Name: short-term free-floating slice cultures from the adult human brain
Uploaded: 2019-11-05T13:30:00
Description: Watch this Scientific Journal Video about Short-Term Free-Floating Slice Cultures from the Adult Human Brain at JoVE.com

This work is supported by FAPESP (Grant 25681-3/2017 to AS), CAPES (Post-Doctoral fellowship PNPD/INCT-HSM to A.F. and Pre-Doctoral fellowship to N.D.M.) and FAEPA. G.M.A. holds a Master&#8217;s fellowship from FAPESP (MS 2018/06614-4). N.G.C. holds a CNPq Research Fellowship. We thank the patients and their families for donating the resected tissues for this study. We would like to acknowledge the support of residents, nurses, technicians, and the CIREP team, from the Clinical Hospital at the Ribeir&#227;o Preto Medical School, University of S&#227;o Paulo, who helped in various stages of the process.

Live adult brain tissues were obtained from patients undergoing resective neurosurgery for the treatment of pharmacoresistant temporal lobe epilepsy (Figure 1A). All procedures were approved by the Ethics Committee from the Clinics Hospital at the Ribeir&#227;o Preto Medical School (17578/2015), and patients (or their legal responsible person) agreed and signed the informed consent terms. Collection of the tissue was done by the neurosurgery team at the Epilepsy Surgery Cent...

This protocol for producing free-floating, short-term slice cultures is an alternative method for culturing adult human neocortical slices. Such a protocol for slice cultures may be amenable for studies on (but not restricted to) optogenetics1,44,45, electrophysiology2,3,4,5, short-term plasticity<sup ...

The use of human samples in research is unequivocally a great option to study human brain pathologies, and modern techniques have opened new ways for robust and ethical experimentation using patient-derived tissue. Methods like organotypic/slice cultures prepared from adult human brain have been increasingly used in paradigms such as optogenetics1, electrophysiology2,3,4,5, plasticity6,7,8,9, neurotoxicity/neuroprotection10,11,12,13, cell therapy14, drug screening15,16,17, genetics and gene editing12,18,19,20, among others, as a strategy for better understanding neurological diseases during adulthood.
The comprehension of mechanisms underlying human brain pathologies depends on experimental strategies that require a large number of subjects. Conversely, in the case of slice cultures, although access to human samples is still difficult, the possibility of generating up to 50 slices from a single cortical sample partially circumvents the requirement of recruiting multiple volunteers by increasing the number of replicates and performed assays per collected tissue21.
Several protocols for brain organotypic/slice cultures have been described, ranging from the classical oculo drafts22,23 to roller tube24,25,26, semi-permeable membranes interface27,28,29,30, and free-floating slices31,32. Depending on the particularities of an experimental design, each technique has its own advantages and disadvantages. Short-term, free-floating slices cultures from adult human brains is in some cases advantageous over the method used by Stoppini et al.27, if considering the fact that although long-term cell survival in vitro is usually a major concern when evaluating a culture method, in many experiments only short periods of time in culture are needed12,31,32,33,34,35. Under these conditions, the use of free-floating cultures presents the advantage of being simpler and more cost-effective, as well as more accurately resembling the original human tissue condition than slices kept in culture over 2-3 weeks.
Despite the potential of slice cultures to neuroscience, studies using adult nervous tissue to prepare such cultures are still scarce, particularly from human subjects. This article describes a protocol to use collected brain tissue from living human donors submitted to resective brain surgery to prepare free-floating slice cultures. Procedures to maintain and perform biochemical and cell biology assays using these cultures are detailed. This protocol has been proven valuable for analyzing viability and neuronal function in investigations on the mechanisms of neuropathologies linked to adulthood.

