ברצוננו להודות מיכאל Feyder ו טרל הולוויי על סיועם במהלך ההגדרה הראשונית במעלה של טכניקת מעבדה ד&quot;ר פומי של אונו עבור גישה אל מיקרוסקופ confocal שלהם. מחקר זה מומן על ידי המכון הלאומי לבריאות בארה&quot;ב באמצעות תוכנית עירונית של NIAAA ו NINDS.

<ol>
	<li>Gan, W. B., Grutzendler, J., Wong, W. T., Wong, R. O., Lichtman, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multicolor+"DiOLISTIC"+labeling+of+the+nervous+system+using+lipophilic+dye+combinations.">Multicolor "DiOLISTIC" labeling of the nervous system using lipophilic dye combinations.</a> Neuron. 27, 219-225 (2000).</li><li>Gan, W. B., Grutzendler, J., Wong, R. O., Lichtman, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ballistic+delivery+of+dyes+for+structural+and+functional+studies+of+the+nervous+system.">Ballistic delivery of dyes for structural and functional studies of the nervous system.</a> Cold Spring Harb Protoc. , pdb.prot5202-pdb.prot5202 (2009).</li><li>Grutzendler, J., Tsai, J., Gan, W. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+labeling+of+neuronal+populations+by+ballistic+delivery+of+fluorescent+dyes.">Rapid labeling of neuronal populations by ballistic delivery of fluorescent dyes.</a> Methods. 30, 79-85 (2003).</li><li>Lee, K. W., Kim, Y., Kim, A. M., Helmin, K., Nairn, A. C., Greengard, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cocaine-induced+dendritic+spine+formation+in+D1+and+D2+dopamine+receptor-containing+medium+spiny+neurons+in+nucleus+accumbens.">Cocaine-induced dendritic spine formation in D1 and D2 dopamine receptor-containing medium spiny neurons in nucleus accumbens.</a> Proc. Natl. Acad. Sci. U S A. 103, 3399-3404 (2006).</li><li>Matsubayashi, Y., Iwai, L., Kawasaki, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+double-labeling+with+carbocyanine+neuronal+tracing+and+immunohistochemistry+using+a+cholesterol-specific+detergent+digitonin.">Fluorescent double-labeling with carbocyanine neuronal tracing and immunohistochemistry using a cholesterol-specific detergent digitonin.</a> J Neurosci Methods. 174, 71-81 (2008).</li><li>Neely, S. t. a. n. w. o. o. d., Deutch, G. D., Y, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combination+of+diOlistic+labeling+with+retrograde+tract+tracing+and+immunohistochemistry.">Combination of diOlistic labeling with retrograde tract tracing and immunohistochemistry.</a> J Neurosci Methods. 184, 332-336 (2009).</li><li>O'Brien, J. A., Lummis, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diolistics:+incorporating+fluorescent+dyes+into+biological+samples+using+a+gene+gun.">Diolistics: incorporating fluorescent dyes into biological samples using a gene gun.</a> Trends Biotechnol. 25, 530-534 (2007).</li><li>Shen, H. W., Toda, S., Moussawi, K., Bouknight, A., Zahm, D. S., Kalivas, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Altered+dendritic+spine+plasticity+in+cocaine-+withdrawn+rats.">Altered dendritic spine plasticity in cocaine- withdrawn rats.</a> J. Neurosci. 29, 2876-2884 (2009).</li></ol>

הנהלים כל חיה בוצעו בעקבות הדרכה טיפול בבעלי חיים ועדת השתמש ב NIAAA ואת הלאומית אורגון מרכז מחקר הפרימאטים. המחברים אין לחשוף.

