Wir möchten Justin Riceberg für die technische Unterstützung bei der Prüfung der headstage anzuerkennen. Diese Arbeit wurde teilweise durch National Institutes of Health Grants MH65658, MH073689 und F30 AG034003-01A1, und der Mount Sinai School of Medicine unterstützt.

1. Headstage Design und Herstellung Übersicht Ein ausgefülltes headstage Vorverstärker-System besteht aus den folgenden Komponenten: <ol><li> Ein Computer entwickelt integrierte Platine mit vier Kanälen von Aufnahme-und zwei Kanäle der Stimulation. </li><li> Elektroden, die die Aufnahmen und Stimulationskanäle mit den entsprechenden Anschlüssen auf die Tiere den Kopf Bühne Relais. </li><li> Eine Leine Kabel und Schnittstelle, leitet die Ableitung und Stimulation Kanäle zu einem Schleifring-Kollektor. </li><li> Zwei Formen der Abdichtung auf den Kopf der Bühne und auf der integrierten Schaltung. </li></ol> 2. Design und Layout der Headstage Wir haben eine gedruckte integrierte Platine mit 4 Quelle Anhänger und 2 durchlaufen Stimulationskanäle mit einem kommerziell erhältlichen Software CAD-Paket (www.expresspcb.com). Ein headstage ist so konzipiert, und die Design-Pattern ist gefliest über einen größeren Bogen der Leiterplatte zu vielen headstages zu geringeren Kosten bieten. Die CAD-Datei wird auf der Leiterplatte (PCB) Fertigungsdienstleister, wo doppelseitige, zweischichtige Platten sind gedruckt oben und unten Kupferschichten mit allen Bohrungen durchkontaktiert übertragen. Die Boards verwenden Zinn / Blei-Lot überzogen Spuren und Pads, die auf Industrie-Standard FR-4 Laminat entsprechen. Die PCB kann bestellt werden und spätestens am nächsten Werktag. Individuelle headstages sind von der großen gefliesten PCB Blatt geschnitten und elektronischen Bauteile sind mit Lot verbunden. Ein Beispiel Layout der headstage in diesem Protokoll wird angezeigt (Abbildung 1). Bitte beachten Sie die Webseite des Herstellers für detaillierte Anweisungen und Tipps zur Gestaltung eines PCB. 3. Vorbereitung und Löten von elektronischen Komponenten Alle elektronischen Bauteile im Sinne dieses Protokolls sind die Surface Mount Device (SMD)-Typ. Der Fußabdruck eines jeden Gerätetyp (Widerstand, Kondensator, etc.) wurde gewählt, um verschwendeten Speicherplatz auf der headstage zu minimieren, aber auch größere SMD-Bauteile verwendet werden, wenn es erforderlich ist. <ol><li> Organisieren Sie Ihre Komponenten auf der Platine und bereiten sie für das Löten. </li><li> Legen Sie eine kleine Menge Lot auf dem Zinn / Blei-Pad gelötet werden und bringen die Spitze des Lötkolbens in der Nähe zu schmelzen und zu halten das Lot auf dem Pad. </li><li> Löten Sie die Kondensatoren zunächst Widerstände nächsten, und dann die Operationsverstärker. </li><li> Die Op-Amps kann durch Überhitzung zerstört werden. Wir verwendeten eine variable Wärme Lötkolben und die niedrigste nötige Wärme, um das Lot zu schmelzen. Minimieren Sie die Heizzeit verwendet werden, um eine gute Lötstelle zu machen. Wir fanden es praktisch, einen kleinen Vorrat an Lot, die in die Bilanz Pad fließt durch die Anwendung Lot entlang der Kommunikation oder Power Spuren zu schaffen. </li><li> Testen Sie, ob der Widerstand über Ihre Widerständen der erwartete Wert mit einem Ohmmeter erfüllt. </li><li> Überprüfen Sie jedes Pad eng um sicherzustellen, dass kein Lot verbindet oder Überbrückung benachbarten Pads. Wenn es eine Lötbrücke, Wärme und schmelzen das Lötzinn und verwenden Sie eine Pinzette, um die Brücke zu brechen. </li></ol> 4. Montage und Fertigung von Implantat und