Diese Arbeit wurde von den kanadischen Instituten für Gesundheitsforschung und Naturwissenschaften unterstützt.

<ol>
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Laminar distribution of theta field potentials.</a> Exp Brain Res. 67 (3), 493-501 (1987).</li><li>Vertes, R. P., Kocsis, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brainstem-diencephalo-septohippocampal+systems+controlling+the+theta+rhythm+of+the+hippocampus.">Brainstem-diencephalo-septohippocampal systems controlling the theta rhythm of the hippocampus.</a> Neuroscience. 81 (4), 893-926 (1997).</li><li>Bland, B. H., Colom, L. V., Konopacki, J., Roth, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracellular+records+of+carbachol-induced+theta+rhythm+in+hippocampal+slices.">Intracellular records of carbachol-induced theta rhythm in hippocampal slices.</a> Brain Res. 447 (2), 364-368 (1988).</li><li>Cobb, S. R., Buhl, E. H., Halasy, K., Paulsen, O., Somogyi, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synchronization+of+neuronal+activity+in+hippocampus+by+individual+GABAergic+interneurons.">Synchronization of neuronal activity in hippocampus by individual GABAergic interneurons.</a> Nature. 378 (6552), 75-78 (1995).</li><li>Williams, J. H., Kauer, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Properties+of+carbachol-induced+oscillatory+activity+in+rat+hippocampus.">Properties of carbachol-induced oscillatory activity in rat hippocampus.</a> J Neurophysiol. 78 (5), 2631-2640 (1997).</li><li>Chapman, C. A., Lacaille, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cholinergic+induction+of+theta-frequency+oscillations+in+hippocampal+inhibitory+interneurons+and+pacing+of+pyramidal+cell+firing.">Cholinergic induction of theta-frequency oscillations in hippocampal inhibitory interneurons and pacing of pyramidal cell firing.</a> J Neurosci. 19 (19), 8637-8645 (1999).</li><li>Strata, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intrinsic+oscillations+in+CA3+hippocampal+pyramids:+physiological+relevance+to+theta+rhythm+generation.">Intrinsic oscillations in CA3 hippocampal pyramids: physiological relevance to theta rhythm generation.</a> Hippocampus. 8 (6), 666-679 (1998).</li><li>Kocsis, B., Bragin, A., Buzsaki, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interdependence+of+multiple+theta+generators+in+the+hippocampus:+a+partial+coherence+analysis.">Interdependence of multiple theta generators in the hippocampus: a partial coherence analysis.</a> J Neurosci. 19 (14), 6200-6212 (1999).</li><li>Fellous, J. M., Sejnowski, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cholinergic+induction+of+oscillations+in+the+hippocampal+slice+in+the+slow+(0.5-2+Hz),+theta+(5-12+Hz),+and+gamma+(35-70+Hz)+bands.">Cholinergic induction of oscillations in the hippocampal slice in the slow (0.5-2 Hz), theta (5-12 Hz), and gamma (35-70 Hz) bands.</a> Hippocampus. 10 (2), 187-197 (2000).</li><li>Gillies, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+model+of+atropine-resistant+theta+oscillations+in+rat+hippocampal+area+CA1.">A model of atropine-resistant theta oscillations in rat hippocampal area CA1.</a> J Physiol. 543 (Pt 3), 779-793 (2002).</li><li>Gloveli, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orthogonal+arrangement+of+rhythm-generating+microcircuits+in+the+hippocampus.">Orthogonal arrangement of rhythm-generating microcircuits in the hippocampus.</a> Proc Natl Acad Sci U S A. 102 (37), 13295-13300 (2005).</li><li>Konopacki, J., Eckersdorf, B., Kowalczyk, T., Golebiewski, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Firing+cell+repertoire+during+carbachol-induced+theta+rhythm+in+rat+hippocampal+formation+slices.">Firing cell repertoire during carbachol-induced theta rhythm in rat hippocampal formation slices.</a> Eur J Neurosci. 23 (7), 1811-1818 (2006).</li><li>Hajos, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maintaining+network+activity+in+submerged+hippocampal+slices:+importance+of+oxygen+supply.">Maintaining network activity in submerged hippocampal slices: importance of oxygen supply.</a> Eur J Neurosci. 29 (2), 319-327 (2009).</li><li>Manseau, F., Goutagny, R., Danik, M., Williams, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+hippocamposeptal+pathway+generates+rhythmic+firing+of+GABAergic+neurons+in+the+medial+septum+and+diagonal+bands:+an+investigation+using+a+complete+septohippocampal+preparation+in+vitro.">The hippocamposeptal pathway generates rhythmic firing of GABAergic neurons in the medial septum and diagonal bands: an investigation using a complete septohippocampal preparation in vitro.</a> J Neurosci. 28 (15), 4096-4107 (2008).</li><li>Goutagny, R., Jackson, J., Williams, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Self-generated+theta+oscillations+in+the+hippocampus.">Self-generated theta oscillations in the hippocampus.</a> Nat Neurosci. 12 (12), 1491-1493 (2009).</li><li>Jackson, J., Goutagny, R., Williams, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fast+and+slow+gamma+rhythms+are+intrinsically+and+independently+generated+in+the+subiculum.">Fast and slow gamma rhythms are intrinsically and independently generated in the subiculum.</a> J Neurosci. 31 (34), 12104-12117 (2011).</li><li>Amilhon, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Parvalbumin+Interneurons+of+Hippocampus+Tune+Population+Activity+at+Theta+Frequency.">Parvalbumin Interneurons of Hippocampus Tune Population Activity at Theta Frequency.</a> Neuron. 86 (5), 1277-1289 (2015).</li><li>Huh, C. 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Während elektrophysiologische Aufnahmen von akuten Hippocampusscheiben eine Standard- In-vitro- Technik darstellen, unterscheiden sich die hier vorgestellten Methoden erheblich vom klassischen Ansatz. Anders als die dünnen Scheibenpräparate, bei denen spezifische Zellschichten an der Oberfläche sichtbar sind und direkt untersucht werden können, sind die intakten Hippocampuspräparate eher in in vivo- Konfigurationen verwandt, bei denen Elektroden in gezielte Hirnregionen abgesenkt werden,...

