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. Effective automated tracking methods have not been developed for low contrast objects such as unstained cilia in video-enhanced contrast-DIC. Although the method to track ciliary motion is manual in this technique, the amount of effort in ciliary motion tracking analysis is optimally reduced compared with using general purpose software packages for image analysis.
Sample dissection
To prepare ex vivo CPEC samples, rapid and gentle manipulations are necessary to preserve the viability of the tissues, which ensures the motility of the cilia ex vivo. Because contamination by erythrocytes blurs the field of observation, gentle but intricate rinsing of the dissected tissue with phosphate buffered saline is strongly recommended. To avoid bleeding, care must be exercised to avoid tearing the posterior choroid artery that can be identified as a prominent reddish thread-like structure adhered to the lamina affixa of the colloid plexus.
Microscope
An inverted microscope equipped with DIC optics and a high-power transmission light source is essential for this method. Because mercury lamps are usually incapable of frequently switching on and off, a shutter in front of the lamp housing is necessary. Either a manual or electrical shutter can be used for this purpose. To protect specimens and the observer&#8217;s eyes from UV and IR light, optical filters are required to allow only visible light (400&#8211;700 band pass or a combination of UV and IR cut filters). ND filters are also necessary to alter the light power that differs according to the situation: monitoring by eye, focusing with a video camera, and high-speed time-lapse recording. An objective lens with a high numerical aperture is necessary for a high resolution. There is some distance between the top of the coverslip and the focal point because of the morphology and thickness of the tissue. Therefore, a water immersion lens rather than an oil immersion lens is preferred for better image quality. Vibration isolation is also necessary to yield stable image stacks. Air dumper-type tables are useful for this purpose, but simpler cushioning of the microscope by inserting tennis balls beneath the microscope base with a steady table may also work.
Video camera
A CCD camera capable of at least 200 frames/sec is necessary to track the movement of cilia. During the past decade, CCD cameras with faster frame rates than the standard video rate (25&#8211;30 Hz) have become available at much lower costs. Camera models capable of shorter expose times than the frame interval are useful to reduce blurring due to the movement of cilia without increasing the amount of data. An exposure time of 0.1 msec and a 5 msec frame interval (200 Hz) are minimum conditions to obtain ciliary images of CPECs with sufficient quality.
Software
The analysis to track the motion of each cilium is time consuming, especially when general purpose software packages for image analysis are used to track each ciliary tip. Reducing the steps of repeated tasks, such as mouse clicking on the ciliary tip position on the monitor, selecting a menu to record the clicked position, and clicking on a button to move to next image frame, results in a significant reduction of time and effort. In this study, a special routine was added to the custom-made TI Workbench software. In the ciliary tracking mode of the TI Workbench software, the user keeps looping the following simple two-step operation: moving the mouse pointer to the ciliary tip and pressing an arrow key on the keyboard to advance the frame, which does not require moving the mouse pointer or the user&#8217;s eyes to shift (to menus and buttons on the computer screen) from the ciliary tips on the computer screen. The software keeps track of the ciliary tip positions, displays the recorded trajectory to assist the user, and creates a table of ciliary motion information for further analysis. Most general purpose software for image analysis permits programing macros for batch processing of such repeated tasks. Such custom programing to reduce repeated steps is strongly recommended.
Analysis of trajectories
Extraction of the trajectories was carried out using the custom-made TI Workbench software, as described above. Relatively simple analysis and image processing were also carried out using the same software. For fitting analyses, the trajectory of each ciliary tip was transferred to Igor Pro software. Other advanced analysis software such as MATLAB can also be used for this purpose.
In the current study, because of difficulties in categorizing the trajectories into back-and-forth or rotational trajectories, the trajectories were classified by eye in a blinded fashion, which were confirmed by another observer, resulting in consistent classification. Nevertheless, more mathematically rigorous measures to categorize the trajectories without any possible arbitrariness would be preferable. Ellipse fitting of the trajectories appears to be ideal, which could quantify the extent of ellipticity as the aspect ratio of the fitted ellipse () in both back-and-forth and rotational movements. However, an attempt to use the distribution of the aspect ratio to define a threshold value for classification was ineffective. The fitting often failed for back-and-forth trajectories, the parameters frequently failed to converge, and the converged fitting was apparently illusive. Therefore, ellipse fitting was not adopted to automatically categorize the trajectories or quantify the ellipticity of each trajectory. The fitting was carried out to extract the beating direction of rotationally moving tips as the major axis of the fitted ellipse.
In the current study, AR was proposed to quantify the extent that a trajectory deviates from an ideal linear back-and-forth motion. The parameter is the ratio of the width of distribution perpendicular to the beating direction to that along the direction. The value should be zero when the trajectory is a straight line, and one when the trajectory is a circle, resembling the aspect ratio of the ellipse mentioned above.
In practice, obtaining the AR value can be relatively easy by rotating the trajectory, so that the beating direction becomes parallel to x-axis (Figure 4B). This quantification leads to considerably distinct values for the two modes of motion, suggesting the potential use of the parameter not only to quantify the characteristics of each trajectory, but also to more rigorously classify the trajectories. However, it should be noted that the beating direction itself is already the result of distinct fitting processes for the two modes in the current method.
Further improvement of the analysis, such as a more advanced fitting algorithm, might solve the problems of possible arbitrariness.
An aspect regarding the ellipticity of the trajectory is that the beating of each CPEC cilium may not be taking place in the plane that is strictly perpendicular to the x-y plane of observation. In fact, the results of SEM imaging implied that CPEC cilia are often tilted, and the tilt may lead to apparent ellipticity or anisotropy of the trajectories.
Preparation for SEM
During the preparation for SEM observation, there are several important points that ensure the acquisition of high quality images. First, post-fixation by osmium tetroxide must be performed carefully, including pre-washing with a 10% sucrose solution. Without proper fixation by the osmification procedure, the subsequent steps cannot maintain or restore the condition of the specimens, leading to a lower quality of the preparation. Because aldehyde fixatives are reducing agents, any remaining aldehydes within the specimen inhibit the activity of osmium tetroxide, a strong oxidizing reagent. To ensure elimination of superfluous aldehydes in specimens, careful washing with the sucrose solution is imperative. In cases of suboptimal post-fixation, the color of the specimen does not change from brown to black. Second, the volume of osmium tetroxide must be at least 50-fold larger than that of the sample. Otherwise, sufficient fixation cannot be expected. Third, it is important to avoid complete drying of the specimens, particularly during the dehydration process that employs highly pure ethanol and isoamyl acetate. Drying of the specimen destroys the fine surface structures such as cilia, resulting in poor images.

