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All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
1. Preparation and Cultivation of Cortical Astrocytes
NOTE: Complete these steps of the protocol at least 7 d before proceeding to the next steps, as the astrocyte cultures should develop into confluent monolayers before the neurons are prepared. Primary astrocytes are derived from mixed glial cultures obtained from mouse pups around postnatal day (P) 0-3. Three brains (6 cortices) per T75 flask are to be used.
<ol>
	<li>Prepare the astrocyte medium by supplementing Dulbecco&#39;s Modified Eagle Medium (DMEM) with 10% v/v horse serum and 0.1% v/v gentamicin under sterile conditions. Store the medium at 4 &#176;C for up to 2 weeks.</li>
	<li>Coat 3x T75 flasks with 10 &#181;g/mL&#160;poly-D-Lysine (PDL; in cell-culture-grade water) for at least 1 h&#160;at 37 &#176;C in the presence of 6% v/v CO2. After coating, wash the flasks twice with phosphate-buffered Saline (PBS) to remove unbound cations, and add 9 mL&#160;astrocyte medium.</li>
	<li>For the preparation of the brains, add 10 mL&#160;Hank&#39;s Balanced Salt Solution (HBSS) to 1x 10 cm Petri dish and 1 mL&#160;HBSS to 1x 15 mL tube (regardless of the number of brains that will be used). Keep a pair of surgical scissors, 2 fine forceps, and a binocular within reach for the procedure.</li>
	<li>Decapitate 3 pups quickly with the surgical scissors and collect the heads in an empty 10 cm dish.
	<ol>
		<li>Perform the preparation of the cortices under the binoculars. Using two fine forceps, remove the dorsal skin from the skull at the midline, starting from the neck up towards the level of the eyes. Thereafter, the brain with its blood vessels is visible under the skull.</li>
		<li>Fix the head at the rostral end with a pair of forceps and incise the midline of the skull, starting at the posterior end. Subsequently, clip off the right and the left halves of the skull to expose the brain.</li>
		<li>Close the tip of the forceps and position it ventrally under the brain. Lift the brain out of the skull and transfer it into the HBSS-filled 10 cm Petri dish. Proceed in the same manner with the remaining specimen until all brains are collected in the dish.</li>
	</ol>
	</li>
	<li>After collecting the brains, start with the separation of the cortices by pinching off the hindbrain using a pair of forceps like a pair of scissors. Perform a midline incision between the two hemispheres with one pair of forceps. Carefully fix the brain with a forceps and cut off the midbrain and the olfactory bulbs using a second forceps to end up with the cortical halves.</li>
	<li>Fix one cortical half with one pair of forceps and peel the meninges from the hemispheres by detaching them from the lateral edge and subsequently pulling them from the cortical surface using a second forceps.</li>
	<li>Flip the cortical half with its surface oriented down towards the dish; carefully dissect and remove the crescent-shaped hippocampus using one pair of forceps. Transfer the single cortices into the conical 15 mL&#160;tube using one closed forceps to carry an individual cortex.</li>
	<li>After collecting all cortices, transit to the sterile laminar flow hood and begin with the preparations for the dissociation of the cortical tissue.</li>