Hippocampale Theta-Oszillationen (4 - 12 Hz) gehören zu den vorherrschenden Formen der rhythmischen Aktivität im Säugetiergehirn und werden geglaubt, um Schlüsselrollen in kognitiven Funktionen wie die Verarbeitung von räumlich-zeitlichen Informationen und die Bildung episodischer Erinnerungen 1 , 2 , 3 zu spielen . Während mehrere In-vivo- Studien, die das Verhältnis von theta-modulierten Ort-Zellen mit räumlichen Navigations- und Läsionsstudien hervorheben, sowie klinische Evidenz unterstützen die Ansicht, dass hippocampale Theta-Oszillationen in die Gedächtnisbildung 4 , 5 , 6 involviert sind, Mit der Erzeugung von hippocampalen Theta-Oszillationen sind noch nicht vollständig verstanden In frühen In-vivo- Untersuchungen wurde vorgeschlagen, dass die Theta-Aktivität hauptsächlich von extrinsischen Oszillatoren, insbesondere rhythmischen Inputs, abhingVon afferenten Hirnstrukturen wie dem Septum und dem entorhinalen Kortex 7 , 8 , 9 , 10 . Eine Rolle für intrinsische Faktoren - interne Konnektivität von hippocampalen neuronalen Netzwerken zusammen mit den Eigenschaften von Hippocampusneuronen - wurde auch auf der Basis von in vitro Beobachtungen 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 postuliert. Abgesehen von einigen Landmarkstudien 19 , 20 , 21 sind jedoch Schwierigkeiten bei der Entwicklung von Ansätzen, die physiologisch realistische Populationsaktivitäten in einer einfachen In-vitro- Schichtvorbereitung replizieren könntenS hat seit langem eine detailliertere experimentelle Untersuchung der intrinsischen Fähigkeiten des Hippocampus und der verwandten Gebiete zur Selbst-Erzeugung von Theta-Schwingungen verzögert. Ein wichtiger Nachteil der Standard- In-vitro- Dünnschicht-Versuchsanpassung ist, dass die 3D-zelluläre und synaptische Organisation von Hirnstrukturen in der Regel kompromittiert wird. Dies bedeutet, dass viele Formen von konzertierten Netzwerkaktivitäten, die auf räumlich verteilten Zellanordnungen basieren, von lokalisierten Gruppen (≤1 mm Radius) bis hin zu Populationen von Neuronen, die sich über ein oder mehrere Gehirnbereiche (&gt; 1 mm) erstrecken, nicht unterstützt werden können. Angesichts dieser Überlegungen war eine andere Art von Ansatz erforderlich, um zu untersuchen, wie Theta-Oszillationen im Hippocampus entstehen und sich auf verwandte kortikale und subkortikale Ausgangsstrukturen ausbreiten. In den letzten Jahren wurde die anfängliche Entwicklung der &quot;kompletten septo-hippocampalen&quot; Präparation zur bidirektionalen Intera untersuchtCtions der beiden Strukturen 22 und die anschließende Evolution der &quot;isolierten Hippocampus&quot; -Präparation haben ergeben, dass intrinsische Theta-Oszillationen spontan im Hippocampus ohne externe rhythmische Input 23 auftreten . Der Wert dieser Ansätze liegt in der ersten Einsicht, dass die gesamte funktionale Struktur dieser Regionen bewahrt werden musste, um als ein Theta-Rhythmus-Generator in vitro zu funktionieren 22 .