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			<td height="40" style="height:40px;width:521px;">Acrylamide/Bis-Acrylamide, 30% solution</td>
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			<td>Santa Cruz Biotecnology</td>
			<td>sc-7383</td>
			<td>Dilution 1:1,000 in BSA 2.5%</td>
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			<td height="40" style="height:40px;">BDNF</td>
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			<td height="40" style="height:40px;width:521px;">Bovine Serum Albumin</td>
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			<td height="40" style="height:40px;width:521px;">Bradford 1x Dye Reagent</td>
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			<td style="width:344px;">500-0205</td>
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			<td height="40" style="height:40px;width:521px;">EDTA</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:344px;">T3924</td>
			<td style="width:505px;">Used in RIPA buffer</td>
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		<tr height="40">
			<td height="40" style="height:40px;">Glucose</td>
			<td>Merck</td>
			<td>108337</td>
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		<tr height="40">
			<td height="40" style="height:40px;">Glutamax</td>
			<td>Gibco</td>
			<td>35050-061</td>
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			<td height="40" style="height:40px;">Hank&#39;s Balanced Salts</td>
			<td>Sigma Aldrich</td>
			<td>H1387-10X1L</td>
			<td></td>
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			<td height="40" style="height:40px;">Hepes</td>
			<td>Sigma Aldrich</td>
			<td>H4034</td>
			<td></td>
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		<tr height="40">
			<td height="40" style="height:40px;width:521px;">Hydrochloric acid</td>
			<td style="width:200px;">Merck</td>
			<td style="width:344px;">1003171000</td>
			<td style="width:505px;"></td>
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		<tr height="40">
			<td height="40" style="height:40px;width:521px;">Hydrogen Peroxide (H2O2)</td>
			<td style="width:200px;">Vetec</td>
			<td align="right" style="width:344px;">194</td>
			<td style="width:505px;"></td>
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		<tr height="40">
			<td height="40" style="height:40px;width:521px;">Mouse IgG, HRP-linked whole Ab (anti-mouse)</td>
			<td style="width:200px;">GE</td>
			<td style="width:344px;">NA931-1ML</td>
			<td style="width:505px;"></td>
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			<td height="40" style="height:40px;width:521px;">NaCl</td>
			<td style="width:200px;">Merck</td>
			<td align="right" style="width:344px;">1064041000</td>
			<td style="width:505px;">Used in RIPA buffer</td>
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		<tr height="40">
			<td height="40" style="height:40px;">Neurobasal A</td>
			<td>Gibco</td>
			<td>10888-022</td>
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		<tr height="40">
			<td height="40" style="height:40px;width:521px;">Non-fat dry milk (Molico)</td>
			<td style="width:200px;">Nestl&#233;</td>
			<td style="width:344px;"></td>
			<td style="width:505px;">Used for membrane blocking</td>
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			<td height="40" style="height:40px;width:521px;">PBS Buffer pH 7,2</td>
			<td>Laborclin</td>
			<td align="right">590338</td>
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			<td height="40" style="height:40px;">Penicilin/Streptomicin</td>
			<td>Sigma Aldrich</td>
			<td>P4333</td>
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			<td height="32" style="height:32px;width:521px;">Potassium Chloride</td>
			<td>Merck</td>
			<td align="right">1049361000</td>
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			<td height="31" style="height:31px;width:521px;">Prime Western Blotting Detection Reagent</td>
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			<td style="width:344px;">RPN2232</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:521px;">Rabbit IgG, HRP-linked whole Ab (anti-rabbit)</td>
			<td>GE</td>
			<td>NA934-1ML</td>
			<td></td>
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		<tr height="32">
			<td height="32" style="height:32px;width:521px;">SDS</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:344px;">L5750</td>
			<td style="width:505px;">Used in RIPA buffer</td>
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		<tr height="34">
			<td height="34" style="height:34px;width:521px;">TEMED</td>
			<td style="width:200px;">GE</td>
			<td style="width:344px;">17-1312-01</td>
			<td style="width:505px;"></td>
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			<td height="40" style="height:40px;">Thiazolyl Blue Tetrazolium Bromide (MTT)</td>
			<td>Sigma Aldrich</td>
			<td>M5655</td>
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		<tr height="40">
			<td height="40" style="height:40px;width:521px;">Tris</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:344px;">T-1378</td>
			<td style="width:505px;">Used in RIPA buffer</td>
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			<td height="41" style="height:42px;width:521px;">Triton x-100</td>
			<td style="width:200px;">Sigma</td>
			<td style="width:344px;">X100</td>
			<td style="width:505px;">Used in RIPA buffer</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:521px;">Ultrapure Water</td>
			<td style="width:200px;">Millipore</td>
			<td style="width:344px;"></td>
			<td style="width:505px;">Sterile water, derived from MiliQ water purification system</td>
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			<td height="38" style="height:39px;width:521px;">Equipment and Material</td>
			<td style="width:200px;"></td>
			<td style="width:344px;"></td>
			<td style="width:505px;"></td>
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			<td height="49" style="height:50px;">24-well plates</td>
			<td>Corning</td>
			<td>CL S3526</td>
			<td>Flat Bottom with Lid</td>
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		<tr height="44">