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 motion of two cilia with different modes of movement, back-and-forth and rotational movements, from the data shown in Movies 1 and 2. Figure 3 shows a simple analysis of the trajectories of the cilia, in which the phase difference in the two coordinates is obvious in the rotational movement.

Analysis of CPEC ciliary tip trajectories
Detailed methods to quantitatively analyze each trajectory are shown in Figure 4 with schematic illustrations of the beating angle &#952; definitions (A) and a flow chart of the analysis with representative results (B).
To define the beating angle &#952; for back-and-forth trajectories, fit the positions of the ciliary tip during multiple cycles to a straight line y = ax + b, and define the beating direction as that along the fitted line. Define the beating angle here as &#952; = Arc tan a. Because line fitting often fails to extract the direction in cases of rotational movement, fit the rotational trajectories to an ellipse, and define the direction as that along the long axis of the fitted ellipse. More precisely, the tip positions (x, y) during multiple beating cycles are fitted to the function below. 
<img alt="Equation 1" fo:content-width="2in" src="/files/ftp_upload/52991/52991eq1.jpg" width="310" />
where 
<img alt="Equation 2" fo:content-width="2in" src="/files/ftp_upload/52991/52991eq2.JPG" width="200" />
The ellipse fitting involves five fitting parameters: x0, y0, a, b, and &#952;. The x- and y-spatial coordinates of the center of the ellipse are x0 and y0, respectively. The major and minor radii of the ellipse are a and b, respectively. Angle &#952; is the angle that the major axis makes with the x-axis, or the beating angle. A schematic representation of these parameters is shown in the right panel of Figure 4A. The fitting is carried out using Igor Pro software by defining the explicit function described above. Then, a histogram of beating angle &#952; for all cilia observed in the same cell is plotted as a circular histogram (Figure 2 in Narita et al.8). The frequency is normalized to the number of analyzed ciliary tips. It should be noted that each cilium is interpreted to have two &#952; values in the circular histogram, e.g. &#960;/4 and 3&#960;/4, leading to symmetrical distribution of the direction.
To define generalized aspect ratio AR, the positions of the ciliary tip during multiple cycles are rotated by -&#952; (Figure 4B). According to the rotation, both back-and-forth and rotational trajectories become distributed approximately parallel to the x-axis, in which the widths of distribution A and B, along the x- and y-axes, respectively, are defined as half of the difference between the minimum and maximum. Therefore, these parameters are more relevant to the major and minor radii of the ellipse, a and b. AR is then defined as the ratio between A and B by AR = B/A.
Observations of choroid plexus epithelium by SEM
SEM allows observation of the fine surface structure of specimens. The presence of cilia on CPECs is confirmed throughout the developmental time course. The emergence of multiple cilia on CPECs is observed by embryonic day (E) 13, shortly after choroid plexus development begins in the lateral ventricles around E11. At this stage, the cells are small with a variable immature appearance, and the ciliary tips are pointing toward various directions. At E15, a tuft of multiple cilia is established on the top of the apical surface, which are standing out from the surrounding microvilli. At postnatal day (P) 2, many cilia are fixed at a bent position, reflecting the ciliary motility observed by live imaging. At P14, most cells possess multiple cilia that are non-motile as well as microvilli with a finer texture compared with the earlier stages. Figure 5 shows SEM images of CPECs with cilia at these stages. Based on the movies shown in Figure 1 and Movie 1, it is obvious that motile cilia are easily recognized by live imaging. However, it is difficult to distinguish non-motile cilia by DIC microscopy. Consequently, SEM is indispensable to understand overall ciliary states.
