Diese Arbeit wurde durch die NIH / NIDDK (DK077106 ECM) unterstützt.

<ol>
	<li>McNay, E. C., Fries, T. M., Gold, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decreases+in+rat+extracellular+hippocampal+glucose+concentration+associated+with+cognitive+demand+during+a+spatial+task.">Decreases in rat extracellular hippocampal glucose concentration associated with cognitive demand during a spatial task.</a> Proc. Natl. Acad. Sci. U.S.A. 97 (6), 2881 (2000).</li><li>McNay, E. C., Gold, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age-related+differences+in+hippocampal+extracellular+fluid+glucose+concentration+during+behavioral+testing+and+following+systemic+glucose+administration.">Age-related differences in hippocampal extracellular fluid glucose concentration during behavioral testing and following systemic glucose administration.</a> J. Gerontol. A. Biol. Sci. Med. Sci. 56 (2), 66 (2001).</li><li>McNay, E. C., McCarty, R. C., Gold, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluctuations+in+brain+glucose+concentration+during+behavioral+testing:+dissociations+between+brain+areas+and+between+brain+and+blood.">Fluctuations in brain glucose concentration during behavioral testing: dissociations between brain areas and between brain and blood.</a> Neurobiol. Learn. Mem. 75 (3), 325 (2001).</li><li>McNay, E. C., Gold, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+glucose+concentrations+in+the+rat+hippocampus+measured+by+zero-net-flux:+effects+of+microdialysis+flow+rate.">Extracellular glucose concentrations in the rat hippocampus measured by zero-net-flux: effects of microdialysis flow rate.</a> 72 (2), 785 (1999).</li><li>McNay, E. C., Sherwin, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+recurrent+hypoglycemia+on+spatial+cognition+and+cognitive+metabolism+in+normal+and+diabetic+rats.">Effect of recurrent hypoglycemia on spatial cognition and cognitive metabolism in normal and diabetic rats.</a> Diabetes. 53 (2), 418 (2004).</li><li>McNay, E. C., 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=Hippocampal+memory+processes+are+modulated+by+insulin+and+high-fat-induced+insulin+resistance.">Hippocampal memory processes are modulated by insulin and high-fat-induced insulin resistance.</a> Neurobiology of Learning and Memory. 93 (4), 546 (2010).</li><li>McNay, E. C., McCarty, R. C., Gold, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluctuations+in+brain+glucose+concentration+during+behavioral+testing:+dissociations+between+brain+areas+and+between+brain+and+blood.">Fluctuations in brain glucose concentration during behavioral testing: dissociations between brain areas and between brain and blood.</a> Neurobiology of Learning &amp; Memory. 75 (3), 325 (2001).</li><li>McNay, E. C., Williamson, A., McCrimmon, R. J., Sherwin, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cognitive+and+neural+hippocampal+effects+of+long-term+moderate+recurrent+hypoglycemia.">Cognitive and neural hippocampal effects of long-term moderate recurrent hypoglycemia.</a> Diabetes. 55 (4), 1088 (2006).</li><li>McNay, E. C., Sherwin, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+artificial+cerebro-spinal+fluid+(aCSF)+to+artificial+extracellular+fluid+(aECF):+microdialysis+perfusate+composition+effects+on+in+vivo+brain+ECF+glucose+measurements.">From artificial cerebro-spinal fluid (aCSF) to artificial extracellular fluid (aECF): microdialysis perfusate composition effects on in vivo brain ECF glucose measurements.</a> Journal of Neuroscience Methods. 132 (1), 35 (2004).</li><li>McNay, E. C., 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=Hippocampal+memory+processes+are+modulated+by+insulin+and+high-fat-induced+insulin+resistance.">Hippocampal memory processes are modulated by insulin and high-fat-induced insulin resistance.</a> Neurobiology of Learning and Memory. 93 (4), 546 (2010).