We are grateful to Dr. Sachiko Sato and Julie-Christine L&#233;vesque at the Bioimaging Platform of the Centre de recherche du CHU de Qu&#233;bec for their technical assistance. Grants from the Natural Sciences and Engineering Research Council of Canada (NSERC) RGPIN-2014-05308, The Banting Research Foundation, and The Scottish Rite Charitable Foundation of Canada to M.E.T supported this work.
H.E.H. is recipient of a scholarship from the Lebanese Ministry of Education and Higher Education, and K.B. from the Facult&#233; de m&#233;decine of Universit&#233; Laval.

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The authors have nothing to disclose.

פרוטוקול זה מסביר גישה המצטרפת למיקוד פלאק Aβ ליבה צפופה עם EM. Methoxy-X04 הזרקת vivo מאפשרת בחירה מהירה של חלקים במוח המכילים פלאק Aβ בתוך אזורים מסוימים ושכבות של עניין, למשל CA1 בהיפוקמפוס, radiatum שכבות, ו lacunosum-moleculare. בדוגמה הנוכחית, methoxy-X04-הקרנת טרום אוחד עם טרום הטבעה immun...

היווצרות הפלאק עמילואיד Aβ היא סימן ההיכר נוירו העיקרי של מחלת אלצהיימר (AD). עם זאת ראיה נוספת להשערה מציעה תפקידים חשובים של המערכת החיסונית 1,2 התקדמות מחלה. בפרט, נתונים חדשים ממחקרים פרה-קליניים וקליניים הוקמו תפקוד לקוי חיסון כנהג ראשי תורם לפתולוגיה לספירה. עם ממצאים אלו, תאי מערכת חיסון מרכזיים והיקפיים צמחו מטרות טיפוליות מבטיחות ובאשר לספירה 3. הפרוטוקול הבא משלב מיקרוסקופ אור אלקטרונים (EM) כדי לייצר תובנה חדשות אודות הקשר בין בתצהיר פלאק Aβ לבין שינויי פנוטיפי microglial של מחלת אלצהיימר. פרוטוקול זה מאפשר תיוג של הפלאק Aβ במודלים של עכברים של מחלת אלצהיימר באמצעות הזרקת vivo של צבע פלואורסצנטי-X04 methoxy. Methoxy-X04 הוא נגזרת האדום קונגו שיכולים בקלות לחצות את המחסום שבין הדם למוח להיכנס parenchyma המוח לאגד יריעות β-קפלים עם גבוהffinity. מאז לצבוע הוא פלורסנט, ניתן להשתמש בו לצורך זיהוי in vivo של בתצהיר פלאק Aβ עם שני הפוטונים מיקרוסקופיה 4. לאחר כבול Aβ, methoxy-X04 לא לנתק או להפיץ מחדש הרחק הפלאק, והוא שומר הקרינה לאורך זמן. זה מנוהל בדרך כלל שולי כדי לאפשר הדמיה לא פולשנית של דינמיקת מוח 5. הקרינה גם נשארת הבאה קיבעון אלדהיד, המאפשר שלאחר מוות גומל מנתח, לרבות