<table><tbody><tr><td>&lt;strong&gt;Reagents&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Sodium Chloride</td><td>Sigma Aldrich</td><td>S9625</td><td></td></tr><tr><td>Sucrose</td><td>Sigma Aldrich</td><td>S9378</td><td></td></tr><tr><td>Sodium Bicarbonate</td><td>Sigma Aldrich</td><td>S5761</td><td></td></tr><tr><td>NaH&lt;sub&gt;2&lt;/sub&gt;PO&lt;sub&gt;4&lt;/sub&gt; - sodium phosphate monobasic</td><td>Sigma Aldrich</td><td>S8282</td><td></td></tr><tr><td>Magnesium sulfate</td><td>Sigma Aldrich</td><td>M7506</td><td></td></tr><tr><td>Potassium Chloride</td><td>Sigma Aldrich</td><td>P3911</td><td></td></tr><tr><td>D-(+)-Glucose</td><td>Sigma Aldrich</td><td>G7528</td><td></td></tr><tr><td>Calcium chloride dihydrate</td><td>Sigma Aldrich</td><td>C5080</td><td></td></tr><tr><td>Sodium Ascorbate</td><td>Sigma Aldrich</td><td>A7631-25G</td><td></td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Standard Dissecting Scissors</td><td>Fisher Scientific</td><td>08-951-25</td><td>brain extraction</td></tr><tr><td>Scalpel Handle #4, 14 cm</td><td>WPI</td><td>500237</td><td>brain extraction</td></tr><tr><td>Filter forceps, flat jaws, straight (11 cm)</td><td>WPI</td><td>500456</td><td>brain extraction</td></tr><tr><td>Paragon Stainless Steel Scalpel Blades #20</td><td>Ultident</td><td>02-90010-20</td><td>brain extraction</td></tr><tr><td>Fine Point Curved Dissecting Scissors</td><td>Thermo Fisher Scientific</td><td>711999</td><td>brain extraction</td></tr><tr><td>Teflon (PTFE) -coated thin spatula</td><td>VWR</td><td>82027-534</td><td>hippocampal preparation</td></tr><tr><td>Hayman Style Microspatula</td><td>Fisher Scientific</td><td>21-401-25A</td><td>hippocampal preparation</td></tr><tr><td>Lab spoon</td><td>Fisher Scientific</td><td>14-375-20</td><td>hippocampal preparation</td></tr><tr><td>Borosilicate Glass Pasteur Pipets</td><td>Fisher Scientific</td><td>13-678-20A</td><td>hippocampal preparation</td></tr><tr><td>Droper</td><td>Fisher Scientific</td><td></td><td>hippocampal preparation</td></tr><tr><td>Razor blades Single edged</td><td>VWR</td><td>55411-055</td><td>hippocampal preparation</td></tr><tr><td>Lens paper (4 x 6&quot;)</td><td>VWR</td><td>52846-001</td><td>hippocampal preparation</td></tr><tr><td>Glass petri dishes (100 x 20 mm)</td><td>VWR</td><td>25354-080</td><td>hippocampal preparation</td></tr><tr><td>Plastic tray for ice; size 30 x 20 x 5 cm</td><td>n.a.</td><td>n.a.</td><td>hippocampal preparation</td></tr><tr><td>Single Inline Solution Heater</td><td>Warner Instruments</td><td>SH-27B</td><td>perfusion system</td></tr><tr><td>Aquarium air stones for bubbling</td><td>n.a.</td><td>n.a.</td><td>perfusion system</td></tr><tr><td>Tygon E-3603 tubing (ID 1/16 OD 1/8)</td><td>Fisherbrand</td><td>14-171-129</td><td>perfusion system</td></tr><tr><td>Electric Skillet</td><td>Black &amp;amp; Decker</td><td>n.a.</td><td>perfusion system</td></tr><tr><td>95% O&lt;sub&gt;2&lt;/sub&gt;/5% CO&lt;sub&gt;2&lt;/sub&gt; gas mixture (carbogen)&amp;nbsp;</td><td>Vitalaire</td><td>SG466204A</td><td>perfusion system</td></tr><tr><td>Glass bottles/flasks (4 x 1 L)</td><td>n.a.