</li><li>Benveniste, H., Drejer, J., Schousboe, A., Diemer, N. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regional+cerebral+glucose+phosphorylation+and+blood+flow+after+insertion+of+a+microdialysis+fiber+through+the+dorsal+hippocampus+in+the+rat.">Regional cerebral glucose phosphorylation and blood flow after insertion of a microdialysis fiber through the dorsal hippocampus in the rat.</a> Journal of Neurochemistry. 49 (3), 729 (1987).</li><li>Benveniste, H., Diemer, N. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+reactions+to+implantation+of+a+microdialysis+tube+in+the+rat+hippocampus.">Cellular reactions to implantation of a microdialysis tube in the rat hippocampus.</a> Acta Neuropathologica. 74 (3), 234 (1987).</li><li>McNay, E. C., Fries, T. M., Gold, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decreases+in+rat+extracellular+hippocampal+glucose+concentration+associated+with+cognitive+demand+during+a+spatial+task.">Decreases in rat extracellular hippocampal glucose concentration associated with cognitive demand during a spatial task.</a> Proceedings of the National Academy of Sciences of the United States of America. 97 (6), 2881 (2000).</li><li>McNay, E. C., 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=Hippocampal+memory+processes+are+modulated+by+insulin+and+high-fat-induced+insulin+resistance.">Hippocampal memory processes are modulated by insulin and high-fat-induced insulin resistance.</a> Neurobiol. Learn Mem. 93 (4), 546 (2010).</li><li>Lonnroth, P., Jansson, P. -. A., Smith, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+microdialysis+method+allowing+characterization+of+intercellular+water+space+in+humans.">A microdialysis method allowing characterization of intercellular water space in humans.</a> American Journal of Physiology. 1987, E228 (1987).</li><li>McNay, E. C., Gold, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+glucose+concentrations+in+the+rat+hippocampus+measured+by+zero-net-flux:+effects+of+microdialysis+flow+rate.">Extracellular glucose concentrations in the rat hippocampus measured by zero-net-flux: effects of microdialysis flow rate.</a> 72 (2), 785 (1999).</li><li>Lalonde, R. o. b. e. r. t. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+neurobiological+basis+of+spontaneous+alternation.">The neurobiological basis of spontaneous alternation.</a> Neuroscience &amp; Biobehavioral Reviews. 26 (1), 91 (2002).</li><li>Richman, C., Dember, W., Kim, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spontaneous+alternation+behavior+in+animals:+A+review.">Spontaneous alternation behavior in animals: A review.</a> Current Psychology. 5 (4), 358 (1986).</li><li>McNay, E. C., Canal, C. E., Sherwin, R. S., Gold, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+memory+with+septal+injections+of+morphine+and+glucose:+effects+on+extracellular+glucose+levels+in+the+hippocampus.">Modulation of memory with septal injections of morphine and glucose: effects on extracellular glucose levels in the hippocampus.</a> Physiol. Behav. 87 (2), 298 (2006).</li><li>McNay, E. C., Gold, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Memory+modulation+across+neural+systems:+intra-amygdala+glucose+reverses+deficits+caused+by+intraseptal+morphine+on+a+spatial+task+but+not+on+an+aversive+task.">Memory modulation across neural systems: intra-amygdala glucose reverses deficits caused by intraseptal morphine on a spatial task but not on an aversive task.</a> Journal of Neuroscience. 18 (10), 3853 (1998).</li><li>Rex, A., Bert, B., Fink, H., Voigt, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimulus-dependent+changes+of+extracellular+glucose+in+the+rat+hippocampus+determined+by+in+vivo+microdialysis.">Stimulus-dependent changes of extracellular glucose in the rat hippocampus determined by in vivo microdialysis.</a> Physiol. Behav. 98 (4), 467 (2009).</li></ol>

