienstleistungen </td><td> 1104 </td><td> 10Pack/Case </td></tr><tr valign="bottom"><td> Gaze 2 &quot;x 2&quot; </td><td> Materiel Dienstleistungen </td><td> 1630 </td><td> 25Pack/Case </td></tr><tr valign="bottom"><td> Nadelspitze, 23 GA x 1 &quot; </td><td> Materiel Dienstleistungen </td><td> 39412 </td><td> Verkauft von Fall </td></tr><tr valign="bottom"><td> Nadelspitze, 27 GA x 1,25 &quot; </td><td> Materiel Dienstleistungen </td><td> 25251 </td><td></td></tr><tr valign="bottom"><td> Nadelspitze, 30 GA x 0.5 &quot; </td><td> Materiel Dienstleistungen </td><td> 22023 </td><td> 10Box/Case </td></tr><tr valign="bottom"><td> Salbe, Triple Antibiotikum 0.6g </td><td> Materiel Dienstleistungen </td><td> 2528 </td><td></td></tr><tr valign="bottom"><td> Pouch, Self Seal Sterilisation Kratzmöbel<html> s, 3,5 &quot;x 8&quot; </td><td> Materiel Dienstleistungen </td><td> 1023 </td><td> 10Box/Case </td></tr><tr valign="bottom"><td> Ringer-Lösung 1000ml </td><td> Materiel Dienstleistungen </td><td> 5263 </td><td> 12Bag/Case </td></tr><tr valign="bottom"><td> Skalpellklinge sterilen # 15 </td><td> Materiel Dienstleistungen </td><td> 1975 </td><td> 3Box/Case </td></tr><tr valign="bottom"><td> Suture, Nylon w/P-3 Needle, 5-0, 18in. </td><td> Materiel Dienstleistungen </td><td> 4618 </td><td> 12/Box </td></tr><tr valign="bottom"><td> Unterlage, Einweg-23 &quot;x 36&quot; </td><td> Materiel Dienstleistungen </td><td> 2545 </td><td> 15Pack/Case </td></tr><tr valign="bottom"><td> Schmiermittel, Jelly Sterile OP- </td><td> Materiel Dienstleistungen </td><td> 2538 </td><td> 12Box/Case </td></tr>&quot;&gt; <td> Resorbierbare Schaumgel 2cmx6cmx7mm </td><td> Materiel Dienstleistungen </td><td> 3107 </td><td></td></tr><tr valign="bottom"><td> Sechs teiliges Set-Screw-Schraubendreher-Set </td><td> Nationale Jewelers Supplies </td><td> ETSCR98001 </td><td></td></tr><tr valign="bottom"><td> Kwik Sil Adhesive </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> Chronische Silizium-Elektroden 16 bis 64 Seiten </td><td> NeuroNexus Technologies </td><td> Variiert auf Probe Gestaltung </td><td></td></tr><tr valign="top"><td> Chronische Dünnschichtoberfläche Elektroden (microECoG) 16 bis 32 Seiten </td><td> NeuroNexus Technologies </td><td> Variiert auf Probe Gestaltung </td><td>&nbsp;
 </td>
 </tr>
 </tbody>
</table>

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

Der Erfolg der langfristigen elektrophysiologischen hängt oft von der Qualität der Implantation Chirurgie. Hier haben wir nützliche Informationen für Chirurgen, die das Erlernen der Prozess der Implantation von Elektroden-Systeme sind. Wir zeigen die Implantation von sowohl einem durchdringenden und einer Oberflächenelektrode. Das chirurgische Verfahren ist von Anfang bis zum Ende beschrieben, darunter auch detaillierte Beschreibungen der einzelnen Schritte während des gesamten Verfahrens. Es ist auch anzumerken, dass dieses Video Guide zu Verfahren in Tiermodellen und anderen kleinen Tiermodellen durchgeführt wird, fokussiert werden. Modifikationen der beschriebenen Verfahren sind machbar für andere Tiermodelle.

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

Wir geben Ihnen nützliche Informationen für Chirurgen, die das Erlernen der Prozess der Implantation von chronischen neuronalen Aufnahme Elektroden werden. Techniken für beide durchdringenden und der Oberflächenelektrode sind in einem Nagetier-Modell beschrieben.