<img alt="Figure 1" src="/files/ftp_upload/52991/52991fig1.jpg" /> 
Figure 1: Overview of the workflow. (a) Stereo microscope. (b) Inverted microscope equipped with a charged-coupled device (CCD) camera. (c) Computer screen during analysis. (d) Ion sputter. (e) Specimen for SEM. (f) Scanning electron microscope.
Movie 1. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/52991/Figure_2.mov" target="_blank">Movie of the top view of CPECs and the cilia from a P2 mouse pup in high-speed video microscopy.</a> Because of the irregular surface of the choroid plexus tissue, this snapshot contains both in-focus and out-of-focus planes. The area in the box is expanded and shown in Movie 2. Scale bar: 2 &#181;m.
Movie 2. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/52991/Figure_3.mov" target="_blank">Movie of the expanded view of the tissue sample in Movie 1.</a> Beating cilia showed either rotational or back-and-forth movements. Scale bar: 1 &#181;m.
<img alt="Figure 4" src="/files/ftp_upload/52991/52991fig4.jpg" /> 
Figure 2: Reconstitution of the trajectory of CPEC cilia from the time-lapse images in Movie 2. (A) Cilia with back-and-forth movement (top) and rotational movement (bottom). DIC images from the movie data are presented at 50 msec intervals (1&#8211;8, scale bar: 1 &#181;m). The position of the target ciliary tip is indicated by an arrowhead. (B) The trajectories (broken line) and positions of ciliary tips (colored circles) shown in images are overlaid.
<img alt="Figure 5" src="/files/ftp_upload/52991/52991fig5.jpg" /> 
Figure 3: Two modes of CPEC ciliary tip movement reconstituted from movie data. Representative ciliary tip movements, back-and-forth movement (A) and rotational movement (B), over multiple cycles are presented as trajectories (top, scale bars: 0.5 &#181;m). Time courses of x- and y-coordinates of the tip position are plotted, respectively (middle). To demonstrate a phase-shift between the two coordinates, x- and y-coordinates were normalized to [-1,1] and overlaid (bottom, red and blue lines, respectively).
<img alt="Figure 6" src="/files/ftp_upload/52991/52991fig6.jpg" /> 
Figure 4: Schematic illustrations describing the analysis of ciliary tip trajectories. (A) Definitions of the beating angle&#160;&#952; for back-and-forth (left panel) and rotational (right panel) trajectories. Parameters in the formula describing the fitted ellipse, a, b, x0, and y0, are shown in the right panel. (B) Flow chart of the fitting analysis of the trajectories to define the beating angle &#952; and AR. Actual results of the fitting of the representative trajectories are presented in the right panels.
<img alt="Figure 7" src="/files/ftp_upload/52991/52991fig7.jpg" /> 
Figure 5: SEM image of cilia. Representative SEM micrographs of CPECs at E13, E15, P2, and P14. During the time course, CPECs increased in size, and developed microvilli and cilia on the apical surface. A tuft of cilia at E13 is yet to acquire motility. At P2, when the ratio of cilia with motility reached the highest point, many bent cilia are observed. At P14, cilia lose motility. Scale bar: 5 &#181;m.

