PDK נתמך על ידי מענק ההפעלה CIHR (MOP 86523)

<ol>
	<li>Bahr, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+or+let+die+-+retinal+ganglion+cell+death+and+survival+during+development+and+in+the+lesioned+adult+CNS.">Live or let die - retinal ganglion cell death and survival during development and in the lesioned adult CNS.</a> Trends Neurosci. 23, 483-4890 (2000).</li><li>Isenmann, S., Kretz, A., Cellerino, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+determinants+of+retinal+ganglion+cell+development,+survival,+and+regeneration.">Molecular determinants of retinal ganglion cell development, survival, and regeneration.</a> Prog Retin Eye Res. 22, 483-543 (2003).</li><li>Koeberle, P. D., Bahr, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+and+guidance+cues+for+regenerating+axons:+where+have+they+gone.">Growth and guidance cues for regenerating axons: where have they gone.</a> J Neurobiol. 59, 162-180 (2004).</li><li>Weishaupt, J. H., Bahr, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Degeneration+of+axotomized+retinal+ganglion+cells+as+a+model+for+neuronal+apoptosis+in+the+central+nervous+system+-+molecular+death+and+survival+pathways.">Degeneration of axotomized retinal ganglion cells as a model for neuronal apoptosis in the central nervous system - molecular death and survival pathways.</a> Restor. Neurol. Neurosci. 19, 1-2 (2001).</li><li>Valenzuela, G. a. r. c. i. a., E, S. C. S. h. a. r. m. a. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rescue+of+retinal+ganglion+cells+from+axotomy-induced+apoptosis+through+TRK+oncogene+transfer.">Rescue of retinal ganglion cells from axotomy-induced apoptosis through TRK oncogene transfer.</a> Neuroreport. 9, 3165-3170 (1998).</li><li>Kugler, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transduction+of+axotomized+retinal+ganglion+cells+by+adenoviral+vector+administration+at+the+optic+nerve+stump:+an+in+vivo+model+system+for+the+inhibition+of+neuronal+apoptotic+cell+death.">Transduction of axotomized retinal ganglion cells by adenoviral vector administration at the optic nerve stump: an in vivo model system for the inhibition of neuronal apoptotic cell death.</a> Gene Ther. 6, 1759-1767 (1999).</li><li>Lingor, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Down-regulation+of+apoptosis+mediators+by+RNAi+inhibits+axotomy-induced+retinal+ganglion+cell+death+in+vivo.">Down-regulation of apoptosis mediators by RNAi inhibits axotomy-induced retinal ganglion cell death in vivo.</a> Brain. 128, 550-558 (2005).</li><li>Koeberle, P. D., Gauldie, J., Ball, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+adenoviral-mediated+gene+transfer+of+interleukin-10,+interleukin-4,+and+transforming+growth+factor-beta+on+the+survival+of+axotomized+retinal+ganglion+cells.">Effects of adenoviral-mediated gene transfer of interleukin-10, interleukin-4, and transforming growth factor-beta on the survival of axotomized retinal ganglion cells.</a> Neuroscience. 125, 903-920 (2004).</li><li>Berkelaar, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Axotomy+results+in+delayed+death+and+apoptosis+of+retinal+ganglion+cells+in+adult+rats.">Axotomy results in delayed death and apoptosis of retinal ganglion cells in adult rats.</a> J Neurosci. 14, 4368-4374 (1994).</li><li>Villegas-Perez, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influences+of+peripheral+nerve+grafts+on+the+survival+and+regrowth+of+axotomized+retinal+ganglion+cells+in+adult+rats.">Influences of peripheral nerve grafts on the survival and regrowth of axotomized retinal ganglion cells in adult rats.</a> J Neurosci. 8, 265-280 (1988).</li><li>Villegas-Perez, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+and+protracted+phases+of+retinal+ganglion+cell+loss+follow+axotomy+in+the+optic+nerve+of+adult+rats.">Rapid and protracted phases of retinal ganglion cell loss follow axotomy in the optic nerve of adult rats.</a> J Neurobiol. 24, 23-36 (1993).</li><li>Quigley, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinal+ganglion+cell+death+in+experimental+glaucoma+and+after+axotomy+occurs+by+apoptosis.">Retinal ganglion cell death in experimental glaucoma and after axotomy occurs by apoptosis.</a> Invest Ophthalmol Vis Sci. 36, 774-786 (1995).</li><li>Thanos, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specific+transcellular+carbocyanine-labelling+of+rat+retinal+microglia+during+injury-induced+neuronal+degeneration.">Specific transcellular carbocyanine-labelling of rat retinal microglia during injury-induced neuronal degeneration.</a> Neurosci Lett. 127, 108-1012 (1991).</li><li>Thanos, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specific+transcellular+staining+of+microglia+in+the+adult+rat+after+traumatic+degeneration+of+carbocyanine-filled+retinal+ganglion+cells.">Specific transcellular staining of microglia in the adult rat after traumatic degeneration of carbocyanine-filled retinal ganglion cells.</a> Exp Eye Res. 55, 101-117 (1992).</li></ol>

