We thank the Yale Stem Cell Core (YSCC), and the Yale Cancer Center (YCC) for assistance. We thank Dr. Jung Kim for his neuropathology review. This work was supported by Connecticut Regenerative Medicine Research Fund, March of Dimes, and NHLBI R01HL131793 (S.G.K.), the Yale Cancer Center and the Yale Cancer Biology Training Program NCI CA193200 (E.B.) and a generous unrestricted gift from Joseph and Lucille Madri.

1. Stem Cell Maintenance
<ol>
	<li>Maintain H9 hESCs on a layer of growth factor reduced basement membrane matrix (see the Table of Materials, henceforth simply referred to as matrix) according to the manufacturer&#39;s instructions.
	<ol>
		<li>To coat one 6-well plate or one 10 cm dish, combine 100 &#181;L of matrix with 5.9 mL of ice-cold Dulbecco&#39;s modified Eagle medium (DMEM)/F12 media. Wrap plates in paraffin film and store overnight at 4 &#176;C. Use them on the next day for passaging cells after the excess matrix/media is aspirated.</li>
	</ol>
	</li>
	<li>Culture the cells week to week at approximately a 1:12 split ratio every 7 days. Maintain the cells using mTESR-1 media in a 37 &#176;C, low oxygen incubator (5% O2, 5% CO2). Refresh media daily. Weed out differentiating cells from the culture between passages using glass tools.</li>
	<li>H9 cells should be passaged four to six days prior to utilizing them to produce organoids. The cells should be passaged at approximately a 1:8 ratio of cell clusters. To do this, start by rinsing the cells with DMEM F12 media and dissociate the cells with a neutral protease (e.g., dispase, henceforth referred to simply as protease), rinse with DMEM/F-12, and plate as 30-60 cell clusters across 4 plates (6-well or 10 cm) at ~20% confluency. Two days prior to harvest, transition them to a regular incubator (21% O2, 5% CO2). Plates should reach ~80% confluency when starting organoid formation.</li>
</ol>
2. Dissociation of the hESCs for Organoid Culture
<ol>
	<li>Aliquot the protease stock solution (5 U/mL). 
	NOTE: We typically freeze down 1 mL aliquots at -20 &#176;C for use over several months.</li>
	<li>Dilute the protease stock solution to the working concentration by adding 1 mL of the stock solution plus 5 mL of DMEM/F12 for each 6-well or 10 cm plate of hESCs.</li>
	<li>Aspirate and remove cell culture media, then cover the hESCs with the protease solution. Place plates in the incubator for 10-15 min or until the edges of the colonies round up and begin to separate from the matrix.</li>
	<li>Tilt the plate, aspirate the protease solution, and gently wash the cells with DMEM/F12 three times. Use 2 mL/well for each wash when using a 6-well plate and 6 mL when using a 10 cm plate. Make sure colonies stay attached to the matrix when performing this step.</li>
	<li>Add back about 1.5 mL of fresh mTESR media to each well (or 5 mL for a 10 cm plate) and flush the cells off the plate using gentle pipetting.</li>
	<li>Using a 10 mL pipette, gently aspirate and dispense hESC within the plate until they reach approximately 1/30th of their original size. Colony clusters should resemble ~250-350 &#181;m sized squares at the completion of these steps.</li>
</ol>
3. Generation of Organoids
<ol>
	<li>Transfer cells into a single ultra-low attachment T75 flask containing 30 mL of mTESR media without basic fibroblast growth factor (bFGF).</li>
	<li>The next day, tilt the flask(s) such that the live cells pool in the corner (this may take 5-10 min on the first day, but will get quicker as the clusters get larger). 
	NOTE: If there are a large number of cells that have adhered to the bottom of the flask at this step or any subsequent steps, transfer the cells to a new flask. It is normal to have a high population of dead cells for the first two days. When performing media changes, be sure to remove as much of the cell debris as possible.</li>
	<li>Once the cells settle, aspirate off the media and dead cells leaving about 10 mL of media containing the live cells.</li>
	<li>Add ~20 mL of low bFGF media (DMEM/F12 supplemented with 1x N2, 1x B27, 1x L-glutamine, 1x NEAA, 0.05% bovine serum albumin (BSA), and 0.1 mM monothioglycerol (MTG) supplemented with 30 ng/mL bFGF).</li>
	<li>Check the cells on day 2. If most of the cells look healthy and bright, there is no need to do anything. However, if more than a third of the cells appear dark, replace the media (using the same tilting technique as in step 3.2) with ~20 mL of low bFGF media supplemented with 20 ng/mL bFGF.</li>
	<li>On day 3, replace half of the media (using the tilting technique in step 3.2) with 20 mL of low bFGF media supplemented with 10 ng/mL bFGF.</li>
	<li>On day 5, replace half of the medium (using the tilting technique in step 3.2) with 20 mL of neural induction media (NIM: DMEM/F12, 1x N2 supplement, 0.1 mM MEM NEAA, 2 &#181;g/mL heparin). 
