Name: uptake of fluorescent labeled small extracellular vesicles in vitro and in spinal cord
Uploaded: 2021-05-23T14:00:00
Description: Watch this Scientific Journal Video about Uptake of Fluorescent Labeled Small Extracellular Vesicles In Vitro and in Spinal Cord at JoVE.com

This study was supported by grants from NIH NINDS R01NS102836 and the Pennsylvania Department of Health Commonwealth Universal Research Enhancement (CURE) awarded to Seena K. Ajit. We thank Dr. Bradley Nash for critical reading of the manuscript.

NOTE: All procedures were performed in compliance with the NIH Guide for the Care and Use of Laboratory Animals and approved by the Institutional Animal Care &#38; Use Committee of Drexel University College of Medicine. Timed-pregnant CD-1 mice were used for astrocytic culture, and all dams were received 15 days after impregnation. Ten-twelve weeks old C57BL/6 mice were used for in vivo uptake experiments.
1. Isolation of sEVs from RAW 264.7 macrophage cells
<ol>
	<li>Culture RAW 26...

<ol>
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In this protocol, we showed the labeling of sEVs with PKH dyes and the visualization of their uptake in the spinal cord. PKH lipophilic fluorescent dyes are widely used for labeling cells by flow cytometry and fluorescent microscopy3,5,6,12,24,25. Due to their relatively long half-life and low cytotoxicity, PKH dyes can be us...

