Supported by NIH Grants NS14837, R01 NS38537, R24 HD050838 to Dr. Michael E. Selzer; Shriners Research Grant SHC-85220 to Dr. Michael E Selzer; and Shriners Research Grant SHC-85310 to Dr. Michael I. Shifman. Dr. Ant&#243;n Barreiro-Iglesias was supported by the Fundaci&#243;n Barri&#233; (Spain) and the Xunta de Galicia (Galicia, Spain).

Bu protokolde kullanılan tüm malzemeler için Tablo 1&#39;e bakınız. Deneyler Temple Üniversitesi Kurumsal Hayvan Bakım ve Kullanım Kurulu tarafından kabul edildi. 1. Hayvanlar <ol><li> Yabanitip larva deniz lamprey balıklarının (Petromyzon marinus L.) elde, 10 - Maine Delaware Nehri (Pennsylvania) veya akışları yan kolları, Michigan Gölü besleyen derelerden - (7 yaşında 4) uzunluğu 14 cm. </li><li> 16 ° C&#39;de 50 galon tatlı su tanklarında 100 hayvanlar - Laboratuvarda, 50 gruplar halinde larvaları korumak. Çizgi çakıl bir inç ile tankları larvalar yuva için, ve su kömür süzüldü ve onlara lamprey balıklarının yerleştirmeden önce klor ve diğer kirleri çıkarmak için en az 48 saat süreyle hava taşlarla şartına bağlıdır. Kullanım güne kadar, kendi sifonlanarak geri dönüşüm hayvanları beslemek için gerek yoktur. </li></ol> 2. Tam SpinalKordon Kesisi <ol><li> Omurilik cerrahisi önce aşağıdaki kompozisyona sahip bir taşemen Ringer çözeltisi hazırlayın: 110 mM NaCI, 2.1 mM KCI, 2.6 mM CaCl2, 1.8 mM MgCI2 ve 10 mM Tris tamponu; pH 7,4. </li><li> Omurilik transeksiyonu gerçekleştirmek için, küçük bir kap içinde larva yerleştirin buz gibi soğuk Ringer çözeltisi içinde% 1 tricaine metansülfonat ile anestezi edilmesi. </li><li> Anestezi uygulanmış yerde bir kez yarı Sylgard (silikon) ile doldurulmuş bir petri kabına hayvanlar ve bir kuyruk, hayvanın burun az birini yerleştirilir (cerrahi pozisyonda tutmak için hayvanlar 4 böcek pimleri (0.15 mm çapında) kullanın ve iki 5. solungaç seviyesinde). Neredeyse Ringer çözeltisi ile üstüne kadar petri doldurun. Stereomicroscope altında ameliyat yaparken buz üzerinde larva ile çanak koyun. </li><li> Omurilik transection bir dorsal gerçekleştirmek için, orta hat, 5 inci seviyesinde bir neşter (# 11) ile uzunlamasına bir kesi yapmaksolungaç omurilik görselleştirmek için. Başlangıçta cilt yukarı bakacak ve omurilik Yukarıda anlatılanlardan görülebileceği kadar Daha sonra kas dokusu çok yavaşça kesilir neşter bıçak ucu sokarak açıktır. Moda iki böcek pimleri gelen kancalar ve omurilik kesiye yaparken vücut duvarları açık tutmak için bunları kullanın. </li><li> Tamamen, bir makas (8 Castroviejo #) kullanılarak 5. solungaç seviyesinde omurilik transeksiyonu omurilik dik olarak makas yerleştirin. Omurilik tamamen temiz bir kesim ile nakledilmiş olması gerekir. Omurilik tamamen transected teyit etmek stereomicroscope altında omurilik kesilmiş uçlara gözünüzde canlandırın. Daha sonra, bir çift forseps (# 5) ile transeksiyonu sonra omurilik kesilmiş uçlara yeniden hizalayın. </li><li> Omurilik