	NOTE: If there are any large clusters of cells or organoids that are much larger than the others, they should be removed from the culture. Size is estimated by appearance under the microscope; for example, using an eyepiece with reticle. The majority of organoids are similarly sized (roughly 100 &#177; 20 &#181;m). We removed organoids that were approximately 2x smaller or larger than the others.</li>
	<li>Replace half of the medium (~15 mL) (using the tilting technique) with NIM every other day.</li>
	<li>After 3 weeks in culture, add 100x penicillin/streptomycin to the media (NIM: DMEM/F12, 1x N2 supplement, 0.1 mM MEM NEAA, 2 &#181;g/mL heparin) at a final concentration of 1x if desired. Refresh the media every other day. 
	NOTE: In this fashion, we maintained the organoids for up to 6 months in culture.</li>
</ol>
4. RNA Extraction and Preparation
<ol>
	<li>Gently extract approximately 15 organoids (depending upon size) from the flask using a 10 mL pipette and place into a 1.5 mL tube.
	<ol>
		<li>Gently pellet the organoids in the centrifuge (200 x g for 1 min), and rinse with 1x Dulbecco&#39;s PBS (DPBS) three times.</li>
	</ol>
	</li>
	<li>Extract RNA using validated system or protocol (e.g., RNeasy kit).</li>
	<li>Measure the optical density value of each sample at 260 and 280 nm.</li>
	<li>Prepare cDNA using a validated system or protocol (e.g., iScript cDNA synthesis kit).</li>
	<li>Perform qRT-PCR using pre-validated primers (Table 1) including at least one housekeeping gene.</li>
</ol>
5. Immunohistochemistry
<ol>
	<li>Fixation
	<ol>
		<li>Prepare a 4% paraformaldehyde (PFA) solution and place it at 4 &#176;C.</li>
		<li>Using a sterile razor, cut the tip off of a sterile transfer pipette.</li>
		<li>Gently extract organoids using the cut transfer pipette, as they can be easily broken apart, especially when they grow large, and place them into a 6-well plate with additional media or DPBS.</li>
		<li>Tilt the plate, aspirate the media, and replace with 1x DPBS. Rinse the cells with 1x DPBS two additional times.</li>
		<li>Replace the DPBS with 4% PFA solution and place on a shaker at 4 &#176;C. 
		NOTE: While we fixed for 2 days (for small organoids) to 7 days (for organoids &#62;3 months), shorter times (e.g., 16-24 h) may also be possible.</li>
		<li>Prepare 30%, 20% and 10% sucrose solutions in DPBS.</li>
		<li>After fixation in PFA, replace with the 10% sucrose solution and place on a shaker at 4 &#176;C for 24 h.</li>
		<li>Replace the 10% sucrose with 20% sucrose and place on a shaker at 4 &#176;C for 24 h.</li>
		<li>Replace the 20% sucrose with 30% sucrose and place on a shaker at 4 &#176;C for 24 h.</li>
	</ol>
	</li>
	<li>Frozen sections
	<ol>
		<li>Prepare a flat layer of dry ice and place a labeled plastic mold on top of it.</li>
		<li>Pour a thin layer of optimal cutting temperature medium (OCT) into the mold and let it start to harden (within a few seconds).</li>
		<li>Place a few organoids on the top of the OCT in the mold using a transfer pipette with the tip cut off and pay close attention to the location of the organoids.</li>
		<li>Slowly add in OCT until the mold is full and the organoids are covered. Let it harden completely for an additional 10 min. 
		NOTE: While freezing over 10 min helps ensure ideal relative placement of multiple organoids for sectioning, it is possible to use an ethanol-dry ice mix or liquid nitrogen to freeze more quickly.</li>
		<li>Mark the relative location of the organoids with a marker to make it easier to find them when cutting.</li>
		<li>Place the molds in a bag or box and store at -80 &#176;C until ready to cut the sections.</li>
		<li>Using a cryostat, slice 10 &#181;m sections and place the tissue onto labeled, positively charged slides.</li>
	</ol>
	</li>
	<li>Staining
	<ol>
		<li>Prepare blocking solution (0.3% Triton X-100, 4% normal donkey serum in PBS).</li>
		<li>Use a hydrophobic pap pen to draw around the perimeter of the tissue.</li>
		<li>Rinse the slides with PBS 3 times for 5 min each.</li>
		<li>Replace PBS with blocking solution for 1 h at room temperature.</li>
		<li>Replace the blocking solution with antibody solution (antibody at appropriate concentration, 0.1% Triton X-100, 4% normal donkey serum in PBS) at 4 &#176;C overnight.</li>
		<li>On the following day, wash the slide 3 times with PBS for 10 min each.</li>
		<li>Replace PBS with the appropriate secondary antibody (at the appropriate concentration) diluted in antibody solution for 1 h at room temperature.</li>
		<li>Rinse 3 times for 10 min each time with 1x PBS.</li>
		<li>Apply the 4&#39;,6-diamidino-2-phenylindole (DAPI) stain and rinse three times for 10 min each with 1x PBS.</li>
		<li>Affix coverslips to the front of the slides with mounting solution, let dry at room temperature in the dark, and store in the dark at 4 &#176;C.</li>
	</ol>
	</li>
</ol>