			<td height="44" style="height:44px;">Amersham Potran Premium (nitrocellulose membrane)&#160;</td>
			<td>GE</td>
			<td>29047575</td>
			<td></td>
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		<tr height="41">
			<td height="41" style="height:42px;width:521px;">Carbogen Mixture</td>
			<td style="width:200px;">White Martins</td>
			<td style="width:344px;"></td>
			<td style="width:505px;">95% O2, 5% CO2</td>
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		<tr height="45">
			<td height="45" style="height:46px;width:521px;">CO2 incubator</td>
			<td style="width:200px;">New Brunswick Scientific</td>
			<td style="width:344px;">CO-24</td>
			<td style="width:505px;">Incubation of slices 5% CO2, 36&#186;C</td>
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			<td style="width:344px;"></td>
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			<td height="44" style="height:44px;width:521px;">Microtubes</td>
			<td style="width:200px;">Greiner</td>
			<td style="width:344px;">001608</td>
			<td style="width:505px;">1,5mL microtube</td>
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			<td height="44" style="height:44px;width:521px;">Motorized pestle</td>
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			<td height="39" style="height:39px;width:521px;">Plastic spoon</td>
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			<td style="width:344px;"></td>
			<td style="width:505px;">Size of a dessert spoon</td>
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			<td height="39" style="height:39px;width:521px;">Razor Blade</td>
			<td style="width:200px;">Bic</td>
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			<td style="width:505px;">Chrome Platinum, used in slicing with vibratome</td>
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		<tr height="36">
			<td height="36" style="height:37px;width:521px;">Scalpel Blade</td>
			<td style="width:200px;">Becton Dickinson (BD)</td>
			<td style="width:344px;">Number 24</td>
			<td style="width:505px;">Used for slicing of tissue; recommended same size or smaller</td>
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		<tr height="33">
			<td height="33" style="height:34px;width:521px;">Superglue (Loctite Super Bonder)</td>
			<td style="width:200px;">Henkel</td>
			<td style="width:344px;"></td>
			<td style="width:505px;">Composition: Etilcianoacrilato; 2-Propenoic acid; 6,6&#39;-di-terc-butil-2,2&#39;-metilenodi-p-cresol; homopolymer</td>
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		<tr height="39">
			<td height="39" style="height:39px;">Vibratome&#160;</td>
			<td>Leica</td>
			<td>14047235612 - VT1000S</td>
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		<tr height="36">
			<td height="36" style="height:37px;width:521px;">Name of Material/ Equipment for Immunohistochemistry</td>
			<td style="width:200px;"></td>
			<td style="width:344px;"></td>
			<td style="width:505px;"></td>
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		<tr height="40">
			<td height="40" style="height:41px;">Antibody anti-NeuN (mouse)</td>
			<td>Millipore&#160;</td>
			<td>MAB377</td>
			<td>Dilution 1:1,000 in Phosphate Buffer</td>
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		<tr height="48">
			<td height="48" style="height:48px;width:521px;">Antibody anti-GFAP (mouse)</td>
			<td style="width:200px;">Merck</td>
			<td style="width:344px;">MAB360</td>
			<td>Dilution 1:1,000 in Phosphate Buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:521px;">Antibody anti-Iba1 (rabbit)</td>
			<td style="width:200px;">Abcam</td>
			<td style="width:344px;">EPR16588 - ab178846</td>
			<td>Dilution 1:2,000 in Phosphate Buffer</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:521px;">Biotinylated anti-mouse IgG Antibody (H+L)</td>
			<td style="width:200px;">Vector</td>
			<td style="width:344px;">BA-9200</td>
			<td style="width:505px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:521px;">DAB</td>
			<td style="width:200px;">Sigma Aldrich</td>
			<td style="width:344px;">D-9015</td>
			<td style="width:505px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:521px;">Entellan</td>
			<td style="width:200px;">Merck</td>
			<td align="right" style="width:344px;">107960</td>
			<td style="width:505px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:521px;">Ethanol</td>
			<td style="width:200px;">Merck</td>
			<td style="width:344px;">1.00983.1000</td>
			<td style="width:505px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:521px;">Gelatin</td>
			<td style="width:200px;">Synth</td>
			<td style="width:344px;">00G1002.02.AE</td>
			<td style="width:505px;">Used for coating slides</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microtome</td>
			<td>Leica</td>
			<td>SM2010R</td>
			<td>Equipped with Freezing Stage (BFS-10MP, Physiotemp), set to -40&#186;C</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Normal Donkey Serum</td>
			<td>Jackson Immuno Research</td>
			<td>017-000-121</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:521px;">Paraformaldehyde</td>
			<td style="width:200px;">Sigma Aldrich</td>
			<td style="width:344px;">158127</td>
			<td style="width:505px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:521px;">Rabbit IgG, HRP-linked whole Ab (anti-rabbit)</td>
			<td>GE</td>
			<td>NA934-1ML</td>
			<td style="width:505px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Slides (Star Frost)</td>
			<td>Knittel Glaser</td>
			<td></td>
			<td>Gelatin coated slides</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sucrose</td>
			<td style="width:200px;">Vetec</td>
			<td>60REAVET017050</td>
			<td style="width:505px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:521px;">Vectastain ABC HRP Kit (Peroxidase, Standard)</td>
			<td style="width:200px;">Vector</td>
			<td style="width:344px;">PK-4000, Kit Standard</td>
			<td style="width:505px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:521px;">Xylene</td>
			<td style="width:200px;">Synth</td>
			<td style="width:344px;">01X1001.01.BJ</td>
			<td style="width:505px;"></td>
		</tr>
	</tbody>
</table>