אין ניגודי אינטרסים הכריז.

ישנן וריאציות רבות של הליך זה כירורגית כמה צעדים בפרוטוקול זה לא הכרחי. הוא רק צריך לחזור בו השרירים לשכב על עצב הראייה על מנת לקבל גישה העצב. עם זאת, התוצאות במרחב עבודה מוגבל מאוד סביב העצב שהופך בשלבים הסופיים קריטית של חיתוך רוחב קשה יותר. במצבים מסוימים רצוי transfect ...

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<td>Stereotaxic Frame</td>
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<td>Stoelting, Kopf, WPI</td>
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<td>Rat Gas Mask</td>
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<td>Stoelting, Kopf, WPI</td>
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<td>VetEquip</td>
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<td>Baxter Corp</td>
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optic nerve transection: a model of adult neuron apoptosis in the central nervous system

בתאי גנגליון רשתית (RGCs) הם נוירונים במערכת העצבים המרכזית, כי פלט מידע חזותי מהרשתית אל המוח, באמצעות עצב הראייה. העצב האופטי ניתן לגשת בתוך מסלולו של העין transected לחלוטין (axotomized), חיתוך האקסונים של האוכלוסייה RGC כולו. חיתוך רוחב עצב הראייה הוא מודל לשחזור של מוות תאים אפופטוטיים נוירונים ב CNS הבוגרת 1-4. מודל זה הינו אטרקטיבי במיוחד מאחר קאמרית הזגוגית של העין פועלת כמו כמוסה עבור משלוח הסמים אל הרשתית, המתיר מניפולציות ניסיוני באמצעות זריקות התוך עיני. דיפוזיה של חומרים דרך הנוזל הזגוגי מבטיחה כי הם פועלים על האוכלוסייה RGC כולו. יתר על כן, RGCs ניתן transfected סלקטיבי על ידי יישום RNAs התערבות קצר (siRNAs), פלסמידים, או וקטורים ויראליים לסוף חתך של וקטורים עצב הראייה 5-7 או הזרקה לתוך היעד שלהם, colliculus מעולה 8. הדבר מאפשר לחוקרים לבחון מנגנונים אפופטוטיים באוכלוסייה העצבית הרצויה ללא תופעות בלבול על נוירונים אחרים או עובר אורח גליה שמסביב. יתרון נוסף הוא הקלות והדיוק שבה הישרדות התא ניתן לכמת לאחר פציעה. הרשתית היא רקמה שטוח, שכבות RGCs מרוכזים בשכבה הפנימית ביותר, השכבה תא גנגליון. ההישרדות של RGCs ניתן לעקוב לאורך זמן על ידי יישום נותב ניאון (3% Fluorogold) בסוף לחתוך של עצב הראייה בזמן axotomy, או על ידי הזרקת נותב אל colliculus מעולה (יעד RGC) שבוע לפני axotomy. נותב מועבר retrogradely, תיוג האוכלוסייה RGC כולו. מאחר השכבה תא גנגליון הוא monolayer (תא אחד עבה), צפיפות RGC ניתן לכמת ברקמות שטוח רכוב, ללא צורך stereology. חיתוך רוחב עצב הראייה מוביל למוות אפופטוטיים של 90% RGCs פצוע בתוך 14 ימים postaxotomy 9-11. RGC אפופטוזיס יש מאפיין זמן כמובן לפיה מוות של תאים מתעכב postaxotomy 3-4 ימים, אחרי אשר התאים להידרדר במהירות. זה מספק חלון הזמן מניפולציות ניסיוני נגד מסלולים מעורב אפופטוזיס.