	<li>Add 1 mL&#160;DMEM to a 2 mL&#160;reaction tube and add 0.1% w/v papain (30 units). Incubate the suspension in a water bath at 37 &#176;C until a clarified solution develops (about 3 min). Add 0.24 mg/mL&#160;L-cysteine and 20 &#181;g/mL&#160;DNAse and shake gently. 
	NOTE: For digestion, approximately 1 mL&#160;of enzyme solution is needed.</li>
	<li>Filter (0.22 &#181;m pore size) to obtain 1 mL&#160;sterile solution before adding it to the cortical tissue. Incubate the tubes for 30 min - 1 h&#160;at 37 &#176;C (i.e., in a water bath). 
	NOTE: Steps 1.11 - 1.14 are critical and should be completed within 15 min.</li>
	<li>To terminate the digestion reaction, add 1 mL&#160;astrocyte medium and carefully triturate the digested tissue using a 1 mL&#160;pipette. For trituration, gently move the pipette plunger, thereby aspirating and extruding the cortical tissue suspension.</li>
	<li>Once the tissue has been dissociated into a single-cell suspension, add 5 mL&#160;astrocyte medium and centrifuge for 5 min at 216 x g.</li>
	<li>Aspirate the supernatant carefully from the resulting pellet and resuspend the cells in 1 mL&#160;astrocyte medium.</li>
	<li>Add the cell suspensions to T75 flasks replenished with 9 mL astrocyte medium (see 1.2).</li>
	<li>Incubate the cells at 37 &#176;C in the incubator in the presence of 6% v/v CO2. After 4 d, perform the first complete medium change (10 mL). Thereafter, change the culture medium every 2 - 3 days.</li>
	<li>After 7 days, check if the cells have formed a confluent monolayer. If not, wait for another 2 - 3 days until complete confluence of the culture is attained. 
	NOTE: Astrocytes display large, flattened cell bodies, localize at the bottom of the flask, and do not develop notable cellular processes. They differ from the small phase-contrast bright progenitor cells and microglia residing on top&#160;of the monolayer.</li>
	<li>In order to get rid of the progenitor cells and obtain a pure astrocyte culture, place the T75 flasks on an orbital shaker and shake the cultures O/N at 250 rpm. Ensure that the temperature is adjusted to 37 &#176;C and that the filter of the flask is sealed with laboratory film to prevent evaporation of the CO2.</li>
	<li>The next day, aspirate the medium and add 10 mL fresh culture medium replenished with 20 &#181;M cytosine-1-&#946;-D-arabinofuranoside (AraC) to eliminate residual dividing cells.&#160;&#160;&#160;&#160;&#160; 
	NOTE: incubation with AraC for 2 - 3 d in the incubator at 37 &#176;C,&#160;6% CO2&#160;will result in a pure astrocyte culture.</li>
	<li>Monitor the purity of the astrocyte cultures by visual inspection under the light microscope. If residual phase-contrast bright progenitor cells and microglia still reside on top of the astrocytic monolayer&#160;(see step 1.16), repeat steps 1.18 and 1.19. 
	NOTE: The confluent and pure astrocyte monolayers can be maintained for up to 14 d in the incubator (37 &#176;C, 6% v/v CO2) before proceeding to the next step. Change half of the medium every 3 d. Do not collect, freeze and thaw the astrocytes, as these cells will lose their neuronal supportive properties through the storage procedure.</li>
</ol>
2. Preparing Astrocytes for the Indirect Coculture
NOTE: 48 - 72 h&#160;before preparing the neurons, transfer astrocytes to the cell-culture inserts. Generally, a single&#160;T75 flask delivers a sufficient number of cells to support the neuronal cultures obtained with one preparation.
<ol>