<ol><li>Northcutt, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Understanding+vertebrate+brain+evolution%5BTitle%5D)+AND+%22Integrative+and+Comparative+Biology%22%5BJournal%5D)">Understanding vertebrate brain evolution.</a> Integrative and Comparative Biology. 42 (4), 743-756 (2002).</li>
<li>Roth, G. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aRoth%2C+G+%22The+Long+Evolution+of+Brains+and+Minds%22">The Long Evolution of Brains and Minds</a>. , Springer Netherlands. (2013).</li>
<li>Herculano-Houzel, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+human+brain+in+numbers%3A+a+linearly+scaled-up+primate+brain%5BTitle%5D)+AND+%22Frontiers+in+Human+Neuroscience%22%5BJournal%5D)">The human brain in numbers: a linearly scaled-up primate brain.</a> Frontiers in Human Neuroscience. 3, 31(2009).</li>
<li>Roth, G., Dicke, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Evolution+of+the+brain+and+intelligence%5BTitle%5D)+AND+%22Trends+in+Cognitive+Sciences%22%5BJournal%5D)">Evolution of the brain and intelligence.</a> Trends in Cognitive Sciences. 9 (5), 250-257 (2005).</li>
<li>Eiraku, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Self-organized+formation+of+polarized+cortical+tissues+from+ESCs+and+its+active+manipulation+by+extrinsic+signals%5BTitle%5D)+AND+%22Cell+Stem+Cell%22%5BJournal%5D)">Self-organized formation of polarized cortical tissues from ESCs and its active manipulation by extrinsic signals.</a> Cell Stem Cell. 3 (5), 519-532 (2008).</li>
<li>Watanabe, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Directed+differentiation+of+telencephalic+precursors+from+embryonic+stem+cells%5BTitle%5D)+AND+%22Nature+Neuroscience%22%5BJournal%5D)">Directed differentiation of telencephalic precursors from embryonic stem cells.</a> Nature Neuroscience. 8 (3), 288-296 (2005).</li>
<li>Kadoshima, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Self-organization+of+axial+polarity%2C+inside-out+layer+pattern%2C+and+species-specific+progenitor+dynamics+in+human+ES+cell-derived+neocortex%5BTitle%5D)+AND+%22Proceedings+of+the+National+Academy+of+Sciences+of+the+United+States+of+America%22%5BJournal%5D)">Self-organization of axial polarity, inside-out layer pattern, and species-specific progenitor dynamics in human ES cell-derived neocortex.</a> Proceedings of the National Academy of Sciences of the United States of America. 110 (50), 20284-20289 (2013).</li>
<li>Lancaster, M. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Cerebral+organoids+model+human+brain+development+and+microcephaly%5BTitle%5D)+AND+%22Nature%22%5BJournal%5D)">Cerebral organoids model human brain development and microcephaly.</a> Nature. 501 (7467), 373-379 (2013).</li>
<li>Li, X. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Specification+of+motoneurons+from+human+embryonic+stem+cells%5BTitle%5D)+AND+%22Nature+Biotechnology%22%5BJournal%5D)">Specification of motoneurons from human embryonic stem cells.</a> Nature Biotechnology. 23 (2), 215-221 (2005).</li>
<li>Zhang, S. C., Wernig, M., Duncan, I. D., Brustle, O., Thomson, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((In+vitro+differentiation+of+transplantable+neural+precursors+from+human+embryonic+stem+cells%5BTitle%5D)+AND+%22Nature+Biotechnology%22%5BJournal%5D)">In vitro differentiation of transplantable neural precursors from human embryonic stem cells.</a> Nature Biotechnology. 19 (12), 1129-1133 (2001).</li>
<li>Pasca, A. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Functional+cortical+neurons+and+astrocytes+from+human+pluripotent+stem+cells+in+3D+culture%5BTitle%5D)+AND+%22Nat+Methods%22%5BJournal%5D)">Functional cortical neurons and astrocytes from human pluripotent stem cells in 3D culture.</a> Nat Methods. 12 (7), 671-678 (2015).</li>
<li>Hughes, C. S., Postovit, L. M., Lajoie, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Matrigel%3A+a+complex+protein+mixture+required+for+optimal+growth+of+cell+culture%5BTitle%5D)+AND+%22Proteomics%22%5BJournal%5D)">Matrigel: a complex protein mixture required for optimal growth of cell culture.</a> Proteomics. 10 (9), 1886-1890 (2010).</li>
<li>Qian, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Brain-Region-Specific+Organoids+Using+Mini-bioreactors+for+Modeling+ZIKV+Exposure%5BTitle%5D)+AND+%22Cell%22%5BJournal%5D)">Brain-Region-Specific Organoids Using Mini-bioreactors for Modeling ZIKV Exposure.</a> Cell. 165 (5), 1238-1254 (2016).</li>
<li>Sloan, S. A., Andersen, J., Pasca, A. M., Birey, F., Pasca, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Generation+and+assembly+of+human+brain+region-specific+three-dimensional+cultures%5BTitle%5D)+AND+%22Nature+Protocols%22%5BJournal%5D)">Generation and assembly of human brain region-specific three-dimensional cultures.</a> Nature Protocols. 13 (9), 2062-2085 (2018).</li>
<li>Kelava, I., Lancaster, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Stem+Cell+Models+of+Human+Brain+Development%5BTitle%5D)+AND+%22Cell+Stem+Cell%22%5BJournal%5D)">Stem Cell Models of Human Brain Development.</a> Cell Stem Cell. 18 (6), 736-748 (2016).</li>
<li>Boisvert, E. M., Means, R. E., Michaud, M., Madri, J. A., Katz, S. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Minocycline+mitigates+the+effect+of+neonatal+hypoxic+insult+on+human+brain+organoids%5BTitle%5D)+AND+%22Cell+Death+and+Disease%22%5BJournal%5D)">Minocycline mitigates the effect of neonatal hypoxic insult on human brain organoids.</a> Cell Death and Disease. 10 (4), 325(2019).</li>
<li>Bergmann, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Blood-brain-barrier+organoids+for+investigating+the+permeability+of+CNS+therapeutics%5BTitle%5D)+AND+%22Nature+Protocols%22%5BJournal%5D)">Blood-brain-barrier organoids for investigating the permeability of CNS therapeutics.</a> Nature Protocols. 13 (12), 2827-2843 (2018).</li>
<li>Mansour, A. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((An+in+vivo+model+of+functional+and+vascularized+human+brain+organoids%5BTitle%5D)+AND+%22Nature+Biotechnology%22%5BJournal%5D)">An in vivo model of functional and vascularized human brain organoids.</a> Nature Biotechnology. 36 (5), 432-441 (2018).</li>
<li>Pham, M. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Generation+of+human+vascularized+brain+organoids%5BTitle%5D)+AND+%22Neuroreport%22%5BJournal%5D)">Generation of human vascularized brain organoids.</a> Neuroreport. 29 (7), 588-593 (2018).</li>
<li>Boisvert, E. M., Denton, K., Lei, L., Li, X. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+specification+of+telencephalic+glutamatergic+neurons+from+human+pluripotent+stem+cells%5BTitle%5D)+AND+%22Journal+of+Visualized+Experiments%22%5BJournal%5D)">The specification of telencephalic glutamatergic neurons from human pluripotent stem cells.</a> Journal of Visualized Experiments. (74), (2013).</li>
</ol>

