Name: fluorescence and bioluminescence imaging of subcellular ca2+ in aged hippocampal neurons
Uploaded: 2015-12-01T15:00:00.000+00:00
Duration: 13 min 24 s
Description: Watch this Scientific Journal Video about Fluorescence and Bioluminescence Imaging of Subcellular Ca2+ in Aged Hippocampal Neurons at JoVE.com

This work was supported by Ministerio de Econom&#236;a y competitividad (BFU2012-37146) and Junta de Castilla y Le&#242;n (BIO103/VA45/11, VA145U13 and BIO/VA33/13), Spain. MCR was supported by Junta de Castilla y Le&#242;n (Spain) and the European Social Fund. We thank the late Dr. Philippe Br&#251;let (1947-2013) for the mitochondrial GFP Aequorin plasmid.

<ol>
	<li>Sattler, R., Tymianski, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+mechanisms+of+glutamate+receptor-mediated+excitotoxic+neuronal+cell+death.">Molecular mechanisms of glutamate receptor-mediated excitotoxic neuronal cell death.</a> Molecular Neurobiology. 24 (1-3), 107-129 (2001).</li><li>MacDermott, A. B., Mayer, M. L., Westbrook, G. L., Smith, S. J., Barker, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NMDA-receptor+activation+increases+cytoplasmic+calcium+concentration+in+cultured+spinal+cord+neurones.">NMDA-receptor activation increases cytoplasmic calcium concentration in cultured spinal cord neurones.</a> Nature. 321 (6069), 519-522 (1986).</li><li>Choi, D. W., Maulucci-Gedde, M., Kriegstein, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glutamate+neurotoxicity+in+cortical+cell+culture.">Glutamate neurotoxicity in cortical cell culture.</a> The Journal of Neuroscience. 7 (2), 357-368 (1987).</li><li>Kure, S., Tominaga, T., Yoshimoto, T., Tada, K., Narisawa, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glutamate+triggers+internucleosomal+DNA+cleavage+in+neuronal+cells.">Glutamate triggers internucleosomal DNA cleavage in neuronal cells.</a> Biochemical and Biophysical Research Communications. 179 (1), 39-45 (1991).</li><li>Calvo, M., Sanz-Blasco, S., Caballero, E., Villalobos, C., Nunez, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Susceptibility+to+excitotoxicity+in+aged+hippocampal+cultures+and+neuroprotection+by+non-steroidal+anti-inflammatory+drugs:+role+of+mitochondrial+calcium.">Susceptibility to excitotoxicity in aged hippocampal cultures and neuroprotection by non-steroidal anti-inflammatory drugs: role of mitochondrial calcium.</a> Journal of Neurochemistry. 132 (4), 403-417 (2015).</li><li>Liu, Y., 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=NMDA+receptor+subunits+have+differential+roles+in+mediating+excitotoxic+neuronal+death+both+in+vitro+and+in+vivo.">NMDA receptor subunits have differential roles in mediating excitotoxic neuronal death both in vitro and in vivo.</a> The Journal of Neuroscience. 27 (11), 2846-2857 (2007).</li><li>Zhou, M., Baudry, M. <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+NMDA+neurotoxicity+reflect+developmental+changes+in+subunit+composition+of+NMDA+receptors.">Developmental changes in NMDA neurotoxicity reflect developmental changes in subunit composition of NMDA receptors.</a> The Journal of Neuroscience. 26 (11), 2956-2963 (2006).</li><li>Brewer, L. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+vulnerability+of+hippocampal+neurons+with+age+in+culture:+temporal+association+with+increases+in+NMDA+receptor+current,+NR2A+subunit+expression+and+recruitment+of+L-type+calcium+channels.">Increased vulnerability of hippocampal neurons with age in culture: temporal association with increases in NMDA receptor current, NR2A subunit expression and recruitment of L-type calcium channels.</a> Brain Research. 1151, 20-31 (2007).</li><li>Berridge, 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=Calcium+signalling+remodelling+and+disease.">Calcium signalling remodelling and disease.</a> Biochemical Society Transactions. 40 (2), 297-309 (2012).</li><li>Stout, A. K., Raphael, H. M., Kanterewicz, B. I., Klann, E., Reynolds, I. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glutamate-induced+neuron+death+requires+mitochondrial+calcium+uptake.">Glutamate-induced neuron death requires mitochondrial calcium uptake.</a> Nature Neuroscience. 1 (5), 366-373 (1998).</li><li>Pivovarova, N. B., 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=Excitotoxic+calcium+overload+in+a+subpopulation+of+mitochondria+triggers+delayed+death+in+hippocampal+neurons.">Excitotoxic calcium overload in a subpopulation of mitochondria triggers delayed death in hippocampal neurons.</a> The Journal of Neuroscience. 24 (24), 5611-5622 (2004).</li><li>Morris, R. G., Garrud, P., Rawlins, J. N., O'Keefe, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Place+navigation+impaired+in+rats+with+hippocampal+lesions.">Place navigation impaired in rats with hippocampal lesions.</a> Nature. 297 (5868), 681-683 (1982).</li><li>Geinisman, Y., Detoledo-Morrell, L., Morrell, F., Heller, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hippocampal+markers+of+age-related+memory+dysfunction:+behavioral,+electrophysiological+and+morphological+perspectives.">Hippocampal markers of age-related memory dysfunction: behavioral, electrophysiological and morphological perspectives.</a> Progress in Neurobiology. 45 (3), 223-252 (1995).</li><li>Sodero, A. O., Weissmann, C., Ledesma, M. D., Dotti, C. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+stress+from+excitatory+neurotransmission+contributes+to+cholesterol+loss+in+hippocampal+neurons+aging+in+vitro.">Cellular stress from excitatory neurotransmission contributes to cholesterol loss in hippocampal neurons aging in vitro.</a> Neurobiology of Aging. 32 (6), 1043-1053 (2011).</li><li>Brini, M., 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=Transfected+aequorin+in+the+measurement+of+cytosolic+Ca2++concentration+([Ca2+]c).+A+critical+evaluation.">Transfected aequorin in the measurement of cytosolic Ca2+ concentration ([Ca2+]c). A critical evaluation.</a> The Journal of Biological Chemistry. 270 (17), 9896-9903 (1995).</li><li>Villalobos, C., Alonso, M. T., Garc&#236;a-Sancho, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioluminescence+imaging+of+calcium+oscillations+inside+intracellular+organelles.">Bioluminescence imaging of calcium oscillations inside intracellular organelles.</a> Methods in Molecular Biology. 574, 203-214 (2009).</li><li>Villalobos, C., 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=Redistribution+of+Ca2++among+cytosol+and+organella+during+stimulation+of+bovine+chromaffin+cells.">Redistribution of Ca2+ among cytosol and organella during stimulation of bovine chromaffin cells.</a> FASEB Journal. 16, 343-353 (2002).</li><li>Rogers, K. L., 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=Visualization+of+local+Ca2++dynamics+with+genetically+encoded+bioluminescent+reporters.">Visualization of local Ca2+ dynamics with genetically encoded bioluminescent reporters.</a> The European Journal of Neuroscience. 21 (3), 597-610 (2005).</li><li>Barreto-Chang, O. L., Dolmetsch, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+imaging+of+cortical+neurons+using+Fura-2+AM.">Calcium imaging of cortical neurons using Fura-2 AM.</a> Journal of Visualized Experiments. (23), 1067 (2009).</li></ol>