</td><td>n.a.</td><td>perfusion system</td></tr><tr><td>Submerged recording Chamber</td><td>custom design (FM)</td><td>n.a.</td><td>Commercial alternative may be used</td></tr><tr><td>Glass pipettes (1.5/0.84 OD/ID (mm) )</td><td>WPI</td><td>1B150F-4</td><td>electrophysiology</td></tr><tr><td>Hum Bug 50/60 Hz Noise Eliminator</td><td>Quest Scientific</td><td>Q-Humbug</td><td>electrophysiology</td></tr><tr><td>Multiclamp 700B patch-clamp amplifier</td><td>Molecular devices</td><td>MULTICLAMP</td><td>electrophysiology</td></tr><tr><td>Multiclamp 700B Commander Program</td><td>Molecular devices</td><td>MULTICLAMP</td><td>electrophysiology</td></tr><tr><td>Digital/Analogue converter</td><td>Molecular devices</td><td>DDI440</td><td>electrophysiology</td></tr><tr><td>PCLAMP10</td><td>Molecular devices</td><td>PCLAMP10</td><td>electrophysiology</td></tr><tr><td>Vibration isolation table&amp;nbsp;</td><td>Newport</td><td>n.a.</td><td>electrophysiology</td></tr><tr><td>Micromanipulators (manually operated )</td><td>Siskiyou&amp;nbsp;</td><td>MX130</td><td>electrophysiology (LFP)</td></tr><tr><td>Micromanipulators (automated)</td><td>Siskiyou&amp;nbsp;</td><td>MC1000e</td><td>electrophysiology (patch)</td></tr><tr><td>Audio monitor&amp;nbsp;</td><td>A-M Systems</td><td>Model 3300</td><td>electrophysiology</td></tr><tr><td>Micropipette/Patch pipette puller</td><td>Sutter</td><td>P-97</td><td>electrophysiology</td></tr><tr><td>Custom-built upright fluorescence microscope</td><td>Siskiyou</td><td>n.a.</td><td>Imaging</td></tr><tr><td>Analogue video camera</td><td>COHU</td><td>4912-2000/0000</td><td>Imaging</td></tr><tr><td>Digital frame grabber with imaging software</td><td>EPIX, Inc</td><td>PIXCI-SV7</td><td>Imaging</td></tr><tr><td>Olympus 2.5X objective</td><td>Olympus</td><td>MPLFLN</td><td>Imaging</td></tr><tr><td>Olympus 40X water immersion objective</td><td>Olympus</td><td>UIS2 LUMPLFLN</td><td>Imaging</td></tr><tr><td>Custom-made Light-Emitting Diode (LED) system&amp;nbsp;</td><td>custom</td><td>n.a.</td><td>optogenetic stimulation (Amhilon et al., 2015)</td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Animals&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>PV::Cre (KI) mice</td><td>Jackson Laboratory</td><td>stock number 008069</td><td>Allow&amp;nbsp; Cre-directed gene expression in PV interneurons</td></tr><tr><td>Constitutive-conditional Ai9 mice (R26-lox-stop-lox-tdTomato (KI))</td><td>Jackson Laboratory</td><td>stock number 007905</td><td>Express TdTomato following Cre-mediated recombination</td></tr><tr><td>Ai32 mice (R26-lox-stop-lox-ChR2(H134R)-EYFP</td><td>Jackson Laboratory</td><td>stock&lt;br/&gt; number 012569</td><td>Express the improved channelrhodopsin-2/EYFP fusion protein following exposure to Cre recombinase</td></tr><tr><td>PVChY mice</td><td>In house breeding</td><td>n.a.</td><td>Offspring obtained from cross-breeding the PV-Cre line with Ai32 mice (R26-lox-stop-lox-ChR2(H134R)-EYFP</td></tr></tbody></table>