Small extracellular vesicles (sEVs) are nanosized, membrane-derived vesicles with a size range of 50-150 nm. They originate from multi-vesicular bodies (MVBs) and are released from cells upon fusion of the MVBs with the plasma membrane. sEVs contain miRNAs, mRNAs, proteins, and bioactive lipids, and these molecules are transferred between cells in the form of cell-to-cell communication. sEVs can be internalized by recipient cells by a variety of endocytic pathways, and this capture of sEVs by recipient cells is mediated by the recognition of surface molecules on both EVs and the target cells1.
sEVs have gained interest due to their capacity to trigger molecular and phenotypic changes in acceptor cells, their utility as a therapeutic agent, and their potential as carriers for cargo molecules or pharmacological agents. Due to their small size, the imaging and tracking of sEVs can be challenging, especially for in vivo studies and clinical settings. Therefore, many methods have been developed to label and image sEVs to assist their biodistribution and tracking in vitro and in vivo2.
The most common technique to study sEV biodistribution and target cell interactions involves labeling them with fluorescent dye molecules3,4,5,6,7. EVs were initially labeled with cell membrane dyes that were commonly used to image cells. These fluorescent dyes generally stain the lipid bilayer or proteins of interest on sEVs. Several lipophilic dyes display a strong fluorescent signal when incorporated into the cytosol, including DiR (1,1&#8242;-dioctadecyl-3,3,3&#8242;,3&#8242;-tetramethylindotricarbocyanine iodide), DiL (1, 1&#8242;-dioctadecyl-3, 3, 3&#8242;, 3&#8242;-tetramethyl indocarbocyanine perchlorate), and DiD (1, 1&#8242;-dioctadecyl-3, 3, 3&#8242;, 3&#8242;-tetramethyl indocarbocyanine 4-chlorobenzenesulfonate salt)8,9,10,11.
Other lipophilic dyes, such as PKH67 and PKH26, have a highly fluorescent polar head group and a long aliphatic hydrocarbon tail that readily intercalates into any lipid structure and leads to long-term dye retention and stable fluorescence12. PKH dyes can also label EVs, which allows the study of EV properties in vivo13. Many other dyes have been used to observe exosomes using fluorescence microscopy and flow cytometry, including lipid-labeling dyes14 and cell-permeable dyes such as carboxyfluorescein diacetate succinimidyl ester (CFDA-SE)15,16 and calcein acetoxymethyl (AM) ester17.
Studies of sEV-mediated crosstalk between different cells in the CNS have provided important insights on the pathogenesis of neuroinflammatory and neurodegenerative diseases18. For example, sEVs from neurons can spread beta-amyloid peptides and phosphorylated tau proteins and aid in the pathogenesis of Alzheimer&#39;s disease19. Additionally, EVs derived from erythrocytes contain large amounts of alpha-synuclein and can cross the blood-brain barrier and contribute to Parkinson&#39;s pathology20. The ability of sEVs to cross physiological barriers21 and transfer their biomolecules to target cells makes them convenient tools to deliver therapeutic drugs to the CNS22.
Visualizing sEV uptake by myriad CNS cells in the spinal cord will enable both mechanistic studies and the evaluation of the therapeutic benefits of exogenously administered sEVs from various cellular sources. This paper describes the methodology to label sEVs derived from macrophages and image their uptake in vitro and in vivo in the lumbar spinal cord by neurons, microglia, and astrocytes to qualitatively confirm sEV delivery by visualization.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Amicon Ultra 0.5 mL centrifugal filters</td>
			<td>MilliporeSigma</td>
			<td>Z677094</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Alix Antibody</td>
			<td>Abcam</td>
			<td>ab186429</td>
			<td>1:1000</td>
		</tr>
		<tr>
			<td>Anti-Calnexin Antibody</td>
			<td>Abcam</td>
			<td>Ab10286</td>
			<td>1:1000</td>
		</tr>
		<tr>
			<td>Anti-CD81 Antibody</td>
			<td>Santa Cruz Biotechnology</td>
			<td>sc-166029</td>
			<td>1:1000</td>
		</tr>
		<tr>
			<td>Anti-GAPDH Monoclonal Antibody (14C10)</td>
			<td>Cell Signaling Technology</td>
			<td>2118</td>
			<td>1:1000</td>
		</tr>
		<tr>
			<td>Anti-Glial Fibrillary Acidic Protein Antibody</td>
			<td>Sigma-Aldrich</td>
			<td>MAB360</td>
			<td>1:500 for IF; 1:1000 for IHC</td>
		</tr>
		<tr>
			<td>Anti-Iba1 Antibody</td>
			<td>Wako</td>
			<td>019-19741</td>
			<td>1:2000</td>
		</tr>
		<tr>
			<td>Anti-MAP2A Antibody</td>
			<td>Sigma-Aldrich</td>
			<td>MAB378</td>
			<td>1:500</td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin (BSA)</td>
			<td>VWR</td>
			<td>0332</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell Strainer, 40 &#956;m</td>
			<td>VWR</td>
			<td>15-1040-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge Tubes</td>
			<td>Thermo Scientific</td>
			<td>3118-0050</td>
			<td>12,000 x g</td>
		</tr>
		<tr>
			<td>Coverslip, 12-mm, #1.5</td>
			<td>Electron Microscopy Sciences</td>
			<td>72230-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Coverslip, 18-mm, #1.5</td>
			<td>Electron Microscopy Sciences</td>
			<td>72222-01</td>
			<td></td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>Sigma-Aldrich</td>
			<td>D9542-1MG</td>