תיוג DiOLISTIC הוא אחד המגוונים ביותר טכניקות זמין עבור התאים fluorescently תיוג כי זה יכול להיות מיושם על חלקים רקמות ממינים שונים, למגוון רחב של גילאים, וכדי להשיג רקמה טרי או מקבע-perfused בעלי חיים (ראה גם גן ואח&#39; . 2009). התהליך הוא מהיר יחסית כמו זה לוקח 1-2 ימים וזה יכול להיות בשילוב עם גישות אחרות תיוג קלאסיים יותר כגון immunostaining (Lee et al. 2006). תשומת לב מיוחדת צריך להיות משולם להימנע על תיקון ושימוש ריכוזי חומר ניקוי גבוה פתרונות הדגירה כי אלה יהוו את שלמות הממברנה lipophilic ולגרום לצבוע לדלוף של התאים. חדירה נוגדן יכול להיות בהנחייתם של ריכוזים נמוכים של טריטון X-100 (Lee et al., 2006), כמו גם digitonin או saponin בפתרון הדגירה (Matsubayashi et al. 2008). כמה שינויים כי ניתן ליישם טכניקה זו כוללות את השימוש בכדורי עם צבעים מרובים כפי שתואר על ידי גן et al. (2000) או לשנות את אורך וסוג החשיפה נוגדן (Neely et al. 2009). באופן מסורתי, DiI נעשה שימוש כדי להתחקות אחר תחזיות העצבית במוח. תיוג DiOLISTIC מרחיבה את היישום שלה באמצעות תיאור שיטה שימושית לבדיקת מורפולוגיה התא. מורפולוגיה העצבית מעוררת עניין רב בשל המגוון הגדול נמצא המוח ספקולציות כי צורת התא יכול לחשוב על ריבוי פונקציה של אוכלוסיות נוירונים במערכת העצבים. אחת הדוגמאות לכך היא העובדה כי נוירונים רבים בליטה יונקים מערכת העצבים להציג קטן בשם הקוצים הדנדריטים כי הם באתר של סינפסות glutamatergic. בדרך זו, צפיפות של סינפסות glutamatergic על תא יכול להיות בקורלציה לצפיפות של הקוצים הדנדריטים, אשר ניתן למדוד באמצעות טכניקה תיוג המתוארים כאן. יתר על כן, פרמטרים מורפולוגיים אחרים כגון האורך הכולל דנדריט, דפוס הסתעפות בצורת עמוד השדרה הדנדריטים וצפיפות ניתן לכמת ולמד. השימוש תיוג פלורסנט לחקר המורפולוגיה העצבית יש יתרונות רבים לעומת טכניקות מסורתיות יותר המסתמכים על מיקרוסקופ שדה בהיר (למשל מכתים Golgi) כי זה מאפשר הדמיה ברזולוציה גבוהה confocal. יתרון נוסף של השימוש DiI כמו fluorophore בניסויים שמטרתם מדידת צפיפות עמוד השדרה הדנדריטים ומורפולוגיה הוא lipophilic המאפיינים שלה. מחיצות DiI לתוך הממברנה פלזמה ומספק מתאר מוגדרים היטב של תהליכים עצביים ועל בליטות הדנדריטים. לאור הנפח הקטן של הקוצים הדנדריטים ביותר (פחות מ 1 femtoliter), מכתים קרום הוא יעיל יותר ומאפשר ראיה טובה יותר, דק יותר מאשר בליטות קטנות מכתים cytoplasmic.

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diolistic labeling of neurons from rodent and non-human primate brain slices