	<li>Place as many inserts as needed into 24-well-plates. Coat each insert with 10 &#181;g/mL PDL (dissolved in cell-culture-grade water) for about 1 h at 37 &#176;C, 6% v/v CO2. After the incubation, wash the inserts twice with PBS. In the meantime, proceed with the preparation of astrocytes.&#160;&#160;&#160;&#160;&#160;&#160;&#160; 
	NOTE: The inserts filled with PBS can be kept until the astrocyte cell suspension is ready for use.</li>
	<li>Aspirate the astrocyte medium (with AraC) and wash the culture one time with 10 mL PBS to ensure any residual serum is removed.</li>
	<li>Add 3 mL of 0.05% trypsin-EDTA (Ethylenediaminetetraacetic acid) to the flasks and incubate the cells for trypsinization at 37 &#176;C, 6% v/v CO2&#160;for approximately 10 min.</li>
	<li>Control the cell detachment by visual inspection using a microscope and facilitate the detachment of the cells by tapping the side of the flasks against the desktop. 
	NOTE: Steps 2.5 - 2.8 are critical and should be finished within 15 - 20 min.</li>
	<li>Following the trypsinization, gently resuspend the cells in 7 mL astrocyte medium and transfer the cell suspension to a 15 mL tube. Centrifuge for 5 min at 216 x g.</li>
	<li>Carefully aspirate the supernatant and resuspend the cell pellet in 1 mL astrocyte medium.</li>
	<li>Count the cells using a counting chamber.</li>
	<li>Fill the bottom of the wells of the 24-well-plate with 500 &#181;L astrocyte medium and transfer 25,000 cells in 500 &#181;L astrocyte medium into each individual insert. Incubate the culture at 37 &#176;C, 6% v/v CO2.&#160; 
	NOTE: After 42 - 72 h&#160;the cultures will reach approximately 100% confluence. At this stage the purity of the culture can be verified by immunocytochemistry. The confluent cultures can be maintained for up to 7 d until proceeding to the next step. Change half of the medium every 3 days.</li>
</ol>
3. Preparation of Primary Hippocampal Neurons
NOTE: Primary mouse hippocampal neurons should be derived from E15.5 - E16 embryos of timed pregnant mice.
<ol>
	<li>Prepare neuron medium (MEM with 10 mM sodium pyruvate, 0.1% w/v ovalbumin,&#160;2% v/v B27 medium supplement, and 0.1% v/v gentamicin (sterile filtered)), and preparation medium (HBSS with 0.6% w/v glucose and 10mM HEPES (4-(2-hydroxyethyl)-1-piperazine ethanesulfonic acid)). Pre-warm and pre-equilibrate the neuron medium in filter flasks at 37 &#176;C, 6% v/v CO2.</li>
	<li>Place the glass-coverslips (12 mm diameter) into the wells of 24-well-plates (use the special coverslips, which are notched for the use with cell culture inserts).
	<ol>
		<li>Coat for at least 1 h with 15 &#181;g/mL&#160;Poly-DL-Ornithine in water (cell-culture-grade) at 37 &#176;C. Use at least 500 &#181;L per well to ensure that the coverslips are completely covered. Wash the wells twice with PBS. Leave the PBS in the wells until plating the cells. Ensure that the wells do not dry out.</li>
	</ol>
	</li>
	<li>To dissect the hippocampi, prepare 3x 10 cm dishes filled with preparation medium and 1x 2 mL tube with 1 mL preparation medium. Prepare scissors and 2 fine forceps.</li>
	<li>Sacrifice the pregnant mouse by cervical dislocation, sterilize the abdomen by washing with 70% v/v ethanol, and open the abdomen using sharp scissors. Excise the beaded uterus carefully with scissors and transfer the organ into 1x 10 cm dish filled with preparation medium.</li>
