W.W. conducted, analyzed, and designed the experiments and wrote the manuscript. D.X. and C.P. assisted in figure preparation and conducted the experiments. This work was supported by NSFC (31320103906) and 111 Project (B16013) to T.B.

The animals were maintained in accordance with the established standards of animal care and procedures of the Institutes of Brain Science and State Key Laboratory of Medical Neurobiology of Fudan University, Shanghai, China.
1. Solution Preparation
NOTE: See the Table of Materials.
<ol>
	<li>Prepare the slicing buffer (modified Gey&#39;s solution): 92 mM NaCl, 2.5 mM KCl, 1.25 mM NaH2PO4, 30 mM NaHCO3, 25 mM glucose, 20 mM HEPES, 3 mM Na+-pyruva...

<ol>
	<li>McIlwain, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metabolic+response+in+vitro+to+electrical+stimulation+of+sections+of+mammalian+brain.">Metabolic response in vitro to electrical stimulation of sections of mammalian brain.</a> Biochem J. 48 (4), (1951).</li><li>McIlwain, H., Richards, C. D., Somerville, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Responses+in+vitro+from+the+piriform+cortex+of+the+rat,+and+their+susceptibility+to+centrally-acting+drugs.">Responses in vitro from the piriform cortex of the rat, and their susceptibility to centrally-acting drugs.</a> J Neurochem. 14 (9), 937-938 (1967).</li><li>Yamamoto, C., McIlwain, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrical+activities+in+thin+sections+from+the+mammalian+brain+maintained+in+chemically-defined+media+in+vitro.">Electrical activities in thin sections from the mammalian brain maintained in chemically-defined media in vitro.</a> J Neurochem. 13 (12), 1333-1343 (1966).</li><li>Andersen, P., Bliss, T. V., Lomo, T., Olsen, L. I., Skrede, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lamellar+organization+of+hippocampal+excitatory+pathways.">Lamellar organization of hippocampal excitatory pathways.</a> Acta Physiol Scand. 76 (1), 4-5 (1969).</li><li>Skrede, K. K., Westgaard, R. H. <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 Res. 35 (2), 589-593 (1971).</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 (8), 2876-2886 (1999).</li><li>Schwartzkroin, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characteristics+of+CA1+neurons+recorded+intracellularly+in+the+hippocampal+in+vitro+slice+preparation.">Characteristics of CA1 neurons recorded intracellularly in the hippocampal in vitro slice preparation.</a> Brain Res. 85 (3), 423-436 (1975).</li><li>Schwartzkroin, P. A., Wester, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-lasting+facilitation+of+a+synaptic+potential+following+tetanization+in+the+in+vitro+hippocampal+slice.">Long-lasting facilitation of a synaptic potential following tetanization in the in vitro hippocampal slice.</a> Brain Res. 89 (1), 107-119 (1975).</li><li>Reymann, K. G., Frey, J. U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+late+maintenance+of+hippocampal+LTP:+requirements,+phases,+'synaptic+tagging',+'late-associativity'+and+implications.">The late maintenance of hippocampal LTP: requirements, phases, 'synaptic tagging', 'late-associativity' and implications.</a> Neuropharm. 52 (1), 24-40 (2007).</li><li>Bliss, T. V., Collingridge, G. L., Morris, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synaptic+plasticity+in+health+and+disease:+introduction+and+overview.">Synaptic plasticity in health and disease: introduction and overview.</a> Philos Trans R Soc Lond B Biol Sci. 369 (1633), 20130129 (2014).</li><li>Bliss, T. V., Gardner-Medwin, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-lasting+potentiation+of+synaptic+transmission+in+the+dentate+area+of+the+unanaestetized+rabbit+following+stimulation+of+the+perforant+path.">Long-lasting potentiation of synaptic transmission in the dentate area of the unanaestetized rabbit following stimulation of the perforant path.</a> J Physiol. 232 (2), 357-374 (1973).