מכתים DiOLISTIC משתמש באקדח הגן להציג צבעי ניאון, כגון DiI, לתוך הנוירונים של פרוסות המוח (גן et al, 2009;. אובריין Lummis, 2007; גן et al, 2000).. כאן אנו מספקים תיאור מפורט של כל צעד נדרש יחד עם תמונות למופת של תוצאות טובות ורעות, שיסייע בעת הגדרת את הטכניקה. מניסיוננו, כמה צעדים הוכיח קריטי עבור יישום מוצלח של DiOLISTICS. שיקולים אלה כוללים את איכות DiI מצופים גומי, היקף החשיפה מקבע, ואת הריכוז של חומר הניקוי המשמשים את פתרונות הדגירה. טיפים ופתרונות לבעיות נפוצות מסופקים. זוהי טכניקה תיוג צדדי כי ניתן להחיל על בעלי חיים מרובים בו מגוון רחב של גילאים. שלא כמו אחרים בטכניקות תיוג פלורסנט כי מוגבלים ההכנות של בעלי חיים צעירים או מוגבלת עכברים, כי הם מסתמכים על הביטוי של transgene ניאון, תיוג DiOLISTIC ניתן להחיל על בעלי חיים מכל הגילאים, המינים גנוטיפים וזה יכול להיות בשילוב עם immunostaining לזהות subpopulation מסוימים של תאים. כאן אנו מדגימים את השימוש DiOLISTICS לנוירונים התווית פרוסות המוח של עכברים בוגרים ומבוגרים שאינם בני אדם פרימטים במטרה לכימות דנדריט הסתעפות ומורפולוגיה עמוד השדרה הדנדריטים.

Watch this Scientific Journal Video about DiOLISTIC Labeling of Neurons from Rodent and Non-human Primate Brain Slices at JoVE.com

DiOLISTIC Labeling of Neurons from Rodent and Non-human Primate Brain Slices

אנו מדגימים את השימוש באקדח הגן להציג צבעי ניאון, כגון DiI, לתוך הנוירונים פרוסות המוח של מכרסמים פרימטים שאינם בני אדם בגילאים שונים. במקרה הספציפי הזה, אנו משתמשים בעכברים בוגרים (3-6 חודשים) וקופים cynomologus מבוגר (9-15 שנים). טכניקה זו, שתוארה לראשונה על ידי במעבדה של ד&quot;ר ליכטמן (גן<em&gt; ואח&#39;</em&gt;., 2000), הוא גם מתאים ללימוד הסתעפות הדנדריטים ומורפולוגיה עמוד השדרה הדנדריטים ניתן לשלב עם immunostaining המסורתית, אם דטרגנטים נשמרים בריכוז נמוך.

תיוג DiOLISTIC של הנוירונים מפני מכרסמים שאינן פרוסות המוח האנושי הפרימאטים

DiOLISTIC staining uses the gene gun to introduce fluorescent dyes, such as DiI, into neurons of brain slices (Gan et al., 2009; O'Brien and Lummis, 2007; ...

diolistic-labeling-neurons-from-rodent-non-human-primate-brain

Research

JoVE Journal

Neuroscience

23.8K Views.  NIH. אנו מדגימים את השימוש באקדח הגן להציג צבעי ניאון, כגון DiI, לתוך הנוירונים פרוסות המוח של מכרסמים פרימטים שאינם בני אדם בגילאים שונים. במקרה הספציפי הזה, אנו משתמשים בעכברים בוגרים (3-6 חודשים) וקופים cynomologus מבוגר (9-15 שנים). טכניקה זו, שתוארה לראשונה על ידי במעבדה של ד...

Video: DiOLISTIC Labeling of Neurons from Rodent and Non-human Primate Brain Slices

Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals

Mechanical dissociation of neurons from the central nervous system has the advantage that presynaptic boutons remain attached to the isolated neuron of interest. This allows for examination of synaptic transmission under conditions where the extracellular and postsynaptic intracellular environments can be well controlled. A vibration-based technique without the use of proteases, known as vibrodissociation, is the most popular technique for mechanical isolation. A micropipette, with the tip fire-polished to the shape of a small ball, is placed into a brain slice made from a P1-P21 rodent. The micropipette is vibrated parallel to the slice surface and lowered through the slice thickness resulting in the liberation of isolated neurons. The isolated neurons are ready for study within a few minutes of vibrodissociation. This technique has advantages over the use of primary neuronal cultures, brain slices and enzymatically isolated neurons including: rapid production of viable, relatively mature neurons suitable for electrophysiological and imaging studies; superior control of the extracellular environment free from the influence of neighboring cells; suitability for well-controlled pharmacological experiments using rapid drug application and total cell superfusion; and improved space-clamp in whole-cell recordings relative to neurons in slice or cell culture preparations. This preparation can be used to examine synaptic physiology, pharmacology, modulation and plasticity. Real-time imaging of both pre- and postsynaptic elements in the living cells and boutons is also possible using vibrodissociated neurons. Characterization of the molecular constituents of pre- and postsynaptic elements can also be achieved with immunological and imaging-based approaches.