Tether-Schnittstellen <ol><li> Legen Sie eine 23 Ga hypodermic Schlauch in einen der unbenutzten Ports des 9pol ABS-Steckdose für die mechanische Unterstützung. </li><li> Schneiden Sie sechs 1 cm Länge Stücke von isolierten magnetischen Draht zum Anschluss des weiblichen Amphenol Pins, die ABS-Steckdose. </li><li> Löten Sie die weiblichen Zapfen zu den magnetischen Draht mit einer kleinen Menge von Lot in jedem Pin und durch Erwärmen des Stiftes von der Spitze. </li><li> Löten Sie die anderen Enden der magnetischen Draht in die ABS-Buchsen. </li><li> Positionieren Sie den Stecker - Buchse MillMax Pins über die Pads auf der Leine Seite des headstage, und drücken Sie die Stifte in den PCB zu einem Druck Passform zu gewährleisten. Dann löten jeden Stift zu jedem Pad in Ordnung. </li><li> Positionieren Sie die Überwurfmutter über die Nervenimplantat Stecker und schieben alle weiblichen Stifte in die gewünschten Steckplätze auf der Kunststoff-Basis. </li><li> Bewerben Acrylkleber (Krazy Glue) auf der Oberseite des ABS-Buchse und befestigen Sie es an der Basis der headstage. Kleben Sie die 23Ga Rohr auf die Leine Seite des headstage für die Unterstützung. </li></ol> 5. Abdichtung der Headstage <ol><li> Zur Abdichtung der headstage, umhüllen die gesamte integrierte Schaltung und keine freiliegenden Metallflächen mit 5 Minuten Epoxy. Lassen Sie 5-10 Minuten für die erste Trocknung und 60 Minuten für die dauerhafte Trocknung. </li><li> Poster Tack putty sollte an die Oberfläche der 9-poligen ABS-Buchse auf der ganzen weiblichen Stifte ragen aus der Tier-Ende eingesetzt werden. </li><li> Für maximale Abdichtung, sollte das ABS-Buchse und Stecker ABS gedeckt werden und die Ringmutter sollten verschärft werden. Ein schmaler Streifen Parafilm sollte rund um die Schnittstelle zu Wasser in Kontakt mit der Pin-Anschlüsse zu verhindern gewickelt werden. </li></ol> Secrets to Success <ol><li> Beim Löten der Operationsverstärker nicht überhitzen die Kunststoff-Paket. Wenn essichtbar Brennen oder Schmelzen, entfernen Sie die Op-Amp und ersetzen Sie es. Wenn zuviel Hitze kann der Operationsverstärker ohne sichtbare Schmelz beschädigen. Testen Sie jeden Kanal mit einem Funktionsgenerator nach dem Löten. </li><li> Stellen Sie sicher, es gibt keine streunenden Verbindungen oder Lötbrücken auf der headstage. Entlötlitze kann verwendet werden, um Komponenten zu entfernen oder streunenden Lot sein. </li></ol> 6. Repräsentative Ergebnisse Eine gute Aufnahme wird ein Signal einer Eingangsquelle ohne Schneiden in und out während der Bewegung zu folgen. Um zu testen, die headstage, sollte der Benutzer einen Funktionsgenerator als Eingang für jede Aufnahme pin Nutzung und Auswertung der Signale in der Mühle Max-Header-Ausgang enden. Körperlich Bewegung des headstage sollte keinen Einfluss auf die Form der aufgezeichneten Signale. <img src="/files/ftp_upload/2155/2155fig1.jpg" alt="Abbildung 1" /> Abbildung 1. (A) Schematische Darstellung der obersten Schicht der Leiterplatte (PCB). Rote Linien zeigen Kupferbahnen. Gelbe Linien zeigen optionale Siebdruck-Schicht für die Positionierung von elektronischen Bauteilen. Dargestellt sind die Operationsverstärker Platzierung (Zentral gelbes Quadrat), Widerstände (kleinere gelbe Quadrate) und Kondensatoren (kleinste gelbe Quadrate). (B) Schematische Darstellung der unteren Schicht der Leiterplatte. Grünen Linien Kupferbahnen anzuzeigen. Große grüne gefüllten Bereich stellt Bodenplatte. A-Modell-Datei von dieser schematischen steht zum Download zur Verfügung gestellt.

