Name: slice it hot: acute adult brain slicing in physiological temperature
Uploaded: 2014-10-30T14:00:00
Description: Watch this Scientific Journal Video about Slice It Hot: Acute Adult Brain Slicing in Physiological Temperature at JoVE.com

We would like to acknowledge the significant contribution Dr. Shiwei Huang (Australian National University) in validating the method. Furthermore, we would like to thank Ms. Kasia Pietrajtis for helpful comments regarding Golgi cells and Mr. Vitaly Lerner for the cortex experimental data. This work was supported by PITN-GA-2009-238686 (CEREBNET), FP7-ICT (REALNET), ELSC and ISF.

Alle eksperimentelle procedurer, der er beskrevet i denne protokol blev godkendt af Hebrew University Animal Care og brug Udvalg. 1. Forberedelse af løsninger og værktøjer til udskæring <ol><li> Forbered 1 L standard fysiologisk opløsning (SPS), som indeholder ioner, der er beskrevet i tabel 1. <ol><li> Fremstille en stamopløsning indeholdende saltene ved 10 gange den endelige koncentration på forhånd i et lager glasflaske fyldt med 1.000 ml deioniseret vand (ledni...

<ol>
	<li>Skrede, K., Westgaard, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+transverse+hippocampal+slice:+a+well-defined+cortical+structure+maintained+in+vitro.">The transverse hippocampal slice: a well-defined cortical structure maintained in vitro.</a> Brain Research. 35, 589-593 (1971).</li><li>Aghajanian, G., Rasmussen, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracellular+studies+in+the+facial+nucleus+illustrating+a+simple+new+method+for+obtaining+viable+motoneurons+in+adult+rat+brain+slices.">Intracellular studies in the facial nucleus illustrating a simple new method for obtaining viable motoneurons in adult rat brain slices.</a> Synapse. 3, 331-338 (1989).</li><li>Gueritaud, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrical+activity+of+rat+ocular+motoneurons+recorded+in+vitro.">Electrical activity of rat ocular motoneurons recorded in vitro.</a> Neuroscience. 24, 837-852 (1988).</li><li>Lipton, P., 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=Making+the+best+of+brain+slices:+comparing+preparative+methods.">Making the best of brain slices: comparing preparative methods.</a> Journal of Neuroscience Methods. 59, 151-156 (1995).</li><li>Richerson, G., Messer, C. <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+composition+of+experimental+solutions+on+neuronal+survival+during+rat+brain+slicing.">Effect of composition of experimental solutions on neuronal survival during rat brain slicing.</a> Experimental Neurology. 131, 133-143 (1995).</li><li>Brahma, B., Forman, R., Stewart, E., Nicholson, C., Rice, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ascorbate+inhibits+edema+in+brain+slices.">Ascorbate inhibits edema in brain slices.</a> Journal of Neurochemistry. 74, 1263-1270 (2000).</li><li>Moyer, J. R., Brown, T. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patch-clamp+techniques+applied+to+brain+slices.+In:+Patch-clamp+analysis:+advanced+techniques.">Patch-clamp techniques applied to brain slices. In: Patch-clamp analysis: advanced techniques.</a> Springer. , 135-193 (2002).</li><li>Ye, J. H., Zhang, J., Xiao, C., Kong, J. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patch-clamp+studies+in+the+CNS+illustrate+a+simple+new+method+for+obtaining+viable+neurons+in+rat+brain+slices:+glycerol+replacement+of+NaCl+protects+CNS+neurons.">Patch-clamp studies in the CNS illustrate a simple new method for obtaining viable neurons in rat brain slices: glycerol replacement of NaCl protects CNS neurons.</a> J. Neuroscience Methods. 156, 251-259 (2006).</li><li>Bischofberger, J., Engel, D., Li, L., Geiger, J., Jonas, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patch-clamp+recording+from+mossy+fiber+terminals+in+hippocampal+slices.">Patch-clamp recording from mossy fiber terminals in hippocampal slices.</a> Nature Protocols. 1, 2075-2081 (2006).</li><li>Zhao, S., 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=Cell+type&#8211;specific+channelrhodopsin-2+transgenic+mice+for+optogenetic+dissection+of+neural+circuitry+function.">Cell type&#8211;specific channelrhodopsin-2 transgenic mice for optogenetic dissection of neural circuitry function.</a> Nature Methods. 8, 745-752 (2011).</li><li>Huang, S., Uusisaari, M. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physiological+temperature+during+brain+slicing+enhances+the+quality+of+acute+slice+preparations.">Physiological temperature during brain slicing enhances the quality of acute slice preparations.</a> Front. Cell. Neurosci. 7, (2013).</li><li>Ohe, G. C., Darian-Smith, C., Garner, C. C., Heller, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Journal of Neuroscience. 26 (41), 10590-10598 (2006).</li><li>Voets, 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=The+principle+of+temperature-dependent+gating+in+cold-+and+heat-sensitive+TRP+channels.">The principle of temperature-dependent gating in cold- and heat-sensitive TRP channels.</a> Nature. 430, 748-754 (2004).</li><li>Coulter, D. A., Huguenard, J. R., Prince, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+currents+in+rat+thalamocortical+relay+neurones:+kinetic+properties+of+the+transient,+low-threshold+current.">Calcium currents in rat thalamocortical relay neurones: kinetic properties of the transient, low-threshold current.</a> The Journal of Physiology. 414, 587-604 (1998).</li><li>Gibb, A. J., Edward, F. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patch+clamp+recording+from+cells+in+slice+tissues.">Patch clamp recording from cells in slice tissues.</a> Microelectrode Techniques: the Plymouth workshop handbook. , (1994).</li><li>Lefler, Y., Yarom, Y., Uusisaari, M. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebellar+Inhibitory+Input+to+the+Inferior+Olive+Decreases+Electrical+Coupling+and+Blocks+Subthreshold+Oscillations.">Cerebellar Inhibitory Input to the Inferior Olive Decreases Electrical Coupling and Blocks Subthreshold Oscillations.</a> Neuron. 81 (6), 1389-1400 (2014).</li><li>Bourne, J. N., Kirov, S. A., Sorra, K. E., Harris, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Warmer+preparation+of+hippocampal+slices+prevents+synapse+proliferation+that+might+obscure+LTP-related+structural+plasticity.">Warmer preparation of hippocampal slices prevents synapse proliferation that might obscure LTP-related structural plasticity.</a> Neuropharmacology. 52, 55-59 (2007).</li><li>Kirov, S. A., Sorra, K. E., Harris, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Slices+have+more+synapses+than+perfusion-fixed+hippocampus+from+both+young+and+mature+rats.">Slices have more synapses than perfusion-fixed hippocampus from both young and mature rats.</a> J. Neurosci. 19, 2876-2886 (1999).</li><li>Kirov, S. A., Petrak, L. J., Fiala, J. C., Harris, K. 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Vi viser en fremgangsmåde til fremstilling af akutte hjerneskiver fra mus i fysiologisk stedet iskold temperatur. Det er blevet vist 11 at kvaliteten af skiver opnået under varme forhold er overlegen sammenlignet med dem, der fremstilles med kolde forhold, forudsat at slicer blad har minimal lodret vibration. Udskæring i fysiologisk temperatur kan forhindre fysiologiske artefakter forårsaget af den lave temperatur, såsom dem relateret til ændringer i metaboliske processer <s...