</li><li>Reid, K. H., Edmonds, H. L., Schurr, A., Tseng, M. T., West, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pitfalls+in+the+Use+of+Brain-Slices.">Pitfalls in the Use of Brain-Slices.</a> Prog Neurobiol. 31 (1), 1-18 (1988).</li><li>Rambani, K., Vukasinovic, J., Glezer, A., Potter, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Culturing+thick+brain+slices:+an+interstitial+3D+microperfusion+system+for+enhanced+viability.">Culturing thick brain slices: an interstitial 3D microperfusion system for enhanced viability.</a> J Neurosci Methods. 180 (2), 243-254 (2009).</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>Redondo, R. L., 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=Synaptic+tagging+and+capture:+differential+role+of+distinct+calcium/calmodulin+kinases+in+protein+synthesis-dependent+long-term+potentiation.">Synaptic tagging and capture: differential role of distinct calcium/calmodulin kinases in protein synthesis-dependent long-term potentiation.</a> J Neurosci. 30 (14), 4981-4989 (2010).</li><li>Stopps, M., 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=Design+and+application+of+a+novel+brain+slice+system+that+permits+independent+electrophysiological+recordings+from+multiple+slices.">Design and application of a novel brain slice system that permits independent electrophysiological recordings from multiple slices.</a> J Neurosci Methods. 132 (2), 137-148 (2004).</li><li>Behnisch, T., Matsushita, S., Knopfel, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+of+gene+expression+during+long-term+potentiation.">Imaging of gene expression during long-term potentiation.</a> Neuroreport. 15 (13), 2039-2043 (2004).</li><li>Karpova, A., 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=Encoding+and+transducing+the+synaptic+or+extrasynaptic+origin+of+NMDA+receptor+signals+to+the+nucleus.">Encoding and transducing the synaptic or extrasynaptic origin of NMDA receptor signals to the nucleus.</a> Cell. 152 (5), 1119-1133 (2013).</li><li>Karpova, A., Mikhaylova, M., Thomas, U., Knopfel, T., Behnisch, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Involvement+of+protein+synthesis+and+degradation+in+long-term+potentiation+of+Schaffer+collateral+CA1+synapses.">Involvement of protein synthesis and degradation in long-term potentiation of Schaffer collateral CA1 synapses.</a> J Neurosci. 26 (18), 4949-4955 (2006).</li><li>Weng, W., Chen, Y., Wang, M., Zhuang, Y., Behnisch, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Potentiation+of+Schaffer-Collateral+CA1+Synaptic+Transmission+by+eEF2K+and+p38+MAPK+Mediated+Mechanisms.">Potentiation of Schaffer-Collateral CA1 Synaptic Transmission by eEF2K and p38 MAPK Mediated Mechanisms.</a> Front Cell Neurosci. 10 (247), (2016).</li><li>Meduna, L. J., Jackman, A. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+dioxide+inhalation+therapy.">Carbon dioxide inhalation therapy.</a> Res Publ Assoc Res Nerv Ment Dis. 31, 280-286 (1953).</li><li>Edwards, F. A., Konnerth, A., Sakmann, B., Takahashi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+thin+slice+preparation+for+patch+clamp+recordings+from+neurones+of+the+mammalian+central+nervous+system.">A thin slice preparation for patch clamp recordings from neurones of the mammalian central nervous system.</a> Pflugers Arch. 414 (5), 600-612 (1989).</li><li>Mathis, D. M., Furman, J. L., Norris, C. 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The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Although interface slice chambers exhibit more robust synaptic responses25,26,27,28, submersion chambers provide additional convenience for patch-clamp recording and fluorescence imaging. Thus, we have described several aspects of field potential recordings in acute hippocampal slices using a commercial submersion slice chamber that can easily be extended to the imaging of fluorescence probes i...