<ol>
	<li>Morris, R. G., Garrud, P., Rawlins, J. N., O'Keefe, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Place+navigation+impaired+in+rats+with+hippocampal+lesions.">Place navigation impaired in rats with hippocampal lesions.</a> Nature. 297, 681-683 (1982).</li><li>Rolston, J. D., Gross, R. E., Potter, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+low-cost+multielectrode+system+for+data+acquisition+enabling+real-time+closed-loop+processing+with+rapid+recovery+from+stimulation+artifacts.+Front.">A low-cost multielectrode system for data acquisition enabling real-time closed-loop processing with rapid recovery from stimulation artifacts. Front.</a> Neuroengineering. 2, 12-12 (2009).</li><li>Fee, M. S., Leonardo, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Miniature+motorized+microdrive+and+commutator+system+for+chronic+neural+recording+in+small+animals.">Miniature motorized microdrive and commutator system for chronic neural recording in small animals.</a> J. Neurosci. Methods. 112, 83-94 (2001).</li><li>Shirvalkar, P. R., Rapp, P. R., Shapiro, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bidirectional+changes+to+hippocampal+theta+gamma+oscillations+predict+memory+for+recent+spatial+episodes.">Bidirectional changes to hippocampal theta gamma oscillations predict memory for recent spatial episodes.</a> Proc Natl Acad Sci U S A. 107 (15), 7054-709 (2010).</li></ol>

Wasser Labyrinth auf Verhaltensänderungen Aufgaben bieten effektive Werkzeuge, um Tiere zu kognitiven Fähigkeiten und Darstellungen in Echtzeit 1-Sonde. Die Verwendung von leichten und kostengünstigen headstage Vorverstärker ist besonders kritisch in Verhaltenstherapie Neurophysiologie Anwendungen, bei denen das Wasser Labyrinth. Da entweicht das kalte Wasser bietet die intrinsische Motivation für die Tiere in dieser Aufgaben kann ihr Verhalten in wiederholten Versuchen, ohne die Schwierigkeiten zu motivieren Tiere auf dem Trockenen Labyrinthe getestet werden. Die Low-Cost headstage Vorverstärker hier beschriebene Gerät wird es Wissenschaftlern ermöglichen, Hypothesen der neuronalen Funktion in Wasser Aufgaben ohne die Sorge zu beschädigen teure Ausrüstung zu testen. Dieses Protokoll soll als Ausgangspunkt für eigene headstage Design dienen. Die schematische vorgesehen ist, leicht an weitere Aufnahme oder Stimulation Kanäle umfassen und kann nach den Wünschen des Experimentators skaliert werden. Insbesondere durch die Einbeziehung kommerziellen poligen Stecker Setups kann man bauen headstages, dass mit handelsüblichen Elektroden-Interface-Karten paaren können. Obwohl das Beispiel in diesem Protokoll vorgesehenen bietet Unity-Gain-Quelle im Anschluss an jeden Kanal kann der interessierte Leser diese Verstärkung durch Veränderung der Konfiguration von Widerständen und Kondensatoren (siehe 2 für eine detaillierte Überprüfung der Datenerfassungssysteme) einstellen. Obwohl die Techniken im Zusammenhang mit Elektrodenimplantation und Positionierung über den Rahmen dieses Artikels sind, haben wir die folgende Konfiguration verwendet werden, um aus festen Tiefe Elektroden Record (Shirvalkar et al. In press, 2010). Weitere Einzelheiten zum Aufbau und Implantat beweglichen Elektroden für chronische Aufnahme kann hier gefunden werden: 3.