yaralanması ince forseps ile bir çift dorsal gövde duvarı içindeki yarayı kapatmak ve yara t izin vermek için 1 saat boyunca buz üzerinde larvaları koymak yaptıktan sonrao kurulayın. Buz ve larvaları arasında filtre bir parça kağıt koyun ve taşemen Ringer çözeltisi ile ıslatın. Düşük ısıya sahip olan ve bu nedenle kuru enfeksiyonları önlemek için yardımcı hava yara izin verir, aynı zamanda canlı hayvanları tutar. </li><li> Daha sonra 24 saat boyunca buz gibi soğuk su ile küçük tank Larvalar (tank başına 1 larva) aktarın. </li><li> Davranışsal yaralanma siteye hiçbir hareket kuyruk olduğunu onaylamak için spinal transeksiyondan sonra lezyon larvalar 1 gün inceleyin. Larva (5. solungaç düzeyinde) yaralanma siteye sadece baş rostral taşıyabilirsiniz eğer spinal kord Kesi tam olarak kabul edilir. Bu durumda larva 23 (oda sıcaklığında tatlı su ile tanklar (tank başına 1 larva) transfer edilebilir ° C) onları seçilen zaman noktalarında kurtarmak için izin vermek. </li><li> Iyileşme döneminde her 2 ila 3 gün su değiştirmek. </li></ol> 3. Beyin Diseksiyon ve hazırlanmasıIn situ Hibridizasyon için Beyin <ol><li> Yaralanma sonrası istenilen zaman noktalarında larva deniz lamprey balıklarının yer ve yeniden uyutmak ve yukarıdaki gibi beyin diseksiyon için Ringer çözeltisi ile petri onları pin. </li><li> Beynini incelemek için, önce burun deliği ve epifiz organı arasındaki neşter ile enine kesi yapmak. Buradan forseps bir çift ile tutarak Castroviejo bir makas kullanarak beyni çevreleyen dokuyu kesmek başlar. </li><li> Beyin ortaya çıktığında, bir çift forseps kullanılarak koroid pleksus kaldırmak ve kafatası sinirleri hayvanın baş yaymak ve açığa çıkarmak için kancaları kullanın. Ardından, Castroviejo makasla omurilik enine doğru kesti. Beynini incelemek için kranial sinirler kesmek için forseps başka bir çift kullanırken forseps bir çift omurilik tutun. </li><li> Diseksiyon sonrası, silikon küçük bir parça üzerinde beyin koymak ve 2 ins takarak konumda tutunomurilikte bulbuslarında ve 1 ect&#39;yi pimleri. Sonra, posterior ve makas ile dorsal orta hat boyunca beynin cerebrotectal kommisürlere kesilmiş ve yanal alar plakaları saptırmak ve 4 böcek iğneli (Şekil 2) ile silikon onları düz pin. </li><li> , Bir döndürücü üzerinde 3 saat boyunca oda sıcaklığında sabit olarak fosfat tamponlu tuzlu su içinde% 4 paraformaldehid (pH 7.4) içeren bir tübe beyin ile silikonun parça aktarın. </li><li> Daha önce tarif edildiği gibi tespit edildikten sonra in situ olarak melezleşme wholemount için beyin kullanmak (Swain ve ark., 1994). Kontrol veya sahte ameliyat hayvanlardan alınan beyinler yaralı hayvanların beyinleri ile paralel olarak her zaman çalıştırılmalıdır. Wholemounted larva beyin nedeniyle, düz, ince ve şekli, aynı zamanda, beyin oldukça saydam hale miyelin 10&#39;un bulunmadığı durumlarda, in situ olarak melezleşme ile incelenebilir. </li></ol>