			<td>1 &#181;g/mL</td>
		</tr>
		<tr>
			<td>DC Protein Assay</td>
			<td>Bio-Rad</td>
			<td>500-0116</td>
			<td></td>
		</tr>
		<tr>
			<td>Deoxyribonuclease I (DNAse I)</td>
			<td>MilliporeSigma</td>
			<td>D4513-1VL</td>
			<td></td>
		</tr>
		<tr>
			<td>Donkey Anti-Rabbit IgG H&#38;L (HRP)</td>
			<td>Abcam</td>
			<td>ab16284</td>
			<td>1:10000</td>
		</tr>
		<tr>
			<td>Donkey Anti-Rabbit IgG H&#38;L, Alexa Fluor 488</td>
			<td>Invitrogen</td>
			<td>A-21206</td>
			<td>1:500</td>
		</tr>
		<tr>
			<td>Double Frosted Microscope Slides, #1</td>
			<td>Thermo Scientific</td>
			<td>12-552-5</td>
			<td></td>
		</tr>
		<tr>
			<td>DPBS without Calcium and Magnesium</td>
			<td>Corning</td>
			<td>21-031-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Modified Eagle Medium (DMEM)</td>
			<td>Corning</td>
			<td>10-013-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Exosome-Depleted Fetal Bovine Serum</td>
			<td>Gibco</td>
			<td>A27208-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS)</td>
			<td>Corning</td>
			<td>35-011-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>FluorChem M imaging system</td>
			<td>ProteinSimple</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>FV3000 Confocal Microscope</td>
			<td>Olympus</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Goat Anti-Mouse IgG H&#38;L (HRP)</td>
			<td>Abcam</td>
			<td>ab6789</td>
			<td>1:10000</td>
		</tr>
		<tr>
			<td>Goat Anti-Mouse IgG H&#38;L, Alexa Fluor 488</td>
			<td>Invitrogen</td>
			<td>A-11001</td>
			<td>1:500</td>
		</tr>
		<tr>
			<td>Goat Anti-Mouse IgG1, Alexa Fluor 594</td>
			<td>Invitrogen</td>
			<td>A-21125</td>
			<td></td>
		</tr>
		<tr>
			<td>Hank&#39;s Balanced Salt Solution (HBSS)</td>
			<td>VWR</td>
			<td>02-0121</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Gibco</td>
			<td>15630080</td>
			<td></td>
		</tr>
		<tr>
			<td>HRP Substrate</td>
			<td>Thermo Scientific</td>
			<td>34094</td>
			<td></td>
		</tr>
		<tr>
			<td>Intercept blocking buffer, TBS</td>
			<td>LI-COR Biosciences</td>
			<td>927-60001</td>
			<td></td>
		</tr>
		<tr>
			<td>Laemmli SDS Sample Buffer</td>
			<td>Alfa Aesar</td>
			<td>AAJ61337AC</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro Cover Glass, #1</td>
			<td>VWR</td>
			<td>48404-454</td>
			<td></td>
		</tr>
		<tr>
			<td>Microm HM550</td>
			<td>Thermo Scientific</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>NanoSight NS300 system</td>
			<td>Malvern Panalytical</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>NanoSight NTA 3.2 software</td>
			<td>Malvern Panalytical</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Neuro-2a Cell Line</td>
			<td>ATCC</td>
			<td>CCL-131</td>
			<td></td>
		</tr>
		<tr>
			<td>Normal Goat Serum</td>
			<td>Vector Laboratories</td>
			<td>S-1000</td>
			<td></td>
		</tr>
		<tr>
			<td>O.C.T Compound</td>
			<td>Sakura Finetek</td>
			<td>4583</td>
			<td></td>
		</tr>
		<tr>
			<td>Papain</td>
			<td>Worthington Biochemical Corporation</td>
			<td>NC9597281</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>Electron Microscopy Sciences</td>
			<td>19210</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>Gibco</td>
			<td>15140122</td>
			<td></td>
		</tr>
		<tr>
			<td>PKH26</td>
			<td>Sigma-Aldrich</td>
			<td>MINI26-1KT</td>
			<td></td>
		</tr>
		<tr>
			<td>PKH67</td>
			<td>Sigma-Aldrich</td>
			<td>MINI67-1KT</td>
			<td></td>
		</tr>
		<tr>
			<td>Protease Inhibitor Cocktail</td>
			<td>Thermo Scientific</td>
			<td>1862209</td>
			<td></td>
		</tr>
		<tr>
			<td>PVDF Transfer Membrane</td>
			<td>MDI</td>
			<td>SVFX8302XXXX101</td>
			<td></td>
		</tr>
		<tr>
			<td>RAW 267.4 Cell Line</td>
			<td>ATCC</td>
			<td>TIB-71</td>
			<td></td>
		</tr>
		<tr>
			<td>RIPA Buffer</td>
			<td>Sigma-Aldrich</td>
			<td>R0278</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Chloride</td>
			<td>AMRESCO</td>
			<td>0241-2.5KG</td>
			<td></td>
		</tr>
		<tr>
			<td>Superfrost Plus Gold Slides</td>
			<td>Thermo Scientific</td>
			<td>15-188-48</td>
			<td>adhesive slides</td>
		</tr>
		<tr>
			<td>T-75 Flasks</td>
			<td>Corning</td>
			<td>431464U</td>
			<td></td>
		</tr>
		<tr>
			<td>Tecnai 12 Digital Transmission Electron Microscope</td>
			<td>FEI Company</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>TEM Grids</td>
			<td>Electron Microscopy Sciences</td>
			<td>FSF300-cu</td>
			<td></td>
		</tr>
		<tr>
			<td>Tris-Glycine Protein Gel, 12%</td>
			<td>Invitrogen</td>
			<td>XP00120BOX</td>
			<td></td>
		</tr>
		<tr>
			<td>Tris-Glycine SDS Running Buffer</td>
			<td>Invitrogen</td>
			<td>LC26755</td>
			<td></td>
		</tr>
		<tr>
			<td>Tris-Glycine Transfer Buffer</td>
			<td>Invitrogen</td>
			<td>LC3675</td>
			<td></td>
		</tr>
		<tr>
			<td>TrypLE Express</td>
			<td></td>
			<td>cell dissociation enzyme</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Acros Organics</td>
			<td>327371000</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin, 0.25%</td>
			<td>Corning</td>
			<td>25-053-CL</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween 20</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ultracentrifuge Tubes</td>
			<td>Beckman</td>
			<td>344058</td>
			<td>110,000 x g</td>
		</tr>
	</tbody>
</table>