Watch this Scientific Journal Video about Optic Nerve Transection: A Model of Adult Neuron Apoptosis in the Central Nervous System at JoVE.com

Optic Nerve Transection: A Model of Adult Neuron Apoptosis in the Central Nervous System

חיתוך רוחב עצב הראייה הוא מודל בשימוש נרחב של פגיעה במערכת העצבים המרכזית מבוגר. תשעים אחוז של תאים הגנגליון ברשתית (RGCs) הם אשר אקסונים transected לחלוטין (axotomy) למות בתוך 14 ימים לאחר axotomy. מודל זה מקובל בקלות מניפולציות ניסיוני לשעתקו מאוד.

עצב הראייה חיתוך רוחב: מודל של אפופטוזיס Neuron למבוגרים במערכת העצבים המרכזית

Retinal ganglion cells (RGCs) are CNS neurons that output visual information from the retina to the brain, via the optic nerve. 
The optic nerve can be ...

optic-nerve-transection-model-adult-neuron-apoptosis-central-nervous

Research

JoVE Journal

Neuroscience

20.5K Views.  University of Toronto. חיתוך רוחב עצב הראייה הוא מודל בשימוש נרחב של פגיעה במערכת העצבים המרכזית מבוגר. תשעים אחוז של תאים הגנגליון ברשתית (RGCs) הם אשר אקסונים transected לחלוטין (axotomy) למות בתוך 14 ימים לאחר axotomy. מודל זה מקובל בקלות מניפולציות ניסיוני לשעתקו מאוד.

Video: Optic Nerve Transection: A Model of Adult Neuron Apoptosis in the Central Nervous System

Methods for Experimental Manipulations after Optic Nerve Transection in the Mammalian CNS

Retinal ganglion cells (RGCs) are CNS neurons that output visual information from the retina to the brain, via the optic nerve. The optic nerve can be accessed within the orbit of the eye and completely transected (axotomized), cutting the axons of the entire RGC population. Optic nerve transection is a reproducible model of apoptotic neuronal cell death in the adult CNS 1-4. This model is particularly attractive because the vitreous chamber of the eye acts as a capsule for drug delivery to the retina, permitting experimental manipulations via intraocular injections. The diffusion of chemicals through the vitreous fluid ensures that they act upon the entire RGC population. Viral vectors, plasmids or short interfering RNAs (siRNAs) can also be delivered to the vitreous chamber in order to infect or transfect retinal cells 5-12. The high tropism of Adeno-Associated Virus (AAV) vectors is beneficial to target RGCs, with an infection rate approaching 90% of cells near the injection site 6, 7, 13-15. Moreover, RGCs can be selectively transfected by applying siRNAs, plasmids, or viral vectors to the cut end of the optic nerve 16-19 or injecting vectors into their target the superior colliculus 10. This allows researchers to study apoptotic mechanisms in the injured neuronal population without confounding effects on other bystander neurons or surrounding glia. RGC apoptosis has a characteristic time-course whereby cell death is delayed 3-4 days postaxotomy, after which the cells rapidly degenerate. This provides a window for experimental manipulations directed against pathways involved in apoptosis. Manipulations that directly target RGCs from the transected optic nerve stump are performed at the time of axotomy, immediately after cutting the nerve. In contrast, when substances are delivered via an intraocular route, they can be injected prior to surgery or within the first 3 days after surgery, preceding the initiation of apoptosis in axotomized RGCs. In the present article, we demonstrate several methods for experimental manipulations after optic nerve transection.