This report demonstrates a technique for mechanical isolation of individual viable neurons retaining attached presynaptic boutons. Vibrodissociated neurons have the advantages of rapid production, excellent pharmacological control and improved space-clamp without influence from neighboring cells. This method can be used for imaging of synaptic elements and patch-clamp recording.

Vibrodissociation של נוירונים בין פרוסות המוח מכרסמים לחקר הילוכים Synaptic ותמונה מסופי Presynaptic

Mechanical dissociation of neurons from the central nervous system has the advantage that presynaptic boutons remain attached to the isolated neuron of ...

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 ...

Voltage-sensitive Dye Recording from Axons, Dendrites and Dendritic Spines of Individual Neurons in Brain Slices

Understanding the biophysical properties and functional organization of single neurons and how they process information is fundamental for understanding how the brain works. The primary function of any nerve cell is to process electrical signals, usually from multiple sources. Electrical properties of neuronal processes are extraordinarily complex, dynamic, and, in the general case, impossible to predict in the absence of detailed measurements. To obtain such a measurement one would, ideally, like to be able to monitor, at multiple sites, subthreshold events as they travel from the sites of origin on neuronal processes and summate at particular locations to influence action potential initiation. This goal has not been achieved in any neuron due to technical limitations of measurements that employ electrodes. To overcome this drawback, it is highly desirable to complement the patch-electrode approach with imaging techniques that permit extensive parallel recordings from all parts of a neuron. Here, we describe such a technique - optical recording of membrane potential transients with organic voltage-sensitive dyes (Vm-imaging) - characterized by sub-millisecond and sub-micrometer resolution. Our method is based on pioneering work on voltage-sensitive molecular probes 2. Many aspects of the initial technology have been continuously improved over several decades 3, 5, 11. Additionally, previous work documented two essential characteristics of Vm-imaging. Firstly, fluorescence signals are linearly proportional to membrane potential over the entire physiological range (-100 mV to +100 mV; 10, 14, 16). Secondly, loading neurons with the voltage-sensitive dye used here (JPW 3028) does not have detectable pharmacological effects. The recorded broadening of the spike during dye loading is completely reversible 4, 7. Additionally, experimental evidence shows that it is possible to obtain a significant number (up to hundreds) of recordings prior to any detectable phototoxic effects 4, 6, 12, 13. At present, we take advantage of the superb brightness and stability of a laser light source at near-optimal wavelength to maximize the sensitivity of the Vm-imaging technique. The current sensitivity permits multiple site optical recordings of Vm transients from all parts of a neuron, including axons and axon collaterals, terminal dendritic branches, and individual dendritic spines. The acquired information on signal interactions can be analyzed quantitatively as well as directly visualized in the form of a movie.

An imaging technique for monitoring of membrane potential changes with sub-micrometer spatial and sub-millisecond temporal resolution is described. The technique, based on laser excitation of voltage-sensitive dyes, allows measurements of signals in axons and axon collaterals, terminal dendritic branches, and individual dendritic spines.

הקלטת דיי מתח רגישה מהאקסונים, הדנדריטים וקוצים הדנדריטים של נוירונים בודדים בפרוסות מוח

Understanding the biophysical properties and functional organization of single neurons and how they process information is fundamental for understanding ...