None of the authors have competing interests or conflicting interests.

שיפוץ של Ca 2 + הומאוסטזיס תאיים במוח המזדקן כבר קשור לאובדן הקוגניטיבי, הגדיל את הרגישות לנזק איסכמי, הפעלת יתר רעילה וניוון של מערכת עצבים. כדי לחקור את ההשערה הזאת במבחנה, נהלי ההדמיה Ca 2 + זמינים. למרבה הצער, תרבויות קיימא של נוירונים בהיפוקמפוס ישנים...

הפעלת יתר רעילה היא אחד המנגנונים החשובים ביותר שתרמו לנזק עצבי ומוות של תאים בעלבונות נוירולוגיות כגון איסכמיה, ובחלק ממחלות ניווניות כגון מחלת אלצהיימר 1. סוג זה של רעילויות בעיקר בתיווכו של משחק גלוטמט על Ca 2 +, קולטני -permeable ionotropic NMDA (NMDAR) 2. חשיפה של נוירונים בתרבית לגלוטמט יכולה להוביל להפעלת יתר רעילה 3, מה שגורם לאפופטוזיס העצבי 4. אנו ואחרים דיווחו בעבר כי פגיעות עצביות לאפופטוזיס מושרה NMDA יכולות להשתנות עם התפתחות במבחנה והזדקנות 5-8. זה מקובל שעלייה בריכוז Ca ללא cytosolic 2 + (CYT [Ca 2 +]) מובילה להפעלת תאים. עם זאת, אם עלייה זו היא גבוהה מדי ו / או ספג מספיק, זה יכול לגרום לתא מוות 9. יתר על כן, זה כבר הציעהפעלת יתר רעילה שדורשת Ca 2 + 10 המיטוכונדריה ספיגה, מאז טיפול נוירונים עם נוירונים uncoupler המיטוכונדריה מוגנים מפני מוות של תאים הנגרם גלוטמט 11. אם מיטוכונדריה תופסת הרבה יותר מדי Ca 2 +, הפתיחה הנקבובית מעבר חדירות המיטוכונדריה עלולה להתרחש, שהובילה לשחרורו של ציטוכרום C וגורמים פרו-אפופטוטיים אחרים, ואפופטוזיס התרמה. לאחרונה הראה כי ספיגת Ca 2 + המיטוכונדריה זה קשור באופן ישיר לרגישות תלוית גיל להפעלת יתר רעיל, על ידי מדידה ישירה Ca 2 + ספיגה מושרה NMDA המיטוכונדריה בתאי עצב בהיפוקמפוס יחיד 5, שיטה שבה מדווחת במאמר זה. ההיפוקמפוס, מעורב בתהליכים פיסיולוגיים כגון למידה, זיכרון ותהליכים קוגניטיביים אחרים 12, הוא פגיע מאוד להזדקנות והפרעות ניווניות 13. זה כבר הציע, לאחר מספר שבועות במבחנה, בתרביתנוירונים בהיפוקמפוס להראות מספר המאפיינים הטיפוסיים של נוירונים בגיל 14. בהתאם לכך, תאי עצב בהיפוקמפוס תרבותיים ארוך טווח עשוי לספק מודל מקיף כדי לחקור Ca 2 + מנגנוני תיווך של הפעלת יתר רעילה משופר בהזדקנות. המטרה הכוללת של השיטה שהוצגה היא, אפוא, לחקור שינויים מהותיים בCa 2 + הומאוסטזיס תאיים או שיפוץ Ca 2 + במוח המזדקן כולל תגובות ההפרש Ca 2 + שהושרו על ידי אגוניסטים הקולטן NMDA בנוירונים בהיפוקמפוס תרבותיים לטווח ארוך . השיטה כוללת תיאור מפורט של התרבות של תאי עצב בהיפוקמפוס חולדה והניטור של 2 + ריכוזי Ca cytosolic והמיטוכונדריה על ידי הקרינה והדמיה פליטת אור בנוירונים בודדים, בהתאמה. הדמיה הקרינה של 2 + Ca cytosolic בנוירונים בתרבית היא הליך סטנדרטי. עם זאת, שיטה זו היא פחות אמינה למשנההסלולרי Ca 2 + מדידות כוללים Ca 2 + המיטוכונדריה. סיבות לכך כוללות חוסר המיקוד הנכון של בדיקות סינתטיות וזיקה הולמת לCa 2 + ריכוזים שעשויות לשנות במיטוכונדריה מרמת מיקרומטר הנמוכה אפילו לרמת מ&quot;מ. השימוש בבדיקות 2 + Ca