חקירת מותו העצבי באזור הפלאק Aβ 6. פרוטוקול זה מנצל את המאפיינים של methoxy-X04 כדי לבחור חלקים במוח מעכברים APP SWE / PS1A 246E (APP-PS1; coexpressing מוטציה כפולה הגן APP Lys670Asn / Met671Leu, וגרסא PS1-A264E presenilin האדם) 7 כי התערוכה Aβ הפלאק באזורים ספציפיים של עניין (ההיפוקמפוס CA1, radiatum שכבות, ו-moleculare lacunosumלפני) טרום הטבעת immunostaining נגד מולקולת מתאם מחייב סידן מיונן סמן microglial 1 (IBA1) לדמיין גופי תהליכים בתא microglial עם EM. העכברים מקבלים זריקה intraperitoneal של פתרון methoxy-X04, 24 שעות לפני קיבוע המוח דרך זלוף transcardial. חלקים במוח העטרה מתקבלים באמצעות vibratome. סעיפים המכילים את CA1 בהיפוקמפוס מוקרנים תחת מיקרוסקופ פלואורסצנטי עבור הנוכחות של פלאק Aβ ב radiatum שכבות-moleculare lacunosum. Immunostaining עבור IBA1, שלאחר קיבוע tetroxide אוסמיום, והטבעת שרף פלסטיק מבוצעים אז על החלקים במוח שנבחרו. בסוף פרוטוקול זה, ניתן לזהות קטעים לארכיון ללא השפלה ultrastructural נוספת, מוכן חתך ultrathin ובדיקה ultrastructural. חשוב לציין, את הפלאק עדיין הם פלורסנט לאחר immunostaining עם נוגדנים שונים, למשל IBA1 כמו בפרוטוקול הנוכחי. הם הופכים t כהההאן neuropil הסובבת אותם הבאה tetroxide אוסמיום קיבוע פוסט, ללא תלות מכתים methoxy-X04, אשר מסייע לזהות אזורים של עניין במדויק, למטה, בדרך כלל, כמה מילימטרים רבועים, להיבדק עם מיקרוסקופ אלקטרונים הילוכים. גישה גומלת זו מציעה דרך יעילה לזהות חלקים במוח ספציפיים כדי לבחון ברמת ultrastructural. זה מועיל במיוחד כאשר לומדים פתולוגיה לספירה מוקדם, באיזורים מסויימים במוח או שכבות שעשויות להכיל רק כמה הפלאק Aβ, נוכח רק חלק קטן של קטעי רקמה. בזמנים אלה במיוחד, זה יהיה לא יעיל להשתמש immunostaining עבור Aβ (וסימון כפול עבור סמנים תאיים אחרים כגון IBA1) על חלקים במוח כמה פשוט להניב חלק קטן המכיל לוחות Aβ במיקום הנכון. בנוסף, הזרקה של עכברים חיים עם methoxy-X04 שקדמו להקרבה ועיבוד רקמה לא compromisדואר שימור ultrastructural. שיטות חלופיות כגון מכתים שלאחר מוות עם קונגו אדום, Thioflavin S, Thioflavin T או methoxy-X04 על סעיפי רקמות קבועים דורשות בידול מכתים באתנול, 8-11 אשר גורם ללחץ האוסמוטי ומשבש את ultrastructure. גם האדום קונגו הוא קרצינוגן אדם ידוע 12.