In 1951, the first-reported acute brain slice experiments were conducted1. In 1971, after successful in vitro recordings from the piriform cortex2,3 and the discovery that hippocampal neurons are interconnected transversely along the septotemporal axis of the hippocampus4, one of the first in vitro recordings of hippocampal neuronal activity was achieved5. The similarity of the neurophysiological or neurostructural parameters of neurons under in vivo and in vitro conditions are still the subject of some debate6, but in 1975, Schwartzkroin7 indicated that the basal properties of neurons are maintained in vitro and that high-frequency stimulation (i.e., tetanization) of afferents in the hippocampal formation induces a long-lasting facilitation of synaptic potentials8. Electrophysiological recording of neuronal activity in vitro greatly expanded the study of the cellular mechanisms of activity-dependent synaptic plasticity9,10, which had been discovered in 1973 by Bliss et al.11 in in vivo experiments with rabbits.
The study of neuronal activity or signaling pathways in brain slices, and especially in acute hippocampal slices, is now a standard tool. However, surprisingly, in vitro experiments have yet to be standardized, as evidenced by the multiple approaches that still exist for the preparation and maintenance of acute hippocampal slices. Reid et al. (1988)12 reviewed the methodological challenges for the maintenance of acute brain slices in different types of slice chambers and the choices of bathing medium, pH, temperature, and oxygen level. These parameters are still difficult to control in the recording chamber due to the custom-made elements of in vitro slice-recording setups. Publications can be found that might help to overcome some of the methodological challenges and that describe new types of submersion slice chambers, such as an interstitial 3D microperfusion system13, a chamber with enhanced laminar flow and oxygen supply14, a system with computerized temperature control15, and a multi-chamber recording system16. Since these chambers are not easy to build, most scientists rely on commercially available slice chambers. These chambers can be mounted on a microscope system, thus allowing for the combination of electrophysiology and fluorescence imaging17,18,19. Since these chambers keep the brain slices submerged in artificial cerebrospinal fluid (aCSF), a high flow rate of the buffer solution needs to be maintained, increasing the expense of drug application. To this end, we have incorporated a recycling perfusion system with outflow-carbogenation that provides sufficient stability for the long-term recording of field potentials in a submersion slice chamber using a relatively small aCSF volume. In addition, we summarized how the use of this experimental carbogenation/perfusion system affects the outcome of activity-dependent synaptic plasticity10 and how inhibition of eukaryotic elongation factor-2 kinase (eEF2K) modulates synaptic transmission20.