uptake of fluorescent labeled small extracellular vesicles in vitro and in spinal cord

Small extracellular vesicles (sEVs) are 50-150 nm vesicles secreted by all cells and present in bodily fluids. sEVs transfer biomolecules such as RNA, proteins, and lipids from donor to acceptor cells, making them key signaling mediators between cells. In the central nervous system (CNS), sEVs can mediate intercellular signaling, including neuroimmune interactions. sEV functions can be studied by tracking the uptake of labeled sEVs in recipient cells both in vitro and in vivo. This paper describes the labeling of sEVs from the conditioned media of RAW 264.7 macrophage cells using a PKH membrane dye. It shows the uptake of different concentrations of labeled sEVs at multiple time points by Neuro-2a cells and primary astrocytes in vitro. Also shown is the uptake of sEVs delivered intrathecally in mouse spinal cord neurons, astrocytes, and microglia visualized by confocal microscopy. The representative results demonstrate time-dependent variation in the uptake of sEVs by different cells, which can help confirm successful sEVs delivery into the spinal cord.

After the isolation of sEVs from RAW 264.7 conditioned media via centrifugation, NTA was used to determine the concentration and size distribution of the purified sEVs. The average mean size of RAW 264.7-derived sEVs was 140 nm, and the peak particle size was 121.8 nm, confirming that most detectable particles in the light scattering measurement fell within the size range of exosomes or sEVs at 50-150 nm (Figure 1A). As suggested in the minimal information for studies of extracellular vesicl...

Watch this Scientific Journal Video about Uptake of Fluorescent Labeled Small Extracellular Vesicles In Vitro and in Spinal Cord at JoVE.com

Uptake of Fluorescent Labeled Small Extracellular Vesicles In Vitro and in Spinal Cord

We describe a protocol to label macrophage-derived small extracellular vesicles with PKH dyes and observe their uptake in vitro and in the spinal cord after intrathecal delivery.

Uptake of Fluorescent Labeled Small Extracellular Vesicles In Vitro and in Spinal Cord

Small extracellular vesicles (sEVs) are 50-150 nm vesicles secreted by all cells and present in bodily fluids. sEVs transfer biomolecules such as RNA, ...