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Alle Lösungen in Mikrodialyse verwendet sollte sofort filtriert werden vor der Verwendung mit einem 0,2 um Filter. Nach dem Einführen der Sonde in die Führungskanüle, beobachten zu bestätigen, dass Strömung ungehindert und Probensammelvorrichtung auftritt. Wenn der Durchfluss stoppt nach dem Einsetzen ist die wahrscheinlichste Ursache Beschädigung der Sonde Membran durch unzureichende Pflege beim Einsetzen verursacht, und ein frischer Sonde muss ersetzt werden. Wie oben erwähnt, ein ...

<table border="1"><tbody><tr><td></td><td></td><td></td><td> Die Mehrheit der Reagenzien sind Standard Laborreinheit und kann von einem Anbieter der Wahl erhalten werden. In ähnlicher Weise können Geräte wie Spritzenpumpen und Schläuche von einem von mehreren Herstellern verwendet werden. Bestimmte Elemente welche hier für die Details sind wichtig sind: </td></tr><tr><td> CMA 12 Mikrodialysesonden </td><td> CMA / Microdialysis </td><td> CMA-12-XXX </td><td> Diese sind in verschiedenen Membran Längen und Abschaltungen, die durch spezifische Codes in der angegebenen &#39;XXX. &quot; </td></tr><tr><td> Humaninsulin (Humulin) </td><td> Eli Lilly </td><td> N / a </td><td></td></tr><tr><td> Flüssige Schwenk </td><td> Instech </td><td> 375/D/22QM </td><td> Diese spezifische Drehgelenk hat sehr niedrige Drehmoment und Innenvolumen sowie einen nonreactive Quarz Futter. </td></tr></tbody></table>

hippocampal insulin microinjection and in vivo microdialysis during spatial memory testing

Glukosestoffwechsel ist ein nützlicher Marker für die lokale neuronale Aktivität, die die Grundlage von Methoden wie 2-Desoxyglucose und funktionelle Kernspintomographie. Allerdings solcher Methoden in Tiermodellen erfordert die Verwendung Anästhesie und damit sowohl verändert das Gehirn Zustand und verhindert Verhaltensmaßnahmen. Ein alternatives Verfahren ist die Verwendung von in vivo-Mikrodialyse zur kontinuierlichen Messung des Gehirns extrazellulären Flüssigkeit Konzentrationen von Glukose, Laktat, und verwandte Metaboliten an wachen, ungehemmte Tiere. Diese Technik ist besonders nützlich, wenn mit Aufgaben entworfen, um auf spezifische Hirnregionen und / oder akute pharmakologische Manipulation verlassen kombiniert, zum Beispiel, zeigen Hippocampus Messungen während einer räumlichen Arbeitsgedächtnis Aufgabe (spontane Wechsel) ein erfrischendes Bad im extrazellulären Glukose und Lactatanstiegs, die sind suggestive der verstärkten Glykolyse 1,2 und intrahippocampal Verabreichung von Insulin sowohl verbessert das Gedächtnis und erhöht Hippocampus Glykollyse 3. Substanzen wie Insulin kann der Hippocampus über den gleichen Mikrodialysesonde verwendet, um Metaboliten zu messen geliefert werden. Die Verwendung von spontanen Wechsels als Maß der Hippokampus-Funktion ausgelegt ist, jede von confound belastenden Motivatoren (zB Fußschock), Ruhigstellen oder Belohnungen (zB Nahrungsmittel), die alle beide Aufgabenleistung und Metabolismus verändern kann zu vermeiden; diese Aufgabe stellt auch eine Messung der motorischen Aktivität, die Steuerung ermöglicht für unspezifische Effekte der Behandlung. Zusammen ermöglichen diese Verfahren die direkte Messung der neurochemischen und metabolische Variablen Regelverhalten.

Ratten sollte rasch erholen sich von der Operation und wachsam sein, beweglich und aktiv innerhalb von 30 min nach Beendigung der Narkose. Die Auswirkungen der Kanülenkappe sollte minimal sein, wenn die Operation durchgeführt wird sauber und minimalen Dentalzement verwendet wird. Wenn Anzeichen einer Infektion während der postoperativen Überwachung aufgefallen ist, oder die Ratte ist in keiner Weise zeigt Anzeichen von Leiden oder Beschwerden, sofort beenden das Experiment, das sollte extrem selten. Bei der Handhabu...

Watch this Scientific Journal Video about Hippocampal Insulin Microinjection and In vivo Microdialysis During Spatial Memory Testing at JoVE.com

Hippocampal Insulin Microinjection and In vivo Microdialysis During Spatial Memory Testing

Modulation der hippocampally-abhängige räumliche Arbeitsgedächtnis durch direkte intrahippocampal Mikroinjektion, begleitet und gefolgt von<em&gt; In vivo</em&gt; Mikrodialyse für Metaboliten in der bewussten, sich verhaltenden Tier.