<table border="0" cellpadding="0" cellspacing="0" width="1006">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:523px;">Methoxy-X04</td>
			<td style="width:197px;">Tocris Bioscience</td>
			<td style="width:119px;">4920</td>
			<td style="width:167px;">10 mg substrate per tablet</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Propylene glycol</td>
			<td>Sigma Aldrich</td>
			<td>W294004&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dimethyl sulfoxide (DMSO)</td>
			<td>Fisher BioReagents</td>
			<td>BP231-1</td>
			<td>Caution: toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium Chloride NaCl</td>
			<td>Sigma</td>
			<td>S9625</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium phosphate monobasic monohydrate</td>
			<td>Sigma</td>
			<td>S9638</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium phosphate dibasic</td>
			<td>Sigma</td>
			<td>S0876</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tris Hydrochloride</td>
			<td>Fisher BioReagents</td>
			<td>BP153500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Acrolein&#160;</td>
			<td>Sigma</td>
			<td>110221</td>
			<td>Caution: Toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Paraformaldehyde Granular</td>
			<td>Electron Microscopy Sciences</td>
			<td>19210</td>
			<td>Caution: Toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Filter paper</td>
			<td>Fisher</td>
			<td>09-790-14F</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Peristaltic Pump with Tubing</td>
			<td>ColeParmer</td>
			<td>cp.78023-00</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Excel Winged blood Collection Set Needles 25G&#160;</td>
			<td>Becton Dickinson</td>
			<td>367341</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Extrafine Forceps</td>
			<td>F.S.T</td>
			<td>11152-10</td>
			<td>Tip shape: curved</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Scissors</td>
			<td>F.S.T</td>
			<td>14090-09</td>
			<td>Tip shape: straight</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hartman Hemostats</td>
			<td>F.S.T</td>
			<td>13003-10</td>
			<td>Tip shape: curved</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Surgical Scissors</td>
			<td>F.S.T</td>
			<td>14004-16</td>
			<td>Tip shape: straight</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Micro Dissecting Scissors</td>
			<td>ROBOZ surgical store</td>
			<td>5818</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glass scintillation vials</td>
			<td>Fisher Scientific</td>
			<td>74515-20</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Vibrating Blade Michrotome Leica VT1000 S</td>
			<td>Leica Biosystems&#160;</td>
			<td>14047235612</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Vibratome blades</td>
			<td>Electron microscopy Sciences</td>
			<td>71990</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microscope Slides</td>
			<td>Fisher Scientific</td>
			<td>12-550-15</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">24-well Tissue Culture Plates</td>
			<td>Fisher Scientific</td>
			<td>353047</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ethylene Glycol</td>
			<td>Fisher BioReagents</td>
			<td>BP230-4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glycerol</td>
			<td>Fisher BioReagents</td>
			<td>BP229-4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hydrogen Peroxide, 30%</td>
			<td>J.T.BAKER</td>
			<td>cat: 2186-01</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium borohydride</td>
			<td>Sigma</td>
			<td>480886</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tris HCl</td>
			<td>Fisher</td>
			<td>BP153-500ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fetal bovine Serum (FBS)</td>
			<td>Sigma Aldrich</td>
			<td>F1051</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Bovine serum albumin (BSA), fraction V</td>
			<td>Thomas Scientific</td>
			<td>C001H24</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Triton X-100</td>
			<td>Sigma</td>
			<td>T8787</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Anti IBA1, Rabbit&#160;</td>
			<td>WAKO</td>
			<td>019-19741</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Goat Anti-Rabbit IgG</td>
			<td>Jackson Immunoresearch</td>
			<td>111066046</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">VECTASTAIN Elite ABC Kit (Standard)</td>
			<td>Vector Labs</td>
			<td>PK-6100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">3.3&#39;-Diaminobenzidine tetra-hydrochloride (DAB)</td>
			<td>Sigma</td>
			<td>D5905-50TAB</td>
			<td>Caution: toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Osmium tetroxide, 4% solution</td>
			<td>Electron Microscopy Sciences</td>
			<td>19150</td>
			<td>Caution: toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:523px;">Durcupan&#8482; ACM single component A</td>
			<td>Sigma</td>
			<td>44611</td>
			<td>Resin Caution: Toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:523px;">Durcupan&#8482; ACM single component B</td>
			<td>Sigma</td>
			<td>44612</td>
			<td>Hardener Caution: Toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:523px;">Durcupan&#8482; ACM single component C</td>
			<td>Sigma</td>
			<td>44613</td>
			<td>Plasticizer Caution: Toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:523px;">Durcupan&#8482; ACM single component D</td>
			<td>Sigma</td>
			<td>44614</td>
			<td>Accelerator Caution: Toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ethanol</td>
			<td>LesAlcoolsdeComerce</td>
			<td>151-01-15N</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Propylene oxide</td>
			<td>Sigma</td>
			<td>110205</td>
			<td>Caution: corrosive</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Aluminum weigh dishes</td>
			<td>Electron Microscopy Sciences</td>
			<td>70048-01</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ACLAR&#174;&#8211;Fluoropolymer Films</td>
			<td>Electron Microscopy Sciences</td>
			<td>50425</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Oven/Incubator</td>
			<td>VWR</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