Optic Nerve transection is a widely used model of adult CNS injury. This model is ideal for performing a number of experimental manipulations that target the retina globally or directly target the injured neuronal population of retinal ganglion cells.

שיטות מניפולציות ניסויית, לאחר חיתוך רוחב עצב הראייה של מערכת העצבים המרכזית היונקים

Retinal ganglion cells (RGCs) are CNS neurons that output visual information from the retina to the brain, via the optic nerve. The optic nerve can be ...

Multimodal Imaging of Stem Cell Implantation in the Central Nervous System of Mice

During the past decade, stem cell transplantation has gained increasing interest as primary or secondary therapeutic modality for a variety of diseases, both in preclinical and clinical studies. However, to date results regarding functional outcome and/or tissue regeneration following stem cell transplantation are quite diverse. Generally, a clinical benefit is observed without profound understanding of the underlying mechanism(s)1. Therefore, multiple efforts have led to the development of different molecular imaging modalities to monitor stem cell grafting with the ultimate aim to accurately evaluate survival, fate and physiology of grafted stem cells and/or their micro-environment. Changes observed in one or more parameters determined by molecular imaging might be related to the observed clinical effect. In this context, our studies focus on the combined use of bioluminescence imaging (BLI), magnetic resonance imaging (MRI) and histological analysis to evaluate stem cell grafting.
BLI is commonly used to non-invasively perform cell tracking and monitor cell survival in time following transplantation2-7, based on a biochemical reaction where cells expressing the Luciferase-reporter gene are able to emit light following interaction with its substrate (e.g. D-luciferin)8, 9. MRI on the other hand is a non-invasive technique which is clinically applicable10 and can be used to precisely locate cellular grafts with very high resolution11-15, although its sensitivity highly depends on the contrast generated after cell labeling with an MRI contrast agent. Finally, post-mortem histological analysis is the method of choice to validate research results obtained with non-invasive techniques with highest resolution and sensitivity. Moreover end-point histological analysis allows us to perform detailed phenotypic analysis of grafted cells and/or the surrounding tissue, based on the use of fluorescent reporter proteins and/or direct cell labeling with specific antibodies.
In summary, we here visually demonstrate the complementarities of BLI, MRI and histology to unravel different stem cell- and/or environment-associated characteristics following stem cell grafting in the CNS of mice. As an example, bone marrow-derived stromal cells, genetically engineered to express the enhanced Green Fluorescent Protein (eGFP) and firefly Luciferase (fLuc), and labeled with blue fluorescent micron-sized iron oxide particles (MPIOs), will be grafted in the CNS of immune-competent mice and outcome will be monitored by BLI, MRI and histology (Figure 1).

This article describes an optimized sequence of events for multimodal imaging of cellular grafts in rodent brain using: (i) in vivo bioluminescence and magnetic resonance imaging, and (ii) post mortem histological analysis. Combining these imaging modalities on a single animal allows cellular graft evaluation with high resolution, sensitivity and specificity.

Multimodal הדמיה של השתלת תא גזע במערכת העצבים המרכזית של עכברים

During the past decade, stem cell transplantation has gained increasing interest as primary or secondary therapeutic modality for a variety of diseases, ...

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster

In this article we describe how to individually label neurons in the embryonic CNS of Drosophila melanogaster by juxtacellular injection of the lipophilic fluorescent membrane marker DiI. This method allows the visualization of neuronal cell morphology in great detail. It is possible to label any cell in the CNS: cell bodies of target neurons are visualized under DIC optics or by expression of a fluorescent genetic marker such as GFP. After labeling, the DiI can be transformed into a permanent brown stain by photoconversion to allow visualization of cell morphology with transmitted light and DIC optics. Alternatively, the DiI-labeled cells can be observed directly with confocal microscopy, enabling genetically introduced fluorescent reporter proteins to be colocalised. The technique can be used in any animal, irrespective of genotype, making it possible to analyze mutant phenotypes at single cell resolution.