מבוססים על חלבונים כלaequorin למשל, אפשרו מיקוד לאברונים subcellular ושימוש בנגזרים שונים Ca 2 + זיקות באמצעות coelenterazines שונה או בדיקות שעברו מוטציה חסרת Ca 2 + אתרי קישור ספציפי 15. בדרך זו, הדמיה פליטת אור של תאים לבטא aequorin-ממוקד מיטוכונדריה עשויה לאפשר הניטור של Ca 2 + ריכוזים של המיטוכונדריה בתאי עצב בודד. עם זאת, הליך זה עשוי לדרוש שימוש במצלמות ספירת פוטון או מצלמות CCD רגישות להדמיה פליטת אור 16-18. שיטה זו עשויה להניב תוצאות רומן שצריך להיות מאושרת יותר establמודלים ished הזדקנות המוח כמו, למשל, פרוסות מוח מבעלי חיים ישנים.

<table><tbody><tr><td>Neurobasal Culture Medium</td><td>Gibco</td><td>21103-049</td><td></td></tr><tr><td>HBSS medium</td><td>Gibco</td><td>14170-088</td><td></td></tr><tr><td>Ham&#039;s F-12 medium</td><td>Gibco</td><td>31330-038</td><td></td></tr><tr><td>DNase I (from bovine pancreas)</td><td>Sigma</td><td>D5025-15KU</td><td></td></tr><tr><td>Fetal Bobine Serum</td><td>Lonza</td><td>DE14-801E</td><td></td></tr><tr><td>B27</td><td>Gibco</td><td>17504-044</td><td></td></tr><tr><td>Gentamicin</td><td>Gibco</td><td>15750</td><td></td></tr><tr><td>L-glutamine</td><td>Gibco</td><td>25030-032</td><td></td></tr><tr><td>12 mm glass coverslips</td><td>Labolan</td><td>0111520/20012</td><td></td></tr><tr><td>Papain</td><td>Worthington</td><td>LS003127</td><td></td></tr><tr><td>4-well multidish plaques</td><td>Nunc</td><td>176740</td><td></td></tr><tr><td>Petry dishes</td><td>JD Catalan s.l.</td><td>2120044T</td><td></td></tr><tr><td>Sterile pipettes</td><td>Fisher Scientific</td><td>431030</td><td></td></tr><tr><td>Fura2-AM</td><td>Life Technologies</td><td>F1201</td><td></td></tr><tr><td>Lipofectamine2000</td><td>Invitrogen</td><td>11668-027</td><td></td></tr><tr><td>Coelenterazine n</td><td>Biotium</td><td>BT-10115-2250 uG</td><td></td></tr><tr><td>Digitonin</td><td>Sigma</td><td>D5628</td><td></td></tr><tr><td>NMDA</td><td>Sigma&amp;nbsp;</td><td>M3262</td><td></td></tr><tr><td>Glycine</td><td>Sigma</td><td>50046</td><td></td></tr><tr><td>Zeiss Axiovert S100 TV microscope</td><td>Carl Zeiss Inc.</td><td></td><td></td></tr><tr><td>Xcite ilumination system</td><td>EXFO</td><td></td><td></td></tr><tr><td>ORCA ER fluorescence camera</td><td>Hamamatsu</td><td></td><td></td></tr><tr><td>VIM photon counting CCD camera</td><td>Hamamatsu</td><td></td><td></td></tr><tr><td>VC-8 valve controller</td><td>Warner Instruments</td><td></td><td></td></tr><tr><td>SH-27B heating system&amp;nbsp;</td><td>Warner Instruments</td><td></td><td></td></tr><tr><td>Aquacosmos Software</td><td>Hamamatsu Photonics</td><td></td><td></td></tr></tbody></table>