Visualizing uptake of small extracellular vesicles, also known as sEVs, by different cells in the spinal cord, can confirm a successful delivery of sEVs. This enables both mechanistic and therapeutic studies of intrathecally administered sEVs from various sources in roden models. This protocol can be used to visualize sEVs uptake by cells in a mild spinal cord, and can help evaluate the role of sEVs and its cargo molecules in spinal disorders, pain and inflammation.This procedure will be demonstrated by me, along with and Xuan Luo a nd Zhucheng Lin, the two graduate students in Dr Seena Ajit's lab. Begin by placing 18 millimeter cover slips in the 12 well plate, then plate neuro-2a cells in each well with a total of 1 milliliter of complete DMEM containing 10%FBS and 1%pen strep. When the cell count fluency has reached 80 to 90%change the medium to DMEM exosome depleted medium in each well add one, 5 or 10 micrograms of labeled sEVs.For 1, 4 and 24 hours. For dose and time dependent uptake to the rest of the wells at an equal volume of dye control. Collect the brains of postnatal pups in a 60 millimeter, Petri dish containing ice cold Hanks balanced salt solution supplemented with 10 millimolar hepes, dissect both the cortical lobes and remove the meninges.Then mince the tissues with a sterilized blade. Transfer the tissues into a 15 milliliter conical tube containing Pepane or deoxyribonucleus one dissociation buffer and incubate for 20 minutes at 37 degrees Celsius, swirling the tube every 5 minutes, aspirate the supernatant and add 5 milliliters of complete DMEM to the tube. To inactivate the enzyme activity, try to rate carefully to dissociate the tissues with a 5 milliliter glass serological pipette, and a flame polished pasture pipette.Pass the cell suspension through a 40 micrometer cell strainer, and then centrifuge the cells at 250 times G for 5 minutes at 4 degrees Celsius, aspirate the medium and see the cells in 10 milliliters of complete DMEM in a 75 square centimeter flask. After 4 hours of plating, replace the supernate and medium with 15 milliliters of fresh DMEM medium. After 14 days in vitro to detach the microglia and oligodendrocytes, transfer the flask to an orbital shaker at 320 RPM for 6 hours.Use 5 milliliters of the cell dissociation enzyme for 10 minutes at 37 degrees Celsius. To tripsinize, the remaining astrocytes, to inactivate the enzymatic action, add a 5 milliliters of complete DMEM and then pellet the cells at 250 times G for 5 minutes at 4 degrees Celsius. Resuspend the cells in complete DMEM and see the cells on the 12 millimeter number 1.5 cover slips in a 24 well plate.Using PBS rinse the cells 3 times and then fix them with 4%power formaldehyde or PFA in PBS for 10 minutes at room temperature. Wash the fixed cells 3 times for 5 minutes with PBS and permeabilize them using 0.1%Triton X 100 in PBS for 10 to 15 minutes. Then repeat the washes with PBS.Use 5%normal goat serum or NGS in PBS for 1 hour at room temperature to block the cells, incubate the neuro-2a cells with map two-way antibodies and the primary astrocytes with GFAP antibodies at a 1 to 500 ratio in fresh 5%NGS or PBS overnight at 4 degrees Celsius with gentle shaking. After washing the cells 3 times in PBS, add the fluorophore conjugated secondary antibodies in 5%NGS. Incubate for 2 hours at room temperature protected from light on a rocker.Repeat the washing with PBS and incubate the cell with 1 microgram per milliliter of DAPI for 10 minutes at room temperature. Once again, wash the cells 3 times with PBS. Using an anti fade mounting medium, mount the cover slips on number 1 slides, let them dry overnight in the dark and store the prepared glass slides at 4 degrees Celsius until imaging on a confocal microscope.Dissect the spinal cord and fix it in 4%PFA in PBS at 4 degrees Celsius for 24 hours. Prior protect the tissues in 30%sucrose in PBS at 4 degrees Celsius for 24 hours or until the tissues sink and then store the tissues at 4 degrees Celsius until immunohistochemistry, imbed the L4 L5 spinal cord in OCT compound, then freeze it on dry ice until it is completely solidified. Use a cryostat to section the tissues at 30 micrometres and the collect the sections in a 24 well plate containing PBS.Wash the sections 3 times for 5 minutes each with 0.3%Triton in PBS, Block the non-specific binding sites using 5%MGS in 0.3%Triton PBS for 2 hours at room temperature. Incubate the sections overnight at 4 degrees Celsius on a shaker. Wash the sections 3 times for 5 minutes with 0.3%Triton in Pbs.Then add the appropriate concentration of the secondary antibodies. According to the text manuscript, incubate at room temperature for two hours, wash the sections using only PBS and incubate them in 1 microgram per milliliter of DAPI for 10 minutes at room temperature. Then repeat the PBS washes under a light microscope, mount the sections on a clear adhesive slide with a fine paint brush.Wet the cover slip with the mounting medium and cure overnight in the dark at room temperature, acquire images under a confocal microscope with the respective lasers, The average mean size of RA 2 6 4 0.7 derived sEVs was 140 nanometers and the peak particle size was 121.8 nanometers. With the most detectable particles falling within the size range of exosomes or sEVS. At 50 to 150 nanometers, western blotting of sEVs, Cell Lysate and exodepleted Media, demonstrated that sEV derived protein samples contained the sEV marker proteins Alix CD81 and GAPDH.The cell lysate was enriched with endoplasmic reticulum, resident protein Calnexin thus Calnexin served as a negative marker for cellular contamination as it was absent in the sEVs. It was observed that the uptake of sEVs occurred at 1 hour and for the 1, 5 and 10 microgram sEVs, post incubation fluorescence could be detected at 4 hours, for 4, 5, and 10 micrograms of sEVs. The uptake of PKH 26 labeled sEVs by primary astrocytes was examined and maximum fluorescence from sEVS uptake in primary cortical astrocytes occurred at 24 hours PKH26-labeled sEVs were taken up and maximum fluorescence was observed at 6 hours, post-injection in neurons astrocytes and microglial cells.The inclusion of controls, unlabeled sEVs, and dye control it create code to a wind false positive recent signals due to now specific labeling Opry dance of Unbound dye patch coasts. The uptake of seVs can be confirmed by investigating biomolecular cargo transfer to recipe and cells and tissues and determining the changes in expression levels of biomolecules or target genes. Behavior studies can also be performed, to investigate the functional impact of sEV delivery.