<table width="982">
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		<col />
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	<tbody>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Reagents required</td>
			<td style="width:244px;"></td>
			<td style="width:179px;"></td>
			<td style="width:251px;"></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">NaCl</td>
			<td style="width:244px;">Sinopharm Chemical Reagent, China</td>
			<td style="width:179px;">10019318</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">KCl</td>
			<td style="width:244px;">Sinopharm Chemical Reagent, China</td>
			<td style="width:179px;">10016318</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">KH2PO4</td>
			<td style="width:244px;">Sinopharm Chemical Reagent, China</td>
			<td style="width:179px;">10017618</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">MgCl2&#183;6H2O</td>
			<td style="width:244px;">Sinopharm Chemical Reagent, China</td>
			<td style="width:179px;">10012818</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">CaCl2</td>
			<td style="width:244px;">Sinopharm Chemical Reagent, China</td>
			<td style="width:179px;">10005861</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">NaHCO3</td>
			<td style="width:244px;">Sinopharm Chemical Reagent, China</td>
			<td style="width:179px;">10018960</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">Glucose</td>
			<td style="width:244px;">Sinopharm Chemical Reagent, China</td>
			<td style="width:179px;">10010518</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">NaH2PO4</td>
			<td style="width:244px;">Sinopharm Chemical Reagent, China</td>
			<td style="width:179px;">20040718</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">HEPES</td>
			<td style="width:244px;">Sigma</td>
			<td style="width:179px;">H3375</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">Sodium pyruvate</td>
			<td style="width:244px;">Sigma</td>
			<td style="width:179px;">A4043</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">MgSO4</td>
			<td style="width:244px;">Sinopharm Chemical Reagent, China</td>
			<td style="width:179px;">20025118</td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="width:311px;height:27px;">NaOH</td>
			<td style="width:244px;">Sinopharm Chemical Reagent, China</td>
			<td style="width:179px;">10019718</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;"></td>
			<td style="width:244px;"></td>
			<td style="width:179px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Tools and materials for dissection</td>
			<td style="width:244px;"></td>
			<td style="width:179px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Decapitators</td>
			<td style="width:244px;">Harvard apparatus</td>
			<td style="width:179px;">55-0012</td>
			<td>for rat decapitation</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Bandage Scissors</td>
			<td style="width:244px;">SCHREIBER</td>
			<td style="width:179px;">12-4227</td>
			<td>for mouse decapitation</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">double-edge blade</td>
			<td style="width:244px;">Flying Eagle, China</td>
			<td style="width:179px;">74-C</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">IRIS Scissors</td>
			<td style="width:244px;">RWD, China</td>
			<td style="width:179px;">S12003-09</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Bone Rongeurs</td>
			<td style="width:244px;">RWD, China</td>
			<td style="width:179px;">S22002-14</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Spoon</td>
			<td style="width:244px;">Hammacher&#160;</td>
			<td style="width:179px;">HSN 152-13</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">dental cement spatula</td>
			<td style="width:244px;">Hammacher&#160;</td>
			<td style="width:179px;">HSN 016-15</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">dental double end excavator</td>
			<td style="width:244px;">Blacksmith Surgical, USA</td>
			<td style="width:179px;">BS-415-017</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Vibrating Microtome</td>
			<td style="width:244px;">Leica, Germany</td>
			<td style="width:179px;">VT1200S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">surgical blade&#160;</td>
			<td style="width:244px;">RWD, China</td>
			<td style="width:179px;">S31023-02</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">surgical holder</td>
			<td style="width:244px;">RWD, China</td>
			<td style="width:179px;">S32007-14</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;"></td>
			<td style="width:244px;"></td>
			<td style="width:179px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="width:311px;height:42px;">Electrophysiology equipment and materials</td>
			<td style="width:244px;"></td>
			<td style="width:179px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Vertical Pipette Puller</td>
			<td style="width:244px;">Narishige, Japan</td>
			<td style="width:179px;">PC-10</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Vibration isolation table</td>
			<td style="width:244px;">Meirits, Japan</td>
			<td style="width:179px;">ADZ-A0806</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">submerged type recording chamber</td>
			<td style="width:244px;">Warner Instruments</td>
			<td style="width:179px;">RC-26GLP</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">thermostatic water bath</td>
			<td style="width:244px;">Zhongcheng Yiqi&#65292;China</td>
			<td style="width:179px;">HH-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">4 Axis Micromanipulator</td>
			<td style="width:244px;">Sutter, USA</td>
			<td style="width:179px;">MP-285, MP-225</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Platinum Wire</td>
			<td style="width:244px;">World Precision Instruments</td>
			<td style="width:179px;">PTP406</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Amplifier</td>
			<td style="width:244px;">Molecular Devices, USA</td>
			<td style="width:179px;">Multiclamp 700B</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Data Acquisition System</td>
			<td style="width:244px;">Molecular Devices, USA</td>
			<td style="width:179px;">Digidata 1440A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Anaysis software</td>
			<td style="width:244px;">Molecular Devices, USA</td>
			<td style="width:179px;">Clampex 10.2</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Fluorescence Microscope</td>
			<td style="width:244px;">Nikon, Japan</td>
			<td style="width:179px;">FN1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">LED light source</td>
			<td style="width:244px;">Lumen Dynamics Group, Canada</td>
			<td style="width:179px;">X-cite 120LED</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">micropipettes</td>
			<td style="width:244px;">Harvard apparatus</td>
			<td style="width:179px;">GC150TF</td>
			<td>extracelluar recording</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">borosilicate micropipettes</td>
			<td style="width:244px;">Sutter, USA</td>
			<td style="width:179px;">BF150-86</td>
			<td>patch clamp</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">tungsten electrode</td>
			<td style="width:244px;">A-M Systems, USA</td>
			<td style="width:179px;">575500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">peristaltic pump</td>
			<td style="width:244px;">Longer, China</td>
			<td style="width:179px;">BT00-300T</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">tubes for peristaltic pump</td>
			<td style="width:244px;">ISMATEC, Wertheim, Germany</td>
			<td style="width:179px;">SC0309</td>
			<td>1x inflow, ID: 1.02mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">tubes for peristaltic pump</td>
			<td style="width:244px;">ISMATEC, Wertheim, Germany</td>
			<td style="width:179px;">SC0319</td>
			<td>2x tubes for outflow, ID: 2.79 mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">CCD camera</td>
			<td style="width:244px;">PCO, Germany</td>
			<td style="width:179px;">pco.edge sCMOS</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">lens cleaning paper</td>
			<td style="width:244px;">Kodak</td>
			<td style="width:179px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">50 ml conical centrifuge tube</td>
			<td style="width:244px;">Thermo scientific</td>
			<td style="width:179px;">339652</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Prechamber</td>
			<td style="width:244px;">Warner Instruments</td>
			<td style="width:179px;">BSC-PC</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Inline heater</td>
			<td style="width:244px;">Warner Instruments</td>
			<td style="width:179px;">SF-28</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:311px;height:21px;">Temperature Controller</td>
			<td style="width:244px;">Warner Instruments</td>
			<td style="width:179px;">TC-324B</td>
			<td></td>
		</tr>
	</tbody>
</table>

