This work was supported by a Project for Private Universities: matching fund subsidy from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan (T.I.) and Grants-in-Aid for Scientific Research (C) from MEXT (S.T. and K.N).

The protocols and use of experimental animals were approved by the institutional animal care and use committees at the University of Yamanashi and Waseda University. Animal care was performed in accordance with institutional guidelines.
1. CPEC Preparation
<ol>
	<li>Prepare the following apparatuses and materials: a stereo microscope, preferably capable of transmitting illumination from the bottom; a pair of watchmaker forceps (Dumont #3 or #4), flame-sterilized, straight operating scissors, flame-sterilized; two sterile 10 cm plastic dishes containing 20 ml ice-cold Leibovitz L-15 medium; 35 mm glass-bottom dishes containing 2 ml RT Leibovitz L-15 medium; a 100 ml beaker containing 70% ethanol; neonatal mouse pups.</li>
	<li>Briefly immerse a neonatal mouse in 70% ethanol and euthanize quickly by decapitation using the operating scissors.</li>
	<li>Place the head immediately in ice-cold Leibovitz L-15 medium in the sterile 10 cm dish.</li>
	<li>Remove the skin from the calvaria using the pair of watchmaker forceps, cut open the skull to expose the brain, and then cut the cranial nerves to isolate the whole brain.</li>
	<li>Transfer the brain to a new dish containing ice-cold Leibovitz L-15 medium and observe under the stereo microscope, making sure that the brain is completely immersed in the medium.</li>
	<li>Set the dorsal aspect of the brain facing up, and orient the brain so that the olfactory bulbs reside at the three o&#8217;clock position (for right-handed persons). Hold the brain gently with the forceps in the left hand.</li>
	<li>Using the fine dissection forceps (Dumont #3 or #4) in the right hand, cut the corpus callosum and underneath the parenchyma connecting the cerebral hemispheres, along the longitudinal fissure of the cerebrum.</li>
	<li>Gently push the cerebral hemispheres away to the lateral sides and expose the transverse cerebral fissure.</li>
	<li>Separate the hemispheres by pinching out the parenchyma between the hemisphere and thalamus.</li>
	<li>Gently pull out the lateral ventricular choroid plexus that is attached to the lateral side of the hippocampus by the lamina affixa.</li>
	<li>Transfer the isolated choroid plexus to the 35 mm glass-bottom dish containing fresh Leibovitz L-15 medium, and overlay a weight (Materials List) gently to hold the tissue in place.</li>
</ol>
2. Live Imaging of CPEC Cilia
<ol>
	<li>Confirm proper ultraviolet (UV) and inferred (IR) cut filter(s) to block light shorter than 400 nm and longer than 700 nm, and that neutral density (ND) filters (25% and 6%) are inserted in the light path of the inverted microscope.</li>
	<li>Adjust the focus of the objective lens roughly by eye, and then adjust the condenser so that the center and focus to conform to the K&#246;hler illumination. Insert an appropriate differential interference contrast (DIC) prism, a DIC element, as well as analyzer and polarizer elements in the light path to conform to the DIC optics.</li>
	<li>Adjust the contrast of view by the DIC prism position so that the structure of the tissue surface is most recognizable. If all cilia of the target cells are motile, a clear view of motile cilia cannot be obtained by eye because of their movement.</li>
	<li>Change the light path to the video camera, and remove the ND filters to increase the light power.</li>
	<li>Use the camera in focusing mode to adjust the field of view and focus. During focusing, in which video images are displayed at real-time on the monitor, a clear view of motile cilia is not available.</li>
	<li>Use the camera at 200 Hz with an exposure time of 0.1 msec for the desired period (seconds to minutes). After acquisition of the image stack, single frames will display clear ciliary structures. If ciliary edges are blurred, increase the frame rate or use a shorter exposure time.</li>
	<li>Record the motion of CPEC cilia within 25&#8211;60 min after euthanasia in Leibovitz L-15 medium.</li>
</ol>
3. Analysis of Ciliary Motion
<ol>
	<li>Manually track beating patterns of each cilium on the computer monitor. Mark ciliary tip positions in each frame with the mouse pointer, which are assembled for trajectory information of each cilium. Either analyze the trajectory information using the same software or export to other more general applications for further analysis. The efficiency of this analysis step is described in the Discussion.</li>
	<li>Classify the trajectories into two modes of motion, back-and-forth or rotational, by eye.</li>
	<li>Calculate the ciliary beating frequency (CBF) using the following formula: [CBF = (number of frames per second)/(average number of frames for a single beat)]14, which can be obtained from a ciliary tip motion diagram (Figure 3). Repeat this calculation for multiple ciliary beating cycles, because other cilia on the same cell can interfere with the motion of each cilium, resulting in irregularity.</li>
	<li>To analyze the angular uniformity of the ciliary beating axes within a single cell, define the beating angle&#160;&#952; for each trajectory (Figure 4). For back-and-forth trajectories, fit the positions of the cilia tip to a straight line, and define &#952; as the angle the line makes with x-axis. For rotational trajectories, fit the positions to an ellipse, and define &#952; as the angle the major axis of the ellipse makes with x-axis. Details of the fitting are described in the Representative Results section.</li>
	<li>For quantitative description of each trajectory, calculate generalized aspect ratio AR. Briefly, rotate the trajectory by -&#952; and define AR as the ratio between the widths of the distribution along x- and y-axes (Figure 4B). Details are shown in the Representative Results section, and the interpretation, significance, and the limitation of the parameter are described in the Discussion.</li>
</ol>
4. Sample Preparation for SEM
Note: SEM is an important method to evaluate the status of cilia on CPECs in a comprehensive manner. To prepare specimens for SEM, a standard procedure reported previously15 is employed with slight modifications.
<ol>
	<li>Before dissecting the tissue from the brain, prepare the fixative in a 5 ml glass vial with a polyethylene cap. The fixative consists of 2% paraformaldehyde, 2.5% glutaraldehyde (half Karnovsky&#8217;s solution16) in 0.1 M phosphate buffer, pH 7.4.</li>
	<li>Dissect out the tissue from the brain as described in step 1.</li>
	<li>Briefly rinse the isolated tissue with Hank&#8217;s balanced salt solution (HBSS) in a new dish and then fix the tissue in the fixative in the glass vial for 1 hr at room temperature. Use disposable transfer pipettes and handle the specimens gently. After rinsing in HBSS, the tissue becomes sticky.
	<ol>
		<li>To transfer the specimens into the fixative solution, slowly expel a small amount of solution containing the tissue from the transfer pipette as a droplet and add to the fixative.</li>
	</ol>
	</li>
	<li>After fixation, discard the fixative and rinse the tissue with phosphate buffer three times.</li>
	<li>Immerse the tissue in a 10% sucrose solution to wash out the remaining aldehydes. To ensure complete elimination of aldehydes, immerse the samples in the solution for 10 min and then repeat twice with fresh 10% sucrose. This step is important to achieve proper post-fixation in subsequent steps.</li>
	<li>Immerse the tissue in a solution of 1% osmium tetroxide in phosphate buffer for 30 min and then place on ice for post-fixation. Judge the degree of osmification by the sample color: when aldehydes are completely removed, the sample is black.</li>
	<li>Wash the post-fixed tissue samples extensively with double distilled water several times.</li>
	<li>Dehydrate the samples by immersion in graded concentrations of ethanol, usually 65%, 75%, 85%, 95%, 99%, and 100%, for 10 min each. Obtain anhydrous ethanol by placing molecular sieves into 99.5% ethanol from a newly purchased bottle. Repeat dehydration with anhydrous ethanol three times.</li>
	<li>Place the dehydrated samples into isoamyl acetate, a substitution reagent for critical point drying, for 10 min. Repeat this step twice. This reagent evaporates rapidly and the sample can become dry, resulting in destruction by surface tension. Therefore, do not dry the sample completely.</li>
	<li>After the final exchange of isoamyl acetate, remove most of the solvent, immediately wrap the open glass vial with aluminum foil, and place the vial on dry ice. Using a needle or fine forceps, make several holes in the foil covering the mouth of the vial, so that liquid carbon dioxide flows easily into the vial in the critical point dryer. Proceed to the next step as quickly as possible.</li>
	<li>In this step, minimize the carryover of isoamyl acetate into the chamber of the dryer, but do not let the sample dry out completely before critical point drying. In addition, do not leave the sample on dry ice for an unnecessarily long time to avoid the formation of frost on the vial.</li>
	<li>Transfer the foil-wrapped glass vials containing the tissue samples into the critical point dryer that ensures the surface structure of the tissue remains intact while removing water contained in the tissue. Detailed information on operating the critical point dryer can be obtained from the manufacturer&#8217;s instructions.</li>
	<li>Handle the samples carefully using a toothpick to minimize mechanical damage. The resulting dried tissue samples are fragile. Mount the samples on metal stubs and coat with gold-palladium using an ion sputter.</li>
</ol>
5. Observation by SEM
<ol>
	<li>Observe by SEM and record images with a digital camera equipped to scanning electron microscope.</li>
	<li>Transfer digital image data to a PC for analysis.</li>
</ol>