S.G.K. is a SAB member for Dansar IT and Gene-in-Cell.

Similar to other organoid models, this is an artificial system that comes with several caveats. Although there was little batch to batch variation in terms of overall expression levels, individual organoids did exhibit differences. For example, the location of Sox-2 positive areas were not identical in every organoid (Figure 3). While qPCR is suitable to look for overall changes in batches of cells, additional techniques such as single cell RNAseq will be utilized in future studies to gather more informa...

Due to myriad practical and ethical limitations, there has been a great deal of difficulty in studying the human brain. While studies utilizing rodents have been critical to our understanding of the human brain, the mouse brain has many dissimilarities1,2. Interestingly, mice have a neuronal density that is at least 7 times less than the primate brain3,4. Although primates are closer to humans than rodents from an evolutionary standpoint, it is not practical for most researchers to work with them. The purpose of this protocol was to recapitulate many important features of the human brain using a simplified and less expensive method without the need for a heterologous basement membrane matrix or exogenous growth factors while maintaining brain cell diversity and cellular organization.
Formative work from the Sasai lab used the serum free culture of embryoid bodies (SFEBq) method to generate two- and three- dimensional neuronal cell types from signalized embryonic stem cells (ESCs)5,6. Many human brain organoid methods have followed a relatively similar path from signalized ESCs7,8. In contrast, this protocol starts with clusters of detached human ESCs (hESCs), similar to the initial steps of seminal work of the Thomson and Zhang laboratories prior to the plating steps9,10 as well as the initial step of the brain organoid protocol of the Pasca laboratory before the addition of exogenous growth factors11. Basement membrane matrices (e.g., matrigel) have been utilized in many brain organoid protocols and it has been shown to be an effective scaffold8. However, most commonly used basement membrane matrices do not come without complications as they co-purify with unknown quantities of growth factors with batch to batch variability during production12. In addition, these matrices can complicate imaging, and increase the risk of contamination and cost.
While human brain organoids can be used to answer many questions, there are certain limitations to bear in mind. For one, starting from embryonic stem cells, organoids more closely resemble immature brains than aged brains and as such may not be ideal models for diseases that occur in old age, like Alzheimer&#39;s disease. Second, while our protocol found markers of forebrain, midbrain and hindbrain development which are useful to study the effect of a treatment or disease on cells from multiple brain regions in concert, other protocols can be followed to concentrate on specific brain regions13,14. Finally, another limitation of organoid models is that of size, while the average length of a human brain approximately 167 mm, brain organoids made with the use of agitation grow up to 4 mm8 and the organoids formed by this protocol grow to 1-2 mm by 10 weeks. Nonetheless, this protocol provides an important tool to study human brain tissue and the interaction of multiple cell types.