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster

We present a technique for labeling single neurons in the central nervous system (CNS) of Drosophila embryos, which allows the analysis of neuronal morphology by either transmitted light or confocal microscopy.

תיוג של תאים בודדים במערכת העצבים המרכזית של<em&gt; דרוזופילה melanogaster</em

In this  article we describe how to individually label neurons in the embryonic CNS of Drosophila melanogaster by juxtacellular injection of the ...

Direct Intraventricular Delivery of Drugs to the Rodent Central Nervous System

Due to an inability to cross the blood brain barrier, certain drugs need to be directly delivered into the central nervous system (CNS). Our lab focuses specifically on antisense oligonucleotides (ASOs), though the techniques shown in the video here can also be used to deliver a plethora of other drugs to the CNS. Antisense oligonucleotides (ASOs) have the capability to knockdown sequence-specific targets 1 as well as shift isoform ratios of specific genes 2. To achieve widespread gene knockdown or splicing in the CNS of mice, the ASOs can be delivered into the brain using two separate routes of administration, both of which we demonstrate in the video.
The first uses Alzet osmotic pumps, connected to a catheter that is surgically implanted into the lateral ventricle. This allows the ASOs to be continuously infused into the CNS for a designated period of time. The second involves a single bolus injection of a high concentration of ASO into the right lateral ventricle. Both methods use the mouse cerebral ventricular system to deliver the ASO to the entire brain and spinal cord, though depending on the needs of the study, one method may be preferred over the other.

We describe a method to target drugs to the central nervous system by either implanting a catheter or performing a bolus injection into the right lateral ventricle in mice. We focus specifically on the delivery of antisense oligonucleotides. This technique is readily adaptable to other drugs and to rats.

משלוח תוך חדרי ישיר של תרופות למערכת העצבים המרכזית מכרסם

Due to an inability to cross the blood brain barrier, certain drugs need to be directly delivered into the central nervous system (CNS). Our lab focuses ...

In vivo Interrogation of Central Nervous System Translatome by Polyribosome Fractionation

Multiple processes are involved in gene expression including transcription, translation and stability of mRNAs and proteins. Each of these steps are tightly regulated, affecting the final dynamics of protein abundance. Various regulatory mechanisms exist at the translation step, rendering mRNA levels alone an unreliable indicator of gene expression. In addition, local regulation of mRNA translation has been particularly implicated in neuronal functions, shifting &#39;translatomics&#39; to the focus of attention in neurobiology. The presented method can be used to bridge transcriptomics and proteomics.
Here we describe essential modifications to the technique of polyribosome fractionation, which interrogates the translatome based on the association of actively translated mRNAs to multiple ribosomes and their differential sedimentation in sucrose gradients. Traditionally, working with in vivo samples, particularly of the central nervous system (CNS), has proven challenging due to the restricted amounts of material and the presence of fatty tissue components. In order to address this, the described protocol is specifically optimized for use with minimal amount of CNS material, as demonstrated by the use of single mouse spinal cord and brain. Briefly, CNS tissues are extracted and translating ribosomes are immobilized on mRNAs with cycloheximide. Myelin flotation is then performed to remove lipid rich components. Fractionation is performed on a sucrose gradient where mRNAs are separated according to their ribosomal loading. Isolated fractions are suitable for a range of downstream assays, including new genome wide assay technologies.

In vivo Interrogation of Central Nervous System Translatome by Polyribosome Fractionation

This protocol illustrates essential modifications of polyribosome fractionation in order to study the translatome of in vivo CNS samples. It allows global assessment of translation and transcription regulation through the isolation and comparison of total RNA to ribosome bound RNA fractions.

בחקירתו vivo של Translatome מערכת עצבים המרכזי על ידי Polyribosome היפוך חלוק

Multiple processes are involved in gene expression including transcription, translation and stability of mRNAs and proteins. Each of these steps are ...