correlative light and electron microscopy to study microglial interactions with &#946;-amyloid plaques

פרוטוקול מפורט מסופק כאן כדי לזהות פלאק Aβ עמילואיד חלקים במוח ממודלי עכבר מחלת אלצהיימר לפני immunostaining טרום הטבעה (במיוחד עבור מולקולת מתאם מחייב סידן מיונן 1 (IBA1), חלבון מחייב סידן שהביע microglia) ועיבוד רקמה במיקרוסקופ אלקטרונים (EM). Methoxy-X04 הוא צבע פלואורסצנטי כי חוצה את מחסום הדם-מוח סלקטיבי נקשר בטא קפלים גליונות נמצא הפלאק Aβ ליבה צפופה. הזרקה של החיות עם methoxy-X04 שקדם להקרבת קיבעון במוח מאפשר הקרנת טרום וגיוס כוח החלקים במוח המכיל פלאק לעיבוד נוסף עם מניפולציות זמן רב. זה מועיל במיוחד כאשר לומדים פתולוגיה לספירה מוקדם באיזורים מסויימים במוח או שכבות שעשויות להכיל הפלאק מעט מאוד, נוכח רק חלק קטן של חלקים. עיבוד פוסט מורטם של סעיפים רקמה עם האדום קונגו, Thioflavin S, ו ThioflT יבין (או אפילו עם methoxy-X04) יכול לתייג יריעות β-קפלים, אבל דורשת סליקה נרחבת עם אתנול להסיר עודפי צבע והנהלים אלה אינם עולים בקנה אחד עם שימור ultrastructural. זה גם יהיה לא יעיל לבצע תיוג עבור Aβ (ו סמנים תאיים אחרים כגון IBA1) על כל החלקים במוח מן האזורים של עניין, רק כדי להניב חלק קטן המכיל לוחות Aβ במיקום הנכון. חשוב לציין, הפלאק Aβ עדיין גלויים לאחר עיבוד רקמות עבור EM, המאפשר זיהוי מדויק של אזורים (בדרך כלל עד כמה מרובע מילימטרים) לבחון עם מיקרוסקופ אלקטרונים.

סעיף זה ממחיש את התוצאות ניתן לקבל שלבים קריטיים שונים של הפרוטוקול. בפרט התוצאות מראות דוגמאות של חלקים במוח המכיל methoxy-X04 הפלאק מוכתמים באזור מסוים ושכבות של עניין: CA1 בהיפוקמפוס, רבדים radiatum, ו lacunosum-moleculare. הפלאק ואת ארגון אזורי / שבשבת של ההיפוקמפוס ...

Watch this Scientific Journal Video about Correlative Light and Electron Microscopy to Study Microglial Interactions with ÃŽÂ²-Amyloid Plaques at JoVE.com

Correlative Light and Electron Microscopy to Study Microglial Interactions with &#946;-Amyloid Plaques

מאמר זה מתאר פרוטוקול המאפשר הדמיה פלאק Aβ עמילואיד בעכברי מודל למחלת אלצהיימר באמצעות methoxy-X04, אשר חוצה את מחסום הדם-מוח סלקטיבי נקשר בטא קפלים גליונות נמצא הפלאק Aβ ליבה צפופה. זה מאפשר הקרנת טרום סעיפים רקמה המכילה פלאק לפני immunostaining ועיבוד עבור במיקרוסקופ אלקטרונים.

גומל אור מיקרוסקופי אלקטרונים ללמוד microglial אינטראקציות עם הפלאק β-עמילואיד

A detailed protocol is provided here to identify amyloid A&#946; plaques in brain sections from Alzheimer&#39;s disease mouse models before pre-embedding ...

correlative-light-electron-microscopy-to-study-microglial

Research

JoVE Journal

Neuroscience

11.2K Views.  CHU de Québec Research Center.  מאמר זה מתאר פרוטוקול המאפשר הדמיה פלאק Aβ עמילואיד בעכברי מודל למחלת אלצהיימר באמצעות methoxy-X04, אשר חוצה את מחסום הדם-מוח סלקטיבי נקשר בטא קפלים גליונות נמצא הפלאק Aβ ליבה צפופה. זה מאפשר הקרנת טרום סעיפים רקמה המכילה פלאק לפני immunostaining ועיבו?...

Video: Correlative Light and Electron Microscopy to Study Microglial Interactions with β-Amyloid Plaques

Focussed Ion Beam Milling and Scanning Electron Microscopy of Brain Tissue

This protocol describes how biological samples, like brain tissue, can be imaged in three dimensions using the focussed ion beam/scanning electron microscope (FIB/SEM). The samples are fixed with aldehydes, heavy metal stained using osmium tetroxide and uranyl acetate. They are then dehydrated with alcohol and infiltrated with resin, which is then hardened. Using a light microscope and ultramicrotome with glass knives, a small block containing the region interest close to the surface is made. The block is then placed inside the FIB/SEM, and the ion beam used to roughly mill a vertical face along one side of the block, close to this region. Using backscattered electrons to image the underlying structures, a smaller face is then milled with a finer ion beam and the surface scrutinised more closely to determine the exact area of the face to be imaged and milled. The parameters of the microscope are then set so that the face is repeatedly milled and imaged so that serial images are collected through a volume of the block. The image stack will typically contain isotropic voxels with dimenions as small a 4 nm in each direction. This image quality in any imaging plane enables the user to analyse cell ultrastructure at any viewing angle within the image stack.