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 critical aspect to evaluate the quality and health of cultured slices is the presence and typical morphology of the expected neural cell types, neurons, and glial cells. The typical architecture of the human cortical lamination was observed in a slice at DIV4, revealed by neuronal immunolabeling (Figure 2D). In addition, the expected presence of microglia and astroglia (Figure 2B,C) was also observed. These results demonstrate...

Watch this Scientific Journal Video about Short-Term Free-Floating Slice Cultures from the Adult Human Brain at JoVE.com

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

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.

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

We present a protocol to prepare free-floating slice cultures from brain tissue collected from living human donors submitted to resective brain surgery. This culture is amenable to perform biochemical and cell biology assays or immunohistochemistry. It is expected to contribute to the elucidation of the mechanism underlying neurodegeneration in associated brain diseases.The main advantage of this technique is that it's a simpler and cost effective alternative to the classic slice culture protocol using membrane inserts. Although the overall protocol is not complex, some steps such as removal of meninges, gluing the tissue to the vibratome specimen disc, and resection for immunohistochemistry are best understood when demonstrated visually. Helping to demonstrate the procedure will be Niele Mendes and Glaucia Almedia who are grad students, and Giovanna Nogueira, another grad student.To begin this procedure, add salt to a bucket of ice. Transfer the slicing solution to this bucket and let it rest under carbogen mixture bubbling for at least 20 minutes prior to use. Next, prepare a block of 3%agarose that is about two centimeters by two centimeters by two centimeters.Super glue the agarose block to the vibratome specimen disc in order to create additional mechanical support to the tissue sample during slicing. On the vibratome, set the section thickness to 200 micrometers, the vibration frequency to 100 hertz, and choose a slicing speed between 0.5 and 1.0 millimeters per second. Then lock the vibratome buffer tray to the vibratome base and add ice to keep it refrigerated prior to receiving the slicing solution and the sample and throughout the slicing procedure.First, set up a transport apparatus that consists of a portable gas cylinder containing a carbogen mixture connected to a pressure flux valve that controls the gas output connected to silicone tubing that connects that gas output to the transport vessel and the transport vessel which contains the transport solution and ice for sample cooling during transport. Collect and transport the specimen and transport as outlined in the text protocol. Transfer the specimen to a Petri dish containing slicing solution.Using fine surgical tools, carefully remove as much of the remaining meninges as possible. Choose the best specimen orientation for producing slices with the particular characteristics of the experimental design and use a number 24 scalpel blade to trim a flat surface to be the base that will be glued to the specimen disc. Using a disposal plastic spoon and delicate paintbrushes, collect the fragment from the Petri dish and dry off excess solution with filter paper.Next, use super glue to attach the tissue to the vibratome specimen dish until it is firmly adhered to the dish and in contact with the agarose block. Place the vibratome specimen disc into the vibratome buffer tray. Lock the knife holder in place with the razor blade firmly fixed.Add slicing solution and ensure that it is covering both the specimen and the blade. Then begin slicing the specimen into 200 micrometer slices. Transfer the slices from the buffer tray to a Petri dish containing slicing solution and trim any loose edges and excess white matter to a proportion of approximately 70%cortex and 30%white matter.In a laminar flow cabinet, add 600 microliters of culture medium to each well of a 24-well plate and incubate at 36 degrees Celsius with 5%carbon dioxide for at least 20 minutes prior to plating the slices. After this, use a paintbrush to plate one slice in each well. If there are any unused wells in the plate, fill them with 400 microliters of sterile water.Incubate at 36 degrees Celsius with 5%carbon dioxide. Supplement 10 milliliters of the previously prepared culture medium with brain derived neurotrophic factor at a concentration of 50 nanograms per milliliter. After eight to 16 hours, remove 333 microliters of the conditioned medium from each well and add 133 microliters of fresh BDNF supplemented medium.Replace one-third of the conditioned medium with fresh BDNF supplemented medium every 24 hours. First, transfer the slices from the wells containing culture medium to a new 24-well plate containing PBS. Remove the PBS from each well and replace it with one milliliter of 4%paraformaldehyde.Incubate overnight at four degrees Celsius. The next day, carefully remove the paraformaldehyde from the wells and replace it with one milliliter of 30%sucrose solution. Incubate at four degrees Celsius for 48 hours.After 48 hours, set the freezing microtome to negative 40 degrees Celsius. Prepare a sucrose base on the microtome stage where the slices should be placed. After it is frozen completely, cut some of the frozen sucrose to produce a flat surface on which the slice will be placed.Next, place each slice over a stretched plastic film and use a paintbrush to flatten the tissue. In a single move, transfer the stretched slice to the frozen sucrose base. After the slice has rested for five to 10 minutes to freeze properly, cut the slice into 30 micrometer sections.Transfer the 30 micrometer sections to a Petri dish containing PBS and proceed to a histology protocol adequate for the experimental design. When determining the quality and health of cultured slices, a critical aspect to evaluate is the presence and typical morphology of the expected neural cell types, neurons and glial cells. The typical architecture of the human cortical lamination is observed in a slice at day in vitro four revealed by neuronal immunolabeling.In addition, the expected presence of microglia and astroglia is also observed. These results demonstrate that tissue architecture is not significantly affected either by the surgical procedure, the sample processing, or by the short-term period in vitro. The neuronal response to potassium chloride-induced depolarization have also been quantified in cultured slices by following ERK phosphorylation.Interestingly, a clear increase in ERK phosphorylation is seen in potassium chloride-treated slices at day in vitro four. Finally, the response of slices at day in vitro four to a toxic challenge is evaluated with a known oxidative stress inducer hydrogen peroxide. Exposing the slices to 300 millimolar hydrogen peroxide for 24 hours led to a robust decrease in MTT reduction.Taken together, the massive cell death observed in day in vitro five slices after the hydrogen peroxide challenge and the potassium chloride-induced depolarization results indicate the preserved general health of slices at day in vitro four which respond to a toxic stimulus such as oxidative stress. This protocol is mainly devoted to studies based on assays lasting than one week such as the investigation of molecular mechanisms of neurotoxicity and neuroprotection by candidate drugs. Although this protocol is devoted to using cortical tissue collected from patients submitted to surgical treatment for micro resistant temporal lobe epilepsy, it's likely that tissue collected from other brain regions or conditions could also be sources to produce free-floating slice cultures.Slice cultures from adult human brain may be key in advancing our understanding of human neuropathologies due to their unique cellular circuitry and molecular machinery lacking in slices produced from rodent brains.