fluorescence and bioluminescence imaging of subcellular ca2+ in aged hippocampal neurons

רגישות למוות של תאי עצב הקשורים לניוון של מערכת עצבים ואיסכמיה גדלה מאוד במוח בגיל אבל מנגנונים אחראים ידועים קשה. הפעלת יתר רעילה, תהליך האמין לתרום לניזק הנגרם על ידי תא עצב שני העלבונות, מתווכת על ידי הפעלה של קולטני גלוטמט שמקדם Ca 2 + זרם ועומס Ca 2 + המיטוכונדריה. שינוי מהותי בCa 2 + הומאוסטזיס או שיפוץ תאיים של הומאוסטזיס Ca 2 + תאיים עשוי להעדיף נזק נוירון בנוירונים ישנים. לחקירת שיפוץ Ca 2 + בהזדקנות השתמשנו הדמיה תא חי בתרבויות ארוכת טווח של תאי עצב בהיפוקמפוס העכברוש שדומות בכמה היבטים בגילי נוירונים in vivo. לשם כך, תאים בהיפוקמפוס הם, במקום הראשון, התפזרו טרי מhippocampi החולדה נולדה חדשה ומצופה על coverslips מצופה, זכוכית Poli-D ליזין. אז תרבויות נשמרות בתקשורת מבוקרת במשך כמה ימים או כמה weeks לחקירת נוירונים צעירים וזקנים, בהתאמה. שנית, נוירונים בתרבית נטענים עם fura2 ונתונים למדידות של ריכוז Ca 2 + cytosolic באמצעות הדמיה יחס הקרינה דיגיטלית. שלישית, נוירונים בתרבית הם transfected עם פלסמידים להביע טנדם של aequorin נמוכה הזיקה וGFP הממוקד למיטוכונדריה. לאחר 24 שעות, aequorin בתוך תאים מחדש עם coelenterazine ונוירונים חשופים להדמית פליטת אור לניטור של ריכוז Ca 2 + המיטוכונדריה. הליך בן שלושת שלבים זה מאפשר הניטור של cytosolic ותגובות Ca 2 + המיטוכונדריה לגירויים רלוונטיים כמו למשל אגוניסט קולטן גלוטמט NMDA ולהשוות בין תגובות אלה ואחרים מושפעות הזדקנות. הליך זה עשוי להניב תובנות חדשות באשר לאופן הזדקנות cytosolic השפעה ותגובות המיטוכונדריה Ca 2 + לגירויים שנבחרו, כמו גם הבדיקות של תרופות שנבחרו נועדו למנוע תא עצבמוות במחלות הקשורות לגיל.

כאן אנו מתארים שיטה פשוטה להעריך שיפוץ Ca 2 + ואת ההשפעות של NMDA בcytosolic והמיטוכונדריה [Ca 2 +] בתאי עצב בגיל. איור 1 מציג את סכמטי של הליך הבידוד וculturing תאי עצב בהיפוקמפוס של חולדות בילוד. לפני שמתחיל, אנחנו צריכים להכין coverslips סטרילי, פולי-D ליזין המצופה, ז?...

Watch this Scientific Journal Video about Fluorescence and Bioluminescence Imaging of Subcellular Ca2+ in Aged Hippocampal Neurons at JoVE.com

Fluorescence and Bioluminescence Imaging of Subcellular Ca2+ in Aged Hippocampal Neurons

Intracellular Ca2+ remodeling in aging may contribute to excitotoxicity and neuron damage, processes mediated by Ca2+ overload. We aimed at investigating Ca2+ remodeling in the aging brain using fluorescence and bioluminescence imaging of cytosolic and mitochondrial Ca2+ in long-term cultures of rat hippocampal neurons, a model of neuronal aging.