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		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
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<tr>
<td>Custom designed Integrated Circuit Board</td>
<td>&nbsp;</td>
<td>ExpressPCB.com</td>
<td>Custom</td>
<td>2 layer double sided PCB</td>
</tr>
<tr>
<td>Surface mount Resistors</td>
<td>&nbsp;</td>
<td>Mouser Electronics</td>
<td>RK73B1JTTDD156J</td>
<td>1/10 W, 15 M Ohm 0603, Thick film</td>
</tr>
<tr>
<td>SMD Capacitors </td>
<td>&nbsp;</td>
<td>Newark Electronics</td>
<td>0402YD104KAT2A</td>
<td>0.1 uF (0402)</td>
</tr>
<tr>
<td>SMD Operational Amplifier (quad FET)</td>
<td>&nbsp;</td>
<td>Mouser Electronics</td>
<td>595-TLC2274AIPW</td>
<td>Quad FET - low noise</td>
</tr>
<tr>
<td>9 pin ABS socket</td>
<td>&nbsp;</td>
<td>Ginder Scientific</td>
<td>GS09SKT-220</td>
<td>For animal connection</td>
</tr>
<tr>
<td>9-pin ABS Plug</td>
<td>&nbsp;</td>
<td>Ginder Scientific</td>
<td>GS09PLG-220</td>
<td>To be implanted in animal</td>
</tr>
<tr>
<td>Black Delrin Ring Nut</td>
<td>&nbsp;</td>
<td>Ginder Scientific</td>
<td>GS09BDN-220</td>
<td>&nbsp;</td>
<tr>
<td>Black Delrin Cap Nut</td>
<td>&nbsp;</td>
<td>Ginder Scientific</td>
<td>GS09BDC-220</td>
<td>For protecting animal's implant</td>
</tr>
<tr>
<td>Amphenol pins (male)</td>
<td>&nbsp;</td>
<td>Ginder Scientific</td>
<td>220-P02</td>
<td>&nbsp;</td>
<tr>
<td>Amphenol pins (female)</td>
<td>&nbsp;</td>
<td>Ginder Scientific</td>
<td>220-S02</td>
<td>&nbsp;</td>
<tr>
<td>5-minute epoxy</td>
<td>&nbsp;</td>
<td>Devcon Inc.</td>
<td>S-208 / 20845</td>
<td>&nbsp;</td>
<tr>
<td>Poster Tack Putty</td>
<td>&nbsp;</td>
<td>Elmer's</td>
<td>026000015318</td>
<td>&nbsp;</td>
<tr>
<td>Rosin Core Solder</td>
<td>&nbsp;</td>
<td>Radio Shack</td>
<td>64-009</td>
<td>&nbsp;</td>
<tr>
<td>Soldering Iron </td>
<td>&nbsp;</td>
<td>Weller</td>
<td>Pyropen WSTA6</td>
<td>(adjustable heat)</td>
</tr>
<tr>
<td>Metal tweezers</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>Size 5</td>
<td>&nbsp;</td>
<tr>
<td>Parafilm sheets</td>
<td>&nbsp;</td>
<td>American National Can</td>
<td>Parafilm 4" x 250'</td>
<td>&nbsp;</td>
<tr>
<td>Magnet wire</td>
<td>&nbsp;</td>
<td>Belden</td>
<td>8052</td>
<td>Enamel Coated</td>
</tr>
<tr>
<td>Ammeter/ Multimeter</td>
<td>&nbsp;</td>
<td>Fluke Mfg Co.</td>
<td>77 Multimeter</td>
<td>&nbsp;</td>
<tr>
<td>Millmax Double Row Headers</td>
<td>&nbsp;</td>
<td>Millmax / Mouser</td>
<td>575 - 002101</td>
<td>0.05"</td>
</tr>
<tr>
<td>Solder Wick</td>
<td>&nbsp;</td>
<td>Chemtronics</td>
<td>7-10L</td>
<td>0.75 in.</td>
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design and construction of a cost effective headstage for simultaneous neural stimulation and recording in the water maze