tuning in the hippocampal theta band in vitro: methodologies for recording from the isolated rodent septohippocampal circuit

Dieses Protokoll beschreibt die Verfahren für die Vorbereitung und Aufzeichnung aus dem isolierten ganzen Hippocampus, von WT und transgenen Mäusen, zusammen mit den jüngsten Verbesserungen in Methoden und Anwendungen für das Studium der Theta-Oszillationen. Es wird eine einfache Charakterisierung des isolierten Hippocampuspräparates vorgestellt, wobei die Beziehung zwischen internen hippocampalen Theta-Oszillatoren zusammen mit der Aktivität von Pyramidenzellen und GABAergischen Interneuronen der Cornu-Ammoni-1 (CA1) und Subiculum (SUB) -Flächen untersucht wird. Insgesamt zeigen wir, dass der isolierte Hippocampus in der Lage ist, intrinsische Theta-Oszillationen in vitro zu erzeugen, und die innerhalb des Hippocampus erzeugte Rhythmizität kann durch optogenetische Stimulation von parvalbumin-positiven (PV) Interneuronen präzise manipuliert werden. Die in vitro isolierte Hippocampuspräparation bietet eine einmalige Gelegenheit, simultane Feld- und intrazelluläre Patch-Clamp-Aufnahmen von visuell identifiziertem neu zu verwendenRons, um die Mechanismen zu verstehen, die der Theta-Rhythmus-Generation zugrunde liegen.

<html> Dieser Abschnitt veranschaulicht Beispiele für Ergebnisse, die durch das Studium der Theta-Oszillationen in der Maus isolierten Hippocampus-Präparation in vitro erhalten werden können . Das Sektionsverfahren zum Extrahieren des isolierten Hippocampus ist in Fig. 1 dargestellt . Mit dieser Vorbereitung können intrinsische Theta-Oszillationen bei der Platzierung von Mehrfachfeld-Elektroden untersucht werden, wobei die Gesamtaktivität und di...

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Tuning in the Hippocampal Theta Band In Vitro: Methodologies for Recording from the Isolated Rodent Septohippocampal Circuit

Hier präsentieren wir ein Protokoll zur Aufzeichnung von rhythmischen neuronalen Netzwerk-Theta und Gamma-Oszillationen aus einer isolierten ganzen Hippocampus-Präparation. Wir beschreiben die experimentellen Schritte von der Extraktion des Hippocampus bis hin zu Details der Feld-, Einheits- und Ganzzell-Patch-Clamp-Aufnahmen sowie der optogenetischen Stimulation des Theta-Rhythmus.

Tuning in der Hippocampal Theta Band<em&gt; In vitro</em&gt;: Methoden für die Aufnahme aus dem isolierten Nagetier Septohippocampal Circuit

This protocol outlines the procedures for preparing and recording from the isolated whole hippocampus, of WT and transgenic mice, along with recent ...

tuning-hippocampal-theta-band-vitro-methodologies-for-recording-from

Research

JoVE Journal

Neuroscience

Tuning in the Hippocampal Theta Band In Vitro: Methodologies for Recording from the Isolated Rodent Septohippocampal Circuit

9.7K Aufrufe.  McGill University.  Hier präsentieren wir ein Protokoll zur Aufzeichnung von rhythmischen neuronalen Netzwerk-Theta und Gamma-Oszillationen aus einer isolierten ganzen Hippocampus-Präparation. Wir beschreiben die experimentellen Schritte von der Extraktion des Hippocampus bis hin zu Details der Feld-, Einheits- und Ganzzell-Patch-Clamp-Aufnahmen sowie der optogenetischen Stimulation des Theta-Rhythmus. 

Serie: Tuning in the Hippocampal Theta Band In Vitro: Methodologies for Recording from the Isolated Rodent Septohippocampal Circuit

Automatic Detection of Highly Organized Theta Oscillations in the Murine EEG

Theta activity is generated in the septohippocampal system and can be recorded using deep intrahippocampal electrodes and implantable electroencephalography (EEG) radiotelemetry or tether system approaches. Pharmacologically, hippocampal theta is heterogeneous (see dualistic theory) and can be differentiated into type I and type II theta. These individual EEG subtypes are related to specific cognitive and behavioral states, such as arousal, exploration, learning and memory, higher integrative functions, etc. In neurodegenerative diseases such as Alzheimer&#39;s, structural and functional alterations of the septohippocampal system can result in impaired theta activity/oscillations. A standard quantitative analysis of the hippocampal EEG includes a Fast-Fourier-Transformation (FFT)-based frequency analysis. However, this procedure does not provide details about theta activity in general and highly-organized theta oscillations in particular. In order to obtain detailed information on highly-organized theta oscillations in the hippocampus, we have developed a new analytical approach. This approach allows for time- and cost-effective quantification of the duration of highly-organized theta oscillations and their frequency characteristics.