Growing Neural Stem Cells from Conventional and Nonconventional Regions of the Adult Rodent Brain

Recent work demonstrates that central nervous system (CNS) regeneration and tumorigenesis involves populations of stem cells (SCs) resident within the adult brain. However, the mechanisms these normally quiescent cells employ to ensure proper functioning of neural networks, as well as their role in recovery from injury and mitigation of neurodegenerative processes are little understood. These cells reside in regions referred to as &#34;niches&#34; that provide a sustaining environment involving modulatory signals from both the vascular and immune systems. The isolation, maintenance, and differentiation of CNS SCs under defined culture conditions which exclude unknown factors, makes them accessible to treatment by pharmacological or genetic means, thus providing insight into their in vivo behavior. Here we offer detailed information on the methods for generating cultures of CNS SCs from distinct regions of the adult brain and approaches to assess their differentiation potential into neurons, astrocytes, and oligodendrocytes in vitro. This technique yields a homogeneous cell population as a monolayer culture that can be visualized to study individual SCs and their progeny. Furthermore, it can be applied across different animal model systems and clinical samples, being used previously to predict regenerative responses in the damaged adult nervous system.

Neural stem cells harvested from the adult brain are increasing utilized in applications ranging from the basic research of nervous system development to exploring potential clinical applications in regenerative medicine. This makes rigorous control in the isolation and culturing conditions used to grow these cells critical to sound experimental outcomes.

גידול בתאי גזע עצבי מאזורים קונבנציונליים ולא קונבנציונליים של המוח מכרסם מבוגרים

Recent work demonstrates that central nervous system (CNS) regeneration and tumorigenesis involves populations of stem cells (SCs) resident within the ...

Isolation, Culture and Long-Term Maintenance of Primary Mesencephalic Dopaminergic Neurons From Embryonic Rodent Brains

Degeneration of mesencephalic dopaminergic (mesDA) neurons is the pathological hallmark of Parkinson&#8217;s diseae. Study of the biological processes involved in physiological functions and vulnerability and death of these neurons is imparative to understanding the underlying causes and unraveling the cure for this common neurodegenerative disorder. Primary cultures of mesDA neurons provide a tool for investigation of the molecular, biochemical and electrophysiological properties, in order to understand the development, long-term survival and degeneration of these neurons during the course of disease. Here we present a detailed method for the isolation, culturing and maintenance of midbrain dopaminergic neurons from E12.5 mouse (or E14.5 rat) embryos. Optimized cell culture conditions in this protocol result in presence of axonal and dendritic projections, synaptic connections and other neuronal morphological properties, which make the cultures suitable for study of the physiological, cell biological and molecular characteristics of this neuronal population.

The causes of degeneration of midbrain dopaminergic neurons during Parkinson&#8217;s disease are not fully understood. Cellular culture systems provide an essential tool for study of the neurophysiological properties of these neurons. Here we present an optimized protocol, which can be utilized for in vitro modeling of neurodegeneration.

בידוד, תרבות והטווח ארוך תחזוקה של יסודיים mesencephalic דופאמין נוירונים ממוח עוברי מכרסם

Degeneration of mesencephalic dopaminergic (mesDA) neurons is the pathological hallmark of Parkinson&#8217;s diseae. Study of the biological processes ...

Preparation of Non-human Primate Brain Tissue for Pre-embedding Immunohistochemistry and Electron Microscopy

Despite all the technological advances at the light microscopy&#160;level, electron microscopy remains the only tool in neuroscience to examine and characterize ultrastructural and morphological details of neurons, such as synaptic contacts. Good preservation of brain tissue for electron microscopy can be obtained by rigorous cryo-fixation methods, but these techniques are rather costly and limit the use of immunolabeling, which is crucial to understand the connectivity of identified neuronal systems. Freeze-substitution methods have been developed to allow the combination of cryo-fixation with immunolabeling. However, the reproducibility of these methodological approaches usually relies on costly freezing devices. Moreover, achieving reliable results with this technique is very time-consuming and skill-challenging. Hence, the traditional chemically fixed brain, particularly with acrolein fixative, remains a time-efficient and low-cost method to combine electron microscopy with immunohistochemistry. Here, we provide a reliable experimental protocol using chemical acrolein fixation that leads to the preservation of primate brain tissue and is compatible with pre-embedding immunohistochemistry and transmission electron microscopic examination.