Formålet med den foreliggende fremgangsmåde er at få høj kvalitet akutte hjerneskiver til in vitro elektrofysiologiske eksperimenter, især når anvendelse af voksne eller endda gamle dyr. Den akutte hjerne udskæring metode, som beskrevet af Skrede og Westgaard 1 i to elegante sætninger, er blevet en del af grundlaget for den moderne neurovidenskabelig forskning og er ansat i utallige variationer over hele verden. Kvaliteten af ​​skiverne afspejles i antallet af levende neuroner pr skive, den periode, hvor cellerne holde deres elektrofysiologiske og morfologiske egenskaber såvel som i integritet af vævet. Desuden er den maksimale varighed for stabile optagelser afhænger af kvaliteten af ​​skiverne. Således langs årtier, den oprindelige udskæring metoden er blevet videreudviklet af individuelle forskergrupper at forbedre skive genopretning efter opskæring 2-10, ofte ved komplekse ændringer af sammensætningen af opskæring or recovery løsninger (såsom tilføjelse ascorbat, thiourinstof eller endda H 2 O 2) samt intra-kardiale pre-perfusion af dyret med afkølede fysiologiske opløsninger. Som det for nylig blevet vist 11, fysiologisk temperatur under udskæring synes at være mere fordelagtig end afkøling til neuronal sundhed; forbedringen er mest slående, når man arbejder med voksne (2-8 måneder) gnavere. Undgå dramatiske temperaturændringer forhindrer artefakter som følge af temperaturafhængige processer i celler, såsom plasticitet 13 og ionkanaler kinetik 13,14. Sådanne ændringer kunne påvirke membran spænding og intracellulært calcium signalering, spike tærskel, og spike form. &quot;Hot&quot; akut skive forberedelse metode præsenteres her er en generel procedure for opnåelse af høj kvalitet akutte hjerneskiver fra enhver hjerne region, herunder lillehjernen, cortex og hippocampus, hjernestammer 16 &lt;/ Sup&gt; samt lugtekolben, både i rotter og mus. Især den fysiologiske temperatur udskæring procedure kræver, at klingen vibrerer næsten perfekt vandret og er uden strukturelle defekter. Sådan præcision ikke kan opnås med ældre pålægsmaskine modeller; i sådanne tilfælde anbefaler vi at udføre forberedelse skive i frostvejr kolde betingelser som den lave temperatur synes at gøre vævet mere modstandsdygtige over for mekaniske skader, selvom på bekostning af metaboliske aberration.