Headstage Vorverstärker und Quelle Anhänger werden üblicherweise verwendet, um neuronale Aktivität in der Verhaltensforschung Neurophysiologie Experimenten zu studieren. Verfügbaren kommerziellen Produkte sind oft teuer und nicht leicht angepasst, und nicht Tauchpumpe. Hier beschreiben wir eine Methode zur Planung und Errichtung einer maßgeschneiderten, integrierten Schaltkreis headstage zur gleichzeitigen 4-Kanal-neuronale Aufnahme und 2-Kanal-Simulation an wachen, sich verhaltenden Tier. Die headstage ist das Ergebnis eines freien, kommerziell erhältlichen CAD-type-Design-Paket, und kann leicht modifiziert werden, um verschiedene Skalen (zB Kanäle hinzufügen) unterzubringen. Eine angepasste Platine ist mit Hilfe Surface Mount Widerstände, Kondensatoren und Operationsverstärkern, die Einheit zu gewinnen Source-Folger-Schaltung zu bauen. Die headstage ist wasserdicht mit einer Kombination von Epoxidharz, Parafilm und ein synthetischer Kautschuk putty gemacht. Wir haben dieses Gerät verwendet, um lokale Feldpotenziale aufzeichnen und stimulieren verschiedene Hirnregionen gleichzeitig über unabhängige Kanäle in Ratten schwimmen in einem Wasser-Labyrinth. Die Gesamtkosten belaufen sich auf &lt;$ 30/unit und können leicht hergestellt werden.

Watch this Scientific Journal Video about Design and Construction of a Cost Effective Headstage for Simultaneous Neural Stimulation and Recording in the Water Maze at JoVE.com

Design and Construction of a Cost Effective Headstage for Simultaneous Neural Stimulation and Recording in the Water Maze

Wir präsentieren eine Low-Cost-Methode zu entwerfen und zu konstruieren ein Licht headstage Vorverstärker mit gleichzeitiger neuronalen Ableitung und Stimulation Fähigkeit. Dieses Gerät kann für den Einsatz abgedichtet werden in schwimmenden Tieren.

Planung und Bau eines kostengünstigen Headstage für Simultaneous Neural Stimulation und Aufnahme in the Water Maze

Headstage preamplifiers and source followers are commonly used to study neural activity in behavioral neurophysiology experiments. Available commercial ...

design-construction-cost-effective-headstage-for-simultaneous-neural

Nanyang Technological University

Research

JoVE Journal

Neuroscience

10.6K Aufrufe.  Mount Sinai School of Medicine. Wir präsentieren eine Low-Cost-Methode zu entwerfen und zu konstruieren ein Licht headstage Vorverstärker mit gleichzeitiger neuronalen Ableitung und Stimulation Fähigkeit. Dieses Gerät kann für den Einsatz abgedichtet werden in schwimmenden Tieren.

Serie: Design and Construction of a Cost Effective Headstage for Simultaneous Neural Stimulation and Recording in the Water Maze

Combining Behavioral Endocrinology and Experimental Economics: Testosterone and Social Decision Making