	<li>Next, remove the embryos from the uterus. Carefully incise the uterus and remove the amnion without harming the embryos by using 2 forceps. Thereafter, decapitate each embryo with a pair of scissors and transfer the heads into a second 10 cm dish supplied with preparation medium.</li>
	<li>Proceed with the preparation of the heads (similar to the preparation described in 1.4 - 1.7).
	<ol>
		<li>Immobilize the head with a pair of forceps and incise the skull and skin in the neck region close to the hindbrain, perpendicular to the neuraxis. Use a second pair of forceps to lift both skull and&#160;covering skin, and bend the soft skull cap towards the rostral end of the head, thereby exposing the brain.</li>
		<li>With the help of 2 forceps, detach the brain from the cranial cavity. To do this, close 1 pair of forceps and separate the brain from the skull starting at the olfactory bulbs and moving&#160;towards the hindbrain. Collect the brains in another 10 cm dish filled with preparation medium.</li>
	</ol>
	</li>
	<li>Dissect the hippocampi from the cortex moieties as described above for the astrocyte preparation (step 1.6). Remove the hippocampi from each hemisphere and collect them in the 2 mL tube filled with preparation medium.</li>
	<li>After completing the dissection, transfer the tube to the sterile laminar flow bench and digest the hippocampal tissue with 1 mL digestion solution containing papain. Prepare the digestion solution as described in step 1.9 - 1.10, but use MEM instead DMEM. 
	NOTE: Steps 3.9 - 3.12 are critical and should be completed within 10 - 15 min.</li>
	<li>After completion of digestion, carefully withdraw the digestion solution by gentle suction with a pipette.</li>
	<li>Wash the hippocampi 3 times with neuron medium by sequentially adding and thereafter carefully aspirating 1 mL fresh culture medium per wash cycle. Do not centrifuge the cell suspension.</li>
	<li>After the final washing step, carefully triturate the tissue in 1 mL neuron medium.</li>
	<li>Count the cells using a counting chamber and plate 35,000 cells in 500 &#181;L neuron medium per a single well of a 24-well-plate (the plate mentioned in 3.2). 
	NOTE: Optionally, a cell aliquot can be counterstained with trypan blue to assess the vitality of the cell preparation. Control the plating density by visual inspection using the microscope (typically 90 - 110 cells per visual field of a standard 10X objective).</li>
	<li>Place neurons in the incubator at 37 &#176;C, 6% v/v CO2&#160;for 1 h.</li>
	<li>Post incubation, take the prepared inserts (seeded with confluent astrocyte monolayers) out of the incubator (see step 2.8). Exchange the medium by aspirating the astrocyte medium and replacing it with 500 &#181;l fresh neuron medium. 
	NOTE: The inserts should harbor confluent astrocyte monolayers after 2 - 3 DIV (Days&#160;In Vitro).</li>
	<li>Place the inserts with astrocytes carefully into the wells that contain the neuron cultures (step 3.13) using sterile forceps.</li>
	<li>Place the resulting indirect neuron-astrocyte co-culture back into the incubator at 37 &#176;C, 6% v/v CO2. 
	NOTE: Under these conditions, neurons can be cultivated for up to 4 weeks in a completely defined medium. No medium change is necessary. For long-time cultures, it is recommended to fill empty wells with sterile water in order to reduce the evaporation from the 24-well plate.</li>
</ol>