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			<td height="26" style="height:26px;width:140px;">Name</td>
			<td style="width:73px;">Company</td>
			<td style="width:69px;">Catalog #</td>
			<td style="width:292px;">Comments</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:140px;">Pentobarbital</td>
			<td style="width:73px;">CTS</td>
			<td style="width:69px;">170066</td>
			<td style="width:292px;">Concentration: 60 mg / ml&#160; in physiological saline.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:41px;width:140px;">Big scissors&#160;</td>
			<td style="width:73px;">FST</td>
			<td style="width:69px;">14001-16</td>
			<td style="width:292px;">Any large scissors or a guillotine with sufficiently sharp edges can be used for decapitation&#160;</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:41px;width:140px;">Iris scissors&#160;</td>
			<td style="width:73px;">Prestige medical</td>
			<td style="width:69px;">48,148</td>
			<td style="width:292px;">Any fine tip scissors can be used, provided the scissor blades are not longer than 1.5 - 2 cm</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:140px;">Fine tip forceps&#160;</td>
			<td style="width:73px;">FST</td>
			<td style="width:69px;">11254-20</td>
			<td style="width:292px;"></td>
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		<tr height="26">
			<td height="26" style="height:27px;width:140px;">Scalpel&#160;</td>
			<td style="width:73px;">FST</td>
			<td style="width:69px;">91003-12</td>
			<td style="width:292px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:140px;">Scalpel blade #11</td>
			<td style="width:73px;">FST</td>
			<td style="width:69px;">10011-00</td>
			<td style="width:292px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:140px;">Small spatula&#160;</td>
			<td style="width:73px;">Fisher&#160;</td>
			<td style="width:69px;">2350</td>
			<td style="width:292px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:140px;">Filter paper</td>
			<td style="width:73px;"></td>
			<td style="width:69px;"></td>
			<td style="width:292px;">Any laboratory brand can be used.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:41px;width:140px;">Petri dishes</td>
			<td style="width:73px;">Duroplan</td>
			<td style="width:69px;">Z231509-1</td>
			<td style="width:292px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:140px;">Glass beakers&#160;</td>
			<td style="width:73px;">SCHOT</td>
			<td style="width:69px;">10022846</td>
			<td style="width:292px;"></td>
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		<tr height="40">
			<td height="40" style="height:41px;width:140px;">Pasteur pipette&#160;</td>
			<td style="width:73px;">Maple Leaf Brand</td>
			<td style="width:69px;">14672-029</td>
			<td style="width:292px;"></td>
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		<tr height="40">
			<td height="40" style="height:41px;width:140px;">Super glue&#160;</td>
			<td style="width:73px;">LOCTITE</td>
			<td style="width:69px;">4091361/1</td>
			<td style="width:292px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:140px;">Slicer</td>
			<td style="width:73px;">Campden</td>
			<td style="width:69px;">7000-smz</td>
			<td style="width:292px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:140px;">Ceramic slicing blade</td>
			<td style="width:73px;">Campden</td>
			<td style="width:69px;">7550-1-C</td>
			<td style="width:292px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:140px;">Magnetic heater/stirrer</td>
			<td style="width:73px;"></td>
			<td style="width:69px;"></td>
			<td style="width:292px;">For heating up the SPS for the procedure</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:140px;">Electric kettle</td>
			<td style="width:73px;"></td>
			<td style="width:69px;"></td>
			<td style="width:292px;">For heating up water for temperature control</td>
		</tr>
		<tr height="55">
			<td height="55" style="height:56px;width:140px;">Slice recovery chamber + heating unit</td>
			<td style="width:73px;">Warner instruments</td>
			<td style="width:69px;">&#160;BSC-HT +&#160; BSC-BUW</td>
			<td style="width:292px;">Home-built models may also be used.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:41px;width:140px;">Thermometer</td>
			<td style="width:73px;"></td>
			<td style="width:69px;"></td>
			<td style="width:292px;">For monitoring SPS temperature during dissection and slicing</td>
		</tr>
	</tbody>
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slice it hot: acute adult brain slicing in physiological temperature