Behavioral endocrinological research in humans as well as in animals suggests that testosterone plays a key role in social interactions. Studies in rodents have shown a direct link between testosterone and aggressive behavior1 and folk wisdom adapts these findings to humans, suggesting that testosterone induces antisocial, egoistic or even aggressive behavior2. However, many researchers doubt a direct testosterone-aggression link in humans, arguing instead that testosterone is primarily involved in status-related behavior3,4. As a high status can also be achieved by aggressive and antisocial means it can be difficult to distinguish between anti-social and status seeking behavior.
We therefore set up an experimental environment, in which status can only be achieved by prosocial means. In a double-blind and placebo-controlled experiment, we administered a single sublingual dose of 0.5 mg of testosterone (with a hydroxypropyl-&beta;-cyclodextrin carrier) to 121 women and investigated their social interaction behavior in an economic bargaining paradigm. Real monetary incentives are at stake in this paradigm; every player A receives a certain amount of money and has to make an offer to another player B on how to share the money. If B accepts, she gets what was offered and player A keeps the rest. If B refuses the offer, nobody gets anything. A status seeking player A is expected to avoid being rejected by behaving in a prosocial way, i.e. by making higher offers.
The results show that if expectations about the hormone are controlled for, testosterone administration leads to a significant increase in fair bargaining offers compared to placebo. The role of expectations is reflected in the fact that subjects who report that they believe to have received testosterone make lower offers than those who say they believe that they were treated with a placebo. These findings suggest that the experimental economics approach is sensitive for detecting neurobiological effects as subtle as those achieved by administration of hormones. Moreover, the findings point towards the importance of both psychosocial as well as neuroendocrine factors in determining the influence of testosterone on human social behavior.

The procedure described in this protocol shows that testosterone administration and folk beliefs about testosterone may be associated with directly opposed social behaviors.

Die Kombination Behavioral Endokrinologie und Experimentelle Wirtschaftsforschung: Testosteron und Social Decision Making

Behavioral endocrinological research in humans as well as in animals suggests that testosterone plays a key role in social interactions. Studies in ...

Forschung

Neurowissenschaften

Combining Transcranial Magnetic Stimulation and fMRI to Examine the Default Mode Network

The default mode network is a group of brain regions that are active when an individual is not focused on the outside world and the brain is at "wakeful rest."1,2,3 It is thought the default mode network corresponds to self-referential or "internal mentation".2,3
It has been hypothesized that, in humans, activity within the default mode network is correlated with certain pathologies (for instance, hyper-activation has been linked to schizophrenia 4,5,6 and autism spectrum disorders 7 whilst hypo-activation of the network has been linked to Alzheimer's and other neurodegenerative diseases 8). As such, noninvasive modulation of this network may represent a potential therapeutic intervention for a number of neurological and psychiatric pathologies linked to abnormal network activation. One possible tool to effect this modulation is Transcranial Magnetic Stimulation: a non-invasive neurostimulatory and neuromodulatory technique that can transiently or lastingly modulate cortical excitability (either increasing or decreasing it) via the application of localized magnetic field pulses.9
In order to explore the default mode network's propensity towards and tolerance of modulation, we will be combining TMS (to the left inferior parietal lobe) with functional magnetic resonance imaging (fMRI). Through this article, we will examine the protocol and considerations necessary to successfully combine these two neuroscientific tools.

In this article, we examine the methodology and considerations relevant to the combination of TMS and fMRI to examine the effects of brain stimulation on the default network.

Die Kombination TMS und fMRT dem Standard-Modus Netzwerk Untersuchen

The default mode network is a group of brain regions that are active when an individual is not focused on the outside world and the brain is at "wakeful ...

Morris Water Maze Test for Learning and Memory Deficits in Alzheimer&#39;s Disease Model Mice

The Morris Water Maze (MWM) was first established by neuroscientist Richard G. Morris in 1981 in order to test hippocampal-dependent learning, including acquisition of spatial memoryand long-term spatial memory 1. The MWM is a relatively simple procedure typically consisting of six day trials, the main advantage being the differentiation between the spatial (hidden-platform) and non-spatial (visible platform) conditions 2-4. In addition, the MWM testing environment reduces odor trail interference 5. This has led the task to be used extensively in the study of the neurobiology and neuropharmacology of spatial learning and memory. The MWM plays an important role in the validation of rodent models for neurocognitive disorders such as Alzheimer&#x2019;s Disease 6, 7. In this protocol we discussed the typical procedure of MWM for testing learning and memory and data analysis commonly used in Alzheimer&#x2019;s disease transgenic model mice.

Morris Water Maze Test for Learning and Memory Deficits in Alzheimer's Disease Model Mice

The Morris Water Maze is a behavioral task to test hippocampal-dependent learning and memory. It has been widely used in the study of neurobiology, neuropharmacology and neurocognitive disorders in rodent models.