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. ...

observation-ciliary-movement-choroid-plexus-epithelial-cells-ex

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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 ...

Rapid Determination of the Thermal Nociceptive Threshold in Diabetic Rats

Painful diabetic neuropathy (PDN) is characterized by hyperalgesia i.e., increased sensitivity to noxious stimulus, and allodynia i.e., hypersensitivity to normally innocuous stimuli1. Hyperalgesia and allodynia have been studied in many different rodent models of diabetes mellitus2. However, as stated by B&ouml;lcskei et al, determination of "pain" in animal models is challenging due to its subjective nature3. Moreover, the traditional methods used to determine behavioral responses to noxious thermal stimuli usually lack reproducibility and pharmacological sensitivity3. For instance, by using the hot-plate method of Ankier4, flinch, withdrawal and/or licking of either hind- and/or fore-paws is quantified as reflex latencies at constant high thermal stimuli (52-55 &deg;C). However, animals that are hyperalgesic to thermal stimulus do not reproducibly show differences in reflex latencies using those supra-threshold temperatures3,5. As the recently described method of B&ouml;lcskei et al.6, the procedures described here allows for the rapid, sensitive and reproducible determination of thermal nociceptive thresholds (TNTs) in mice and rats. The method uses slowly increasing thermal stimulus applied mostly to the skin of mouse/rat plantar surface. The method is particularly sensitive to study anti-nociception during hyperalgesic states such as PDN. The procedures described bellow are based on the ones published in detail by Alm&aacute;si et al 5 and B&ouml;lcskei et al 3. The procedures described here have been approved the Laboratory Animal Care and Use Committee (LACUC), Wright State University.

Here, we describe a rapid reliable and simple procedure to determine the lowest temperature at which rats or mice show nocifensive behavior, i.e. the thermal nociceptive threshold (TNT). This method applies a slowly increasing thermal stimulus allowing precise and reproducible estimation of TNTs with minimum, if any, stress to the animals.

Painful diabetic neuropathy (PDN) is characterized by hyperalgesia i.e., increased sensitivity to noxious stimulus, and allodynia i.e., hypersensitivity ...