Theta activity in the hippocampus is related to specific cognitive and behavioral stages. Here, we describe an analytical method to detect highly-organized theta oscillations within the hippocampus using a time-frequency (i.e., wavelet analysis)-based approach.

Automatische Erkennung von hochorganisierten Theta Oszillationen im Murine EEG

Theta activity is generated in the septohippocampal system and can be recorded using deep intrahippocampal electrodes and implantable ...

Forschung

Verhalten

Dual Electrophysiological Recordings of Synaptically-evoked Astroglial and Neuronal Responses in Acute Hippocampal Slices

Astrocytes form together with neurons tripartite synapses, where they integrate and modulate neuronal activity. Indeed, astrocytes sense neuronal inputs through activation of their ion channels and neurotransmitter receptors, and process information in part through activity-dependent release of gliotransmitters. Furthermore, astrocytes constitute the main uptake system for glutamate, contribute to potassium spatial buffering, as well as to GABA clearance. These cells therefore constantly monitor synaptic activity, and are thereby sensitive indicators for alterations in synaptically-released glutamate, GABA and extracellular potassium levels. Additionally, alterations in astroglial uptake activity or buffering capacity can have severe effects on neuronal functions, and might be overlooked when characterizing physiopathological situations or knockout mice. Dual recording of neuronal and astroglial activities is therefore an important method to study alterations in synaptic strength associated to concomitant changes in astroglial uptake and buffering capacities. Here we describe how to prepare hippocampal slices, how to identify stratum radiatum astrocytes, and how to record simultaneously neuronal and astroglial electrophysiological responses. Furthermore, we describe how to isolate pharmacologically the synaptically-evoked astroglial currents.

The preparation of acute brain slices from isolated hippocampi, as well as the simultaneous electrophysiological recordings of astrocytes and neurons in stratum radiatum during stimulation of schaffer collaterals is described. The pharmacological isolation of astroglial potassium and glutamate transporter currents is demonstrated.

Dual-Elektrophysiologische Recordings synaptisch-evozierte astrogliale und neuronale Antworten in Acute Hippocampusschnitte

Astrocytes form together with neurons tripartite synapses, where they integrate and modulate neuronal activity. Indeed, astrocytes sense neuronal inputs ...

Neurowissenschaften

Improved Preparation and Preservation of Hippocampal Mouse Slices for a Very Stable and Reproducible Recording of Long-term Potentiation

Long-term potentiation (LTP) is a type of synaptic plasticity characterized by an increase in synaptic strength and believed to be involved in memory encoding. LTP elicited in the CA1 region of acute hippocampal slices has been extensively studied. However the molecular mechanisms underlying the maintenance phase of this phenomenon are still poorly understood. This could be partly due to the various experimental conditions used by different laboratories. Indeed, the maintenance phase of LTP is strongly dependent on external parameters like oxygenation, temperature and humidity. It is also dependent on internal parameters like orientation of the slicing plane and slice viability after dissection.
The optimization of all these parameters enables the induction of a very reproducible and very stable long-term potentiation. This methodology offers the possibility to further explore the molecular mechanisms involved in the stable increase in synaptic strength in hippocampal slices. It also highlights the importance of experimental conditions in in vitro investigation of neurophysiological phenomena.

This paper presents a complete methodology to prepare and preserve in vitro acute hippocampal slices from adult mice. This protocol allows the recording of very stable long-lasting long-term potentiation (LTP) for more than 8 hours with a success rate of 95%.

Verbesserte Zubereitung und Konservierung von Hippocampus Maus Slices für eine sehr stabile und reproduzierbare Erfassung der Langzeit-Potenzierung

Long-term potentiation (LTP) is a type of synaptic plasticity characterized by an increase in synaptic strength and believed to be involved in memory ...