This protocol describes how resin embedded brain tissue can be prepared and imaged in the three dimensions in the focussed ion beam, scanning electron microscope.

אלומת יונים ממוקדת כרסום מיקרוסקופיית אלקטרונים של רקמת המוח

This protocol describes how biological samples, like brain tissue, can be imaged in three dimensions using the focussed ion beam/scanning electron ...

Light Preference Assay to Study Innate and Circadian Regulated Photobehavior in Drosophila Larvae

Light acts as environmental signal to control animal behavior at various levels. The Drosophila larval nervous system is used as a unique model to answer basic questions on how light information is processed and shared between rapid and circadian behaviors. Drosophila larvae display a stereotypical avoidance behavior when exposed to light. To investigate light dependent behaviors comparably simple light-dark preference tests can be applied. In vertebrates and arthropods the neural pathways involved in sensing and processing visual inputs partially overlap with those processing photic circadian information. The fascinating question of how the light sensing system and the circadian system interact to keep behavioral outputs coordinated remains largely unexplored. Drosophila is an impacting biological model to approach these questions, due to a small number of neurons in the brain and the availability of genetic tools for neuronal manipulation. The presented light-dark preference assay allows the investigation of a range of visual behaviors including circadian control of phototaxis.

Light Preference Assay to Study Innate and Circadian Regulated Photobehavior in Drosophila Larvae

Here we describe a light-dark preference test for Drosophila larva. This assay provides information about innate and circadian regulation of light sensing and processing photobehavior.

Assay העדפות אור לחקר Photobehavior מוסדר מולדת ויממה ב<em&gt; דרוזופילה</em&gt; זחלים

Light acts as environmental signal to control animal behavior at various levels. The Drosophila larval nervous system is used as a unique model to answer ...

Micron-scale Resolution Optical Tomography of Entire Mouse Brains with Confocal Light Sheet Microscopy

Understanding the architecture of mammalian brain at single-cell resolution is one of the key issues of neuroscience. However, mapping neuronal soma and projections throughout the whole brain is still challenging for imaging and data management technologies. Indeed, macroscopic volumes need to be reconstructed with high resolution and contrast in a reasonable time, producing datasets in the TeraByte range. We recently demonstrated an optical method (confocal light sheet microscopy, CLSM) capable of obtaining micron-scale reconstruction of entire mouse brains labeled with enhanced green fluorescent protein (EGFP). Combining light sheet illumination and confocal detection, CLSM allows deep imaging inside macroscopic cleared specimens with high contrast and speed. Here we describe the complete experimental pipeline to obtain comprehensive and human-readable images of entire mouse brains labeled with fluorescent proteins. The clearing and the mounting procedures are described, together with the steps to perform an optical tomography on its whole volume by acquiring many parallel adjacent stacks. We showed the usage of open-source custom-made software tools enabling stitching of the multiple stacks and multi-resolution data navigation. Finally, we illustrated some example of brain maps: the cerebellum from an L7-GFP transgenic mouse, in which all Purkinje cells are selectively labeled, and the whole brain from a thy1-GFP-M mouse, characterized by a random sparse neuronal labeling.

In this article we describe the full experimental procedure to reconstruct, with high resolution, the fine brain anatomy of fluorescently labeled mouse brains. The described protocol includes sample preparation and clearing, specimen mounting for imaging, data post-processing and multi-scale visualization.

מיקרון בקנה מידת רזולוציה אופטית טומוגרפיה של מוח עכבר השלם עם מיקרוסקופית גיליון Confocal אור

Understanding the architecture of mammalian  brain at single-cell resolution is one of the key issues of neuroscience.  However, mapping neuronal soma and ...