<ol>
	<li>Nonami, Y., Narita, K., Nakamura, H., Inoue, T., Takeda, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+changes+in+ciliary+motility+on+choroid+plexus+epithelial+cells+during+the+perinatal+period.">Developmental changes in ciliary motility on choroid plexus epithelial cells during the perinatal period.</a> Cytoskeleton. 70 (12), 797-803 (2013).</li><li>Bisgrove, B. W., Yost, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+roles+of+cilia+in+developmental+disorders+and+disease.">The roles of cilia in developmental disorders and disease.</a> Development. 133 (21), 4131-4143 (2006).</li><li>Fliegauf, M., Benzing, T., Omran, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=When+cilia+go+bad:+cilia+defects+and+ciliopathies.">When cilia go bad: cilia defects and ciliopathies.</a> Nature Reviews. Molecular Cell Biology. 8 (11), 880-893 (2007).</li><li>Oh, E. C., Katsanis, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cilia+in+vertebrate+development+and+disease.">Cilia in vertebrate development and disease.</a> Development. 139 (3), 443-448 (2012).</li><li>Shah, A. S., Ben-Shahar, Y., Moninger, T. O., Kline, J. N., Welsh, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Motile+cilia+of+human+airway+epithelia+are+chemosensory.">Motile cilia of human airway epithelia are chemosensory.</a> Science(New York, N.Y). 325 (5944), 1131-1134 (2009).</li><li>Kiprilov, E. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+embryonic+stem+cells+in+culture+possess+primary+cilia+with+hedgehog+signaling+machinery).">Human embryonic stem cells in culture possess primary cilia with hedgehog signaling machinery).</a> The Journal of Cell Biology. 180 (5), 897-904 (2008).</li><li>Hirokawa, N., Tanaka, Y., Okada, Y., Takeda, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nodal+flow+and+the+generation+of+left-right+asymmetry.">Nodal flow and the generation of left-right asymmetry.</a> Cell. 125 (1), 33-45 (2006).</li><li>Narita, K., Kozuka-Hata, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteomic+analysis+of+multiple+primary+cilia+reveals+a+novel+mode+of+ciliary+development+in+mammals.">Proteomic analysis of multiple primary cilia reveals a novel mode of ciliary development in mammals.</a> Biology Open. 1 (8), 815-825 (2012).</li><li>Takeda, S., Narita, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+and+function+of+vertebrate+cilia,+towards+a+new+taxonomy.">Structure and function of vertebrate cilia, towards a new taxonomy.</a> Differentiation; Research in Biological Diversity. 83 (2), S4-S11 (2012).</li><li>Ikegami, K., Sato, S., Nakamura, K., Ostrowski, L. E., Setou, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tubulin+polyglutamylation+is+essential+for+airway+ciliary+function+through+the+regulation+of+beating+asymmetry.">Tubulin polyglutamylation is essential for airway ciliary function through the regulation of beating asymmetry.</a> Proceedings of the National Academy of Sciences of the United States of America. 107 (23), 10490-10495 (2010).</li><li>Foster, K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+the+ciliary/flagellar+beating+of+Chlamydomonas.">Analysis of the ciliary/flagellar beating of Chlamydomonas.</a> Methods in Cell Biology. 91, 173-239 (2009).</li><li>Lechtreck, K. -. F., Sanderson, M. J., Witman, G. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-speed+digital+imaging+of+ependymal+cilia+in+the+murine+brain.">High-speed digital imaging of ependymal cilia in the murine brain.</a> Methods in Cell Biology. 91, 255-264 (2009).</li><li>Okada, Y., Hirokawa, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Observation+of+nodal+cilia+movement+and+measurement+of+nodal+flow.">Observation of nodal cilia movement and measurement of nodal flow.</a> Methods in Cell Biology. 91, 265-285 (2009).</li><li>Chilvers, M. A., Rutman, A., O&#8217;Callaghan, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ciliary+beat+pattern+is+associated+with+specific+ultrastructural+defects+in+primary+ciliary+dyskinesia.">Ciliary beat pattern is associated with specific ultrastructural defects in primary ciliary dyskinesia.</a> The Journal of Allergy and Clinical Immunology. 112 (3), 518-524 (2003).</li><li>Takeda, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Left-right+asymmetry+and+kinesin+superfamily+protein+KIF3A:+new+insights+in+determination+of+laterality+and+mesoderm+induction+by+kif3A-/-+mice+analysis.">Left-right asymmetry and kinesin superfamily protein KIF3A: new insights in determination of laterality and mesoderm induction by kif3A-/- mice analysis.</a> The Journal of Cell Biology. 145 (4), 825-836 (1999).</li><li>Karnovsky, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+formaldehyde-glutaraldehyde+fixative+of+high+osmolarity+for+use+in+electron+microscopy.">A formaldehyde-glutaraldehyde fixative of high osmolarity for use in electron microscopy.</a> The Journal of Cell Biology. 27, 137-138A (1965).</li></ol>