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>B27</td>
			<td>Gibco (Life Technologies)</td>
			<td>17504-044</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell culture grade water</td>
			<td>MilliQ</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cell culture grade water</td>
			<td>MilliQ</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cytosine-&#223;-D arabinofuranoside (AraC)</td>
			<td>Sigma-Aldrich</td>
			<td>C1768</td>
			<td>CAUTION: H317, H361</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Gibco (Life Technologies)&#160;</td>
			<td>41966-029</td>
			<td></td>
		</tr>
		<tr>
			<td>DNAse</td>
			<td>Worthington</td>
			<td>LS002007</td>
			<td></td>
		</tr>
		<tr>
			<td>Gentamycin</td>
			<td>Sigma-Aldrich</td>
			<td>G1397</td>
			<td>CAUTION: H317-334</td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Serva</td>
			<td>22700</td>
			<td></td>
		</tr>
		<tr>
			<td>HBSS</td>
			<td>Gibco (Life Technologies)</td>
			<td>14170-088</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Gibco (Life Technologies)</td>
			<td>15630-056</td>
			<td></td>
		</tr>
		<tr>
			<td>Horse serum</td>
			<td>Biochrom AG</td>
			<td>S9135</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Cysteine</td>
			<td>Sigma-Aldrich</td>
			<td>C-2529</td>
			<td></td>
		</tr>
		<tr>
			<td>MEM</td>
			<td>Gibco (Life Technologies)</td>
			<td>31095-029</td>
			<td></td>
		</tr>
		<tr>
			<td>Ovalbumin</td>
			<td>Sigma-Aldrich</td>
			<td>A7641</td>
			<td>CAUTION: H334</td>
		</tr>
		<tr>
			<td>Papain</td>
			<td>Worthington</td>
			<td>3126</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>self-made&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Poly-D-lysine</td>
			<td>Sigma-Aldrich</td>
			<td>P0899</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly-L-ornithine</td>
			<td>Sigma-Aldrich</td>
			<td>P3655</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium pyruvate</td>
			<td>Sigma-Aldrich</td>
			<td>S8636</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin-EDTA</td>
			<td>Gibco (Life Technologies)</td>
			<td>25300054</td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>24 well plates</td>
			<td>Thermoscientific/Nunc</td>
			<td>142475</td>
			<td></td>
		</tr>
		<tr>
			<td>24-wells plate (for the&#160; indirect co-culture)</td>
			<td>BD Falcon</td>
			<td>353504</td>
			<td></td>
		</tr>
		<tr>
			<td>Binocular</td>
			<td>Leica</td>
			<td>MZ6</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell-culture inserts</td>
			<td>BD Falcon</td>
			<td>353095</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Heraeus</td>
			<td>Multifuge 3S-R</td>
			<td></td>
		</tr>
		<tr>
			<td>Counting Chamber</td>
			<td>Marienfeld</td>
			<td>650010</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>FST Dumont (#5)</td>
			<td>11254-20</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass cover slips (12 mm)</td>
			<td>Carl Roth (Menzel- Gl&#228;ser)</td>
			<td>P231.1</td>
			<td></td>
		</tr>
		<tr>
			<td>Incubator</td>
			<td>Thermo Scientific</td>
			<td>Heracell 240i</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro tube (2 ml)</td>
			<td>Sarstedt</td>
			<td>72,691</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Leica</td>
			<td>DMIL</td>
			<td></td>
		</tr>
		<tr>
			<td>Millex Syringe-driven filter unit</td>
			<td>Millipore</td>
			<td>SLGV013SL</td>
			<td></td>
		</tr>
		<tr>
			<td>Orbital shaker</td>
			<td>New Brunswick Scientific</td>
			<td>Innova 4000</td>
			<td></td>
		</tr>
		<tr>
			<td>Parafilm</td>
			<td>Bemis</td>
			<td>PM-996</td>
			<td></td>
		</tr>
		<tr>
			<td>Petri dishes (10 cm)</td>
			<td>Sarstedt</td>
			<td>8,33,902</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipette (1 ml)</td>
			<td>Gilson</td>
			<td>Pipetman 1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile work bench</td>
			<td>The Baker Company</td>
			<td>Laminar Flow SterilGARD III</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical scissors</td>
			<td>FST Dumont</td>
			<td>14094-11</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe</td>
			<td>Henry Schein</td>
			<td>9003016</td>
			<td></td>
		</tr>
		<tr>
			<td>T75 flask</td>
			<td>Sarstedt</td>
			<td>83,39,11,002</td>
			<td></td>
		</tr>
		<tr>
			<td>Tube (15 ml)</td>
			<td>Sarstedt</td>
			<td>6,45,54,502</td>
			<td></td>
		</tr>
		<tr>
			<td>Water bath</td>
			<td>GFL</td>
			<td>Water bath type 1004</td>
			<td></td>
		</tr>
	</tbody>
</table>