Whole-cell Patch-clamp Recordings from Morphologically- and Neurochemically-identified Hippocampal Interneurons

GABAergic inhibitory interneurons play a central role within neuronal circuits of the brain. Interneurons comprise a small subset of the neuronal population (10-20%), but show a high level of physiological, morphological, and neurochemical heterogeneity, reflecting their diverse functions. Therefore, investigation of interneurons provides important insights into the organization principles and function of neuronal circuits. This, however, requires an integrated physiological and neuroanatomical approach for the selection and identification of individual interneuron types. Whole-cell patch-clamp recording from acute brain slices of transgenic animals, expressing fluorescent proteins under the promoters of interneuron-specific markers, provides an efficient method to target and electrophysiologically characterize intrinsic and synaptic properties of specific interneuron types. Combined with intracellular dye labeling, this approach can be extended with post-hoc morphological and immunocytochemical analysis, enabling systematic identification of recorded neurons. These methods can be tailored to suit a broad range of scientific questions regarding functional properties of diverse types of cortical neurons.

Cortical networks are controlled by a small, but diverse set of inhibitory interneurons. Functional investigation of interneurons therefore requires targeted recording and rigorous identification. Described here is a combined approach involving whole-cell recordings from single or synaptically-coupled pairs of neurons with intracellular labeling, post-hoc morphological and immunocytochemical analysis.

Whole-Cell-Patch-Clamp-Aufnahmen aus Morphologically- und neurochemisch identifizierten Hippocampus Inter

GABAergic inhibitory interneurons play a central role within neuronal circuits of the brain. Interneurons comprise a small subset of the neuronal ...

Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice

Extensive data on relationships of neural network oscillations to behavior and organization of neuronal discharge across brain regions call for new tools to selectively manipulate brain rhythms. Here we describe an approach combining projection-specific optogenetics with extracellular electrophysiology for high-fidelity control of hippocampal theta oscillations (5-10 Hz) in behaving mice. The specificity of the optogenetic entrainment is achieved by targeting channelrhodopsin-2 (ChR2) to the GABAergic population of medial septal cells, crucially involved in the generation of hippocampal theta oscillations, and a local synchronized activation of a subset of inhibitory septal afferents in the hippocampus. The efficacy of the optogenetic rhythm control is verified by a simultaneous monitoring of the local field potential (LFP) across lamina of the CA1 area and/or of neuronal discharge. Using this readily implementable preparation we show efficacy of various optogenetic stimulation protocols for induction of theta oscillations and for the manipulation of their frequency and regularity. Finally, a combination of the theta rhythm control with projection-specific inhibition addresses the readout of particular aspects of the hippocampal synchronization by efferent regions.

We describe the use of optogenetics and electrophysiological recordings for selective manipulations of hippocampal theta oscillations (5-10 Hz) in behaving mice. The efficacy of the rhythm entrainment is monitored using local field potential. A combination of opto- and pharmacogenetic inhibition addresses the efferent readout of hippocampal synchronization.

Optogenetische Mitnahme von Hippocampal Theta Schwingungen im Verhalten der Mäuse

Extensive data on relationships of neural network oscillations to behavior and organization of neuronal discharge across brain regions call for new tools ...

Recording and Modulation of Epileptiform Activity in Rodent Brain Slices Coupled to Microelectrode Arrays

Temporal lobe epilepsy (TLE) is the most common partial complex epileptic syndrome and the least responsive to medications. Deep brain stimulation (DBS) is a promising approach when pharmacological treatment fails or neurosurgery is not recommended. Acute brain slices coupled to microelectrode arrays (MEAs) represent a valuable tool to study neuronal network interactions and their modulation by electrical stimulation. As compared to conventional extracellular recording techniques, they provide the added advantages of a greater number of observation points and a known inter-electrode distance, which allow studying the propagation path and speed of electrophysiological signals. However, tissue oxygenation may be greatly impaired during MEA recording, requiring a high perfusion rate, which comes at the cost of decreased signal-to-noise ratio and higher oscillations in the experimental temperature. Electrical stimulation further stresses the brain tissue, making it difficult to pursue prolonged recording/stimulation epochs. Moreover, electrical modulation of brain slice activity needs to target specific structures/pathways within the brain slice, requiring that electrode mapping be easily and quickly performed live during the experiment. Here, we illustrate how to perform the recording and electrical modulation of 4-aminopyridine (4AP)-induced epileptiform activity in rodent brain slices using planar MEAs. We show that the brain tissue obtained from mice outperforms rat brain tissue and is thus better suited for MEA experiments. This protocol guarantees the generation and maintenance of a stable epileptiform pattern that faithfully reproduces the electrophysiological features observed with conventional field potential recording, persists for several hours, and outlasts sustained electrical stimulation for prolonged epochs. Tissue viability throughout the experiment is achieved thanks to the use of a small-volume custom recording chamber allowing for laminar flow and quick solution exchange even at low (1 mL/min) perfusion rates. Quick MEA mapping for real-time monitoring and selection of stimulating electrodes is performed by a custom graphic user interface (GUI).