<ol>
	<li>Rodicio, M. C., Barreiro-Iglesias, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lampreys+as+an+animal+model+in+regeneration+studies+after+spinal+cord+injury.">Lampreys as an animal model in regeneration studies after spinal cord injury.</a> Rev Neurol. 55, 157-166 (2012).</li><li>Davis, G. R., McClellan, A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extent+and+time+course+of+restoration+of+descending+brainstem+projections+in+spinalcord-transected+lamprey.">Extent and time course of restoration of descending brainstem projections in spinalcord-transected lamprey.</a> J Comp Neurol. 344, 65-82 (1994).</li><li>Jacobs, A. J., Swain, G. P., Snedeker, J. A., Pijak, D. S., Gladstone, L. J., Selzer, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recovery+of+neurofilament+expression+selectively+in+regenerating+reticulospinal+neurons.">Recovery of neurofilament expression selectively in regenerating reticulospinal neurons.</a> J Neurosci. 17, 5206-5220 (1997).</li><li>Shifman, M. I., Selzer, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+the+netrin+receptor+UNC-5+in+lamprey+brain+modulation+by+spinal+cord+transection.">Expression of the netrin receptor UNC-5 in lamprey brain modulation by spinal cord transection.</a> Neurorehabil Neural Repair. 14, 49-58 (2000).</li><li>Barreiro-Iglesias, A., Laramore, C., Shifman, M. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+sea+lamprey+UNC5+receptors+cDNA+cloning,+phylogenetic+analysis+and+expression+in+reticulospinal+neurons+at+larval+and+adult+stages+of+development.">The sea lamprey UNC5 receptors cDNA cloning, phylogenetic analysis and expression in reticulospinal neurons at larval and adult stages of development.</a> J Comp Neurol. 520, 4141-4156 (2012).</li><li>Shifman, M. I., Yumu, l. R. E., Laramore, C., Selzer, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+the+repulsive+guidance+molecule+RGM+and+its+receptor+neogenin+after+spinal+cord+injury+in+sea+lamprey.">Expression of the repulsive guidance molecule RGM and its receptor neogenin after spinal cord injury in sea lamprey.</a> Exp Neurol. 217, 242-251 (2009).</li><li>Busch, D. J., Morgan, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synuclein+accumulation+is+associated+with+cell-specific+neuronal+death+after+spinal+cord+injury.">Synuclein accumulation is associated with cell-specific neuronal death after spinal cord injury.</a> J Comp Neurol. 520, 1751-1771 (2012).</li><li>Shifman, M. I., Zhang, G., Selzer, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delayed+death+of+identified+reticulospinal+neurons+after+spinal+cord+injury+in+lampreys.">Delayed death of identified reticulospinal neurons after spinal cord injury in lampreys.</a> J Comp Neurol. 510, 269-282 (2008).</li><li>Swain, G. P., Jacobs, A. J., Frei, E., Selzer, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+in+situ+hybridization+in+wholemounted+lamprey+brain+neurofilament+expression+in+larvae+and+adults.">A method for in situ hybridization in wholemounted lamprey brain neurofilament expression in larvae and adults.</a> Exp. Neurol. 126, 256-269 (1994).</li><li>Bullock, T. H., Moore, J. K., Fields, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+myelin+sheaths:+both+lamprey+and+hagfish+lack+myelin.">Evolution of myelin sheaths: both lamprey and hagfish lack myelin.</a> Neurosci Lett. 48, 145-148 (1984).</li><li>Cohen, A. H., Kiemel, T., Pate, V., Blinder, J., Guan, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature+can+alter+the+function+outcome+of+spinal+cord+regeneration+in+larval+lampreys.">Temperature can alter the function outcome of spinal cord regeneration in larval lampreys.</a> Neuroscience. 90, 957-965 (1999).</li></ol>