The authors declare that they have no competing financial interests. This paper aims at reporting detailed methodology to observe the motility of cilia in isolated choroid plexus tissues. Scientific novelties have been reported in previous studies1,8.

Perspectives of this method
Although the technique described here does not provide a more detailed analysis of cilia than previously published methods, the significance of this technique resides in the simplicity of the system and cost effectiveness, which can be easily applied to screening any kind of ciliary motility ex vivo. In particular, TI Workbench provides a simple and user-friendly interface that enables researchers to observe and analyze ciliary motility more easily. Effecti...

Cilia are hair-like projections on the surface of most vertebrate cells, which have attracted attention by medical researchers because of a class of diseases termed ciliopathies2&#8211;4. Despite the ubiquitous expression of the organelle, a wide variety of ciliary functions have been reported, including motility and biosensing. For example, motile cilia on the mucoepithelial surface transport mucus5 and epithelial debris to the outlet of tracts, thereby preventing disease by clearing the surface of epithelia. Moreover, during early developmental periods and embryonic stages, cilia regulate the proliferation of stem cells6, and are involved in the determination of left&#8211;right asymmetry of the vertebrate body7. 
Choroid plexus epithelial cells (CPECs) are derivatives of neuroepithelial cells that cover the surface of the choroid plexus tissue in the brain, which play important roles in maintaining homeostasis of the intracranial environment by production of cerebrospinal fluid (CSF). It has been previously demonstrated that CPECs have multiple non-motile cilia that regulate the production of CSF through G-protein-coupled receptors that are specifically concentrated on the cilia8. Although these cilia had been regarded as quiescent non-motile cilia, it was discovered that some CPEC cilia exhibit transient motility during the neonatal period1. This finding was quite important because it revealed that so-called non-motile cilia are not necessarily immotile from the beginning of development and might display transient motility during specific time windows, possibly in response to specific physiological demands and functions9. To precisely describe the motile nature of CPEC cilia, it is necessary to develop an ex vivo observation system that encompasses analysis of the kinetic profiles unique to CPEC cilia. 
With respect to motility, although several technical reports have described observations of the motile cilia of the tracheal epithelium5,10, motile single-cell flagella11, so-called conventional motile cilia12, and nodal cilia13, detailed analytical methods applicable to relatively undulated structures such as the choroid plexus have not been well documented so far. Moreover, a high time resolution is required to analyze the ciliary movement of CPECs, in which expensive high-speed cameras are indispensable. To circumvent this necessity and simplify monitoring the ciliary motility of various cell types, a low cost, high-speed camera has been introduced, and an easily accessible and convenient method to record the motility of motile cilia, especially to describe the speed and pattern of motion of each cilium, has been developed1. Moreover, original image analysis software &#8220;TI Workbench&#8221; has been used here to facilitate detailed analysis of motility. Collectively, this method provides a new concise strategy to analyze ciliary motion together with correlative scanning electron microscopy (SEM), which can be adopted in a wide range of cilium research.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>for both live imaging and SEM preparation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>stereo microscope</td>
			<td>Olympus</td>
			<td>SZX7</td>
			<td></td>
		</tr>
		<tr>
			<td>flat paper towel</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>&#934;10-cm plastic dish</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>100-mL beaker</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>straight operating scissors</td>
			<td>Sansyo</td>
			<td>S-2B</td>
			<td></td>
		</tr>
		<tr>
			<td>watchmaker forceps</td>
			<td>Dumont</td>
			<td>No.DU-3 or -4, INOX</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>for live cell imaging</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>glass bottom dish</td>
			<td>Matsunami Glass</td>