Ex vivo Culturing of Whole, Developing Drosophila Brains

We describe a method for ex vivo culturing of whole Drosophila brains. This can be used as a counterpoint to chronic genetic manipulations for investigating the cell biology and development of central brain structures by allowing acute pharmacological interventions and live imaging of cellular processes. As an example of the technique, prior work from our lab1 has shown that a previously unrecognized subcellular compartment lies between the axonal and somatodendritic compartments of axons of the Drosophila central brain. The development of this compartment, referred to as the axon initial segment (AIS)2, was shown genetically to depend on the neuron-specific cyclin-dependent kinase, Cdk5. We show here that ex vivo treatment of wild-type Drosophila larval brains with the Cdk5-specific pharmacological inhibitors roscovitine and olomoucine3 causes acute changes in actin organization, and in localization of the cell-surface protein Fasciclin 2, that mimic the changes seen in mutants that lack Cdk5 activity genetically.
A second example of the ex vivo culture technique is provided for remodeling of the connections of embryonic mushroom body (MB) gamma neurons during metamorphosis from larva to adult. The mushroom body is the center of olfactory learning and memory in the fly4, and these gamma neurons prune their axonal and dendritic branches during pupal development and then re-extend branches at a later timepoint to establish the adult innervation pattern5. Pruning of these neurons of the MB has been shown to occur via local degeneration of neurite branches6, by a mechanism that is triggered by ecdysone, a steroid hormone, acting at the ecdysone receptor B17, and that is dependent on the activity of the ubiquitin-proteasome system6. Our method of ex vivo culturing can be used to interrogate further the mechanism of developmental remodeling. We found that in the ex vivo culture setting, gamma neurons of the MB recapitulated the process of developmental pruning with a time course similar to that in vivo. It was essential, however, to wait until 1.5 hours after puparium formation before explanting the tissue in order for the cells to commit irreversibly to metamorphosis; dissection of animals at the onset of pupariation led to little or no metamorphosis in culture. Thus, with appropriate modification, the ex vivo culture approach can be applied to study dynamic as well as steady state aspects of central brain biology.

Ex vivo Culturing of Whole, Developing Drosophila Brains

This article describes a method by which one can mimic in vivo development of the Drosophila mushroom body in an ex vivo culture system.

We describe a method for ex vivo culturing of whole Drosophila brains. This can be used as a counterpoint to chronic genetic manipulations for ...

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 ...

Acute In Vivo Electrophysiological Recordings of Local Field Potentials and Multi-unit Activity from the Hyperdirect Pathway in Anesthetized Rats

Converging evidence shows that many neuropsychiatric diseases should be understood as disorders of large-scale neuronal networks. To better understand the pathophysiological basis of these diseases, it is necessary to precisely characterize in which way the processing of information is disturbed between the different neuronal parts of the circuit. Using extracellular in vivo electrophysiological recordings, it is possible to accurately delineate neuronal activity within a neuronal network. The application of this method has several advantages over alternative techniques, e.g., functional magnetic resonance imaging and calcium imaging, as it allows a unique temporal and spatial resolution and does not rely on genetically engineered organisms. However, the use of extracellular in vivo recordings is limited since it is an invasive technique that cannot be universally applied. In this article, a simple and easy to use method is presented with which it is possible to simultaneously record extracellular potentials such as local field potentials and multiunit activity at multiple sites of a network. It is detailed how a precise targeting of subcortical nuclei can be achieved using a combination of stereotactic surgery and online analysis of multi-unit recordings. Thus, it is demonstrated, how a complete network such as the hyperdirect cortico-basal ganglia loop can be studied in anesthetized animals in vivo.

Acute In Vivo Electrophysiological Recordings of Local Field Potentials and Multi-unit Activity from the Hyperdirect Pathway in Anesthetized Rats

In this study, the methodology is presented on how to perform multi-site in vivo electrophysiological recordings from the hyperdirect pathway under urethane anesthesia.