short-term-free-floating-slice-cultures-from-the-adult-human-brain

Research

JoVE Journal

Neuroscience

Organotypic Hippocampal Slice Cultures

The hippocampus, a component of the limbic system, plays important roles in long-term memory and spatial navigation 1. Hippocampal neurons can modify the strength of their connections after brief periods of strong activation. This phenomenon, known as long-term potentiation (LTP) can last for hours or days and has become the best candidate mechanism for learning and memory 2. In addition, the well defined anatomy and connectivity of the hippocampus 3 has made it a classical model system to study synaptic transmission and synaptic plasticity4.
As our understanding of the physiology of hippocampal synapses grew and molecular players became identified, a need to manipulate synaptic proteins became imperative. Organotypic hippocampal cultures offer the possibility for easy gene manipulation and precise pharmacological intervention but maintain synaptic organization that is critical to understanding synapse function in a more naturalistic context than routine culture dissociated neurons methods.
Here we present a method to prepare and culture hippocampal slices that can be easily adapted to other brain regions. This method allows easy access to the slices for genetic manipulation using different approaches like viral infection 5,6 or biolistics 7. In addition, slices can be easily recovered for biochemical assays 8, or transferred to microscopes for imaging 9 or electrophysiological experiments 10.

We describe a method to prepare organotypic hippocampal slices that can be easily adapted to other brain regions. Brain slices are laid on porous membranes and culture media is allowed to form an interface. This method preserves the gross architecture of the hippocampus for up to 2 weeks in culture.