Chirurgische Implantation von Elektroden für die Neural Chronische Aufnahme Single Unit Activity und Electrocorticographic Signale

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

Research

JoVE Journal

Neuroscience

47.2K Aufrufe.  University of Michigan. Wir geben Ihnen nützliche Informationen für Chirurgen, die das Erlernen der Prozess der Implantation von chronischen neuronalen Aufnahme Elektroden werden. Techniken für beide durchdringenden und der Oberflächenelektrode sind in einem Nagetier-Modell beschrieben.

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

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from individual neurons are critical for understanding how neural circuits function under natural conditions. Traditionally, these recordings have been performed 'blind', meaning the identity of the recorded cell is unknown at the start of the recording. Cellular identity can be subsequently determined via intracellular1, juxtacellular2 or loose-patch3 iontophoresis of dye, but these recordings cannot be pre-targeted to specific neurons in regions with functionally heterogeneous cell types. Fluorescent proteins can be expressed in a cell-type specific manner permitting visually-guided single-cell electrophysiology4-6. However, there are many model systems for which these genetic tools are not available. Even in genetically accessible model systems, the desired promoter may be unknown or genetically homogenous neurons may have varying projection patterns. Similarly, viral vectors have been used to label specific subgroups of projection neurons7, but use of this method is limited by toxicity and lack of trans-synaptic specificity. Thus, additional techniques that offer specific pre-visualization to record from identified single neurons in vivo are needed. Pre-visualization of the target neuron is particularly useful for challenging recording conditions, for which classical single-cell recordings are often prohibitively difficult8-11. The novel technique described in this paper uses retrograde transport of a fluorescent dye applied using tungsten needles to rapidly and selectively label a specific subset of cells within a particular brain region based on their unique axonal projections, thereby providing a visual cue to obtain targeted electrophysiological recordings from identified neurons in an intact circuit within a vertebrate CNS.
The most significant novel advancement of our method is the use of fluorescent labeling to target specific cell types in a non-genetically accessible model system. Weakly electric fish are an excellent model system for studying neural circuits in awake, behaving animals12. We utilized this technique to study sensory processing by "small cells" in the anterior exterolateral nucleus (ELa) of weakly electric mormyrid fish. "Small cells" are hypothesized to be time comparator neurons important for detecting submillisecond differences in the arrival times of presynaptic spikes13. However, anatomical features such as dense myelin, engulfing synapses, and small cell bodies have made it extremely difficult to record from these cells using traditional methods11, 14. Here we demonstrate that our novel method selectively labels these cells in 28% of preparations, allowing for reliable, robust recordings and characterization of responses to electrosensory stimulation.

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

Retrograde transport of fluorescent dye labels a sub-population of neurons based on anatomical projection. Labeled axons can be visually targeted in vivo, permitting extracellular recording from identified axons. This technique facilitates recording when neurons cannot be labeled through genetic manipulation or are difficult to isolate using 'blind' in vivo approaches.

Retrograde Fluoreszenzmarkierung Ermöglicht Gezielte Extracellular Einzel-Einheit Aufnahme von identifizierten Neuronen<em&gt; In vivo</em

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from ...

Forschung

Neurowissenschaften

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.

Aufnahme Menschliche Electrocorticographic (ECoG) Signale für neurowissenschaftliche Forschung und Real-time Funktionelle kortikale Mapping

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

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.

Optische Aufnahme überschwellige neuronale Aktivität mit Single-Cell-und Single-Spike Auflösung