			<td>D110300</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>for SEM preparation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>alminum foil</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>5-mL glass vial with a polyethylene cap</td>
			<td>Nichiden Rika-Glass</td>
			<td>PS-5A</td>
			<td></td>
		</tr>
		<tr>
			<td>transfer pipette</td>
			<td>Samco Scientific</td>
			<td>SM251-1S</td>
			<td>for specimen tranfer</td>
		</tr>
		<tr>
			<td>toothpick</td>
			<td></td>
			<td></td>
			<td>for specimen transfer</td>
		</tr>
		<tr>
			<td>ion sputter with gold-palladium</td>
			<td>Hitachi</td>
			<td>E-1030</td>
			<td></td>
		</tr>
		<tr>
			<td>critical point dryer</td>
			<td>Hitachi</td>
			<td>HCP-2</td>
			<td></td>
		</tr>
		<tr>
			<td>for live cell imaging</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>inverted microscope</td>
			<td>Olympus</td>
			<td>IX81</td>
			<td></td>
		</tr>
		<tr>
			<td>100 W mercury lump housing and power supply</td>
			<td>Olympus</td>
			<td>U-ULH and BH2-RFL-T3</td>
			<td></td>
		</tr>
		<tr>
			<td>100 W mercury lamp</td>
			<td>Ushio</td>
			<td>USH103D</td>
			<td></td>
		</tr>
		<tr>
			<td>DIC condenser, n.a. 0.55</td>
			<td>Olympus</td>
			<td>IX-LWUCD</td>
			<td></td>
		</tr>
		<tr>
			<td>electrrical shutter</td>
			<td>Vincent Associates</td>
			<td>VS35S22M1R3-24 and VMM-D1</td>
			<td>manual shutter can be used.</td>
		</tr>
		<tr>
			<td>band-pass filter (400-700 nm, &#934;45 mm)</td>
			<td>Koshin Kagaku</td>
			<td>C10-110621-1</td>
			<td></td>
		</tr>
		<tr>
			<td>ND filter (&#934;45 mm)</td>
			<td>Olympus</td>
			<td>45ND6, 45ND25</td>
			<td>combination of 25% and 6% ND filters are used</td>
		</tr>
		<tr>
			<td>objective lens (water immersion) with DIC element</td>
			<td>Olympus</td>
			<td>UApo 40XW/340, n.a., 1.15 with IX-DPAO40</td>
			<td></td>
		</tr>
		<tr>
			<td>high-speed video camera</td>
			<td>Allied Vision Technologies</td>
			<td>GE680</td>
			<td>&#62;= 200 Hz frame rate and 1 msec expose time</td>
		</tr>
		<tr>
			<td>image acquisition / analysis software</td>
			<td>in-hous software</td>
			<td>TI Workbench</td>
			<td>capable of acquisition at high frame rates.</td>
		</tr>
		<tr>
			<td>PC for camera control / analysis</td>
			<td>Apple</td>
			<td>Mac Pro</td>
			<td></td>
		</tr>
		<tr>
			<td>vibration isolation table</td>
			<td>Meiritsu Seiki</td>
			<td>AD0806</td>
			<td></td>
		</tr>
		<tr>
			<td>weight for tissue</td>
			<td>Warner Instruments</td>
			<td>slice anchor kits</td>
			<td>It can be made with nylon mesh glued to a U-shape squashed &#934;0.5mm platinum wire.</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>for SEM</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>inverted microscope</td>
			<td>Olympus</td>
			<td>IX81</td>
			<td></td>
		</tr>
		<tr>
			<td>scanning electron microscope</td>
			<td>JEOL</td>
			<td>JSM-6510</td>
			<td></td>
		</tr>
		<tr>
			<td>for live cell imaging</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>ethanol&#160;</td>
			<td>Wako Chemicals</td>
			<td>057-00456</td>
			<td></td>
		</tr>
		<tr>
			<td>Leibovitz L-15 medium</td>
			<td>Life Technologies</td>
			<td>11415-064</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>for SEM preparation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>ethanol&#160;</td>
			<td>Wako Chemicals</td>
			<td>057-00456</td>
			<td></td>
		</tr>
		<tr>
			<td>Hank&#39;s balanced salt solution</td>
			<td>Life Technologies</td>
			<td>14170112</td>
			<td></td>
		</tr>
		<tr>
			<td>paraformaldehyde&#160;</td>
			<td>Merck</td>
			<td>1040051000</td>
			<td></td>
		</tr>
		<tr>
			<td>glutaraldehyde&#160;</td>
			<td>Nacalai tesque</td>
			<td>17003-05</td>
			<td></td>
		</tr>
		<tr>
			<td>isoamyl acetate</td>
			<td>Nacalai tesque</td>
			<td>02710-95</td>
			<td></td>
		</tr>
		<tr>
			<td>Molecular Sieves 4A 1/8&#160;</td>
			<td>Wako Chemicals</td>
			<td>130-08655</td>
			<td>for preparation of anhydrous ethanol</td>
		</tr>
		<tr>
			<td>phosphate buffer saline (PBS)</td>
			<td>Sigma-Aldrich</td>
			<td>D1408</td>
			<td></td>
		</tr>
		<tr>
			<td>phosphate buffer, 0.1 M</td>
			<td></td>
			<td></td>
			<td>To make 100 ml, mix 19.0 ml of 0.1 M NaH2PO4 and 81.0 ml of 0.1 M Na2HPO4&#160;</td>
		</tr>
		<tr>
			<td>monosodium phosphate (dihydrate)</td>
			<td>Nacalai tesque</td>
			<td>31718-15</td>
			<td></td>
		</tr>
		<tr>
			<td>disodium phosphate (anhydrous)</td>
			<td>Nacalai tesque</td>
			<td>31801-05</td>
			<td></td>
		</tr>
		<tr>
			<td>suclose</td>
			<td>Nacalai tesque</td>
			<td>30406-25</td>
			<td></td>
		</tr>
		<tr>
			<td>osmium tetroxide</td>
			<td>Nisshin EM</td>
			<td align="right">300</td>
			<td></td>
		</tr>
		<tr>
			<td>dry ice</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