In vivo Optogenetic Stimulation of the Rodent Central Nervous System

The ability to probe defined neural circuits in awake, freely-moving animals with cell-type specificity, spatial precision, and high temporal resolution has been a long sought tool for neuroscientists in the systems-level search for the neural circuitry governing complex behavioral states. Optogenetics is a cutting-edge tool that is revolutionizing the field of neuroscience and represents one of the first systematic approaches to enable causal testing regarding the relation between neural signaling events and behavior. By combining optical and genetic approaches, neural signaling can be bi-directionally controlled through expression of light-sensitive ion channels (opsins) in mammalian cells. The current protocol describes delivery of specific wavelengths of light to opsin-expressing cells in deep brain structures of awake, freely-moving rodents for neural circuit modulation. Theoretical principles of light transmission as an experimental consideration are discussed in the context of performing in vivo optogenetic stimulation. The protocol details the design and construction of both simple and complex laser configurations and describes tethering strategies to permit simultaneous stimulation of multiple animals for high-throughput behavioral testing.

In vivo Optogenetic Stimulation of the Rodent Central Nervous System

Optogenetics has become a powerful tool for use in behavioral neuroscience experiments. This protocol offers a step-by-step guide to the design and set-up of laser systems, and provides a full protocol for carrying out multiple and simultaneous in vivo optogenetic stimulations compatible with most rodent behavioral testing paradigms.

בoptogenetic גירוי vivo של מערכת העצבים המרכזית מכרסם

The ability to probe defined neural circuits in awake, freely-moving animals with cell-type specificity, spatial precision, and high temporal resolution ...

Visual Evoked Potential Recording in a Rat Model of Experimental Optic Nerve Demyelination

The visual evoked potential (VEP) recording is widely used in clinical practice to assess the severity of optic neuritis in its acute phase, and to monitor the disease course in the follow-up period. Changes in the VEP parameters closely correlate with pathological damage in the optic nerve. This protocol provides a detailed description about the rodent model of optic nerve microinjection, in which a partial demyelination lesion is produced in the optic nerve. VEP recording techniques are also discussed. Using skull implanted electrodes, we are able to acquire reproducible intra-session and between-session VEP traces. VEPs can be recorded on individual animals over a period of time to assess the functional changes in the optic nerve longitudinally. The optic nerve demyelination model, in conjunction with the VEP recording protocol, provides a tool to investigate the disease processes associated with demyelination and remyelination, and can potentially be employed to evaluate the effects of new remyelinating drugs or neuroprotective therapies.

Focal demyelination is induced in the optic nerve using lysolecithin microinjection. Visual evoked potentials are recorded via skull electrodes implanted over the visual cortex to examine the signal conduction along the visual pathway in vivo. This protocol details the surgical procedures underlying electrode implantation and optic nerve microinjection.

הקלטת פוטנציאל עוררה חזותית במודל עכברוש של demyelination עצב אופטי הניסויי

The visual evoked potential (VEP) recording is widely used in clinical practice to assess the severity of optic neuritis in its acute phase, and to ...

Optical Clearing of the Mouse Central Nervous System Using Passive CLARITY

Traditionally, tissue visualization has required that the tissue of interest be serially sectioned and imaged, subjecting each tissue section to unique non-linear deformations, dramatically hampering one's ability to evaluate cellular morphology, distribution and connectivity in the central nervous system (CNS). However, optical clearing techniques are changing the way tissues are visualized. These approaches permit one to probe deeply into intact organ preparations, providing tremendous insight into the structural organization of tissues in health and disease. Techniques such as Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging-compatible Tissue-hYdrogel (CLARITY) achieve this goal by providing a matrix that binds important biomolecules while permitting light-scattering lipids to freely diffuse out. Lipid removal, followed by refractive index matching, renders the tissue transparent and readily imaged in 3 dimensions (3D). Nevertheless, the electrophoretic tissue clearing (ETC) used in the original CLARITY protocol can be challenging to implement successfully and the use of a proprietary refraction index matching solution makes it expensive to use the technique routinely. This report demonstrates the implementation of a simple and inexpensive optical clearing protocol that combines passive CLARITY for improved tissue integrity and 2,2&#8242;-thiodiethanol (TDE), a previously described refractive index matching solution.