Hippocampus Insulin Mikroinjektion und<em&gt; In vivo</em&gt; Microdialysis Während Spatial Memory Testing

Glucose metabolism is a useful marker for local neural activity, forming the basis of methods such as 2-deoxyglucose and functional magnetic resonance ...

hippocampal-insulin-microinjection-vivo-microdialysis-during-spatial

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JoVE Journal

Neuroscience

Hippocampal Insulin Microinjection and In vivo Microdialysis During Spatial Memory Testing

16.4K Aufrufe.  University at Albany. Modulation der hippocampally-abhängige räumliche Arbeitsgedächtnis durch direkte intrahippocampal Mikroinjektion, begleitet und gefolgt von In vivo Mikrodialyse für Metaboliten in der bewussten, sich verhaltenden Tier.

Serie: Hippocampal Insulin Microinjection and In vivo Microdialysis During Spatial Memory Testing

Selective Viral Transduction of Adult-born Olfactory Neurons for Chronic in vivo Optogenetic Stimulation

Local interneurons are continuously regenerated in the olfactory bulb of adult rodents1-3. In this process, called adult neurogenesis, neural stem cells in the walls of the lateral ventricle give rise to neuroblasts that migrate for several millimeters along the rostral migratory stream (RMS) to reach and incorporate into the olfactory bulb. To study the different steps and the impact of adult-born neuron integration into preexisting olfactory circuits, it is necessary to selectively label and manipulate the activity of this specific population of neurons. The recent development of optogenetic technologies offers the opportunity to use light to precisely activate this specific cohort of neurons without affecting surrounding neurons4,5. Here, we present a series of procedures to virally express Channelrhodopsin2(ChR2)-YFP in a temporally restricted cohort of neuroblasts in the RMS before they reach the olfactory bulb and become adult-born neurons. In addition, we show how to implant and calibrate a miniature LED for chronic in vivo stimulation of ChR2-expressing neurons.

Selective Viral Transduction of Adult-born Olfactory Neurons for Chronic in vivo Optogenetic Stimulation

Adult-born neurons of the olfactory bulb can be optogenetically controlled using Channelrhodopsin2-expressing lentiviral injection in the rostral migratory stream and chronic photostimulation with an implanted miniature LED.

Selektive Viral Transduktion von Adult-geboren olfaktorischen Neuronen für chronische In vivo Optogenetische Stimulation

Local interneurons are continuously regenerated in the olfactory bulb of adult rodents1-3. In this process, called adult neurogenesis, neural stem cells ...

Forschung

Neurowissenschaften

Functional Neuroimaging Using Ultrasonic Blood-brain Barrier Disruption and Manganese-enhanced MRI

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains technically challenging. One approach, Activation-Induced Manganese-enhanced MRI (AIM MRI), has been used successfully to map neuronal activity in rodents 1-5. In AIM MRI, Mn2+ acts a calcium analog and accumulates in depolarized neurons 6,7. Because Mn2+ shortens the T1 tissue property, regions of elevated neuronal activity will enhance in MRI. Furthermore, Mn2+ clears slowly from the activated regions; therefore, stimulation can be performed outside the magnet prior to imaging, enabling greater experimental flexibility. However, because Mn2+ does not readily cross the blood-brain barrier (BBB), the need to open the BBB has limited the use of AIM MRI, especially in mice.
One tool for opening the BBB is ultrasound. Though potentially damaging, if ultrasound is administered in combination with gas-filled microbubbles (i.e., ultrasound contrast agents), the acoustic pressure required for BBB opening is considerably lower. This combination of ultrasound and microbubbles can be used to reliably open the BBB without causing tissue damage 8-11.
Here, a method is presented for performing AIM MRI by using microbubbles and ultrasound to open the BBB. After an intravenous injection of perflutren microbubbles, an unfocused pulsed ultrasound beam is applied to the shaved mouse head for 3 minutes. For simplicity, we refer to this technique of BBB Opening with Microbubbles and UltraSound as BOMUS 12. Using BOMUS to open the BBB throughout both cerebral hemispheres, manganese is administered to the whole mouse brain. After experimental stimulation of the lightly sedated mice, AIM MRI is used to map the neuronal response.
To demonstrate this approach, herein BOMUS and AIM MRI are used to map unilateral mechanical stimulation of the vibrissae in lightly sedated mice 13. Because BOMUS can open the BBB throughout both hemispheres, the unstimulated side of the brain is used to control for nonspecific background stimulation. The resultant 3D activation map agrees well with published representations of the vibrissae regions of the barrel field cortex 14. The ultrasonic opening of the BBB is fast, noninvasive, and reversible; and thus this approach is suitable for high-throughput and/or longitudinal studies in awake mice.