<table><tbody><tr><td>Alexa Fluor 488 goat anti-mouse</td><td>Thermo Fisher Scientific, Waltham, MA, USA</td><td>A11029</td><td></td></tr><tr><td>Alexa Fluor 546 goat anti-rabbit</td><td>Thermo Fisher Scientific, Waltham, MA, USA</td><td>A11035</td><td></td></tr><tr><td>B27 Supplement</td><td>Gibco, Waltham, MA, USA</td><td>17504-044</td><td></td></tr><tr><td>bFGF</td><td>Life Technologies, Carlsbad, CA, USA</td><td>PHG0263</td><td></td></tr><tr><td>BSA</td><td>Sigma-Aldrich, St. Louis, MO, USA</td><td>A9647</td><td></td></tr><tr><td>BX43 microscope</td><td>Olympus, Shinjuku, Tokyo, Japan</td><td></td><td></td></tr><tr><td>DAPI stain</td><td>Thermo Fisher Scientific, Waltham, MA, USA</td><td>D1306</td><td></td></tr><tr><td>Dispase</td><td>STEMCELL Technologies, Vancouver, Canada</td><td>07913</td><td></td></tr><tr><td>DMEM/F12</td><td>Thermo Fisher Scientific, Waltham, MA, USA</td><td>11330-032</td><td></td></tr><tr><td>DPBS</td><td>Gibco, Waltham, MA, USA</td><td>&lt;a href=&quot;https://www.thermofisher.com/order/catalog/product/10010023&quot; target=&quot;_blank&quot;&gt;10010023&lt;/a&gt;</td><td></td></tr><tr><td>FluroSave</td><td>MilliporeSigma, Burlington, MA</td><td>345789</td><td></td></tr><tr><td>GFAP antibody</td><td>NeuroMab, Davis, CA</td><td>N206A/8</td><td></td></tr><tr><td>Growth Factor Reduced Matrigel (Matrix)</td><td>Corning, Corning, NY, USA</td><td>356231</td><td></td></tr><tr><td>H9 hESCs</td><td>WiCell, Madison, WI, USA</td><td>WA09</td><td></td></tr><tr><td>Heparin</td><td>Sigma-Aldrich, St. Louis, MO, USA</td><td>9041-08-1</td><td></td></tr><tr><td>iQ SYBR Green Supermix</td><td>Bio-Rad, Hercules, CA, USA</td><td>1708880</td><td></td></tr><tr><td>iScript cDNA Synthesis Kit</td><td>Bio-Rad, Hercules, CA, USA</td><td>1708891</td><td></td></tr><tr><td>L-glutamine</td><td>Gibco, Waltham, MA, USA</td><td>25030-081</td><td></td></tr><tr><td>Monothioglycerol</td><td>Sigma-Aldrich, St. Louis, MO, USA</td><td>M6145</td><td></td></tr><tr><td>mTESR media</td><td>STEMCELL Technologies, Vancouver, Canada</td><td>85850</td><td></td></tr><tr><td>N2 NeuroPlex</td><td>Gemini Bio Products, West Sacramento, CA, USA</td><td>400-163</td><td></td></tr><tr><td>Nanodrop</td><td>Thermo Fisher Scientific, Waltham, MA, USA</td><td>ND-2000</td><td></td></tr><tr><td>NEAA</td><td>Gibco, Waltham, MA, USA</td><td>11140-050</td><td></td></tr><tr><td>Normal Donkey Serum (NDS)</td><td>ImmunoResearch Laboratories Inc., West Grove, PA, USA</td><td>&lt;a href=&quot;https://www.jacksonimmuno.com/catalog/products/017-000-121&quot; target=&quot;_blank&quot;&gt;017-000-121&lt;/a&gt;</td><td></td></tr><tr><td>OCT</td><td>Sakura Finetek, Torrance, CA, USA</td><td>25608-930</td><td></td></tr><tr><td>PFA</td><td>Electron Microscopy Sciences, Hatfield, PA</td><td>RT15710</td><td></td></tr><tr><td>qPCR machine</td><td>Bio-Rad, CFX96, Hercules, CA, USA</td><td>1855196</td><td></td></tr><tr><td>RNeasy kit</td><td>Qiagen, Hilden, Germany</td><td>74104</td><td></td></tr><tr><td>Sox2</td><td>MilliporeSigma, Burlington, MA</td><td>AB5603</td><td></td></tr><tr><td>TMS-F microscope</td><td>Nikon, Melville, NY, USA</td><td></td><td></td></tr><tr><td>Triton X-100</td><td>Sigma-Aldrich, St. Louis, MO, USA</td><td>T8787-100ML</td><td></td></tr><tr><td>Ultra-low attachment T75 flasks</td><td>Corning, Corning, NY, USA</td><td>3814</td><td></td></tr></tbody></table>

a static self-directed method for generating brain organoids from human embryonic stem cells

Human brain organoids differentiated from embryonic stem cells offer the unique opportunity to study complicated interactions of multiple cell types in a three-dimensional system. Here we present a relatively straightforward and inexpensive method that yields brain organoids. In this protocol human pluripotent stem cells are broken into small clusters instead of single cells and grown in basic media without a heterologous basement membrane matrix or exogenous growth factors, allowing the intrinsic developmental cues to shape the organoid&#39;s growth. This simple system produces a diversity of brain cell types including glial and microglial cells, stem cells, and neurons of the forebrain, midbrain, and hindbrain. Organoids generated from this protocol also display hallmarks of appropriate temporal and spatial organization demonstrated by brightfield images, histology, immunofluorescence and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Because these organoids contain cell types from various parts of the brain, they can be utilized for studying a multitude of diseases. For example, in a recent paper we demonstrated the use of organoids generated from this protocol for studying the effects of hypoxia on the human brain. This approach can be used to investigate an array of otherwise difficult to study conditions such as neurodevelopmental handicaps, genetic disorders, and neurologic diseases.