Research

JoVE Journal

Neuroscience

Dissection and Culture of Commissural Neurons from Embryonic Spinal Cord

Commissural neurons have been widely used to investigate the mechanisms underlying axon guidance during embryonic spinal cord development. The cell bodies ...

Spinal Cord Electrophysiology II: Extracellular Suction Electrode Fabrication

Development of neural circuitries and locomotion can be studied using neonatal rodent spinal cord central pattern generator (CPG) behavior. We demonstrate ...

Lateral Fluid Percussion: Model of Traumatic Brain Injury in Mice

Traumatic brain injury (TBI) research has attained renewed momentum due to the increasing awareness of head injuries, which result in morbidity and ...

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from ...

Spinal Cord Transection in the Larval Zebrafish

Mammals fail in sensory and motor recovery following spinal cord injury due to lack of axonal regrowth below the level of injury as well as an inability ...

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal ...

Two-photon Imaging of Cellular Dynamics in the Mouse Spinal Cord

Two-photon (2P) microscopy is utilized to reveal cellular dynamics and interactions deep within living, intact tissues. Here, we present a method for ...

Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice

Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice

The mammalian brain exhibits marked symmetry across the sagittal plane. However, detailed description of neural dynamics in symmetric brain regions in ...

Laminectomy and Spinal Cord Window Implantation in the Mouse

This protocol describes a method for spinal cord laminectomy and glass window implantation for in vivo imaging of the mouse spinal cord. An integrated ...

Preparation of Rhythmically-active In Vitro Neonatal Rodent Brainstem-spinal Cord and Thin Slice

Mammalian inspiratory rhythm is generated from a neuronal network in a region of the medulla called the preB&#246;tzinger complex (pBC), which produces a ...