A technique is described for broadly opening the blood-brain barrier in the mouse using microbubbles and ultrasound. Using this technique, manganese can be administered to the mouse brain. Because manganese is an MRI contrast agent that accumulates in depolarized neurons, this approach enables imaging of neuronal activity.

Funktionelle Bildgebung mit Ultraschall-Blut-Hirnschranke Störung und Mangan-MRT

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains ...

Microdialysis of Ethanol During Operant Ethanol Self-administration and Ethanol Determination by Gas Chromatography

Operant self-administration methods are commonly used to study the behavioral and pharmacological effects of many drugs of abuse, including ethanol. However, ethanol is typically self-administered orally, rather than intravenously like many other drugs of abuse. The pharmacokinetics of orally administered drugs are more complex than intravenously administered drugs. Because understanding the relationship between the pharmacological and behavioral effects of ethanol requires knowledge of the time course of ethanol reaching the brain during and after drinking, we use in vivo microdialysis and gas chromatography with flame ionization detection to monitor brain dialysate ethanol concentrations over time. 
Combined microdialysis-behavioral experiments involve the use of several techniques. In this article, stereotaxic surgery, behavioral training and microdialysis, which can be adapted to test a multitude of self-administration and neurochemical centered hypotheses, are included only to illustrate how they relate to the subsequent phases of sample collection and dialysate ethanol analysis. Dialysate ethanol concentration analysis via gas chromatography with flame-ionization detection, which is specific to ethanol studies, is described in detail. Data produced by these methods reveal the pattern of ethanol reaching the brain during the self-administration procedure, and when paired with neurochemical analysis of the same dialysate samples, allows conclusions to be made regarding the pharmacological and behavioral effects of ethanol.

A method to determine the time course of ethanol concentration in the brains of rats during operant ethanol self-administration is described. Gas chromatography with flame ionization detection is used to quantify ethanol in the dialysate samples, because it has the sensitivity required for the small volumes that are generated.

Microdialysis Ethanol während operante Ethanol Selbstverwaltung und Ethanol Bestimmung durch Gaschromatographie

Operant self-administration methods are commonly used to study the behavioral and pharmacological effects of many drugs of abuse, including ethanol.  ...

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 ...

In vivo Optogenetic Stimulation of the Rodent Central Nervous System

The ability to probe defined neural circuits in awake, freely-moving animals with cell-type specificity, spatial precision, and high temporal resolution has been a long sought tool for neuroscientists in the systems-level search for the neural circuitry governing complex behavioral states. Optogenetics is a cutting-edge tool that is revolutionizing the field of neuroscience and represents one of the first systematic approaches to enable causal testing regarding the relation between neural signaling events and behavior. By combining optical and genetic approaches, neural signaling can be bi-directionally controlled through expression of light-sensitive ion channels (opsins) in mammalian cells. The current protocol describes delivery of specific wavelengths of light to opsin-expressing cells in deep brain structures of awake, freely-moving rodents for neural circuit modulation. Theoretical principles of light transmission as an experimental consideration are discussed in the context of performing in vivo optogenetic stimulation. The protocol details the design and construction of both simple and complex laser configurations and describes tethering strategies to permit simultaneous stimulation of multiple animals for high-throughput behavioral testing.

In vivo Optogenetic Stimulation of the Rodent Central Nervous System

Optogenetics has become a powerful tool for use in behavioral neuroscience experiments. This protocol offers a step-by-step guide to the design and set-up of laser systems, and provides a full protocol for carrying out multiple and simultaneous in vivo optogenetic stimulations compatible with most rodent behavioral testing paradigms.