Her præsenterer vi en protokol for forberedelse af akutte hjerneskiver. Denne procedure er et kritisk element for elektrofysiologiske patch-clamp-forsøg, der i høj grad bestemmer kvaliteten af ​​resultaterne. Det er blevet vist, at udeladelse af afkølingstrin under skæring procedure er fordelagtig i at opnå sunde skiver og celler, især når det drejer sig meget myelinerede hjernens strukturer fra voksne dyr. Selvom den præcise mekanisme, hvorved forhøjet temperatur understøtter neurale sundhed kan kun spekuleret på, det er indlysende, at når det er muligt, skal temperaturen i hvilken udskæring udføres være tæt på fysiologiske betingelser for at forhindre temperatur relaterede artefakter. En anden vigtig fordel ved denne metode er den enkelhed af proceduren og derfor den korte forberedelsestid. I påvist metode anvendes voksne mus, men den samme fremgangsmåde kan anvendes med yngre mus såvel som rotter. Også de følgende patch clamp Forsøget udføres på horisontale cerebellare skiver, men den samme fremgangsmåde kan også anvendes i andre fly samt andre posteriore områder af hjernen.

Skiver fremstillet på den beskrevne måde kan anvendes til forskellige elektrofysiologiske og optogenetic eksperimenter. I figur 3A og 3C viser vi et repræsentativt eksempel på en horisontal cerebellar skive og en koronale cerebral kortikal skive henholdsvis set under differentiel interferens (DIC) optik. I cerebellar skive, kan flere typer af cerebellare neuroner let genkendes ved deres placering og celle kropsform, tillader målrettet elektrofysiologiske optagelser. I figur...

Watch this Scientific Journal Video about Slice It Hot: Acute Adult Brain Slicing in Physiological Temperature at JoVE.com

Slice It Hot: Acute Adult Brain Slicing in Physiological Temperature

In this paper we show a method for preparing acute brain slices in physiological temperature, using a conventional physiological solution without special modifications for the cutting (such as adding sucrose) and without intracardial perfusion of the animal before slice preparation.

Slice It Hot: Akut voksne hjerne Slicing i fysiologisk temperatur

Here we present a protocol for preparation of acute brain slices. This procedure is a critical element for electrophysiological patch-clamp experiments ...

slice-it-hot-acute-adult-brain-slicing-in-physiological-temperature

Research

JoVE Journal

Neuroscience

State-Dependency Effects on TMS:  A Look at Motive Phosphene Behavior

Transcranial magnetic stimulation (TMS) is 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.1,2 Within the field of TMS, the term state dependency refers to the initial, baseline condition of the particular neural region targeted for stimulation. As can be inferred, the effects of TMS can (and do) vary according to this primary susceptibility and responsiveness of the targeted cortical area.3,4,5

In this experiment, we will examine this concept of state dependency through the elicitation and subjective experience of motive phosphenes. Phosphenes are visually perceived flashes of small lights triggered by electromagnetic pulses to the visual cortex. These small lights can assume varied characteristics depending upon which type of visual cortex is being stimulated. In this particular study, we will be targeting motive phosphenes as elicited through the stimulation of V1/V2 and the V5/MT+ complex visual regions.6

In this article, we examine the effects of visually relevant state dependency on TMS induced motive phosphenic presentations.

Transcranial magnetic stimulation (TMS) is a non-invasive neurostimulatory and neuromodulatory technique that can transiently or lastingly modulate ...