Converging evidence shows that many neuropsychiatric diseases should be understood as disorders of large-scale neuronal networks. To better understand the ...

Ex Vivo Imaging of Cell-specific Calcium Signaling at the Tripartite Synapse of the Mouse Diaphragm

The electrical activity of cells in tissues can be monitored by electrophysiological techniques, but these are usually limited to the analysis of individual cells. Since an increase of intracellular calcium (Ca2+) in the cytosol often occurs because of the electrical activity, or in response to a myriad of other stimuli, this process can be monitored by the imaging of cells loaded with fluorescent calcium-sensitive dyes.&#160; However, it is difficult to image this response in an individual cell type within whole tissue because these dyes are taken up by all cell types within the tissue. In contrast, genetically encoded calcium indicators (GECIs) can be expressed by an individual cell type and fluoresce in response to an increase of intracellular Ca2+, thus permitting the imaging of Ca2+ signaling in entire populations of individual cell types. Here, we apply the use of the GECIs GCaMP3/6 to the mouse neuromuscular junction, a tripartite synapse between motor neurons, skeletal muscle, and terminal/perisynaptic Schwann cells. We demonstrate the utility of this technique in classic ex vivo tissue preparations. Using an optical splitter, we perform dual-wavelength imaging of dynamic Ca2+ signals and a static label of the neuromuscular junction (NMJ) in an approach that could be easily adapted to monitor two cell-specific GECI or genetically encoded voltage indicators (GEVI) simultaneously. Finally, we discuss the routines used to capture spatial maps of fluorescence intensity. Together, these optical, transgenic, and analytic techniques can be employed to study the biological activity of distinct cell subpopulations at the NMJ in a wide variety of contexts.

Ex Vivo Imaging of Cell-specific Calcium Signaling at the Tripartite Synapse of the Mouse Diaphragm

Here we present a protocol to image calcium signaling in populations of individual cell types at the murine neuromuscular junction.

The electrical activity of cells in tissues can be monitored by electrophysiological techniques, but these are usually limited to the analysis of ...

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 ...

Ex Vivo Release of Calcitonin Gene-Related Peptide from the Trigeminovascular System in Rodents

Calcitonin gene-related peptide (CGRP) was first discovered in the 1980s as a splice variant from the calcitonin gene. Since its discovery, its role in migraine pathophysiology has been well established, first by its potent vasodilator properties and subsequently by its presence and function as a neurotransmitter in the sensory trigeminovascular system. The migraine-provoking ability of CGRP gave support to the pharma industry to develop monoclonal antibodies and antagonists inhibiting the effect of CGRP. A new treatment paradigm has proven effective in the prophylactic treatment of migraine. One of the useful tools to further understand migraine mechanisms is the ex vivo model of CGRP release from the trigeminovascular system. It is a relatively simple method that can be used with various pharmacological tools to achieve know-how to further develop new effective migraine treatments. The present protocol describes a CGRP release model and the technique to quantify the effect of pharmacological agents on the amount of CGRP released from the trigeminovascular system in rodents. A procedure describing the experimental approach from euthanasia to the measurement of protein levels is provided. The essential isolation of the trigeminal ganglion and the trigeminal nucleus caudalis from both mice and rats and the preparation of rat dura mater are described in detail. Furthermore, representative results from both species (rats and mice) are presented. The technique is a key tool to investigate the molecular mechanisms involved in migraine pathophysiology by using various pharmacological compounds and genetically modified animals.

Ex Vivo Release of Calcitonin Gene-Related Peptide from the Trigeminovascular System in Rodents

The present protocol describes the ex vivo calcitonin gene-related peptide (CGRP) release model and the strategy to quantify the effect of pharmacological agents on the amount of CGRP released from the trigeminovascular system in rodents.

Calcitonin gene-related peptide (CGRP) was first discovered in the 1980s as a splice variant from the calcitonin gene. Since its discovery, its role in ...

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. ...