הקרינה ופליטת אור הדמיה של Ca subcellular<sup&gt; 2 +</sup&gt; בבני נוירונים בהיפוקמפוס

Susceptibility to neuron cell death associated to neurodegeneration and ischemia are exceedingly increased in the aged brain but mechanisms responsible ...

fluorescence-bioluminescence-imaging-subcellular-ca2-aged-hippocampal

Research

JoVE Journal

Neuroscience

Fluorescence and Bioluminescence Imaging of Subcellular Ca2+ in Aged Hippocampal Neurons

8.3K Views.  Consejo Superior de Investigaciones Cientìficas. Intracellular Ca2+ remodeling in aging may contribute to excitotoxicity and neuron damage, processes mediated by Ca2+ overload. We aimed at investigating Ca2+ remodeling in the aging brain using fluorescence and bioluminescence imaging of cytosolic and mitochondrial Ca2+ in long-term cultures of rat hippocampal neurons, a model of neuronal aging. 

Video: Fluorescence and Bioluminescence Imaging of Subcellular Ca2+ in Aged Hippocampal Neurons

Imaging Calcium Responses in GFP-tagged Neurons of Hypothalamic Mouse Brain Slices

Despite an enormous increase in our knowledge about the mechanisms underlying the encoding of information in the brain, a central question concerning the precise molecular steps as well as the activity of specific neurons in multi-functional nuclei of brain areas such as the hypothalamus remain. This problem includes identification of the molecular components involved in the regulation of various neurohormone signal transduction cascades. Elevations of intracellular Ca2+ play an important role in regulating the sensitivity of neurons, both at the level of signal transduction and at synaptic sites.
New tools have emerged to help identify neurons in the myriad of brain neurons by expressing green fluorescent protein (GFP) under the control of a particular promoter. To monitor both spatially and temporally stimulus-induced Ca2+ responses in GFP-tagged neurons, a non-green fluorescent Ca2+ indicator dye needs to be used. In addition, confocal microscopy is a favorite method of imaging individual neurons in tissue slices due to its ability to visualize neurons in distinct planes of depth within the tissue and to limit out-of-focus fluorescence. The ratiometric Ca2+ indicator fura-2 has been used in combination with GFP-tagged neurons1. However, the dye is excited by ultraviolet (UV) light. The cost of the laser and the limited optical penetration depth of UV light hindered its use in many laboratories. Moreover, GFP fluorescence may interfere with the fura-2 signals2. Therefore, we decided to use a red fluorescent Ca2+ indicator dye. The huge Stokes shift of fura-red permits multicolor analysis of the red fluorescence in combination with GFP using a single excitation wavelength. We had previously good results using fura-red in combination with GFP-tagged olfactory neurons3. The protocols for olfactory tissue slices seemed to work equally well in hypothalamic neurons4. Fura-red based Ca2+ imaging was also successfully combined with GFP-tagged pancreatic &beta;-cells and GFP-tagged receptors expressed in HEK cells5,6. A little quirk of fura-red is that its fluorescence intensity at 650 nm decreases once the indicator binds calcium7. Therefore, the fluorescence of resting neurons with low Ca2+ concentration has relatively high intensity. It should be noted, that other red Ca2+-indicator dyes exist or are currently being developed, that might give better or improved results in different neurons and brain areas.

In this protocol, we update recent progress in imaging Ca2+ signals of GFP-tagged neurons in brain tissue slices using a red fluorescent Ca2+ indicator dye.

תגובות סידן הדמיה בנוירונים GFP-tagged של פרוסות מוח עכבר ההיפותלמוס

Despite an enormous increase in our knowledge about the mechanisms underlying the encoding of information in the brain, a central question concerning the ...

Characterization of Amyloid Structures in Aging C. Elegans Using Fluorescence Lifetime Imaging

Amyloid fibrils are associated with a number of neurodegenerative diseases such as Huntington&#39;s, Parkinson&#39;s, or Alzheimer&#39;s disease. These amyloid fibrils can sequester endogenous metastable proteins as well as components of the proteostasis network (PN) and thereby exacerbate protein misfolding in the cell. There are a limited number of tools available to assess the aggregation process of amyloid proteins within an animal. We present a protocol for fluorescence lifetime microscopy (FLIM) that allows monitoring as well as quantification of the amyloid fibrilization in specific cells, such as neurons, in a noninvasive manner and with the progression of aging and upon perturbation of the PN. FLIM is independent of the expression levels of the fluorophore and enables an analysis of the aggregation process without any further staining or bleaching. Fluorophores are quenched when they are in close vicinity of amyloid structures, which results in a decrease of the fluorescence lifetime. The quenching directly correlates with the aggregation of the amyloid protein. FLIM is a versatile technique that can be applied to compare the fibrilization process of different amyloid proteins, environmental stimuli, or genetic backgrounds in vivo in a non-invasive manner.