Morris Water Maze-Test für Lern-und Gedächtnisstörungen bei Alzheimer-Modell Mäuse

The Morris Water Maze (MWM) was first established by neuroscientist Richard G. Morris in 1981 in order to test hippocampal-dependent learning, including ...

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 ...

Design and Assembly of an Ultra-light Motorized Microdrive for Chronic Neural Recordings in Small Animals

The ability to chronically record from populations of neurons in freely behaving animals has proven an invaluable tool for dissecting the function of neural circuits underlying a variety of natural behaviors, including navigation1 , decision making 2,3, and the generation of complex motor sequences4,5,6. Advances in precision machining has allowed for the fabrication of light-weight devices suitable for chronic recordings in small animals, such as mice and songbirds. The ability to adjust the electrode position with small remotely controlled motors has further increased the recording yield in various behavioral contexts by reducing animal handling.6,7
 Here we describe a protocol to build an ultra-light motorized microdrive for long-term chronic recordings in small animals. Our design evolved from an earlier published version7, and has been adapted for ease-of use and cost-effectiveness to be more practical and accessible to a wide array of researchers. This proven design 8,9,10,11 allows for fine, remote positioning of electrodes over a range of ~ 5 mm and weighs less than 750 mg when fully assembled. We present the complete protocol for how to build and assemble these drives, including 3D CAD drawings for all custom microdrive components.

The design, fabrication and assembly of an ultra-light motorized microdrive is described. The device provides a cost-effective and easy-to-use solution for chronic recordings of single units in small behaving animals.

Konstruktion und Montage eines Ultra-light Motorisierte Microdrive für chronische Neural Recordings in Kleintiere

The ability to chronically record from populations of neurons in freely behaving animals has proven an invaluable tool for dissecting the function of ...

Whole Cell Patch Clamp for Investigating the Mechanisms of Infrared Neural Stimulation

It has been demonstrated in recent years that pulsed, infrared laser light can be used to elicit electrical responses in neural tissue, independent of any further modification of the target tissue. Infrared neural stimulation has been reported in a variety of peripheral and sensory neural tissue in vivo, with particular interest shown in stimulation of neurons in the auditory nerve. However, while INS has been shown to work in these settings, the mechanism (or mechanisms) by which infrared light causes neural excitation is currently not well understood. The protocol presented here describes a whole cell patch clamp method designed to facilitate the investigation of infrared neural stimulation in cultured primary auditory neurons. By thoroughly characterizing the response of these cells to infrared laser illumination in vitro under controlled conditions, it may be possible to gain an improved understanding of the fundamental physical and biochemical processes underlying infrared neural stimulation.

Infrared nerve stimulation has been proposed as an alternative to electrical stimulation in a range of nerve types, including those associated with the auditory system. This protocol describes a patch clamp method for studying the mechanism of infrared nerve stimulation in a culture of primary auditory neurons.

Whole Cell Patch-Clamp für erforschen die Mechanismen der Infrarot Neural Stimulation

It has been  demonstrated in recent years that pulsed, infrared laser light can be used to  elicit electrical responses in neural tissue, independent of ...

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 ...

Time-dependent Increase in the Network Response to the Stimulation of Neuronal Cell Cultures on Micro-electrode Arrays

Micro-electrode arrays (MEAs) can be used to investigate drug toxicity, design paradigms for next-generation personalized medicine, and study network dynamics in neuronal cultures. In contrast with more traditional methods, such as patch-clamping, which can only record activity from a single cell, MEAs can record simultaneously from multiple sites in a network, without requiring the arduous task of placing each electrode individually. Moreover, numerous control and stimulation configurations can be easily applied within the same experimental setup, allowing for a broad range of dynamics to be explored. One of the key dynamics of interest in these in vitro studies has been the extent to which cultured networks display properties indicative of learning. Mouse neuronal cells cultured on MEAs display an increase in response following training induced by electrical stimulation. This protocol demonstrates how to culture neuronal cells on MEAs; successfully record from over 95% of the plated dishes; establish a protocol to train the networks to respond to patterns of stimulation; and sort, plot, and interpret the results from such experiments. The use of a proprietary system for stimulating and recording neuronal cultures is demonstrated. Software packages are also used to sort neuronal units. A custom-designed graphical user interface is used to visualize post-stimulus time histograms, inter-burst intervals, and burst duration, as well as to compare the cellular response to stimulation before and after a training protocol. Finally, representative results and future directions of this research effort are discussed.