Figure 1 shows representative brightfield images of several time points to demonstrate what the cells/organoids look like throughout the different stages of the protocol. The hESCs were removed from the tissue culture plate, broken into small pieces, and placed in a T75 ultra-low attachment flask where they formed spheres. It is important to note that the cells look bright and similar in size, without dark, dying cells in the centers of these clusters. The cells were gradually weaned off bFG...

Watch this Scientific Journal Video about A Static Self-Directed Method for Generating Brain Organoids from Human Embryonic Stem Cells at JoVE.com

A Static Self-Directed Method for Generating Brain Organoids from Human Embryonic Stem Cells

This protocol was generated as a means to produce brain organoids in a simplified, low cost manner without exogenous growth factors or basement membrane matrix while still maintaining the diversity of brain cell types and many features of cellular organization.

Human brain organoids differentiated from embryonic stem cells offer the unique opportunity to study complicated interactions of multiple cell types in a ...

a-static-self-directed-method-for-generating-brain-organoids-from

Research

JoVE Journal

Developmental Biology

8.8K Views.  Yale University School of Medicine. Menselijke hersenorganoïden zijn een belangrijk hulpmiddel om ziekten te bestuderen in een systeem dat gemakkelijk kan worden gemanipuleerd en een menselijke omgeving en de juiste interactie van meerdere celtypen bevat. Deze techniek kan worden toegepast op tal van ziekten van de hersenen te bestuderen, met inbegrip van neurodevelopmental aandoeningen, toxische beledigingen, en de groei en behandeling van kanker in de hersenen. Het belangrijkste voordeel van dit protocol is de mogelijkheid o...

Video: A Static Self-Directed Method for Generating Brain Organoids from Human Embryonic Stem Cells

Generation of iPSC-derived Human Brain Organoids to Model Early Neurodevelopmental Disorders

The restricted availability of suitable in vitro models that can reliably represent complex human brain development is a significant bottleneck that limits the translation of basic brain research into clinical application. While induced pluripotent stem cells (iPSCs) have replaced the ethically questionable human embryonic stem cells, iPSC-based neuronal differentiation studies remain descriptive at the cellular level but fail to adequately provide the details that could be derived from a complex, 3D human brain tissue. 
This gap is now filled through the application of iPSC-derived, 3D brain organoids, "Brains in a dish," that model many features of complex human brain development. Here, a method for generating iPSC-derived, 3D brain organoids is described. The organoids can help with modeling autosomal recessive primary microcephaly (MCPH), a rare human neurodevelopmental disorder. A widely accepted explanation for the brain malformation in MCPH is a depletion of the neural stem cell pool during the early stages of human brain development, a developmental defect that is difficult to recreate or prove in vitro. 
To study MCPH, we generated iPSCs from patient-derived fibroblasts carrying a mutation in the centrosomal protein CPAP. By analyzing the ventricular zone of microcephaly 3D brain organoids, we showed the premature differentiation of neural progenitors. These 3D brain organoids are a powerful in vitro system that will be instrumental in modeling congenital brain disorders induced by neurotoxic chemicals, neurotrophic viral infections, or inherited genetic mutations.

Modeling human brain development has been hindered due to the unprecedented complexity of neural epithelial tissue. Here, a method for the robust generation of brain organoids to delineate early events of human brain development and to model microcephaly in vitro is described.

The restricted availability of suitable in vitro models that can reliably represent complex human brain development is a significant bottleneck that ...

Generation of Standardized and Reproducible Forebrain-type Cerebral Organoids from Human Induced Pluripotent Stem Cells

The human cortex is highly expanded and exhibits a complex structure with specific functional areas, providing higher brain function, such as cognition. Efforts to study human cerebral cortex development have been limited by the availability of model systems. Translating results from rodent studies to the human system is restricted by species differences and studies on human primary tissues are hampered by a lack of tissue availability as well as ethical concerns. Recent development in human pluripotent stem cell (PSC) technology include the generation of three-dimensional (3D) self-organizing organotypic culture systems, which mimic to a certain extent human-specific brain development in vitro. Currently, various protocols are available for the generation of either whole brain or brain-region specific organoids. The method for the generation of homogeneous and reproducible forebrain-type organoids from induced PSC (iPSC), which we previously established and describe here, combines the intrinsic ability of PSC to self-organize with guided differentiation towards the anterior neuroectodermal lineage and matrix embedding to support the formation of a continuous neuroepithelium. More specifically, this protocol involves: (1) the generation of iPSC aggregates, including the conversion of iPSC colonies to a confluent monolayer culture; (2) the induction of anterior neuroectoderm; (3) the embedding of neuroectodermal aggregates in a matrix scaffold; (4) the generation of forebrain-type organoids from neuroectodermal aggregates; and (5) the fixation and validation of forebrain-type organoids. As such, this protocol provides an easily applicable system for the generation of standardized and reproducible iPSC-derived cortical tissue structures in vitro.