an indirect neuron-astrocyte co-culture technique for studying neuron-glia interactions

Source: Gottschling, C. et al., <a href="https://app.jove.com/v/54757">The Indirect Neuron-astrocyte Coculture Assay: An In Vitro Set-up for the Detailed Investigation of Neuron-glia Interactions.</a>&#160;J. Vis. Exp.&#160;(2016)
This video illustrates a method for establishing an indirect neuron-astrocyte co-culture using a compartmentalized approach. In this setup, neurons and astrocytes are spatially separated but share a conditioned medium. Neurotrophic factors released by astrocytes promote neuron differentiation and the formation of synaptic connections, suggesting neuron-glia interactions.

An Indirect Neuron-Astrocyte Co-Culture Technique for Studying Neuron-Glia Interactions

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
1. ...

Begin with a multi-well plate containing a permeable membrane insert coated with poly-D-lysine.
Add astrocyte growth medium to the well and seed astrocytes, a specialized glial cell, into the insert.
Incubate to allow cell adherence on poly-D-lysine via electrostatic interactions and form a monolayer.
Replace the astrocyte medium with a neuron culture medium.
Transfer this insert into a multi-well plate containing adhered primary mouse embryonic neurons over a polymer-coated coverslip.
Incubate to establish an indirect neuron-astrocyte co-culture, where the two cell types are physically separated yet share the same culture medium.
Astrocytes secrete various neurotrophic factors essential for neuron survival and growth.
These factors migrate through the permeable support and interact with primary neurons. This promotes their differentiation and forms neuronal projections.
These projections elongate and establish synaptic connections between neurons, indicating neuron-glial interactions.

an-indirect-neuron-astrocyte-co-culture-technique-for-studying-neuron

Research

JoVE Encyclopedia of Experiments

Neuroscience

Neuronal Culture Techniques

Co-culture and Interaction Studies

176 Görüntüleme. Kaynak: Gottschling, C. et al., Dolaylı Nöron-astrosit Kokültür Testi: Nöron-glia Etkileşimlerinin Ayrıntılı İncelenmesi için İn Vitro Bir Kurulum.J. Vis. Uzm.(2016) Bu video, bölümlere ayrılmış bir yaklaşım kullanarak dolaylı bir nöron-astrosit ko-kültürü oluşturmak için bir yöntemi göstermektedir. Bu kurulumda, nöronlar ve astrositler uzamsal olarak ayrılır, ancak şartlandırılmış bir ortamı paylaşırlar. Astrositler tarafından salınan nörotrofik faktö...

Video: Nöron-glia etkileşimlerini incelemek için dolaylı bir nöron-astrosit ko-kültür tekniği - Kavram

Three-dimensional Tissue Engineered Aligned Astrocyte Networks to Recapitulate Developmental Mechanisms and Facilitate Nervous System Regeneration

Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to replace lost neurons and regenerate axonal pathways. However, during nervous system development, neuronal migration and axonal extension often occur along pathways formed by other cells, referred to as &#34;living scaffolds&#34;. Seeking to emulate these mechanisms and to design a strategy that circumvents the inhibitory environment of the CNS, this manuscript presents a protocol to fabricate tissue engineered astrocyte-based &#34;living scaffolds&#34;. To create these constructs, we employed a novel biomaterial encasement scheme to induce astrocytes to self-assemble into dense three-dimensional bundles of bipolar longitudinally-aligned somata and processes. First, hollow hydrogel micro-columns were assembled, and the inner lumen was coated with collagen extracellular-matrix. Dissociated cerebral cortical astrocytes were then delivered into the lumen of the cylindrical micro-column and, at a critical inner diameter of &#60;350 &#181;m, spontaneously self-aligned and contracted to produce long fiber-like cables consisting of dense bundles of astrocyte processes and collagen fibrils measuring &#60;150 &#181;m in diameter yet extending several cm in length. These engineered living scaffolds exhibited &#62;97% cell viability and were virtually exclusively comprised of astrocytes expressing a combination of the intermediate filament proteins glial-fibrillary acidic protein (GFAP), vimentin, and nestin. These aligned astrocyte networks were found to provide a permissive substrate for neuronal attachment and aligned neurite extension. Moreover, these constructs maintain integrity and alignment when extracted from the hydrogel encasement, making them suitable for CNS implantation. These preformed constructs structurally emulate key cytoarchitectural elements of naturally occurring glial-based &#34;living scaffolds&#34; in vivo. As such, these engineered living scaffolds may serve as test-beds to study neurodevelopmental mechanisms in vitro or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding following CNS degeneration in vivo.

We showcase the development of self-assembled, three-dimensional bundles of longitudinally aligned astrocytic somata and processes within a novel biomaterial encasement. These engineered &#34;living scaffolds&#34;, exhibiting micron-scale diameter yet extending centimeters in length, may serve as test-beds to study neurodevelopmental mechanisms or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding.

Astrocyte ağlar gelişimsel mekanizmaları özetlemek ve sinir sistemi yeniden oluşturma işlemi kolaylaştırmak için tasarlanmış üç boyutlu doku uyumlu

Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to ...