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

Fiber-optic Implantation for Chronic Optogenetic Stimulation of Brain Tissue

Elucidating patterns of neuronal connectivity has been a challenge for both clinical and basic neuroscience. Electrophysiology has been the gold standard for analyzing patterns of synaptic connectivity, but paired electrophysiological recordings can be both cumbersome and experimentally limiting. The development of optogenetics has introduced an elegant method to stimulate neurons and circuits, both in vitro1 and in vivo2,3. By exploiting cell-type specific promoter activity to drive opsin expression in discrete neuronal populations, one can precisely stimulate genetically defined neuronal subtypes in distinct circuits4-6. Well described methods to stimulate neurons, including electrical stimulation and/or pharmacological manipulations, are often cell-type indiscriminate, invasive, and can damage surrounding tissues. These limitations could alter normal synaptic function and/or circuit behavior. In addition, due to the nature of the manipulation, the current methods are often acute and terminal. Optogenetics affords the ability to stimulate neurons in a relatively innocuous manner, and in genetically targeted neurons. The majority of studies involving in vivo optogenetics currently use a optical fiber guided through an implanted cannula6,7; however, limitations of this method include damaged brain tissue with repeated insertion of an optical fiber, and potential breakage of the fiber inside the cannula. Given the burgeoning field of optogenetics, a more reliable method of chronic stimulation is necessary to facilitate long-term studies with minimal collateral tissue damage. Here we provide our modified protocol as a video article to complement the method effectively and elegantly described in Sparta et al.8 for the fabrication of a fiber optic implant and its permanent fixation onto the cranium of anesthetized mice, as well as the assembly of the fiber optic coupler connecting the implant to a light source. The implant, connected with optical fibers to a solid-state laser, allows for an efficient method to chronically photostimulate functional neuronal circuitry with less tissue damage9 using small, detachable, tethers. Permanent fixation of the fiber optic implants provides consistent, long-term in vivo optogenetic studies of neuronal circuits in awake, behaving mice10 with minimal tissue damage.

The development of optogenetics now provides the means to precisely stimulate genetically defined neurons and circuits, both in vitro and in vivo. Here we describe the assembly and implantation of a fiber optic for chronic photostimulation of brain tissue.

LWL-Implantation für chronische optogenetische Stimulation des Hirngewebes

Elucidating patterns of neuronal connectivity has been a challenge for both clinical and basic neuroscience. Electrophysiology has been the gold standard ...

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.

Multi-unit Recording Methoden zur neuronalen Aktivität in der Locust Charakterisieren (<em&gt; Schistocerca Americana</em&gt;) Olfaktorische Circuits

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.

Eine Methode zur systematischen Elektrochemische und elektrophysiologische Bewertung der Neural Aufzeichnungselektroden

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

A Guide to In vivo Single-unit Recording from Optogenetically Identified Cortical Inhibitory Interneurons

A major challenge in neurophysiology has been to characterize the response properties and function of the numerous inhibitory cell types in the cerebral cortex. We here share our strategy for obtaining stable, well-isolated single-unit recordings from identified inhibitory interneurons in the anesthetized mouse cortex using a method developed by Lima and colleagues1. Recordings are performed in mice expressing Channelrhodopsin-2 (ChR2) in specific neuronal subpopulations. Members of the population are identified by their response to a brief flash of blue light. This technique &#8211; termed &#8220;PINP&#8221;, or Photostimulation-assisted Identification of Neuronal Populations &#8211; can be implemented with standard extracellular recording equipment. It can serve as an inexpensive and accessible alternative to calcium imaging or visually-guided patching, for the purpose of targeting extracellular recordings to genetically-identified cells. Here we provide a set of guidelines for optimizing the method in everyday practice. We refined our strategy specifically for targeting parvalbumin-positive (PV+) cells, but have found that it works for other interneuron types as well, such as somatostatin-expressing (SOM+) and calretinin-expressing (CR+) interneurons.

A Guide to In vivo Single-unit Recording from Optogenetically Identified Cortical Inhibitory Interneurons

Here we describe our strategy for obtaining stable, well-isolated single-unit recordings from identified inhibitory interneurons in the anesthetized mouse cortex. Neurons expressing ChR2 are identified by their response to blue light. The method uses standard extracellular recording equipment, and serves as an inexpensive alternative to calcium imaging or visually-guided patching.

Ein Leitfaden zur<em&gt; In vivo</em&gt; Single-Unit-Aufnahme von Optogenetically Identifizierte kortikalen inhibitorischen Inter

A major challenge in neurophysiology has been to characterize the response properties and function of the numerous inhibitory cell types in the cerebral ...

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.

Die extrazelluläre Aufnahme neuronaler Aktivität in Kombination mit Microiontophoretic Anwendung von neuroaktiven Substanzen in Awake Mäuse

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.

Die Herstellung von High-Kontakt-Dichte, Flach-Interface Nerve Elektroden für die Aufnahme und Stimulation Anwendungen

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 von chronischen Silicon Sonden und Aufzeichnung der Hippocampal Platzzellen in eine angereicherte Laufband-Vorrichtung

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

Chirurgische Implantation von Elektroden für die Neural Chronische Aufnahme Single Unit Activity und Electrocorticographic Signale

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Retrograde Fluoreszenzmarkierung Ermöglicht Gezielte Extracellular Einzel-Einheit Aufnahme von identifizierten Neuronen