Here, we provide an easy, low-cost, and time-efficient protocol to chemically fix primate brain tissue with acrolein fixative, allowing for long-term preservation that is compatible with pre-embedding immunohistochemistry for transmission electron microscopy.

הכנה של רקמת מוח הפרימאטים לא-אנושית עבור טרום הטבעת אימונוהיסטוכימיה ו מיקרוסקופי אלקטרונים

Despite all the technological advances at the light microscopy&#160;level, electron microscopy remains the only tool in neuroscience to examine and ...

Application of Automated Image-guided Patch Clamp for the Study of Neurons in Brain Slices

Whole-cell patch clamp is the gold-standard method to measure the electrical properties of single cells. However, the in vitro patch clamp remains a challenging and low-throughput technique due to its complexity and high reliance on user operation and control. This manuscript demonstrates an image-guided automatic patch clamp system for in vitro whole-cell patch clamp experiments in acute brain slices. Our system implements a computer vision-based algorithm to detect fluorescently labeled cells and to target them for fully automatic patching using a micromanipulator and internal pipette pressure control. The entire process is highly automated, with minimal requirements for human intervention. Real-time experimental information, including electrical resistance and internal pipette pressure, are documented electronically for future analysis and for optimization to different cell types. Although our system is described in the context of acute brain slice recordings, it can also be applied to the automated image-guided patch clamp of dissociated neurons, organotypic slice cultures, and other non-neuronal cell types.

This protocol describes how to conduct automatic image-guided patch-clamp experiments using a system recently developed for standard in vitro electrophysiology equipment.

יישום אוטומטי של תמונה מודרך תיקון מהדק לחקר נוירונים של פרוסות המוח

Whole-cell patch clamp is the gold-standard method to measure the electrical properties of single cells. However, the in vitro patch clamp remains a ...

Evaluation of Synapse Density in Hippocampal Rodent Brain Slices

In the brain, synapses are specialized junctions between neurons, determining the strength and spread of neuronal signaling. The number of synapses is tightly regulated during development and neuronal maturation. Importantly, deficits in synapse number can lead to cognitive dysfunction. Therefore, the evaluation of synapse number is an integral part of neurobiology. However, as synapses are small and highly compact in the intact brain, the assessment of absolute number is challenging. This protocol describes a method to easily identify and evaluate synapses in hippocampal rodent slices using immunofluorescence microscopy. It includes a three-step procedure to evaluate synapses in high-quality confocal microscopy images by analyzing the co-localization of pre- and postsynaptic proteins in hippocampal slices. It also explains how the analysis is performed and gives representative examples from both excitatory and inhibitory synapses. This protocol provides a solid foundation for the analysis of synapses and can be applied to any research investigating the structure and function of the brain.

A protocol for accurately identifying and analyzing synapses in hippocampal slices using immunofluorescence is outlined in this article.

הערכה של צפיפות סינפסה פרוסות המוח מכרסמים בהיפוקמפוס

In the brain, synapses are specialized junctions between neurons, determining the strength and spread of neuronal signaling. The number of synapses is ...