Imaging Pheromone Sensing in a Mouse Vomeronasal Acute Tissue Slice Preparation

Peter Karlson and Martin L&uuml;scher used the term pheromone for the first time in 19591 to describe chemicals used for intra-species communication. Pheromones are volatile or non-volatile short-lived molecules2 secreted and/or contained in biological fluids3,4, such as urine, a liquid known to be a main source of pheromones3. Pheromonal communication is implicated in a variety of key animal modalities such as kin interactions5,6, hierarchical organisations3 and sexual interactions7,8 and are consequently directly correlated with the survival of a given species9,10,11. In mice, the ability to detect pheromones is principally mediated by the vomeronasal organ (VNO)10,12, a paired structure located at the base of the nasal cavity, and enclosed in a cartilaginous capsule. Each VNO has a tubular shape with a lumen13,14 allowing the contact with the external chemical world. The sensory neuroepithelium is principally composed of vomeronasal bipolar sensory neurons (VSNs)15. Each VSN extends a single dendrite to the lumen ending in a large dendritic knob bearing up to 100 microvilli implicated in chemical detection16. Numerous subpopulations of VSNs are present. They are differentiated by the chemoreceptor they express and thus possibly by the ligand(s) they recognize17,18. Two main vomeronasal receptor families, V1Rs and V2Rs19,20,21,22, are composed respectively by 24023 and 12024 members and are expressed in separate layers of the neuroepithelium. Olfactory receptors (ORs)25 and formyl peptide receptors (FPRs)26,27 are also expressed in VSNs.
Whether or not these neuronal subpopulations use the same downstream signalling pathway for sensing pheromones is unknown. Despite a major role played by a calcium-permeable channel (TRPC2) present in the microvilli of mature neurons28 TRPC2 independent transduction channels have been suggested6,29. Due to the high number of neuronal subpopulations and the peculiar morphology of the organ, pharmacological and physiological investigations of the signalling elements present in the VNO are complex.
Here, we present an acute tissue slice preparation of the mouse VNO for performing calcium imaging investigations. This physiological approach allows observations, in the natural environment of a living tissue, of general or individual subpopulations of VSNs previously loaded with Fura-2AM, a calcium dye. This method is also convenient for studying any GFP-tagged pheromone receptor and is adaptable for the use of other fluorescent calcium probes. As an example, we use here a VG mouse line30, in which the translation of the pheromone V1rb2 receptor is linked to the expression of GFP by a polycistronic strategy.

In mice, the ability to detect pheromones is principally mediated by the vomeronasal organ (VNO). Here, an acute tissue slice preparation of VNO for performing calcium imaging is described. This physiological approach allows observations of subpopulations and/or individual neurons in a living tissue and is convenient for receptor-ligand identification.

Imaging Pheromone Sensing i en mus Vomeronasal Akut Tissue Slice Forberedelse

Peter Karlson and Martin L&uuml;scher used the term pheromone for the first time in 19591 to describe chemicals used for intra-species communication. ...

Time-lapse Imaging of Neuroblast Migration in Acute Slices of the Adult Mouse Forebrain

There is a substantial body of evidence indicating that new functional neurons are constitutively generated from an endogenous pool of neural stem cells in restricted areas of the adult mammalian brain. Newborn neuroblasts from the subventricular zone (SVZ) migrate along the rostral migratory stream (RMS) to their final destination in the olfactory bulb (OB)1. In the RMS, neuroblasts migrate tangentially in chains ensheathed by astrocytic processes2,3 using blood vessels as a structural support and a source of molecular factors required for migration4,5. In the OB, neuroblasts detach from the chains and migrate radially into the different bulbar layers where they differentiate into interneurons and integrate into the existing network1, 6.
In this manuscript we describe the procedure for monitoring cell migration in acute slices of the rodent brain. The use of acute slices allows the assessment of cell migration in the microenvironment that closely resembling to in vivo conditions and in brain regions that are difficult to access for in vivo imaging. In addition, it avoids long culturing condition as in the case of organotypic and cell cultures that may eventually alter the migration properties of the cells. Neuronal precursors in acute slices can be visualized using DIC optics or fluorescent proteins. Viral labeling of neuronal precursors in the SVZ, grafting neuroblasts from reporter mice into the SVZ of wild-type mice, and using transgenic mice that express fluorescent protein in neuroblasts are all suitable methods for visualizing neuroblasts and following their migration. The later method, however, does not allow individual cells to be tracked for long periods of time because of the high density of labeled cells. We used a wide-field fluorescent upright microscope equipped with a CCD camera to achieve a relatively rapid acquisition interval (one image every 15 or 30 sec) to reliably identify the stationary and migratory phases. A precise identification of the duration of the stationary and migratory phases is crucial for the unambiguous interpretation of results. We also performed multiple z-step acquisitions to monitor neuroblasts migration in 3D. Wide-field fluorescent imaging has been used extensively to visualize neuronal migration7-10. Here, we describe detailed protocol for labeling neuroblasts, performing real-time video-imaging of neuroblast migration in acute slices of the adult mouse forebrain, and analyzing cell migration. While the described protocol exemplified the migration of neuroblasts in the adult RMS, it can also be used to follow cell migration in embryonic and early postnatal brains.