Characterization of Amyloid Structures in Aging C. Elegans Using Fluorescence Lifetime Imaging

Fluorescence lifetime imaging monitors, quantifies and distinguishes the aggregation tendencies of proteins in living, aging, and stressed C. elegans disease models.

אפיון מבני עמילואיד בהזדקנות C. אלגיה באמצעות הדמיה של תקופת החיים הפלואורסצנטית

Amyloid fibrils are associated with a number of neurodegenerative diseases such as Huntington&#39;s, Parkinson&#39;s, or Alzheimer&#39;s disease. These ...

Biochemistry

Longitudinal Two-Photon Imaging of Dorsal Hippocampal CA1 in Live Mice

Two-photon microscopy is a fundamental tool for neuroscience as it permits investigation of the brain of live animals at spatial scales ranging from subcellular to network levels and at temporal scales from milliseconds to weeks. In addition, two-photon imaging can be combined with a variety of behavioral tasks to explore the causal relationships between brain function and behavior. However, in mammals, limited penetration and scattering of light have limited two-photon intravital imaging mostly to superficial brain regions, thus precluding longitudinal investigation of deep-brain areas such as the hippocampus. The hippocampus is involved in spatial navigation and episodic memory and is a long-standing model used to study cellular as well as cognitive processes important for learning and recall, both in health and disease. Here, a preparation that enables chronic optical access to the dorsal hippocampus in living mice is detailed. This preparation can be combined with two-photon optical imaging at cellular and subcellular resolution in head fixed, anesthetized live mice over several weeks. These techniques enable repeated imaging of neuronal structure or activity-evoked plasticity in tens to hundreds of neurons in the dorsal hippocampal CA1. Furthermore, this chronic preparation can be used in combination with other techniques such as micro-endoscopy, head-mounted wide field microscopy or three-photon microscopy, thus greatly expanding the toolbox to study cellular and network processes involved in learning and memory.

This method describes a chronic preparation that allows optical access to the hippocampus of living mice. This preparation can be used to perform longitudinal optical imaging of neuronal structural plasticity and activity-evoked cellular plasticity over a period of several weeks.

אורך שני-פוטון הדמיה של CA1 היפוקמאל בעכברים חיים

Two-photon microscopy is a fundamental tool for neuroscience as it permits investigation of the brain of live animals at spatial scales ranging from ...

Behavior

Fluorescent Calcium Imaging and Subsequent In Situ Hybridization for Neuronal Precursor Characterization in Xenopus laevis

Spontaneous intracellular calcium activity can be observed in a variety of cell types and is proposed to play critical roles in a variety of physiological processes. In particular, appropriate regulation of calcium activity patterns during embryogenesis is necessary for many aspects of vertebrate neural development, including proper neural tube closure, synaptogenesis, and neurotransmitter phenotype specification. While the observation that calcium activity patterns can differ in both frequency and amplitude suggests a compelling mechanism by which these fluxes might transmit encoded signals to downstream effectors and regulate gene expression, existing population-level approaches have lacked the precision necessary to further explore this possibility. Furthermore, these approaches limit studies of the role of cell-cell interactions by precluding the ability to assay the state of neuronal determination in the absence of cell-cell contact. Therefore, we have established an experimental workflow that pairs time-lapse calcium imaging of dissociated neuronal explants with a fluorescence in situ hybridization assay, allowing the unambiguous correlation of calcium activity pattern with molecular phenotype on a single-cell level. We were successfully able to use this approach to distinguish and characterize specific calcium activity patterns associated with differentiating neural cells and neural progenitor cells, respectively; beyond this, however, the experimental framework described in this article could be readily adapted to investigate correlations between any time-series activity profile and expression of a gene or genes of interest.

Fluorescent Calcium Imaging and Subsequent In Situ Hybridization for Neuronal Precursor Characterization in Xenopus laevis

We present a two-part protocol that combines fluorescent calcium imaging with in situ hybridization, allowing the experimenter to correlate patterns of calcium activity with gene expression profiles on a single-cell level.

סידן פלואורסצנטי הדמיה ובעקבות היברידיזציה באתרו לאפיון עצבי בלתי מבשר בקספוס זריזה

Spontaneous intracellular calcium activity can be observed in a variety of cell types and is proposed to play critical roles in a variety of physiological ...