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.

In the protocol section, we described the preparation of acute hippocampal slices from the ventral and intermediate part of the hippocampal formation (Figure 1) of male C57BL/6 mice and male Wistar rats (5-8 weeks). The position of the hemispheres on the slicer platform helps to keep them stable and removes the need of stabilization with agar or agarose. The perfusion system itself is based on a peristaltic pump operated on high rotation to give the required ...

Watch this Scientific Journal Video about Recording Synaptic Plasticity in Acute Hippocampal Slices Maintained in a Small-volume Recycling-, Perfusion-, and Submersion-type Chamber System at JoVE.com

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

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.

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

The overall goal of this procedure is to provide a method to ensure simplified means of carbogenation of small-volume recycling ACSF and to achieve long-term recordings of field potentials using a recording chamber mounted on a fluorescence microscope. This method can help us answer the key questions in the field of neuroplasticities relating to the underlying lignin pathways that regulates the synaptic transmission and formation of memory in a cellular mode of learning and memories. The main advantage of this technique is that it helps to stabilize the oxygen level of a small bio reservoir to enhance the cost efficiency of the experiments using specific antagonists or agonists.The preparation of the acute hippocampus slices is demonstrated by the PhD students, Xia and Weiguang of our laboratory. To begin this procedure, use a cold surgical blade to dissect a piece of the dorsal cortex at a 70 degree angle along the dorsal edge of each hemisphere. With a cold dental cement spatula, transfer each hemisphere to a piece of filter paper to briefly dry the surface.Mount the two hemispheres with freshly cut surfaces on the ice cold slicing platform using fast-acting adhesive glue so the caudal end of the hemispheres face the razor blade. Next, place the slicing platform into the cooling chamber of a vibratome. Fill the chamber with the slicing buffer at two to four degrees Celsius and carbogenate it.After that, cut 350 micrometer slices using adequate vibrotome settings. Isolate the hippocampal formation from the subiculum and the entorhinal cortices using two injection cannulas as scissors. Remove the bubbles from the slice-holding mesh of the previously prepared incubation chamber using a pasteur pipette.Then, transfer the slices that have some transparency at the stratum pyramidal from the slicing platform on the mesh of the incubation chamber with a large-mouth pasteur pipette. In this step, add a three-way tube connector to the outflow of the recycling system. Connect the middle arm of the three-way tube connector to a carbogen supply tube and regulate the flow rate with an airflow meter.After that, add a second three-way tube connector to the inflow of the recycling system. Connect the middle arm to the tube facing the inline heater, the upper arm to a thin silicone tube, and the lower arm to the inflow tube from the reservoir. Then, place a tube squeezer on a thin silicone tube at a position along the tube where the pulsation of the ACSF in the slice chamber generated by the peristolic pump is at its minimum.Now, presoak a small piece of lens-cleaning paper and a nylon mesh fixed on a U-shaped platinum wire in the submersion slice chamber for a few minutes. After that, remove the U-shaped platinum wire. Switch off the recycling and place a slice on the lens-cleaning paper.Then, immediately place the slice-holding mesh on top of the slice. Switch on the pump and let the slice equilibrate for 30 minutes without dipping the objective into ACSF. In the meantime, fill the recording electrode with ACSF and mount it into the pipette holder.Check the insulation of the metal stimulation electrode by placing it into sodium bicarbonate solution. Connect the electrode to the negative pole of a DC voltage generator and observe the formation of bubbles at the tip under a dissection microscope. Next, place the tested apoxy-insulated tungsten stimulation electrode in the manipulator holder and the reference wire in the slice chamber.Add a second reference electrode to the chamber and connect it to the reference socket of the head stage of the recording electrode. In the amplifier control software, click on the zero clamp mode box, then double click the output gain list box. Choose