The hippocampus, a component of the limbic system, plays important roles in long-term memory and spatial navigation 1. Hippocampal neurons can modify the ...

The Analysis of Purkinje Cell Dendritic Morphology in Organotypic Slice Cultures

Purkinje cells are an attractive model system for studying dendritic development, because they have an impressive dendritic tree which is strictly oriented in the sagittal plane and develops mostly in the postnatal period in small rodents 3. Furthermore, several antibodies are available which selectively and intensively label Purkinje cells including all processes, with anti-Calbindin D28K being the most widely used. For viewing of dendrites in living cells, mice expressing EGFP selectively in Purkinje cells 11 are available through Jackson labs. Organotypic cerebellar slice cultures cells allow easy experimental manipulation of Purkinje cell dendritic development because most of the dendritic expansion of the Purkinje cell dendritic tree is actually taking place during the culture period 4. We present here a short, reliable and easy protocol for viewing and analyzing the dendritic morphology of Purkinje cells grown in organotypic cerebellar slice cultures. For many purposes, a quantitative evaluation of the Purkinje cell dendritic tree is desirable. We focus here on two parameters, dendritic tree size and branch point numbers, which can be rapidly and easily determined from anti-calbindin stained cerebellar slice cultures. These two parameters yield a reliable and sensitive measure of changes of the Purkinje cell dendritic tree. Using the example of treatments with the protein kinase C (PKC) activator PMA and the metabotropic glutamate receptor 1 (mGluR1) we demonstrate how differences in the dendritic development are visualized and quantitatively assessed. The combination of the presence of an extensive dendritic tree, selective and intense immunostaining methods, organotypic slice cultures which cover the period of dendritic growth and a mouse model with Purkinje cell specific EGFP expression make Purkinje cells a powerful model system for revealing the mechanisms of dendritic development.

We present a protocol that permits to view and to quantitatively asses the morphology of the dendritic tree of individual Purkinje cells grown in organotypic cerebellar slice cultures. This protocol is intended to promote studies on the mechanisms of Purkinje cell dendritic development.

Purkinje cells are an attractive model system for studying dendritic development, because they have an impressive dendritic tree which is strictly ...

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.

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

Organotypic Slice Cultures to Study Oligodendrocyte Dynamics and Myelination

NG2 expressing cells (polydendrocytes, oligodendrocyte precursor cells) are the fourth major glial cell population in the central nervous system. During embryonic and postnatal development they actively proliferate and generate myelinating oligodendrocytes. These cells have commonly been studied in primary dissociated cultures, neuron cocultures, and in fixed tissue. Using newly available transgenic mouse lines slice culture systems can be used to investigate proliferation and differentiation of oligodendrocyte lineage cells in both gray and white matter regions of the forebrain and cerebellum. Slice cultures are prepared from early postnatal mice and are kept in culture for up to 1 month. These slices can be imaged multiple times over the culture period to investigate cellular behavior and interactions. This method allows visualization of NG2 cell division and the steps leading to oligodendrocyte differentiation while enabling detailed analysis of region-dependent NG2 cell and oligodendrocyte functional heterogeneity. This is a powerful technique that can be used to investigate the intrinsic and extrinsic signals influencing these cells over time in a cellular environment that closely resembles that found in vivo.

A technique to study NG2 cells and oligodendrocytes using a slice culture system of the forebrain and cerebellum is described. This method allows examination of the dynamics of proliferation and differentiation of cells within the oligodendrocyte lineage where the extracellular environment can be easily manipulated while maintaining tissue cytoarchitecture.

NG2 expressing cells (polydendrocytes, oligodendrocyte precursor cells) are the fourth major glial cell population in the central nervous system. During ...

The Analysis of Neurovascular Remodeling in Entorhino-hippocampal Organotypic Slice Cultures

Ischemic brain injury is among the most common and devastating conditions compromising proper brain function and often leads to persisting functional deficits in the affected patients. Despite intensive research efforts, there is still no effective treatment option available that reduces neuronal injury and protects neurons in the ischemic areas from delayed secondary death. Research in this area typically involves the use of elaborate and problematic animal models. Entorhino-hippocampal organotypic slice cultures challenged with oxygen and glucose deprivation (OGD) are established in&#160;vitro models which mimic cerebral ischemia. The novel aspect of this study is that changes of the brain blood vessels are studied in addition to neuronal changes and the reaction of both the neuronal compartment and the vascular compartment can be compared and correlated. The methods presented in this protocol substantially broaden the potential applications of the organotypic slice culture approach. The induction of OGD or hypoxia alone can be applied by rather simple means in organotypic slice cultures and leads to reliable and reproducible damage in the neural tissue. This is in stark contrast to the complicated and problematic animal experiments inducing stroke and ischemia in vivo. By broadening the analysis to include the study of the reaction of the vasculature could provide new ways on how to preserve and restore brain functions. The slice culture approach presented here might develop into an attractive and important tool for the study of ischemic brain injury and might be useful for testing potential therapeutic measures aimed at neuroprotection.