The authors declare that they have no competing financial interests.

Burada larva deniz lamprey balıklarının tam bir omurilik kesiye ve arka beyin diseksiyon gerçekleştirmek için detaylı bir protokol mevcut. Bu prosedür in situ hibridizasyon bir bütün-montaj beyin vasıtasıyla omurilik yaralanması sonrası tanımlanabilir omurilik çıkıntı nöronlar arasında gen ifadesinde analiz farklılıkları sağlar. Prosedürdeki kritik aşama hafifçe bir çift larva burun dokunarak 24 saat sonra stereomicrocope altında omurilik kesilmiş uçlara gözlemleyerek kontrol edilebilir ...

Memelilerde spinal kord yaralanması (SKY) yaralandı aksonlar travma bölgesi üzerinden yeniden ve uygun hedefler yeniden çünkü yaralanma sitenin altındaki fonksiyonlarda kalıcı kaybına yol açan yıkıcı bir durumdur. Memelilerde aksine, lampreys tam omurilik hasarı sonrası lokomosyonu kurtarmak. 1 İlginçtir, lampreys çünkü onların büyük boy 2,3 (Şekil 1) beyin hazırlıklarını monte bütün 36 omurilik ayrı ayrı tanımlanabilir nöronların çıkıntı bir dizi var . Bu omurga verme nöronların tüm üst düzey bir tam omurilik transeksiyonu ile axotomized edilir. Grubumuzun ve diğerleri daha önceki çalışmalar, diğerleri genellikle yaralanma sitesi aracılığıyla akson yeniden ederken bile bu nöronların bazı çok düşük bir rejeneratif kapasitesini göstermek SKY sonrası fonksiyonel iyileşme varlığında, (onlar &quot;kötü rejenatörler&quot; olarak kabul edilir) olduğunu göstermiştir (onlar kabul edilir &quot;gOOD rejeneratörler &quot;). 2,3 Bu özellik Lamprey da girişimi nöronların içsel rejeneratif yeteneği farklılıklara yol açacaktır iyi ve kötü yenileyici spinal çıkıntı nöronlar arasındaki gen ifadesinde farklılıkları incelemek için ilginç bir omurgalı model yapar Aynı dış ortamda aksonlar rejenere. 1 Daha önce göstermiştir ki, bu modeli kullanarak, spinal-projelendirme sırasıyla netrin ve RGM inhibitör eylemi aracılık UNC5 4,5 ve neogenin, 6 gibi akson rehberlik molekül reseptörlerinin düşük rejeneratif yeteneği gösteri ifade ile nöronlar. Buna ek olarak, bu yöntem kullanılarak grup, aynı zamanda, sadece iyi bir rejeneratörler yaralanma sonrası ve yenilenme sürecinde nörofilament ekspresyonunun bir toparlanma göstermektedir göstermiştir. Son zamanlarda, Busch ve Morgan 7 kötü rejeneratörler bir arttırmaya göstermektedir ki, bağışıklık fluorışıması yoluyla göstermiştir&quot;kötü yenileyici&quot; spinal çıkıntı nöronlar yavaş yavaş tam bir omurilik kesisi 5,7,8 sonra ölmek gerçeğine yazarlar tarafından ilgili olmuştur yaralanma sonrası sinüklein ed ifade. Yani, tam bir omurilik yaralanmasının taşemen modeli omurilik çıkıntı nöron axotomy sonra &quot;kötü rejeneratörün&quot; kılan anlamak için çok kullanışlı bir model olarak ortaya çıkmıştır. In situ hibridizasyon Wholemount gerçekleştirmek için yaralanmadan sonra istenilen zaman noktalarında tam bir spinal kord kesisi ameliyat protokolü ve arka beyin diseksiyonu gerçekleştirirken bizim çalışmalar yapmak. Bu yöntem makalede larva Lamprey tam bir omurilik yaralanması cerrahi uygun performansı için detaylı bir protokol mevcut, hayvanların daha sonraki bakım ve in situ melezleme için bir wholemount nihai beyin diseksiyon ve beyin hazırlanması. Ayrıntılı bir protokol pelarva Lamprey beyninde in situ hibridizasyon wholemount rform daha önce rapor edilmiştir. 9 ek olarak, omurilik yaralanması, beyin diseksiyon Bu protokol, aynı zamanda daha sonra imünohistokimya ya da diğer yöntemler için histolojik beyinleri işlemek için kullanılabilir.

<table><tbody><tr><td>Tricaine methane sulfonate</td><td>Spectrum</td><td>TR108</td><td>Benzocaine saturated solution in PBS for sacrifice</td></tr><tr><td>Scalpel #3</td><td>Fine Science Tools (FST)</td><td>10003-12</td><td></td></tr><tr><td>Blades for scalpel: #11</td><td>Fine Science Tools&amp;nbsp;</td><td>10011-00</td><td></td></tr><tr><td>Castroviejo scissors #8</td><td>Fine Science Tools&amp;nbsp;</td><td>15002-08</td><td></td></tr><tr><td>Forceps #4 &amp;amp; #5</td><td>Dumont, Switzerland</td><td>Roboz RS4955</td><td>#4 for dissection of Spinal cord; #5 for stripping menninges</td></tr><tr><td>Dissecting Microscope</td><td>Olympus</td><td>SZ51</td><td></td></tr><tr><td>Sylgard</td><td>Dow Corning Co.</td><td>184</td><td></td></tr><tr><td>Insect pins 0.15, 0.20 mm</td><td>Austerlitz</td><td>No catalogue #</td><td>0.15 mm for pinning brain and spinal cord; 0.20 mm for the body</td></tr><tr><td>7 ml HDPE Scintillation Tubes with Caps</td><td>Fisher Scientific</td><td>03-337-1</td><td></td></tr><tr><td>Paraformaldehyde 16%</td><td>Electron Microscopy Science (EMS)</td><td>19210</td><td>Dilute to 4% in PBS</td></tr></tbody></table>