Developmental Biology

Multi-photon Intracellular Sodium Imaging Combined with UV-mediated Focal Uncaging of Glutamate in CA1 Pyramidal Neurons

Multi-photon fluorescence microscopy has enabled the analysis of morphological and physiological parameters of brain cells in the intact tissue with high spatial and temporal resolution. Combined with electrophysiology, it is widely used to study activity-related calcium signals in small subcellular compartments such as dendrites and dendritic spines. In addition to calcium transients, synaptic activity also induces postsynaptic sodium signals, the properties of which are only marginally understood. Here, we describe a method for combined whole-cell patch-clamp and multi-photon sodium imaging in cellular micro domains of central neurons. Furthermore, we introduce a modified procedure for ultra-violet (UV)-light-induced uncaging of glutamate, which allows reliable and focal activation of glutamate receptors in the tissue. To this end, whole-cell recordings were performed on Cornu Ammonis subdivision 1 (CA1) pyramidal neurons in acute tissue slices of the mouse hippocampus. Neurons were filled with the sodium-sensitive fluorescent dye SBFI through the patch-pipette, and multi-photon excitation of SBFI enabled the visualization of dendrites and adjacent spines. To establish UV-induced focal uncaging, several parameters including light intensity, volume affected by the UV uncaging beam, positioning of the beam as well as concentration of the caged compound were tested and optimized. Our results show that local perfusion with caged glutamate (MNI-Glutamate) and its focal UV-uncaging result in inward currents and sodium transients in dendrites and spines. Time course and amplitude of both inward currents and sodium signals correlate with the duration of the uncaging pulse. Furthermore, our results show that intracellular sodium signals are blocked in the presence of blockers for ionotropic glutamate receptors, demonstrating that they are mediated by sodium influx though this pathway. In summary, our method provides a reliable tool for the investigation of intracellular sodium signals induced by focal receptor activation in intact brain tissue.

We describe the combination of focal UV-induced photo-activation of neuro-active compounds with whole-cell patch-clamp and multi-photon imaging of intracellular sodium transients in dendrites and spines of hippocampal neurons in acute tissue slices of the mouse brain.

רב פוטון תאית נתרן הדמיה בשילוב עם משחרר רפרוף מיקוד בתיווך UV של גלוטמט בCA1 פירמידת נוירונים

Multi-photon fluorescence microscopy has enabled the analysis of morphological and physiological parameters of brain cells in the intact tissue with high ...

In Vivo Functional Brain Imaging Approach Based on Bioluminescent Calcium Indicator GFP-aequorin

Functional in vivo imaging has become a powerful approach to study the function and physiology of brain cells and structures of interest. Recently a new method of Ca2+-imaging using the bioluminescent reporter GFP-aequorin (GA) has been developed. This new technique relies on the fusion of the GFP and aequorin genes, producing a molecule capable of binding calcium and&#160;&#8212; with the addition of its cofactor coelenterazine &#8212; emitting bright light that can be monitored through a photon collector. Transgenic lines carrying the GFP-aequorin gene have been generated for both mice and Drosophila. In Drosophila, the GFP-aequorin gene has been placed under the control of the GAL4/UAS binary expression system allowing for targeted expression and imaging within the brain. This method has subsequently been shown to be capable of detecting both inward Ca2+-transients and Ca2+-released from inner stores. Most importantly it allows for a greater duration in continuous recording, imaging at greater depths within the brain, and recording at high temporal resolutions (up to 8.3 msec). Here we present the basic method for using bioluminescent imaging to record and analyze Ca2+-activity within the mushroom bodies, a structure central to learning and memory in the fly brain.

In Vivo Functional Brain Imaging Approach Based on Bioluminescent Calcium Indicator GFP-aequorin

Here we present a novel Ca2+-imaging approach using a bioluminescent reporter. This approach uses a fused construct GFP-aequorin which binds to Ca2+ and emits light, eliminating the need for light excitation. Significantly this method permits long continuous imaging, access to deep brain structures and high temporal resolution.

בגישת ההדמיה התפקודי של מוח Vivo בהתבסס על סידן Bioluminescent המחוון GFP-aequorin

Functional in vivo imaging has become a powerful approach to study the function and physiology of brain cells and structures of interest. Recently a new ...

Two-photon Calcium Imaging in Neuronal Dendrites in Brain Slices

Calcium (Ca2+) imaging is a powerful tool to investigate the spatiotemporal dynamics of intracellular Ca2+ signals in neuronal dendrites. Ca2+ fluctuations can occur through a variety of membrane and intracellular mechanisms and play a crucial role in the induction of synaptic plasticity and regulation of dendritic excitability. Hence, the ability to record different types of Ca2+ signals in dendritic branches is valuable for groups studying how dendrites integrate information. The advent of two-photon microscopy has made such studies significantly easier by solving the problems inherent to imaging in live tissue, such as light scattering and photodamage. Moreover, through combination of conventional electrophysiological techniques with two-photon Ca2+ imaging, it is possible to investigate local Ca2+ fluctuations in neuronal dendrites in parallel with recordings of synaptic activity in soma. Here, we describe how to use this method to study the dynamics of local Ca2+ transients (CaTs) in dendrites of GABAergic inhibitory interneurons. The method can be also applied to studying dendritic Ca2+ signaling in different neuronal types in acute brain slices.