A protocol for entorhino-hippocampal organotypic slice cultures, which allows reproducing many aspects of ischemic brain injury, is presented. By studying changes of the neurovasculature in addition to changes in the neurons, this protocol is a versatile tool to study plastic changes in neural tissue after injury.

Ischemic brain injury is among the most common and devastating conditions compromising proper brain function and often leads to persisting functional ...

Slice It Hot: Acute Adult Brain Slicing in Physiological Temperature

Here we present a protocol for preparation of acute brain slices. This procedure is a critical element for electrophysiological patch-clamp experiments that largely determines the quality of results. It has been shown that omitting the cooling step during cutting procedure is beneficial in obtaining healthy slices and cells, especially when dealing with highly myelinated brain structures from mature animals. Even though the precise mechanism whereby elevated temperature supports neural health can only be speculated upon, it stands to reason that, whenever possible, the temperature in which the slicing is performed should be close to physiological conditions to prevent temperature related artifacts. Another important advantage of this method is the simplicity of the procedure and therefore the short preparation time. In the demonstrated method adult mice are used but the same procedure can be applied with younger mice as well as rats. Also, the following patch clamp experiment is performed on horizontal cerebellar slices, but the same procedure can also be used in other planes as well as other posterior areas of the brain.

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.

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

Preparation of Primary Mixed Glial Cultures from Adult Mouse Spinal Cord Tissue

It has been well-accepted that spinal cord glial responses contribute significantly to the development of neuropathic pain. Tremendous information regarding glial activities at the cellular and molecular levels has been obtained through in vitro cell culture systems. The in vitro systems utilized, mainly include primary glia derived from neonatal brain cortical tissue and immortalized cell lines. However, these systems may not reflect the characteristics of spinal cord glial cells in vivo. In order to further investigate the roles of spinal cord glial cells in the development of peripheral nerve injury-induced neuropathic pain using a culture system that better reflects the in vivo condition, our laboratory has developed a method to establish primary spinal cord mixed glial cultures from adult mice. Briefly, spinal cords are collected from adult mice and processed through papain digestion followed by myelin removal with a density-gradient medium. Single cell suspensions are cultured in complete Dulbecco&#39;s modified Eagle media (cDMEM) supplemented with 2-mercaptoethanol (2-ME) at 35.9 oC. These culture conditions were optimized specifically for the growth of mixed glial cells. Under these conditions, cells are ready to be used for experimentation between 12 - 14 d&#160;(cells are usually in log phase during this time) after the establishment of the culture (D 0) and can be kept in culture conditions up to D 21. This culture system can be used to investigate the responses of spinal cord glial cells upon stimulation with various substances and agents. Besides neuropathic pain, this system can be used to study glial responses in other diseases that involve pathological changes of spinal cord glial cells.

The development of neuropathic pain involves pathological changes of spinal cord glial cells. A reliable glial culture system derived from adult spinal cord tissue and designed for studying these cells in vitro is lacking. Therefore, we show here how&#160;to establish primary mixed glial cultures from adult mouse spinal cord tissue.

It has been well-accepted that spinal cord glial responses contribute significantly to the development of neuropathic pain. Tremendous information ...

Derivation of Leptomeninges Explant Cultures from Postmortem Human Brain Donors

Even though great progress has been made in the clinical characterization of Parkinson&#39;s disease, several studies report that the diagnosis of Parkinson&#39;s disease is not pathologically confirmed in up to 25% of clinically diagnosed Parkinson&#39;s disease. Therefore, tissue collected from clinically diagnosed patients with idiopathic Parkinson&#39;s disease can have a high rate of misdiagnosis; hence in vitro studies from such tissues to study Parkinson&#39;s disease as a preclinical model can become futile.
By collecting postmortem human leptomeninges with a confirmed neuropathological diagnosis of Parkinson&#39;s disease and characterized by nigrostriatal cell loss and intracellular protein inclusions called Lewy bodies, one can be certain that clinically observed parkinsonism is not caused by another underlying disease process (e.g. tumor, arteriosclerosis).
This protocol presents the dissection and preparation of postmortem human leptomeninges for derivation of a meningeal fibroblast culture. This procedure is robust and has a high success rate. The challenge of the culture is sterility as the brain procurement is generally not performed under sterile conditions. Therefore, it is important to supplement the culture media with a cocktail of penicillin, streptomycin, and amphotericin B.
The derivation of meningeal fibroblasts from autopsy-confirmed cases with Parkinson&#39;s disease provides the foundation for in vitro modeling of Parkinson&#39;s disease. Meningeal fibroblasts appear 3-9 days after sample preparation and about 20-30 million cells can be cryopreserved in 6-8 weeks. The meningeal fibroblast culture is homogenous and the cells express fibronectin, a commonly used marker to identify meninges.