Isolation and RNA Extraction of Neurons, Macrophages and Microglia from Larval Zebrafish Brains

To gain a detailed understanding of the role of different CNS cells during development or the establishment and progression of brain pathologies, it is important to isolate these cells without changing their gene expression profile. The zebrafish model provides a large number of transgenic fish lines in which specific cell types are labelled; for example neurons in the NBT:DsRed line or macrophages/microglia in the mpeg1:eGFP line. Furthermore, antibodies have been developed to stain specific cells, such as microglia with the 4C4 antibody.
Here, we describe the isolation of neurons, macrophages and microglia from larval zebrafish brains. Central to this protocol is the avoidance of an enzymatic tissue digestion at 37 &#176;C, which could modify cellular profiles. Instead a mechanical system of tissue homogenization at 4 &#176;C is used. This protocol entails homogenization of brains into cell suspension, their immuno-staining and the isolation of neurons, macrophages and microglia by FACS. Afterwards, we extracted RNA from those cells and evaluated their quality/quantity. We managed to obtain RNA of high quality (RNA Integrity Number (RIN) &#62; 7) to perform qPCR on macrophages/microglia and neurons, and transcriptomic analysis on microglia. This approach enables a better characterization of these cells, as well as a clearer understanding about their role in development and pathologies.

We present a protocol to isolate neurons, macrophages and microglia from larval zebrafish brains under physiological and pathological conditions. Upon isolation, RNA is extracted from these cells to analyze their gene expression profile. This protocol allows for the collection of high-quality RNA for performing downstream analysis like qPCR and transcriptomics.

בידוד והפקת RNA של נוירונים, מקרופאגים מיקרוגלייה מן המוח זחל דג זברה

To gain a detailed understanding of the role of different CNS cells during development or the establishment and progression of brain pathologies, it is ...

Recording and Modulation of Epileptiform Activity in Rodent Brain Slices Coupled to Microelectrode Arrays

Temporal lobe epilepsy (TLE) is the most common partial complex epileptic syndrome and the least responsive to medications. Deep brain stimulation (DBS) is a promising approach when pharmacological treatment fails or neurosurgery is not recommended. Acute brain slices coupled to microelectrode arrays (MEAs) represent a valuable tool to study neuronal network interactions and their modulation by electrical stimulation. As compared to conventional extracellular recording techniques, they provide the added advantages of a greater number of observation points and a known inter-electrode distance, which allow studying the propagation path and speed of electrophysiological signals. However, tissue oxygenation may be greatly impaired during MEA recording, requiring a high perfusion rate, which comes at the cost of decreased signal-to-noise ratio and higher oscillations in the experimental temperature. Electrical stimulation further stresses the brain tissue, making it difficult to pursue prolonged recording/stimulation epochs. Moreover, electrical modulation of brain slice activity needs to target specific structures/pathways within the brain slice, requiring that electrode mapping be easily and quickly performed live during the experiment. Here, we illustrate how to perform the recording and electrical modulation of 4-aminopyridine (4AP)-induced epileptiform activity in rodent brain slices using planar MEAs. We show that the brain tissue obtained from mice outperforms rat brain tissue and is thus better suited for MEA experiments. This protocol guarantees the generation and maintenance of a stable epileptiform pattern that faithfully reproduces the electrophysiological features observed with conventional field potential recording, persists for several hours, and outlasts sustained electrical stimulation for prolonged epochs. Tissue viability throughout the experiment is achieved thanks to the use of a small-volume custom recording chamber allowing for laminar flow and quick solution exchange even at low (1 mL/min) perfusion rates. Quick MEA mapping for real-time monitoring and selection of stimulating electrodes is performed by a custom graphic user interface (GUI).

We illustrate how to perform recording and electrical modulation of 4-aminopyridine-induced epileptiform activity in rodent brain slices using microelectrode arrays. A custom recording chamber maintains tissue viability throughout prolonged experimental sessions. Live electrode mapping and selection of stimulating pairs are performed by a custom graphical user interface.

הקלטה של אפנון של הפעילות פרוסות המוח מכרסמים מצמידים מערכים Microelectrode

Temporal lobe epilepsy (TLE) is the most common partial complex epileptic syndrome and the least responsive to medications. Deep brain stimulation (DBS) ...