Optical clearing techniques are revolutionizing the way tissues are visualized. In this report we describe modifications of the original Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging-compatible Tissue-hYdrogel (CLARITY) protocol that yields more consistent and less expensive results.

סליקה אופטית של מערכת העצבים המרכזית עכבר שימוש CLARITY הפסיבי

Traditionally, tissue visualization has required that the tissue of interest be serially sectioned and imaged, subjecting each tissue section to unique ...

Partial Optic Nerve Transection in Rats: A Model Established with a New Operative Approach to Assess Secondary Degeneration of Retinal Ganglion Cells

Previous studies have shown that the secondary degeneration of retinal ganglion cells (RGCs) occurs commonly in glaucoma. Partial optic nerve transection is considered a useful and reproducible model. Compared with other optic nerve injury models used commonly for assessing secondary degeneration, e.g. complete optic nerve transection and optic nerve crush models, the partial optic nerve transection model is superior as it distinguishes primary from secondary degeneration in situ. Therefore, it serves as an excellent tool for evaluating secondary degeneration. This study describes a novel operative approach of partial optic nerve transection by directly accessing the area of the retrobulbar optic nerve through the orbital lateral wall of the eyeball. Moreover, we present a newly designed, low cost surgical instrument to assist with transection. As demonstrated by the representative results in distinguishing the boundary of primary and secondary injury areas, the new approach and instrument ensures high efficiency and stability of the model by providing adequate space for surgical operation. This in turn makes it easy to separate the meningeal sheath and ophthalmic vessels from the optic nerve before transection. An additional benefit is that this space-saving operative approach improves the investigators&#39; ability to administer drugs, carriers, or selective RGC tracers to the stump of the partially transected optic nerve, allowing the exploration of mechanisms behind secondary injury in RGCs, in a new way.

Secondary degeneration of retinal ganglion cells (RGCs) occurs commonly in glaucoma. This study describes an innovative operative approach for partial optic nerve transection. The use of this space-saving operative approach extends the model's application range, and allows exploration of secondary injury mechanisms in RGCs in a new way.

חיתוך חלקי עצב הראייה אצל חולדות: מודל הקים עם גישה חדשה פעיל כדי להעריך משני ניוון של תאי גנגליון

Previous studies have shown that the secondary degeneration of retinal ganglion cells (RGCs) occurs commonly in glaucoma. Partial optic nerve transection ...

A Microbiomechanical System for Studying Varicosity Formation and Recovery in Central Neuron Axons

Axonal varicosities are enlarged structures along the shafts of axons with a high degree of heterogeneity. They are present not only in brains with neurodegenerative diseases or injuries, but also in the normal brain. Here, we describe a newly-established micromechanical system to rapidly, reliably, and reversibly induce axonal varicosities, allowing us to understand the mechanisms governing varicosity formation and heterogeneous protein composition. This system represents a novel means to evaluate the effects of compression and shear stress on different subcellular compartments of neurons, different from other in vitro systems that mainly focus on the effect of stretching. Importantly, owing to the unique features of our system, we recently made a novel discovery showing that the application of pressurized fluid can rapidly and reversibly induce axonal varicosities through the activation of a transient receptor potential channel. Our biomechanical system can be utilized conveniently in combination with drug perfusion, live cell imaging, calcium imaging, and patch clamp recording. Therefore, this method can be adopted for studying mechanosensitive ion channels, axonal transport regulation, axonal cytoskeleton dynamics, calcium signaling, and morphological changes related to traumatic brain injury.

This protocol describes a physiologically relevant, pressurized fluid approach for rapid and reversible induction of varicosities in neurons.

מערכת Microbiomechanical ללמוד היווצרות דליות, השחזור של אקסונים נוירון המרכזית

Axonal varicosities are enlarged structures along the shafts of axons with a high degree of heterogeneity. They are present not only in brains with ...