observation of the ciliary movement of choroid plexus epithelial cells ex vivo

The choroid plexus is located in the ventricular wall of the brain, the main function of which is believed to be production of cerebrospinal fluid. Choroid plexus epithelial cells (CPECs) covering the surface of choroid plexus tissue harbor multiple unique cilia, but most of the functions of these cilia remain to be investigated. To uncover the function of CPEC cilia with particular reference to their motility, an ex vivo observation system was developed to monitor ciliary motility during embryonic, perinatal and postnatal periods. The choroid plexus was dissected out of the brain ventricle and observed under a video-enhanced contrast microscope equipped with differential interference contrast optics. Under this condition, a simple and quantitative method was developed to analyze the motile profiles of CPEC cilia for several hours ex vivo. Next, the morphological changes of cilia during development were observed by scanning electron microscopy to elucidate the relationship between the morphological maturity of cilia and motility. Interestingly, this method could delineate changes in the number and length of cilia, which peaked at postnatal day (P) 2, while the beating frequency reached a maximum at P10, followed by abrupt cessation at P14. These techniques will enable elucidation of the functions of cilia in various tissues. While related techniques have been published in a previous report1, the current study focuses on detailed techniques to observe the motility and morphology of CPEC cilia ex vivo.

An overview of the workflow is shown in Figure 1, including images of the devices.
Live motion observations of CPECs
Movie 1 shows a movie of CPECs isolated from a perinatal mouse, and Movie 2 shows an expanded view of the images in Movie 1. It should be noted that individual ciliary tips are less clear in still images compared with those in movies. Figure 2 shows tracking of the mo...

Watch this Scientific Journal Video about Observation of the Ciliary Movement of Choroid Plexus Epithelial Cells Ex Vivo at JoVE.com

Observation of the Ciliary Movement of Choroid Plexus Epithelial Cells Ex Vivo

In this study, a detailed light microscopic technique was optimized for real-time observation and analysis of the motion of CPEC cilia ex vivo together with an electron microscopic method for ultrastructural analysis.

Observation of the Ciliary Movement of Choroid Plexus Epithelial Cells Ex Vivo

The choroid plexus is located in the ventricular wall of the brain, the main function of which is believed to be production of cerebrospinal fluid. ...

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Neuroscience

12.1K Views.  Waseda University. In this study, a detailed light microscopic technique was optimized for real-time observation and analysis of the motion of CPEC cilia ex vivo together with an electron microscopic method for ultrastructural analysis.

Video: Observation of the Ciliary Movement of Choroid Plexus Epithelial Cells Ex Vivo

Ex Vivo Organotypic Corneal Model of Acute Epithelial Herpes Simplex Virus Type I Infection

Herpes keratitis is one of the most severe pathologies associated with the herpes simplex virus-type 1 (HSV-1). Herpes keratitis is currently the leading cause of both cornea-derived and infection-associated blindness in the developed world. Typical presentation of herpes keratitis includes infection of the corneal epithelium and sometimes the deeper corneal stroma and endothelium, leading to such permanent corneal pathologies as scarring, thinning, and opacity 1.
Corneal HSV-1 infection is traditionally studied in two types of experimental models. The in vitro model, in which cultured monolayers of corneal epithelial cells are infected in a Petri dish, offers simplicity, high level of replicability, fast experiments, and relatively low costs. On the other hand, the in vivo model, in which animals such as rabbits or mice are inoculated directly in the cornea, offers a highly sophisticated physiological system, but has higher costs, longer experiments, necessary animal care, and a greater degree of variability. 
In this video article, we provide a detailed demonstration of a new ex vivo model of corneal epithelial HSV-1 infection, which combines the strengths of both the in vitro and the in vivo models. The ex vivo model utilizes intact corneas organotypically maintained in culture and infected with HSV-1. The use of the ex vivo model allows for highly physiologically-based conclusions, yet it is rather inexpensive and requires time commitment comparable to that of the in vitro model.