The leptomeninges explant culture protocol from human postmortem brain is a technically robust and simple way to derive fibronectin-positive meningeal fibroblasts within 6-8 weeks and cryopreserve approximately 20-30 million cells.

Even though great progress has been made in the clinical characterization of Parkinson&#39;s disease, several studies report that the diagnosis of ...

Simple Generation of a High Yield Culture of Induced Neurons from Human Adult Skin Fibroblasts

Induced neurons (iNs), the product of somatic cells directly converted to neurons, are a way to obtain patient-derived neurons from tissue that is easily accessible. Through this route, mature neurons can be obtained in a matter of a few weeks. Here, we describe a straightforward and rapid one-step protocol to obtain iNs from dermal fibroblasts obtained through biopsy samples from adult human donors. We explain each step of the process, including the maintenance of the dermal fibroblasts, the freezing procedure to build a stock of the cell line, seeding of the cells for reprogramming, as well as the culture conditions during the conversion process. In addition, we describe the preparation of glass coverslips for electrophysiological recordings, long-term coating conditions, and fluorescence activated cell sorting (FACS). We also illustrate examples of the results to be expected. The protocol described here is easy to perform and can be applied to human fibroblasts derived from human skin biopsies from patients with various different diagnoses and ages. This protocol generates a sufficient amount of iNs which can be used for a wide array of biomedical applications, including disease modeling, drug screening, and target validation.

Direct neuronal reprogramming generates neurons that maintain the age of the starting somatic cell. Here, we describe a single vector-based method to generate induced neurons from dermal fibroblasts obtained from adult human donors.

Induced neurons (iNs), the product of somatic cells directly converted to neurons, are a way to obtain patient-derived neurons from tissue that is easily ...

Targeting Alpha Synuclein Aggregates in Cutaneous Peripheral Nerve Fibers by Free-floating Immunofluorescence Assay

To date, for most neurodegenerative diseases only a post-mortem histopathological definitive diagnosis is available. For Parkinson&#39;s disease (PD), the diagnosis still relies only on clinical signs of motor involvement that appear later on in the disease course, when most of the dopaminergic neurons are already lost. Hence, there is a strong need for a biomarker that can identify patients at the beginning of disease or at the risk of developing it. Over the last few years, skin biopsy has proved to be an excellent research and diagnostic tool for peripheral nerve diseases such as small fiber neuropathy. Interestingly, a small fiber neuropathy and alpha synuclein (&#945;Syn) neural deposits have been shown by skin biopsy in PD patients. Indeed, skin biopsy has the great advantage of being an easily accessible, minimally invasive and painless procedure that allows the analysis of peripheral nervous tissue prone to the pathology. Moreover, the possibility of repeating the skin biopsy in the course of the follow-up of the same patient allows studying the longitudinal correlation with the disease progression. We set up a standardized reliable protocol to investigate the presence of &#945;Syn aggregates in skin nerve fibers of the PD patient. This protocol involves few short fixation steps, a cryotome sectioning and then a free-floating immunofluorescence double-staining with two specific antibodies: anti Protein Gene Product 9.5 (PGP9.5) to mark the cutaneous nerve fibers and anti 5G4 for detecting &#945;Syn aggregates. It is a versatile, sensitive and easy to perform protocol that can also be applied for targeting other proteins of interest in skin nerves. The ability to mark &#945;Syn aggregates is another step forward to the use of skin biopsy as a tool for establishing a pre-mortem histopathological diagnosis of PD.

Here, we present a protocol for a free-floating indirect immunofluorescence assay on skin biopsy sections that allows for the identification of disease specific conformation variants of alpha synuclein involved in Parkinson disease and multiple proteins of the peripheral nervous system.

To date, for most neurodegenerative diseases only a post-mortem histopathological definitive diagnosis is available. For Parkinson&#39;s disease (PD), the ...