We describe a protocol for real-time videoimaging of neuronal migration in the mouse forebrain. The migration of virally-labeled or grafted neuronal precursors was recorded in acute live slices using wide-field fluorescent imaging with a relatively rapid acquisition interval to study the different phases of cell migration, including the durations of the stationary and migration phases and the speed of migration.

Time-lapse Imaging af neuroblast Migration i Akutte Skiver af den voksne Mouse forhjerne

There is a substantial body of evidence indicating that new functional neurons are constitutively generated from an endogenous pool of neural stem cells ...

Detection of Protein Palmitoylation in Cultured Hippocampal Neurons by Immunoprecipitation and Acyl-Biotin Exchange (ABE)

Palmitoylation is a post-translational lipid modification involving the attachment of a 16-carbon saturated fatty acid, palmitate, to cysteine residues of substrate proteins through a labile thioester bond [reviewed in1]. Palmitoylation of a substrate protein increases its hydrophobicity, and typically facilitates its trafficking toward cellular membranes. Recent studies have shown palmitoylation to be one of the most common lipid modifications in neurons1, 2, suggesting that palmitate turnover is an important mechanism by which these cells regulate the targeting and trafficking of proteins. The identification and detection of palmitoylated substrates can therefore better our understanding of protein trafficking in neurons.
Detection of protein palmitoylation in the past has been technically hindered due to the lack of a consensus sequence among substrate proteins, and the reliance on metabolic labeling of palmitoyl-proteins with 3H-palmitate, a time-consuming biochemical assay with low sensitivity. Development of the Acyl-Biotin Exchange (ABE) assay enables more rapid and high sensitivity detection of palmitoylated proteins2-4, and is optimal for measuring the dynamic turnover of palmitate on neuronal proteins. The ABE assay is comprised of three biochemical steps (Figure 1): 1) irreversible blockade of unmodified cysteine thiol groups using N-ethylmaliemide (NEM), 2) specific cleavage and unmasking of the palmitoylated cysteine's thiol group by hydroxylamine (HAM), and 3) selective labeling of the palmitoylated cysteine using a thiol-reactive biotinylation reagent, biotin-BMCC. Purification of the thiol-biotinylated proteins following the ABE steps has differed, depending on the overall goal of the experiment.
Here, we describe a method to purify a palmitoylated protein of interest in primary hippocampal neurons by an initial immunoprecipitation (IP) step using an antibody directed against the protein, followed by the ABE assay and western blotting to directly measure palmitoylation levels of that protein, which is termed the IP-ABE assay. Low-density cultures of embryonic rat hippocampal neurons have been widely used to study the localization, function, and trafficking of neuronal proteins, making them ideally suited for studying neuronal protein palmitoylation using the IP-ABE assay. The IP-ABE assay mainly requires standard IP and western blotting reagents, and is only limited by the availability of antibodies against the target substrate. This assay can easily be adapted for the purification and detection of transfected palmitoylated proteins in heterologous cell cultures, primary neuronal cultures derived from various brain tissues of both mouse and rat, and even primary brain tissue itself.

Detection of Protein Palmitoylation in Cultured Hippocampal Neurons by Immunoprecipitation and Acyl-Biotin Exchange ABE

The reversible addition of palmitate to proteins is an important regulator of intracellular protein trafficking. This is of particular interest in neurons where many synaptic proteins are palmitoylated. We utilize a simple biochemical method to detect palmitoylated proteins in cultured neurons, which can be adapted for multiple cell types and tissues.

Påvisning af protein palmitoylering i dyrkede hippocampale neuroner ved immunopræcipitation og Acyl-Biotin Exchange (ABE)

Palmitoylation is a post-translational lipid  modification involving the attachment of a 16-carbon saturated fatty acid,  palmitate, to cysteine residues ...

Brain Slice Biotinylation: An Ex Vivo Approach to Measure Region-specific Plasma Membrane Protein Trafficking in Adult Neurons

Regulated endocytic trafficking is the central mechanism facilitating a variety of neuromodulatory events, by dynamically controlling receptor, ion channel, and transporter cell surface presentation on a minutes time scale.&#160;There is a broad diversity of mechanisms that control endocytic trafficking of individual proteins. Studies investigating the molecular underpinnings of trafficking have primarily relied upon surface biotinylation to quantitatively measure changes in membrane protein surface expression in response to exogenous stimuli and gene manipulation.&#160;However, this approach has been mainly limited to cultured cells, which may not faithfully reflect the physiologically relevant mechanisms at play in adult neurons.&#160;Moreover, cultured cell approaches may underestimate region-specific differences in trafficking mechanisms.&#160;Here, we describe an approach that extends cell surface biotinylation to the acute brain slice preparation.&#160;We demonstrate that this method provides a high-fidelity approach to measure rapid changes in membrane protein surface levels in adult neurons.&#160;This approach is likely to have broad utility in the field of neuronal endocytic trafficking.