a gain of 100, double click the high pass filter box vessel, choose three kilohertz, and double click the low pass filter list box AC to choose 0.1 hertz.In the recording software, click on acquire, open protocol. Choose a protocol that has the settings allowing for episodic stimulations and the digitalization of amplified potentials at 10 to 20 kilohertz for 50 to 100 milliseconds and that automatically triggers a stimulus isolator 10 milliseconds after the start of an episodic recording. Place the stimulation and recording electrodes in line and parallel to the stratum pyramidal.Subsequently, click acquire, edit protocol, and choose the trigger tab in the popup window. Click on the trigger source box and choose space bar as the trigger source. Then, click the okay button and click the record button to start the acquisition.In the stimulus isolator software, click on the voltage control box and enter zero. Click the download button. Following that, click on the recording software window and press the space bar.Repeat this cycle by sequentially entering values from 1000 to 8000. Correlate the stimulation strength with FEPSP slope values and determine the stimulation strength required to get 40%of the FEPSP slope maximum. Click the voltage control box and enter the determined value.Then, click the download button. In the recording software, click the stop button and then the acquire menu. Click on edit protocol and choose the trigger tab in the popup window.Afterward, click on the trigger source box and choose the internal timer as the trigger source. Click the okay button, followed by the record button that starts the automatic recording of field potentials every 60 seconds. Click the stop button after 30 to 60 minutes.In the recording software, click acquire, open protocol, and choose the same protocol as the baseline recording. Click the okay button and then click record. Keep automatically running the field potential recordings for two to four hours.When it is finished, click the stop button to terminate the recording. This figure shows the representative recordings of activity-dependent potentiation of synaptic transmission using outflow carbogenation and reservoir carbogenation with the recycling of a small ACSF reservoir. The potentiation was induced after time-point zero by three times 100 hertz per second trains.This figure shows the outflow carbogenation with recycling of a small ACSF reservoir improved the LTD induction in comparison to experiments with reservoir carbogenation only. Once mastered, the slice preparation can be done in five to 10 minutes and a stable field potential recording can also be achieved for many hours if it is performed properly. While attempting this procedure, it is important to adjust your carbogenation level, perfusion speed, the position of the electrodes, and the stimulation stress of your specific equivalence.Following this procedure, other method like the patch clamp, the forensics microscopy can be performed in order to answer the additional questions like the virilization of sap cellular localization of ravin probings in response to the induction of activity-dependent synaptic plasticity. After its development, this technique paves the way for researchers in the field of neuroplasticity to explore activity-dependent synaptic plasticity as a cellular mode of learning and memory in in vitro hippocampal slices of well tab and transgenic mouse genes. After watching this video, you should have a good understanding of how to perform acute slice preparation from the temporal hippocampus and how to obtain stable conditions for long-term recording of synaptic transmissions using a small volume of recycled ACSF.Don't forget that working with animals and chemical compounds can be hazardous and precautions such as wearing gloves and the proper disinfection should always be taken while performing this procedure.

recording-synaptic-plasticity-acute-hippocampal-slices-maintained

Research

JoVE Journal

Neuroscience

11.4K Görüntüleme.  Fudan University. The overall goal of this procedure is to provide a method to ensure simplified means of carbogenation of small-volume recycling ACSF and to achieve long-term recordings of field potentials using a recording chamber mounted on a fluorescence microscope. This method can help us answer the key questions in the field of neuroplasticities relating to the underlying lignin pathways that regulates the synaptic transmission and formation of memory in a cellular mode of learning and memories. The main...

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