We present a method combining whole-cell patch-clamp recordings and two-photon imaging to record Ca2+ transients in neuronal dendrites in acute brain slices.

שני הפוטונים סידן הדמיה של דנדריטים עצביים במוח פרוסות

Calcium (Ca2+) imaging is a powerful tool to investigate the spatiotemporal dynamics of intracellular Ca2+ signals in neuronal dendrites. Ca2+ ...

Real-Time Fluorescent Measurement of Synaptic Functions in Models of Amyotrophic Lateral Sclerosis

Before neuronal degeneration, the cause of motor and cognitive deficits in patients with amyotrophic lateral sclerosis (ALS) and/or frontotemporal lobe dementia (FTLD) is dysfunction of communication between neurons and motor neurons and muscle. The underlying process of synaptic transmission involves membrane depolarization-dependent synaptic vesicle fusion and the release of neurotransmitters into the synapse. This process occurs through localized calcium influx into the presynaptic terminals where synaptic vesicles reside. Here, the protocol describes fluorescence-based live-imaging methodologies that reliably report depolarization-mediated synaptic vesicle exocytosis and presynaptic terminal calcium influx dynamics in cultured neurons.
Using a styryl dye that is incorporated into synaptic vesicle membranes, the synaptic vesicle release is elucidated. On the other hand, to study calcium entry, Gcamp6m is used, a genetically encoded fluorescent reporter. We employ high potassium chloride-mediated depolarization to mimic neuronal activity. To quantify synaptic vesicle exocytosis unambiguously, we measure the loss of normalized styryl dye fluorescence as a function of time. Under similar stimulation conditions, in the case of calcium influx, Gcamp6m fluorescence increases. Normalization and quantification of this fluorescence change are performed in a similar manner to the styryl dye protocol. These methods can be multiplexed with transfection-based overexpression of fluorescently tagged mutant proteins. These protocols have been extensively used to study synaptic dysfunction in models of FUS-ALS and C9ORF72-ALS, utilizing primary rodent cortical and motor neurons. These protocols easily allow for rapid screening of compounds that may improve neuronal communication. As such, these methods are valuable not only for the study of ALS but for all areas of neurodegenerative and developmental neuroscience research.

Two related methods are described to visualize subcellular events required for synaptic transmission. These protocols enable the real-time monitoring of the dynamics of presynaptic calcium influx and synaptic vesicle membrane fusion using live-cell imaging of in vitro cultured neurons.

מדידה פלואורסצנטית בזמן אמת של פונקציות סינפטיות במודלים של טרשת אמיוטרופית לרוחב

Before neuronal degeneration, the cause of motor and cognitive deficits in patients with amyotrophic lateral sclerosis (ALS) and/or frontotemporal lobe ...

Subcellular Imaging of Neuronal Calcium Handling In Vivo

Calcium (Ca2+) imaging has been largely used to examine neuronal activity, but it is becoming increasingly clear that subcellular Ca2+ handling is a crucial component of intracellular signaling. The visualization of subcellular Ca2+ dynamics in vivo,&#160;where neurons can be studied in their native, intact circuitry, has proven technically challenging in complex nervous systems. The transparency and relatively simple nervous system of the nematode Caenorhabditis elegans enable the cell-specific expression and in vivo visualization of fluorescent tags and indicators. Among these are fluorescent indicators that have been modified for use in the cytoplasm as well as various subcellular compartments, such as the mitochondria. This protocol enables non-ratiometric Ca2+ imaging in vivo with a subcellular resolution that permits the analysis of Ca2+ dynamics down to the level of individual dendritic spines and mitochondria. Here, two available genetically encoded indicators with different Ca2+ affinities are used to demonstrate the use of this protocol for measuring relative Ca2+ levels within the cytoplasm or mitochondrial matrix in a single pair of excitatory interneurons (AVA). Together with the genetic manipulations and longitudinal observations possible in C. elegans, this imaging protocol may be useful for answering questions regarding how Ca2+ handling regulates neuronal function and plasticity.

Subcellular Imaging of Neuronal Calcium Handling In Vivo

The current methods describe a non-ratiometric approach for high-resolution, sub-compartmental calcium imaging in vivo in Caenorhabditis elegans using readily available genetically encoded calcium indicators.

הדמיה תת-תאית של טיפול בסידן עצבי ב-Vivo

Calcium (Ca2+) imaging has been largely used to examine neuronal activity, but it is becoming increasingly clear that subcellular Ca2+ handling is a ...

הקרינה ופליטת אור הדמיה של Ca subcellular

Summary

Explore More Videos

Chapters in this video