Cerebral organoids represent a new model system to investigate early human brain development in vitro. This article provides the detailed methodology to efficiently generate homogeneous dorsal forebrain-type organoids from human induced pluripotent stem cells including critical characterization and validation steps.

The human cortex is highly expanded and exhibits a complex structure with specific functional areas, providing higher brain function, such as cognition. ...

Brain Organoid Generation from Induced Pluripotent Stem Cells in Home-Made Mini Bioreactors

The iPSC-derived brain organoid is a promising technology for in vitro modeling the pathologies of the nervous system and drug screening. This technology has emerged recently. It is still in its infancy and has some limitations unsolved yet. The current protocols do not allow obtaining organoids to be consistent enough for drug discovery and preclinical studies. The maturation of organoids can take up to a year, pushing the researchers to launch multiple differentiation processes simultaneously. It imposes additional costs for the laboratory in terms of space and equipment. In addition, brain organoids often have a necrotic zone in the center, which suffers from nutrient and oxygen deficiency. Hence, most current protocols use a circulating system for culture medium to improve nutrition.
Meanwhile, there are no inexpensive dynamic systems or bioreactors for organoid cultivation. This paper describes a protocol for producing brain organoids in compact and inexpensive home-made mini bioreactors. This protocol allows obtaining high quality organoids in large quantities.

Here we describe a protocol for generating brain organoids from human induced pluripotent stem cells (iPSCs). To obtain brain organoids in large quantities and of high quality, we use home-made mini bioreactors.

The iPSC-derived brain organoid is a promising technology for in vitro modeling the pathologies of the nervous system and drug screening. This technology ...

Generation of 3D Midbrain Organoids from Human-Induced Pluripotent Stem Cells

The development of midbrain organoids (MOs) from human pluripotent stem cells (hPSCs) represents a significant advancement in understanding brain development, facilitating precise disease modeling, and advancing therapeutic research. This protocol outlines a method for generating midbrain-specific organoids using induced pluripotent stem cells (iPSCs), employing a strategic differentiation approach. Key techniques include dual-SMAD inhibition to suppress SMAD signaling, administration of fibroblast growth factor 8b (FGF-8b), and activation of the Sonic Hedgehog pathway using the agonist purmorphamine, guiding iPSCs towards a midbrain fate.
The organoids produced by this method achieve diameters up to 2 mm and incorporate a diverse array of neuroepithelial cell types, reflecting the midbrain&#39;s inherent cellular diversity. Validation of these organoids as authentic midbrain structures involves the expression of midbrain-specific markers, confirming their identity. A notable outcome of this methodology is the effective differentiation of iPSCs into dopaminergic neurons, which are characteristic of the midbrain.
The significance of this protocol lies in its ability to produce functionally mature, midbrain-specific organoids that closely replicate essential aspects of the midbrain, offering a valuable model for in-depth exploration of midbrain developmental processes and the pathophysiology of related disorders such as Parkinson&#39;s disease. Thus, this protocol serves as a crucial resource for researchers seeking to enhance our understanding of the human brain and develop new treatments for neurodegenerative diseases, making it an indispensable tool in the field of neurological research.

This protocol describes a novel method for creating 3D midbrain organoids from human induced pluripotent stem cells, guiding their formation to mimic native midbrain tissue, thereby aiding in the study of development and disorders.

The development of midbrain organoids (MOs) from human pluripotent stem cells (hPSCs) represents a significant advancement in understanding brain ...

Generating Human Brain Organoids with Resident Microglia Using iPSC-Derived HPCs

Derivation of a Human Brain Organoid with Microglia Development

Three-dimensional (3D) brain organoid cultures derived from induced pluripotent stem cells (iPSC) provide an important alternative in vitro tool&#160;for studying human brain development and pathogenesis of neurological diseases. However, the lack of incorporation of microglia in the human brain organoids is still a major hurdle for 3D models of neuroinflammation. Current approaches include either the incorporation of fully differentiated microglia into mature brain organoids or the induction of microglial differentiation from the early stage of iPSC-derived embryoid bodies (EBs). The first approach misses the stage when microglial differentiation interacts with the adjacent neural environment, and the later approach is technically challenging, resulting in inconsistency among the final organoids in terms of the quantity and quality of microglia. To model brain organoids with microglia to study the early interactions between microglial and neuronal development, highly pure hematopoietic progenitor cells (HPC) differentiated from human iPSCs were incorporated&#160;into iPSC-derived EBs to make brain organoids. Using immunostaining and single-cell RNA sequencing (sc-RNA-seq) analysis, we confirmed that HPCs were incorporated into the 3D organoids, which eventually developed into brain organoids with both microglia and neurons. Compared to brain organoids without HPCs, this approach produces significant microglial incorporation in the brain organoids. This novel 3D organoid model, which consists of both microglial and neural development properties, can be used to study the early interactions between innate immune and nervous system development and potentially as a model for neuroinflammation and neuroinfectious disorders.

We present a protocol to generate a human brain organoid with resident microglia by incorporating Induced pluripotent stem cell (iPSC)-derived hematopoietic progenitor cells (HPCs) into organoid development.

Three-dimensional (3D) brain organoid cultures derived from induced pluripotent stem cells (iPSC) provide an important alternative in vitro tool&#160;for ...