JoVE Journal

Biyomühendislik

Monitoring Astrocyte Reactivity and Proliferation in Vitro Under Ischemic-Like Conditions

Ischemic stroke is a complex brain injury caused by a thrombus or embolus obstructing blood flow to parts of the brain. This leads to deprivation of oxygen and glucose, which causes energy failure and neuronal death. After an ischemic stroke insult, astrocytes become reactive and proliferate around the injury site as it develops. Under this scenario, it is difficult to study the specific contribution of astrocytes to the brain region exposed to ischemia. Therefore, this article introduces a methodology to study primary astrocyte reactivity and proliferation under an in vitro model of an ischemia-like environment, called oxygen glucose deprivation (OGD). Astrocytes were isolated from 1-4 day-old neonatal rats and the number of non-specific astrocytic cells was assessed using astrocyte selective marker Glial Fibrillary Acidic Protein (GFAP) and nuclear staining. The period in which astrocytes are subjected to the OGD condition can be customized, as well as the percentage of oxygen they are exposed to. This flexibility allows scientists to characterize the duration of the ischemic-like condition in different groups of cells in vitro. This article discusses the timeframes of OGD that induce astrocyte reactivity, hypertrophic morphology, and proliferation as measured by immunofluorescence using Proliferating Cell Nuclear Antigen (PCNA). Besides proliferation, astrocytes undergo energy and oxidative stress, and respond to OGD by releasing soluble factors into the cell medium. This medium can be collected and used to analyze the effects of molecules released by astrocytes in primary neuronal cultures without cell-to-cell interaction. In summary, this primary cell culture model can be efficiently used to understand the role of isolated astrocytes upon injury.

Monitoring Astrocyte Reactivity and Proliferation in Vitro Under Ischemic-Like Conditions

Ischemic stroke is a complex event in which the specific contribution of astrocytes to the affected brain region exposed to oxygen glucose deprivation (OGD) is difficult to study. This article introduces a methodology to obtain isolated astrocytes and study their reactivity and proliferation under OGD conditions.

Astrocyte reaktivite ve nükleer silahların yayılmasına karşı Vitro iskemik benzeri koşullar altında izleme

Ischemic stroke is a complex brain injury caused by a thrombus or embolus obstructing blood flow to parts of the brain. This leads to deprivation of ...

Nörobilim

A Cell Culture Model for Studying the Role of Neuron-Glia Interactions in Ischemia

Ischemic stroke is a clinical condition characterized by hypoperfusion of brain tissue, leading to oxygen and glucose deprivation, and the consequent neuronal loss. Numerous evidence suggests that the interaction between glial and neuronal cells exert beneficial effects after an ischemic event. Therefore, to explore potential protective mechanisms, it is important to develop models that allow studying neuron-glia interactions in an ischemic environment. Herein we present a simple approach to isolate astrocytes and neurons from the rat embryonic cortex, and that by using specific culture media, allows the establishment of neuron- or astrocyte-enriched cultures or neuron-glia cultures with high yield and reproducibility.
To study the crosstalk between astrocytes and neurons, we propose an approach based on a co-culture system in which neurons cultured in coverslips are maintained in contact with a monolayer of astrocytes plated in multiwell plates. The two cultures are maintained apart by small paraffin spheres. This approach allows the independent manipulation and the application of specific treatments to each cell type, which represents an advantage in many studies.
To simulate what occurs during an ischemic stroke, the cultures are subjected to an oxygen and glucose deprivation protocol. This protocol represents a useful tool to study the role of neuron-glia interactions in ischemic stroke.

Here, we present a simple approach using specific culture media that allows the establishment of neuron- and astrocyte-enriched cultures, or neuron-glia cultures from the embryonic cortex, with high yield and reproducibility.

İskemide Nöron-Glia Etkileşimlerinin Rolünü Nörade İncelemek İçin Hücre Kültürü Modeli

Ischemic stroke is a clinical condition characterized by hypoperfusion of brain tissue, leading to oxygen and glucose deprivation, and the consequent ...

An Indirect Neuron-Astrocyte Co-Culture Technique for Studying Neuron-Glia Interactions

TRANSKRIPT

An Indirect Neuron-Astrocyte Co-Culture Technique for Studying Neuron-Glia Interactions