In vivo optogenetische Stimulation des Nager Central Nervous System

The ability to probe defined neural circuits in awake, freely-moving animals with cell-type specificity, spatial precision, and high temporal resolution ...

Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System

An In vivo electroretinogram (ERG) signal is composed of several overlapping components originating from different retinal cell types, as well as noise from extra-retinal sources. Ex vivo ERG provides an efficient method to dissect the function of retinal cells directly from an intact isolated retina of animals or donor eyes. In addition, ex vivo ERG can be used to test the efficacy and safety of potential therapeutic agents on retina tissue from animals or humans. We show here how commercially available in vivo ERG systems can be used to conduct ex vivo ERG recordings from isolated mouse retinas. We combine the light stimulation, electronic and heating units of a standard in vivo system with custom-designed specimen holder, gravity-controlled perfusion system and electromagnetic noise shielding to record low-noise ex vivo ERG signals simultaneously from two retinas with the acquisition software included in commercial in vivo systems. Further, we demonstrate how to use this method in combination with pharmacological treatments that remove specific ERG components in order to dissect the function of certain retinal cell types.

Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System

Ex vivo ERG can be used to record electrical activity of retinal cells directly from isolated intact retinas of animals or humans. We demonstrate here how common in vivo ERG systems can be adapted for ex vivo ERG recordings in order to dissect the electrical activity of retinal cells.

Gleichzeitig<em&gt; Ex vivo</em&gt; Funktionsprüfung von zwei Netzhäute von<em&gt; In vivo</em&gt; Elektroretinogramm-System

An In vivo electroretinogram (ERG) signal is composed of several overlapping components originating from different retinal cell types, as well as noise ...

Immunohistochemical Visualization of Hippocampal Neuron Activity After Spatial Learning in a Mouse Model of Neurodevelopmental Disorders

Induction of phosphorylated extracellular-regulated kinase (pERK) is a reliable molecular readout of learning-dependent neuronal activation. Here, we describe a pERK immunohistochemistry protocol to study the profile of hippocampal neuron activation following exposure to a spatial learning task in a mouse model characterized by cognitive deficits of neurodevelopmental origin. Specifically, we used pERK immunostaining to study neuronal activation following Morris water maze (MWM, a classical hippocampal-dependent learning task) in Engrailed-2 knockout (En2-/-) mice, a model of autism spectrum disorders (ASD). As compared to wild-type (WT) controls, En2-/- mice showed significant spatial learning deficits in the MWM. After MWM, significant differences in the number of pERK-positive neurons were detected in specific hippocampal subfields of En2-/- mice, as compared to WT animals. Thus, our protocol can robustly detect differences in pERK-positive neurons associated to hippocampal-dependent learning impairment in a mouse model of ASD. More generally, our protocol can be applied to investigate the profile of hippocampal neuron activation in both genetic or pharmacological mouse models characterized by cognitive deficits.

We describe an immunohistochemistry protocol to study the profile of hippocampal neuron activation following exposure to a spatial learning task in a mouse model characterized by cognitive deficits of neurodevelopmental origin. This protocol can be applied to both genetic or pharmacological mouse models characterized by cognitive deficits.

Immunhistochemische Visualisierung von Hippocampus-Aktivität nach Spatial Learning in einem Mausmodell für neurologische Entwicklungsstörungen

Induction of phosphorylated extracellular-regulated kinase (pERK) is a reliable molecular readout of learning-dependent neuronal activation. Here, we ...

Assessing Spatial Learning and Memory in Small Squamate Reptiles

Clinical research has leveraged a variety of paradigms to assess cognitive decline, commonly targeting spatial learning and memory abilities. However, interest in the cognitive processes of nonmodel species, typically within an ecological context, has also become an emerging field of study. In particular, interest in the cognitive processes in reptiles is growing although experimental studies on reptilian cognition are sparse. The few reptilian studies that have experimentally tested for spatial learning and memory have used rodent paradigms modified for use in reptiles. However, ecologically important aspects of the physiology and behavior of this taxonomic group must be taken into account when testing for spatially based cognition. Here, we describe modifications of the dry land Barnes maze and associated testing protocol that can improve performance when probing for spatial learning and memory ability in small squamate reptiles. The described paradigm and procedures were successfully used with male side-blotched lizards (Uta stansburiana), demonstrating that spatial learning and memory can be assessed in this taxonomic group with an ecologically relevant apparatus and protocol.