Genetic Manipulation of Cerebellar Granule Neurons In Vitro and In Vivo to Study Neuronal Morphology and Migration

Developmental events in the brain including neuronal morphogenesis and migration are highly orchestrated processes. In vitro and in vivo analyses allow for an in-depth characterization to identify pathways involved in these events. Cerebellar granule neurons (CGNs) that are derived from the developing cerebellum are an ideal model system that allows for morphological analyses. Here, we describe a method of how to genetically manipulate CGNs and how to study axono- and dendritogenesis of individual neurons. With this method the effects of RNA interference, overexpression or small molecules can be compared to control neurons. In addition, the rodent cerebellar cortex is an easily accessible in vivo system owing to its predominant postnatal development. We also present an in vivo electroporation technique to genetically manipulate the developing cerebella and describe subsequent cerebellar analyses to assess neuronal morphology and migration.

Genetic Manipulation of Cerebellar Granule Neurons In Vitro and In Vivo to Study Neuronal Morphology and Migration

Neuronal morphogenesis and migration are crucial events underlying proper brain development. Here, we describe methods to genetically manipulate cultured cerebellar granule neurons and the developing cerebellum for the assessment of morphology and migratory characteristics of neurons.

מניפולציה גנטית של Cerebellar גרגיר נוירונים<em&gt; במבחנה</em&gt; ו<em&gt; בVivo</em&gt; ללמוד עצבי מורפולוגיה וגירה

Developmental events in the brain including neuronal morphogenesis and migration are highly orchestrated processes. In vitro and in vivo analyses allow ...

The Olfactory System as a Model to Study Axonal Growth Patterns and Morphology In Vivo

The olfactory system has the unusual capacity to generate new neurons throughout the lifetime of an organism. Olfactory stem cells in the basal portion of the olfactory epithelium continuously give rise to new sensory neurons that extend their axons into the olfactory bulb, where they face the challenge to integrate into existing circuitry. Because of this particular feature, the olfactory system represents a unique opportunity to monitor axonal wiring and guidance, and to investigate synapse formation. Here we describe a procedure for in vivo labeling of sensory neurons and subsequent visualization of axons in the olfactory system of larvae of the amphibian Xenopus laevis. To stain sensory neurons in the olfactory organ we adopt the electroporation technique. In vivo electroporation is an established technique for delivering fluorophore-coupled dextrans or other macromolecules into living cells. Stained sensory neurons and their axonal processes can then be monitored in the living animal either using confocal laser-scanning or multiphoton microscopy. By reducing the number of labeled cells to few or single cells per animal, single axons can be tracked into the olfactory bulb and their morphological changes can be monitored over weeks by conducting series of in vivo time lapse imaging experiments. While the described protocol exemplifies the labeling and monitoring of olfactory sensory neurons, it can also be adopted to other cell types within the olfactory and other systems.

The Olfactory System as a Model to Study Axonal Growth Patterns and Morphology In Vivo

We describe a protocol for in vivo labeling of olfactory sensory neurons by electroporation and subsequent confocal laser-scanning or multiphoton microscopy to visualize neuronal morphology and its development over time.

מערכת חוש הריח כמודל לחקר דפוסי axonal צמיחה ומורפולוגיה<em&gt; In vivo</em

The olfactory system has the unusual capacity to generate new neurons throughout the lifetime of an organism. Olfactory stem cells in the basal portion of ...

A Human Blood-Brain Interface Model to Study Barrier Crossings by Pathogens or Medicines and Their Interactions with the Brain

The early screening of nervous system medicines on a pertinent and reliable in cellulo BBB model for their penetration and their interaction with the barrier and the brain parenchyma is still an unmet need. To fill this gap, we designed a 2D in cellulo model, the BBB-Minibrain, by combining a polyester porous membrane culture insert human BBB model with a Minibrain formed by a tri-culture of human brain cells (neurons, astrocytes and microglial cells). The BBB-Minibrain allowed us to test the transport of a neuroprotective drug candidate (e.g., Neurovita), through the BBB, to determine the specific targeting of this molecule to neurons and to show that the neuroprotective property of the drug was preserved after the drug had crossed the BBB. We have also demonstrated that BBB-Minibrain constitutes an interesting model to detect the passage of virus particles across the endothelial cells barrier and to monitor the infection of the Minibrain by neuroinvasive virus particles. The BBB-Minibrain is a reliable system, easy to handle for researcher trained in cell culture technology and predictive of the brain cells phenotypes after treatment or insult. The interest of such in cellulo testing would be twofold: introducing derisking steps early in the drug development on the one hand and reducing the use of animal testing on the other hand.