Brain Slice Biotinylation: An Ex Vivo Approach to Measure Region-specific Plasma Membrane Protein Trafficking in Adult Neurons

Neuronal membrane trafficking dynamically controls plasma membrane protein availability and significantly impacts neurotransmission.&#160;To date, it has been challenging to measure neuronal endocytic trafficking in adult neurons.&#160;Here, we describe a highly effective, quantitative method to measure rapid changes in surface protein expression ex vivo in acute brain slices.

Brain Slice Biotinylering: En<em&gt; Ex Vivo</em&gt; Tilgang til Measure Region-specifikke plasmamembranprotein Trafficking in Adult neuroner

Regulated endocytic trafficking is the central mechanism facilitating a variety of neuromodulatory events, by dynamically controlling receptor, ion ...

Lineage-reprogramming of Pericyte-derived Cells of the Adult Human Brain into Induced Neurons

Direct lineage-reprogramming of non-neuronal cells into induced neurons (iNs) may provide insights into the molecular mechanisms underlying neurogenesis and enable new strategies for in vitro modeling or repairing the diseased brain. Identifying brain-resident non-neuronal cell types amenable to direct conversion into iNs might allow for launching such an approach in situ, i.e. within the damaged brain tissue. Here we describe a protocol developed in the attempt of identifying cells derived from the adult human brain that fulfill this premise. This protocol involves: (1) the culturing of human cells from the cerebral cortex obtained from adult human brain biopsies; (2) the in vitro expansion (approximately requiring 2-4 weeks) and characterization of the culture by immunocytochemistry and flow cytometry; (3) the enrichment by fluorescence-activated cell sorting (FACS) using anti-PDGF receptor-&#946; and anti-CD146 antibodies; (4) the retrovirus-mediated transduction with the neurogenic transcription factors sox2 and ascl1; (5) and finally the characterization of the resultant pericyte-derived induced neurons (PdiNs) by immunocytochemistry (14 days to 8 weeks following retroviral transduction). At this stage, iNs can be probed for their electrical properties by patch-clamp recording. This protocol provides a highly reproducible procedure for the in vitro lineage conversion of brain-resident pericytes into functional human iNs.

Targeting brain-resident cells for direct lineage-reprogramming offers new perspectives for brain repair. Here we describe a protocol of how to prepare cultures enriched for brain-resident pericytes from the adult human cerebral cortex and convert these into induced neurons by retrovirus-mediated expression of the transcription factors Sox2 and Ascl1.

Lineage-omprogrammering af pericyt-afledte Celler af Voksen Menneskelige hjerne til Inducerede Neuroner

Direct lineage-reprogramming of non-neuronal cells into induced neurons (iNs) may provide insights into the molecular mechanisms underlying neurogenesis ...

In-depth Physiological Analysis of Defined Cell Populations in Acute Tissue Slices of the Mouse Vomeronasal Organ

In most mammals, the vomeronasal organ (VNO) is a chemosensory structure that detects both hetero- and conspecific social cues. Vomeronasal sensory neurons (VSNs) express a specific type of G protein-coupled receptor (GPCR) from at least three different chemoreceptor gene families allowing sensitive and specific detection of chemosensory cues. These families comprise the V1r and V2r gene families as well as the formyl peptide receptor (FPR)-related sequence (Fpr-rs) family of putative chemoreceptor genes. In order to understand the physiology of vomeronasal receptor-ligand interactions and downstream signaling, it is essential to identify the biophysical properties inherent to each specific class of VSNs.
The physiological approach described here allows identification and in-depth analysis of a defined population of sensory neurons using a transgenic mouse line (Fpr-rs3-i-Venus). The use of this protocol, however, is not restricted to this specific line and thus can easily be extended to other genetically modified lines or wild type animals.

Here, we describe a physiological approach that allows identification and in-depth analysis of a defined population of sensory neurons in acute coronal tissue slices of the mouse vomeronasal organ using whole-cell patch-clamp recordings.

Dybdegående Fysiologisk Analyse af Definerede Cell populationer i Akut Tissue Skiver af Mouse vomeronasale organ

In most mammals, the vomeronasal organ (VNO) is a chemosensory structure that detects both hetero- and conspecific social cues. Vomeronasal sensory ...