This paper describes a modification of the Barnes maze, a standard rodent paradigm used to assess spatial memory and learning, for use in small squamate reptiles.

Die Beurteilung räumliches Lernen und Gedächtnis in Klein squamate Reptilien

Clinical research has leveraged a variety of paradigms to assess cognitive decline, commonly targeting spatial learning and memory abilities. However, ...

An In Ovo Model for Testing Insulin-mimetic Compounds

Elevated blood glucose levels in type 2 diabetes mellitus (T2DM), a complex and multifactorial metabolic disease, are caused by insulin resistance and &#946;-cell failure. Various strategies, including the injection of insulin or the usage of insulin-sensitizing drugs, were pursued to treat T2DM or at least reduce the symptoms. In addition, the application of herbal compounds has attracted increasing attention. Thus, it is necessary to find efficient test systems to identify and characterize insulin-mimetic compounds. Here we developed a modified chick embryo model, which enables testing of synthetic compounds and herbal extracts with insulin-mimetic properties. Using a fluorescence microscopy-based primary screen, which quantifies the translocation of Glucose transporter 4 (Glut4) to the plasma membrane, we were able to identify compounds, mainly herbal extracts, which lead to an increase of intracellular glucose concentrations in adipocytes. However, the efficacy of these substances requires further verification in a living organism. Thus, we used an in-ovo approach to identify their blood glucose-reducing properties. The approval by an ethics committee is not needed since the use of chicken embryos during the first two-thirds of embryonic development is not considered an animal experiment. Here, the application of this model is described in detail.

An In Ovo Model for Testing Insulin-mimetic Compounds

In this study, we describe an in-ovo system as a promising tool to test insulin-mimetic compounds in a living organism. The main advantages include adequate throughput rates and acceptable costs, which enable the identification of phytochemicals with insulin-mimetic properties.

Ein In Ovo -Modell zum Testen Insulin-mimetischen Verbindungen

Elevated blood glucose levels in type 2 diabetes mellitus (T2DM), a complex and multifactorial metabolic disease, are caused by insulin resistance and ...

Microdialysis of Excitatory Amino Acids During EEG Recordings in Freely Moving Rats

Microdialysis is a well-established neuroscience technique that correlates the changes of neurologically active substances diffusing into the brain interstitial space with the behavior and/or with the specific outcome of a pathology (e.g., seizures for epilepsy). When studying epilepsy, the microdialysis technique is often combined with short-term or even long-term video-electroencephalography (EEG) monitoring to assess spontaneous seizure frequency, severity, progression and clustering. The combined microdialysis-EEG is based on the use of several methods and instruments. Here, we performed in vivo microdialysis and continuous video-EEG recording to monitor glutamate and aspartate outflow over time, in different phases of the natural history of epilepsy in a rat model. This combined approach allows the pairing of changes in the neurotransmitter release with specific stages of the disease development and progression. The amino acid concentration in the dialysate was determined by liquid chromatography. Here, we describe the methods and outline the principal precautionary measures one should take during in vivo microdialysis-EEG, with particular attention to the stereotaxic surgery, basal and high potassium stimulation during microdialysis, depth electrode EEG recording and high-performance liquid chromatography analysis of aspartate and glutamate in the dialysate. This approach may be adapted to test a variety of drug or disease induced changes of the physiological concentrations of aspartate and glutamate in the brain. Depending on the availability of an appropriate analytical assay, it may be further used to test different soluble molecules when employing EEG recording at the same time.

Here, we describe a method for in vivo microdialysis to analyze aspartate and glutamate release in the ventral hippocampus of epileptic and non-epileptic rats, in combination with EEG recordings. Extracellular concentrations of aspartate and glutamate may be correlated with the different phases of the disease.

Mikrodialyse exzitatorischen Aminosäuren während der EEG-Ableitungen in Ratten frei beweglich

Microdialysis is a well-established neuroscience technique that correlates the changes of neurologically active substances diffusing into the brain ...