Robust and Highly Reproducible Generation of Cortical Brain Organoids for Modelling Brain Neuronal Senescence In Vitro

Brain organoids are three-dimensional models of the developing human brain and provide a compelling, cutting-edge platform for disease modeling and large-scale genomic and drug screening. Due to the self-organizing nature of cells in brain organoids and the growing range of available protocols for their generation, issues with heterogeneity and variability between organoids have been identified. In this protocol paper, we describe a robust and replicable protocol that largely overcomes these issues and generates cortical organoids from neuroectodermal progenitors within 1 month, and that can be maintained for more than 1 year. This highly reproducible protocol can be easily carried out in a standard tissue culture room and results in organoids with a rich diversity of cell types typically found in the developing human cortex. Despite their early developmental make-up, neurons and other human brain cell types will start to exhibit the typical signs of senescence in neuronal cells after prolonged in vitro culture, making them a valuable and useful platform for studying aging-related neuronal processes. This protocol also outlines a method for detecting such senescent cells in cortical brain organoids using senescence-associated beta-galactosidase staining.

Robust and Highly Reproducible Generation of Cortical Brain Organoids for Modelling Brain Neuronal Senescence In Vitro

In this study, we provide a detailed technique for a simple yet robust cortical organoid culture system using standard feeder-free hPSC cultures. This is a rapid, efficient, and reproducible protocol for generating organoids that model aspects of brain senescence in vitro.

Brain organoids are three-dimensional models of the developing human brain and provide a compelling, cutting-edge platform for disease modeling and ...

Neuroscience

An In Vitro Method to Generate Human Brain Organoids

Source: Gabriel, E., et al., <a href="https://app.jove.com/v/55372">Generation of iPSC-derived Human Brain Organoids to Model Early Neurodevelopmental Disorders.</a> J. Vis. Exp. (2017)
The video demonstrates a method for generating human brain organoids from induced pluripotent stem cells. It shows how the neurosphere forms a neuroectodermal layer, which suppresses the formation of other germ layers. The neurospheres are embedded in a 3D gel matrix and form neuroepithelial buds. When incubated with organoid media, these neuroepithelial buds differentiate into specific brain regions, resulting in the formation of mature brain organoids.

All procedures involving sample collection have been performed in accordance with the institute&#39;s IRB guidelines.
1. Generation of Brain Organoids (23 ...

JoVE Encyclopedia of Experiments

Neuronal Culture Techniques

Advanced Neuronal Models

Generating Induced Pluripotent Stem Cell-Derived Cerebral Organoids

Source: Koch, L. S., et al. <a href="https://app.jove.com/v/64586">Robust Tissue Fabrication for Long-Term Culture of iPSC-Derived Brain Organoids for Aging Research.</a> J. Vis. Exp. (2023).
This video demonstrates an assay to generate cerebral organoids from induced pluripotent stem cells (iPSCs). Human iPSCs are induced to form embryoid bodies (EBs). The EBs are cultured over a polymer scaffold using an induction medium, promoting differentiation into neural stem cells, progenitor cells, and immature neurons. Finally, the EBs are embedded in a matrix and transferred to a maintenance medium for cerebral organoid formation.

All procedures involving sample collection have been performed in accordance with the institute&#39;s IRB guidelines.
Figure 1 illustrates a schematic ...

Generation of Dopaminergic Neuronal Organoids from Human Embryonic Stem Cells

Source: Cosset, E. et al. <a href="https://app.jove.com/v/59682">Human Neural Organoids for Studying Brain Cancer and Neurodegenerative Diseases.</a> J. Vis. Exp. (2019)
This video demonstrates the differentiation of human embryonic stem cells (hESCs) into dopaminergic neurons, to provide a model for studying Parkinson&#39;s disease. The hESCs are cultured in a neural induction medium in a microwell plate to form 3D neurospheres. These are then cultured in a neural induction medium to promote the differentiation into dopaminergic progenitor neurons. The final maturation of the neurons occurs in a culture insert under air-liquid interface conditions, resulting in 3D organoids consisting of mature dopaminergic neurons.

1. hESC-derived dopaminergic organoids for Parkinson&#39;s Disease (PD) studies

	Day 0: Amplify hESCs in 2D culture up to 60% confluency (day 0), then ...

Neuropathology

Neurodegenerative Diseases

Generating Forebrain-Type Cerebral Organoids from Human-Induced Pluripotent Stem Cells

Source: Krefft, O. et al., <a href="https://app.jove.com/v/56768">Generation of Standardized and Reproducible Forebrain-type Cerebral Organoids from Human Induced Pluripotent Stem Cells.</a> J. Vis. Exp. (2018).
This video outlines the creation of forebrain-type organoids from human induced pluripotent stem cells (iPSCs), demonstrating the progression from stem cell aggregates to complex structures that mimic the brain&#39;s cortex and differentiate into various neuron types.

1. Generation of iPSC Aggregates

	Generation of single-cell monolayer cultures from iPSC colonies
	
		Prepare a basement membrane extract (BME) coated ...

A Static Self-Directed Method for Generating Brain Organoids from Human Embryonic Stem Cells

Samenvatting

Meer video's verkennen