Recording Synaptic Plasticity in Acute Hippocampal Slices Maintained in a Small-volume Recycling-, Perfusion-, and Submersion-type Chamber System

Even though experiments on brain slices have been in use since 1951, problems remain that reduce the probability of achieving a stable and successful analysis of synaptic transmission modulation when performing field potential or intracellular recordings. This manuscript describes methodological aspects that might be helpful in improving experimental conditions for the maintenance of acute brain slices and for recording field excitatory postsynaptic potentials in a commercially available submersion chamber with an outflow-carbogenation unit. The outflow-carbogenation helps to stabilize the oxygen level in experiments that rely on the recycling of a small buffer reservoir to enhance the cost-efficiency of drug experiments. In addition, the manuscript presents representative experiments that examine the effects of different carbogenation modes and stimulation paradigms on the activity-dependent synaptic plasticity of synaptic transmission.

This protocol describes the stabilization of the oxygen level in a small volume of recycled buffer and methodological aspects of recording activity-dependent synaptic plasticity in submerged acute hippocampal slices.

Optagelse synaptisk plasticitet i akut hippocampus skiver vedligeholdes i en lille-volumen genanvendelse - Perfusion- og neddykning-type kammer System

Even though experiments on brain slices have been in use since 1951, problems remain that reduce the probability of achieving a stable and successful ...

A Temperature Gradient Assay to Determine Thermal Preferences of Drosophila Larvae

Many animals, including the fruit fly, Drosophila melanogaster, are capable of discriminating minute differences in&#160;environmental temperature, which enables them to seek out their preferred thermal landscape. To define the temperature preferences of larvae over a defined linear range, we developed an assay using a temperature gradient. To establish a single-directional gradient, two aluminum blocks are connected to independent water baths, each of which controls the temperature of individual blocks. The two blocks set the lower and upper limits of the gradient. The temperature gradient is established by placing an agarose-coated aluminum plate over the two water-controlled blocks so that the plate spans the distance between them. The ends of the aluminum plate that is set on the top of the water blocks defines the minimum and maximum temperatures, and the regions in-between the two blocks form a linear temperature gradient. The gradient assay can be applied to&#160;larvae of different ages and can be used to identify mutants that exhibit phenotypes, such as those with mutations affecting genes encoding TRP channels and opsins, which are required for temperature discrimination.

A Temperature Gradient Assay to Determine Thermal Preferences of Drosophila Larvae

Here, we present a protocol to determine the preferred environmental temperature of Drosophila larvae using a continuous thermal gradient.

En temperaturgradient Assay til at fastlægge termisk præferencer af Drosophila larver

Many animals, including the fruit fly, Drosophila melanogaster, are capable of discriminating minute differences in&#160;environmental temperature, which ...

Short-Term Free-Floating Slice Cultures from the Adult Human Brain

Organotypic, or slice cultures, have been widely employed to model aspects of the central nervous system functioning in vitro. Despite the potential of slice cultures in neuroscience, studies using adult nervous tissue to prepare such cultures are still scarce, particularly those from human subjects. The use of adult human tissue to prepare slice cultures is particularly attractive to enhance the understanding of human neuropathologies, as they hold unique properties typical of the mature human brain lacking in slices produced from rodent (usually neonatal) nervous tissue. This protocol describes how to use brain tissue collected from living human donors submitted to resective brain surgery to prepare short-term, free-floating slice cultures. Procedures to maintain and perform biochemical and cell biology assays using these cultures are also presented. Representative results demonstrate that the typical human cortical lamination is preserved in slices after 4 days in vitro (DIV4), with expected presence of the main neural cell types. Moreover, slices at DIV4 undergo robust cell death when challenged with a toxic stimulus (H2O2), indicating the potential of this model to serve as a platform in cell death assays. This method, a simpler and cost-effective alternative to the widely used protocol using membrane inserts, is mainly recommended for running short-term assays aimed to unravel mechanisms of neurodegeneration behind age-associated brain diseases. Finally, although the protocol is devoted to using cortical tissue collected from patients submitted to surgical treatment of pharmacoresistant temporal lobe epilepsy, it is argued that tissue collected from other brain regions/conditions should also be considered as sources to produce similar free-floating slice cultures.

A protocol to prepare free-floating slice cultures from adult human brain is presented. The protocol is a variation of the widely used slice culture method using membrane inserts. It is simple, cost-effective, and recommended for running short-term assays aimed to unravel mechanisms of neurodegeneration behind age-associated brain diseases.

Kortsigtede fritflydende udsnit kulturer fra den voksne menneskelige hjerne

Organotypic, or slice cultures, have been widely employed to model aspects of the central nervous system functioning in vitro. Despite the potential of ...