Here we present a protocol describing the setting of an in cellulo BBB (Blood brain barrier)-Minibrain polyester porous membrane culture insert system in order to evaluate the transport of biomolecules or infectious agents across a human BBB and their physiological impact on the neighboring brain cells.

מודל ממשק מוח-דם אנושי ללמוד מכשול המעברים על ידי פתוגנים או תרופות והאינטראקציה שלהם עם המוח

The early screening of nervous system medicines on a pertinent and reliable in cellulo BBB model for their penetration and their interaction with the ...

Light-Induced Molecular Adsorption of Proteins Using the PRIMO System for Micro-Patterning to Study Cell Responses to Extracellular Matrix Proteins

Cells sense a variety of extracellular cues, including the composition and geometry of the extracellular matrix, which is synthesized and remodeled by the cells themselves. Here, we present the method of Light-Induced Molecular Adsorption of Proteins (LIMAP) using the PRIMO system as a patterning technique to produce micro-patterned extracellular matrix (ECM) substrates using a single or combination of proteins. The method enables printing of ECM patterns in micron resolution with excellent reproducibility. We provide a step-by-step protocol and demonstrate how this can be applied to study the processes of neuronal pathfinding. LIMAP has significant advantages over existing micro-printing methods in terms of the ease of patterning more than one component and the ability to generate a pattern with any geometry or gradient. The protocol can easily be adapted to study the contribution of almost any chemical component towards cell fate and cell behavior. Finally, we discuss common issues that can arise and how these can be avoided.

Our overall aim is to understand how cells sense extracellular cues that lead to directed axonal growth. Here, we describe the methodology of Light-Induced Molecular Adsorption of Proteins, used to produce defined micro-patterns of extracellular matrix components in order to study specific events that govern axon outgrowth and pathfinding.

המושרה באור Adsorption מולקולרית של חלבונים באמצעות מערכת פרימו עבור מיקרו הפנינג כדי ללמוד התגובות לתא מטריצות חלבונים מטריקס

Cells sense a variety of extracellular cues, including the composition and geometry of the extracellular matrix, which is synthesized and remodeled by the ...

Serial Block-Face Scanning Electron Microscopy (SBEM) for the Study of Dendritic Spines

Three-dimensional electron microscopy (3D EM) gives a possibility to analyze morphological parameters of dendritic spines with nanoscale resolution. In addition, some features of dendritic spines, such as volume of the spine and post-synaptic density (PSD) (representing post-synaptic part of the synapse), presence of presynaptic terminal, and smooth endoplasmic reticulum or atypical form of PSD (e.g., multi-innervated spines), can be observed only with 3D EM. By employing serial block-face scanning electron microscopy (SBEM) it is possible to obtain 3D EM data easier and in a more reproducible manner than when performing traditional serial sectioning. Here we show how to prepare mouse hippocampal samples for SBEM analysis and how this protocol can be combined with immunofluorescence study of dendritic spines. Mild fixation perfusion allows us to perform immunofluorescence studies with light microscopy on one half of the brain, while the other half was prepared for SBEM. This approach reduces the number of animals to be used for the study.

Serial Block-Face Scanning Electron Microscopy SBEM for the Study of Dendritic Spines

Serial Block-Face Scanning Electron Microscopy (SBEM) is applied to image and analyze dendritic spines in the murine hippocampus.

מיקרוסקופיית אלקטרונים סריקה טורית של פרצוף בלוק (SBEM) לחקר קוצים דנדריטים

Three-dimensional electron microscopy (3D EM) gives a possibility to analyze morphological parameters of dendritic spines with nanoscale resolution. In ...