Ex Vivo Organotypic Corneal Model of Acute Epithelial Herpes Simplex Virus Type I Infection

In this video article we describe the use of a new ex vivo model of acute herpes simplex virus type I corneal epithelial infection.

Herpes keratitis is one of the most severe pathologies associated with the herpes simplex virus-type 1 (HSV-1).  Herpes keratitis is currently the leading ...

A Visual Description of the Dissection of the Cerebral Surface Vasculature and Associated Meninges and the Choroid Plexus from Rat Brain

This video presentation was created to show a method of harvesting the two most important highly vascular structures, not residing within the brain proper, that support forebrain function. They are the cerebral surface (superficial) vasculature along with associated meninges (MAV) and the choroid plexus which are necessary for cerebral blood flow and cerebrospinal fluid (CSF) homeostasis. The tissue harvested is suitable for biochemical and physiological analysis, and the MAV has been shown to be sensitive to damage produced by amphetamine and hyperthermia 1,2. As well, the major and minor cerebral vasculatures harvested in MAV are of potentially high interest when investigating concussive types of head trauma. The MAV dissected in this presentation consists of the pial and some of the arachnoid membrane (less dura) of the meninges and the major and minor cerebral surface vasculature. The choroid plexus dissected is the structure that resides in the lateral ventricles as described by Oldfield and McKinley3,4,5,6. The methods used for harvesting these two tissues also facilitate the harvesting of regional cortical tissue devoid of meninges and larger cerebral surface vasculature, and is compatible with harvesting other brain tissues such as striatum, hypothalamus, hippocampus, etc. The dissection of the two tissues takes from 5 to 10 min total. The gene expression levels for the dissected MAV and choroid plexus, as shown and described in this presentation can be found at GSE23093 (MAV) and GSE29733 (choroid plexus) at the NCBI GEO repository. This data has been, and is being, used to help further understand the functioning of the MAV and choroid plexus and how neurotoxic events such as severe hyperthermia and AMPH adversely affect their function.

This video presentation shows a method of harvesting the two most important highly vascular structures that support forebrain function. They are the cerebral surface (superficial) vasculature along with associated meninges (MAV) and the choroid plexus which are necessary for cerebral blood flow and cerebrospinal fluid (CSF) homeostasis.

This video presentation was created to show a method of harvesting the two most important highly vascular structures, not residing within the brain ...

Ex Vivo Preparations of the Intact Vomeronasal Organ and Accessory Olfactory Bulb

The mouse accessory olfactory system (AOS) is a specialized sensory pathway for detecting nonvolatile social odors, pheromones, and kairomones. The first neural circuit in the AOS pathway, called the accessory olfactory bulb (AOB), plays an important role in establishing sex-typical behaviors such as territorial aggression and mating. This small (&#60;1 mm3) circuit possesses the capacity to distinguish unique behavioral states, such as sex, strain, and stress from chemosensory cues in the secretions and excretions of conspecifics. While the compact organization of this system presents unique opportunities for recording from large portions of the circuit simultaneously, investigation of sensory processing in the AOB remains challenging, largely due to its experimentally disadvantageous location in the brain. Here, we demonstrate a multi-stage dissection that removes the intact AOB inside a single hemisphere of the anterior mouse skull, leaving connections to both the peripheral vomeronasal sensory neurons (VSNs) and local neuronal circuitry intact. The procedure exposes the AOB surface to direct visual inspection, facilitating electrophysiological and optical recordings from AOB circuit elements in the absence of anesthetics. Upon inserting a thin cannula into the vomeronasal organ (VNO), which houses the VSNs, one can directly expose the periphery to social odors and pheromones while recording downstream activity in the AOB. This procedure enables controlled inquiries into AOS information processing, which can shed light on mechanisms linking pheromone exposure to changes in behavior.

Ex Vivo Preparations of the Intact Vomeronasal Organ and Accessory Olfactory Bulb

The mouse accessory olfactory bulb (AOB) has been difficult to study in the context of sensory coding. Here, we demonstrate a dissection that produces an ex vivo preparation in which AOB neurons remain functionally connected to their peripheral inputs, facilitating research into information processing of mouse pheromones and kairomones.

The mouse accessory olfactory system (AOS) is a specialized sensory pathway for detecting nonvolatile social odors, pheromones, and kairomones. The first ...

In vivo Calcium Imaging in Mouse Inferior Olive

Inferior olive (IO), a nucleus in the ventral medulla, is the only source of climbing fibers that form one of the two input pathways entering the cerebellum. IO has long been proposed to be crucial for motor control and its activity is currently considered to be at the center of many hypotheses of both motor and cognitive functions of the cerebellum. While its physiology and function have been relatively well studied on single-cell level in vitro, presently there are no reports on the organization of the IO network activity in living animals. This is largely due to the extremely challenging anatomical location of the IO, making it difficult to subject to conventional fluorescent imaging methods, where an optic path must be created through the entire brain located dorsally to the region of interest.
Here we describe an alternative method for obtaining state-of-the-art -level calcium imaging data from the IO network. The method takes advantage of the extreme ventral location of the IO and involves a surgical procedure for inserting a gradient-refractive index (GRIN) lens through the neck viscera to come into contact with the ventral surface of the calcium sensor GCaMP6s-expressing IO in anesthetized mice. A representative calcium imaging recording is shown to demonstrate the feasibility to record IO neuron activity after the surgery. While this is a non-survival surgery and the recordings must be conducted under anesthesia, it avoids damage to life-critical brainstem nuclei and allows conducting large variety of experiments investigating spatiotemporal activity patterns and input integration in the IO. This procedure with modifications could be used for recordings in other, adjacent regions of the ventral brainstem.