We illustrate how to perform recording and electrical modulation of 4-aminopyridine-induced epileptiform activity in rodent brain slices using microelectrode arrays. A custom recording chamber maintains tissue viability throughout prolonged experimental sessions. Live electrode mapping and selection of stimulating pairs are performed by a custom graphical user interface.

Aufnahme und Modulation der Epileptiformen Aktivität in Nagetier Gehirnscheiben gekoppelt mit Mikroelektrode Arrays

Temporal lobe epilepsy (TLE) is the most common partial complex epileptic syndrome and the least responsive to medications. Deep brain stimulation (DBS) ...

Recording Spatially Restricted Oscillations in the Hippocampus of Behaving Mice

The local field potential (LFP) emerges from ion movements across neural membranes. Since the voltage recorded by LFP electrodes reflects the summed electrical field of a large volume of brain tissue, extracting information about local activity is challenging. Studying neuronal microcircuits, however, requires a reliable distinction between truly local events and volume-conducted signals originating in distant brain areas. Current source density (CSD) analysis offers a solution for this problem by providing information about current sinks and sources in the vicinity of the electrodes. In brain areas with laminar cytoarchitecture such as the hippocampus, one-dimensional CSD can be obtained by estimating the second spatial derivative of the LFP. Here, we describe a method to record multilaminar LFPs using linear silicon probes implanted into the dorsal hippocampus. CSD traces are computed along individual shanks of the probe. This protocol thus describes a procedure to resolve spatially restricted neuronal network oscillations in the hippocampus of freely moving mice.

This protocol describes the recording of local field potentials with multi-shank linear silicon probes. Conversion of the signals using current source density analysis allows the reconstruction of local electrical activity in the mouse hippocampus. With this technique, spatially restricted brain oscillations can be studied in freely moving mice.

Aufzeichnung von räumlich eingeschränkt Schwingungen im Hippocampus Verhalten der Mäuse

The local field potential (LFP) emerges from ion movements across neural membranes. Since the voltage recorded by LFP electrodes reflects the summed ...

Selective Manipulation of Theta Oscillations in a Mouse Model

Source: Bender, F. et al., <a href="https://app.jove.com/v/57349">Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice.</a> J. Vis. Exp (2018)
This video demonstrates a protocol to modulate theta oscillations in a genetically engineered mouse model with light-sensitive ion channels in its GABAergic medial septum neurons. By delivering light pulses to the hippocampus, the protocol aims to synchronize neuronal activity and generate theta oscillations, which are recorded as local field potentials.

Selektive Manipulation von Theta-Oszillationen in einem Mausmodell

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
PV-Cre ...

JoVE Encyclopedia of Experiments

Neurophysiology

Stimulation and Modulation Techniques

Optogenetic Control of Hippocampal Network Dynamics

Source: Manseau, F., et al. <a href="https://app.jove.com/v/55851">Tuning in the Hippocampal Theta Band In Vitro: Methodologies for Recording from the Isolated Rodent Septohippocampal Circuit.</a> J. Vis. Exp. (2017)
This video demonstrates the method to use optogenetics to modulate hippocampal network dynamics by activating genetically modified light-sensitive interneurons in a mouse brain slice, enhancing theta oscillation synchronization and studying neural circuit behavior.

Optogenetische Kontrolle der Netzwerkdynamik im Hippocampus

All procedures involving animal samples have been reviewed and approved by the appropriate animal ethical review committee.

	Optogenetic control in the ...

In Vitro Recording of Theta Oscillations in the Mouse Hippocampus

Source: Manseau, F., et.al. <a href="https://app.jove.com/v/55851">Tuning in the Hippocampal Theta Band In Vitro: Methodologies for Recording from the Isolated Rodent Septohippocampal Circuit.</a> J. Vis. Exp. (2017).
This video demonstrates the recording of rhythmic neuronal network activity, also known as theta oscillations, in an isolated hippocampus. Electrodes are inserted into various layers and spatial positions to detect and analyze theta oscillations. This shows the unique neuronal compositions and the connectivity of the neuronal network across different layers of the hippocampus.

Tuning in der Hippocampal Theta Band

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