Primary Cultures of Rat Astrocytes and Microglia and Their Use in the Study of Amyotrophic Lateral Sclerosis

This protocol demonstrates how to prepare primary cultures of glial cells, astrocytes, and microglia from the cortices of Sprague Dawley rats and how to use these cells for the purpose of studying the pathophysiology of amyotrophic lateral sclerosis (ALS) in the rat hSOD1G93A model. First, the protocol shows how to isolate and culture astrocytes and microglia from postnatal rat cortices, and then how to characterize and test these cultures for purity by immunocytochemistry using the glial fibrillary acidic protein (GFAP) marker of astrocytes and the ionized calcium-binding adaptor molecule 1 (Iba1) microglial marker. In the next stage, methods are described for dye-loading (calcium-sensitive Fluo 4-AM) of cultured cells and the recordings of Ca2+ changes in video imaging experiments on live cells.
The examples of video recordings consist of: (1) cases of Ca2+ imaging of cultured astrocytes acutely exposed to immunoglobulin G (IgG) isolated from ALS patients, showing a characteristic and specific response compared to the response to ATP as demonstrated in the same experiment. Examples also show a more pronounced transient rise in intracellular calcium concentration evoked by ALS IgG in hSOD1G93A astrocytes compared to non-transgenic controls; (2) Ca2+ imaging of cultured astrocytes during a depletion of calcium stores by thapsigargin (Thg), a non-competitive inhibitor of the endoplasmic reticulum Ca2+ ATPase, followed by store-operated calcium entry elicited by the addition of calcium in the recording solution, which demonstrates the difference between Ca2+ store operation in hSOD1G93A and in non-transgenic astrocytes; (3) Ca2+ imaging of the cultured microglia showing predominantly a lack of response to ALS IgG, whereas ATP application elicited a Ca2+ change. This paper also emphasizes possible caveats and cautions regarding critical cell density and purity of cultures, choosing the correct concentration of the Ca2+ dye and dye-loading techniques.

We present here a protocol on how to prepare primary cultures of glial cells, astrocytes, and microglia from rat cortices for time-lapse video imaging of intracellular Ca2+ for research on pathophysiology of amyotrophic lateral sclerosis in the hSOD1G93A rat model.

תרביות ראשוניות של אסטרוציטים ומיקרוגליה של חולדות והשימוש בהן בחקר טרשת אמיוטרופית צידית

This protocol demonstrates how to prepare primary cultures of glial cells, astrocytes, and microglia from the cortices of Sprague Dawley rats and how to ...

Coherent Anti-Stokes Raman Spectroscopy (CARS) Application for Imaging Myelination in Brain Slices

Coherent anti-Stokes Raman spectroscopy (CARS) is a technique classically employed by chemists and physicists to produce a coherent signal of signature vibrations of molecules. However, these vibrational signatures are also characteristic of molecules within anatomical tissue such as the brain, making it increasingly useful and applicable for Neuroscience applications. For example, CARS can measure lipids by specifically exciting chemical bonds within these molecules, allowing for quantification of different aspects of tissue, such as myelin involved in neurotransmission. In addition, compared to other techniques typically used to quantify myelin, CARS can also be set up to be compatible with immunofluorescent techniques, allowing for co-labeling with other markers such as sodium channels or other components of synaptic transmission. Myelination changes are an inherently important mechanism in demyelinating diseases such as multiple sclerosis or other neurological conditions such as Fragile X Syndrome or autism spectrum disorders is an emerging area of research. In conclusion, CARS can be utilized in innovative ways to answer pressing questions in Neuroscience and provide evidence for underlying mechanisms related to many different neurological conditions.

Coherent Anti-Stokes Raman Spectroscopy CARS Application for Imaging Myelination in Brain Slices

Visualizing myelination is an important goal for many researchers studying the nervous system. CARS is a technique that is compatible with immunofluorescence that can natively image lipids within tissue such as the brain illuminating specialized structures such as myelin.

יישום ספקטרוסקופיית ראמן קוהרנטית נגד סטוקס (CARS) להדמיית מיאלינציה בפרוסות מוח

Coherent anti-Stokes Raman spectroscopy (CARS) is a technique classically employed by chemists and physicists to produce a coherent signal of signature ...

גומל אור מיקרוסקופי אלקטרונים ללמוד microglial אינטראקציות עם הפלאק β-עמילואיד

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