In vivo Calcium Imaging in Mouse Inferior Olive

We present a protocol to expose the brainstem of adult mouse from the ventral side. By using a gradient-refractive index lens with a miniature microscope, calcium imaging can be used to examine the activity of inferior olive neural somata in vivo.

Inferior olive (IO), a nucleus in the ventral medulla, is the only source of climbing fibers that form one of the two input pathways entering the ...

Preparation of Rat Sciatic Nerve for Ex Vivo Neurophysiology

Ex vivo preparations enable the study of many neurophysiological processes in isolation from the rest of the body while preserving local tissue structure. This work describes the preparation of rat sciatic nerves for ex vivo neurophysiology, including buffer preparation, animal procedures, equipment setup and neurophysiological recording. This work provides an overview of the different types of experiments possible with this method. The outlined method aims to provide 6 h of stimulation and recording on extracted peripheral nerve tissue in tightly controlled conditions for optimal consistency in results. Results obtained using this method are A-fibre compound action potentials (CAP) with peak-to-peak amplitudes in the millivolt range over the entire duration of the experiment. CAP amplitudes and shapes are consistent and reliable, making them useful to test and compare new electrodes to existing models, or the effects of interventions on the tissue, such as the use of chemicals, surgical alterations, or neuromodulatory stimulation techniques. Both conventional commercially available cuff electrodes with platinum-iridium contacts and custom-made conductive elastomer electrodes were tested and gave similar results in terms of nerve stimulus strength-duration response.

Preparation of Rat Sciatic Nerve for Ex Vivo Neurophysiology

This protocol describes the preparation of rat whole sciatic nerve tissue for ex vivo electrophysiological stimulation and recording in an environmentally-regulated, two-compartment, perfused saline bath.

Ex vivo preparations enable the study of many neurophysiological processes in isolation from the rest of the body while preserving local tissue structure. ...

Organotypic Cultures of Adult Human Cortex as an Ex vivo Model for Human Stem Cell Transplantation and Validation

Neurodegenerative disorders are common and heterogeneous in terms of their symptoms and cellular affectation, making their study complicated due to the lack of proper animal models that fully mimic human diseases and the poor availability of post-mortem human brain tissue. Adult human nervous tissue culture offers the possibility to study different aspects of neurological disorders. Molecular, cellular, and biochemical mechanisms could be easily addressed in this system, as well as testing and validating drugs or different treatments, such as cell-based therapies. This method combines long-term organotypic cultures of the adult human cortex, obtained from epileptic patients undergoing resective surgery, and ex vivo intracortical transplantation of induced pluripotent stem cell-derived cortical progenitors. This method will allow the study of cell survival, neuronal differentiation, the formation of synaptic inputs and outputs, and the electrophysiological properties of human-derived cells after transplantation into intact adult human cortical tissue. This approach is an important step prior to the development of a 3D human disease modeling platform that will bring basic research closer to the clinical translation of stem cell-based therapies for patients with different neurological disorders and allow the development of new tools for reconstructing damaged neural circuits.

Organotypic Cultures of Adult Human Cortex as an Ex vivo Model for Human Stem Cell Transplantation and Validation

This protocol describes long-term organotypic cultures of adult human cortex combined with ex vivo intracortical transplantation of induced pluripotent stem cell-derived cortical progenitors, which present a novel methodology to further test stem cell-based therapies for human neurodegenerative disorders.

Neurodegenerative disorders are common and heterogeneous in terms of their symptoms and cellular affectation, making their study complicated due to the ...

Microdissection and Whole Mount Scanning Electron Microscopy Visualization of Mouse Choroid Plexus

The choroid plexus (CP), a highly vascularized structure protruding into the ventricles of the brain, is one of the most understudied tissues in neuroscience. As it is becoming increasingly clear that this tiny structure plays a crucial role in health and disease of the central nervous system (CNS), it is of utmost importance to properly dissect the CP out of the brain ventricles in a way that allows downstream processing, ranging from functional to structural analysis. Here, isolation of the lateral and fourth brain ventricle mouse CP without the need for specialized tools or equipment is described. This isolation technique preserves the viability, function, and structure of cells within the CP. On account of its high vascularization, the CP can be visualized floating inside the ventricular cavities of the brain using a binocular microscope. However, transcardial perfusion required for downstream analysis can complicate the identification of the CP tissue. Depending on the further processing steps (e.g., RNA and protein analysis), this can be solved by visualizing the CP via transcardial perfusion with bromophenol blue. After isolation, the CP can be processed using several techniques, including RNA, protein, or single cell analysis, to gain further understanding on the function of this special brain structure. Here, scanning electron microscopy (SEM) on whole mount CP is used to get an overall view of the structure.

The choroid plexus (CP), an understudied tissue in neuroscience, plays a key role in health and disease of the central nervous system. This protocol describes a microdissection technique for isolating the CP and the use of scanning electron microscopy to obtain an overall view of its cellular structure.