Mouse neuronal cells cultured on multi-electrode arrays display an increase in response following electrical stimulation. This protocol demonstrates how to culture neurons, how to record activity, and how to establish a protocol to train the networks to respond to patterns of stimulation.

Zeitabhängige Erhöhung der Netzwerkreaktion auf die Stimulation von neuronalen Zellkulturen auf Mikroelektroden-Arrays

Micro-electrode arrays (MEAs) can be used to investigate drug toxicity, design paradigms for next-generation personalized medicine, and study network ...

Simultaneous Recordings of Cortical Local Field Potentials, Electrocardiogram, Electromyogram, and Breathing Rhythm from a Freely Moving Rat

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls body functions and internal organ rhythms when animals are exposed to emotional challenges and changes in their living environments. In general experiments, signals from different organs, such as the brain and the heart, are recorded by independent recording systems that require multiple recording devices and different procedures for processing the data files. This study describes a new method that can simultaneously monitor electrical biosignals, including tens of local field potentials in multiple brain regions, electrocardiograms that represent the cardiac rhythm, electromyograms that represent awake/sleep-related muscle contraction, and breathing signals, in a freely moving rat. The recording configuration of this method is based on a conventional micro-drive array for cortical local field potential recordings in which tens of electrodes are accommodated, and the signals obtained from these electrodes are integrated into a single electrical board mounted on the animal's head. Here, this recording system was improved so that signals from the peripheral organs are also transferred to an electrical interface board. In a single surgery, electrodes are first separately implanted into the appropriate body parts and the target brain areas. The open ends of all of these electrodes are then soldered to individual channels of the electrical board above the animal's head so that all of the signals can be integrated into the single electrical board. Connecting this board to a recording device allows for the collection of all of the signals into a single device, which reduces experimental costs and simplifies data processing, because all data can be handled in the same data file. This technique will aid the understanding of the neurophysiological correlates of the associations between central and peripheral organs.

This study introduces a method for the simultaneous recording of local field potentials in the brain, electrocardiograms, electromyograms, and breathing signals of a freely moving rat. This technique, which reduces experimental costs and simplifies data analysis, will contribute to the understanding of the interactions between the brain and peripheral organs.

Gleichzeitige Aufnahmen der kortikalen lokales Feld Potentiale, Elektrokardiogramm, Elektromyogramm und Atemrhythmus aus einem frei beweglichen Ratte

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls ...

Construction of an Improved Multi-Tetrode Hyperdrive for Large-Scale Neural Recording in Behaving Rats

Monitoring the activity patterns of a large population of neurons over many days in awake animals is a valuable technique in the field of systems neuroscience. One key component of this technique consists of the precise placement of multiple electrodes into desired brain regions and the maintenance of their stability. Here, we describe a protocol for the construction of a 3D-printable hyperdrive, which includes eighteen independently adjustable tetrodes, and is specifically designed for in vivo extracellular neural recording in freely behaving rats. The tetrodes attached to the microdrives can either be individually advanced into multiple brain regions along the track, or can be used to place an array of electrodes into a smaller area. The multiple tetrodes allow for simultaneous examination of action potentials from dozens of individual neurons, as well as local field potentials from populations of neurons in the brain during active behavior. In addition, the design provides for simpler 3D drafting software that can easily be modified for differing experimental needs.

We present the construction of a 3D-printable hyperdrive with eighteen independently adjustable tetrodes. The hyperdrive is designed to record brain activity in freely behaving rats over a period of several weeks.