The choroid plexus (CP), a highly vascularized structure protruding into the ventricles of the brain, is one of the most understudied tissues in ...

Selective Gene Silencing in the Choroid Plexus

Targeted Knockdown of Genes in the Choroid Plexus

The choroid plexus (ChP) serves as a critical gateway for immune cell infiltration into the central nervous system (CNS) under both physiological and pathological conditions. Recent research has shown that regulating ChP activity may offer protection against CNS disorders. However, studying the biological function of the ChP without affecting other brain regions is challenging due to its delicate structure. This study presents a novel method for gene knockdown in ChP tissue using adeno-associated viruses (AAVs) or cyclization recombination enzyme (Cre) recombinase protein consisting of TAT sequence (CRE-TAT). The results demonstrate that after injecting AAV or CRE-TAT into the lateral ventricle, the fluorescence was exclusively concentrated in the ChP. Using this approach, the study successfully knocked down the adenosine A2A receptor (A2AR) in the ChP using RNA interference (RNAi) or Cre/locus of X-overP1 (Cre/LoxP) systems, and showed that this knockdown could alleviate the pathology of experimental autoimmune encephalomyelitis (EAE). This technique may have important implications for future research on the ChP's role in CNS disorders.

Author Spotlight: Insights and Innovations in Gene Expression Manipulation Techniques for Choroid Plexus Research 

Here, we describe a method to selectively alter gene expressions in the choroid plexus while avoiding any impact in other brain areas.

The choroid plexus (ChP) serves as a critical gateway for immune cell infiltration into the central nervous system (CNS) under both physiological and ...

Monitoring Epileptiform Events in Drosophila via Calcium Imaging

Ex Vivo Calcium Imaging for Drosophila Model of Epilepsy

Epilepsy is a neurological disorder characterized by recurrent seizures, partially correlated with genetic origin, affecting over 70 million individuals worldwide. Despite the clinical importance of epilepsy, the functional analysis of neural activity in the central nervous system is still to be developed. Recent advancements in imaging technology, in combination with stable expression of genetically encoded calcium indicators, such as GCaMP6, have revolutionized the study of epilepsy at both brain-wide and single-cell resolution levels. Drosophila melanogaster has emerged as a tool for investigating the molecular and cellular mechanisms underlying epilepsy due to its sophisticated molecular genetics and behavioral assays. In this study, we present a novel and efficient protocol for ex vivo calcium imaging in GCaMP6-expressing adult Drosophila to monitor epileptiform activities. The whole brain is prepared from cac, a well-known epilepsy gene, knockdown flies for calcium imaging with a confocal microscope to identify the neural activity as a follow-up to the bang-sensitive seizure-like behavior assay. The cac knockdown flies showed a higher rate of seizure-like behavior and abnormal calcium activities, including more large spikes and fewer small spikes than wild-type flies. The calcium activities were correlated to seizure-like behavior. This methodology serves as an efficient methodology in screening the pathogenic genes for epilepsy and exploring the potential mechanism of epilepsy at the cellular level.

Author Spotlight: Insights into the Techniques and Findings of Recent Advancements in Epilepsy Research 

Here, we present a protocol for ex vivo calcium imaging in GCaMP6-expressing adult Drosophila to monitor epileptiform activities. The protocol provides a valuable tool for investigating ictal events in adult Drosophila through ex vivo calcium imaging, allowing for exploration of the potential mechanisms of epilepsy at the cellular levels.

Epilepsy is a neurological disorder characterized by recurrent seizures, partially correlated with genetic origin, affecting over 70 million individuals ...

Enhancing Neuroimaging Analysis in Brain Disorders

Manual Segmentation of the Human Choroid Plexus Using Brain MRI

The choroid plexus has been implicated in neurodevelopment and a range of brain disorders. Evidence demonstrates that the choroid plexus is critical for brain maturation, immune/ inflammatory regulation, and behavioral/cognitive functioning. However, current automated neuroimaging segmentation tools are poor at accurately and reliably segmenting the lateral ventricle choroid plexus. Furthermore, there is no existing tool that segments the choroid plexus located in the third and fourth ventricles of the brain. Thus, a protocol delineating how to segment the choroid plexus in the lateral, third, and fourth ventricle is needed to increase the reliability and replicability of studies examining the choroid plexus in neurodevelopmental and brain disorders. This protocol provides detailed steps to create separately labeled files in 3D Slicer for the choroid plexus based on DICOM or NIFTI images. The choroid plexus will be manually segmented using the axial, sagittal, and coronal planes of T1w images making sure to exclude voxels from gray or white matter structures bordering the ventricles. Windowing will be adjusted to assist in the localization of the choroid plexus and its anatomical boundaries. Methods for assessing accuracy and reliability will be demonstrated as part of this protocol. Gold standard segmentation of the choroid plexus using manual delineations can be used to develop better and more reliable automated segmentation tools that can be openly shared to elucidate changes in the choroid plexus across the lifespan and within various brain disorders.

Author Spotlight: Bridging Gaps in Anatomy and Establishing a Foundation for Algorithmic Studies 

Despite the crucial role of the choroid plexus in the brain, neuroimaging studies of this structure are scarce due to the lack of reliable automated segmentation tools. The present protocol aims to ensure gold-standard manual segmentation of the choroid plexus that can inform future neuroimaging studies.

The choroid plexus has been implicated in neurodevelopment and a range of brain disorders. Evidence demonstrates that the choroid plexus is critical for ...