complete spinal cord injury and brain dissection protocol for subsequent wholemount in situ hybridization in larval sea lamprey

Tam bir omurilik yaralanması sonrası, ilk deniz lampreys kesisi seviyesinin altında felç. Ancak, birkaç hafta sonra lokomosyonu kurtarmak ve bu propriyospinal akson ve beyin sapından spinal çıkıntı akson kısa mesafe rejenerasyon (birkaç mm) eşlik ediyor. 36 büyük tanımlanabilir spinal çıkıntı nöronlar arasında, bazı iyi rejeneratörler ve diğerleri kötü rejeneratörler vardır. Bu nöronlar en kolay Wholemount MSS hazırlıkları tespit edilebilir. Lehine nöron-iç mekanizmaları anlamak veya omurgalıların MSS yaralanmadan sonra akson rejenerasyonu inhibe etmek için, biz iyi ve kötü rejeneratörlerde arasında gen ifadesinde farklılıkları belirlemek ve nasıl ifade omurilik transection etkilenir. Bu kağıt mikroskopik görüş altında tam omurilik kesilerde üreten ve br hazırlama, tatlı su tankları konut larva teknikleri ve son zamanlarda dönüştürülmüş yetişkin deniz lamprey balıklarının göstermektedirain ve in situ melezleme için omurilik wholemounts. Kısacası, hayvanlar 16 tutulmaktadır &#160; C ° ve taşemen Ringer% 1 Benzokain anastezi. Omurilik bir dorsal yaklaşım ile iridektomi makas ile nakledilmiştir ve hayvan 23 ° C&#39;de tatlı su tanklarında kurtarmak için izin verilir. In situ hibridizasyon için, hayvanlar tekrar uyutuldu ve beyin ve kord dorsal yaklaşım ile kaldırıldı.

Bu yöntemi kullanarak elde edilebilir sonuçlarından bir örnek olarak, tanımlanabilir omurilik verme kontrolü, nöronlar ve 2 hafta içinde neogenin transkriptlerinin ekspresyonunu gösteren wholemounted beyinleri temsili görüntüleri lezyon larva deniz lampreys Şekil 2&#39;de gösterilmiştir sonrası. okuyucular tam omurilik transection ve tüm ayrıntılar için deniz lamprey nöronları çıkıntı tanımlanabilir omurilik rejeneratif yeteneği sonra neogenin ifade arasındaki ilişkiyi bild...

Watch this Scientific Journal Video about Complete Spinal Cord Injury and Brain Dissection Protocol for Subsequent Wholemount In Situ Hybridization in Larval Sea Lamprey at JoVE.com

Complete Spinal Cord Injury and Brain Dissection Protocol for Subsequent Wholemount In Situ Hybridization in Larval Sea Lamprey

Lamprey tam omurilik hasarı sonrası lokomosyonu kurtarmak. Ancak, bazı spinal çıkıntı nöronlar iyi rejeneratörler ve diğerleri değildir. Bu kağıt tam omurilik kesilerde üreten ve in situ hibridizasyon için Wholemount beyinleri ve omurilik hazırlama, konut deniz taşemen larvaları (ve son zamanlarda dönüştürülmüş yetişkinler) için teknikleri göstermektedir.

Sonradan wholemount için komple Omurilik Yaralanmalı ve Beyin Diseksiyon Protokolü<em&gt; Yerinde</em&gt; Larva Deniz taşemen içinde Hibritleşme

After a complete spinal cord injury, sea lampreys at first are paralyzed below the level of transection. However, they recover locomotion after several ...

complete-spinal-cord-injury-brain-dissection-protocol-for-subsequent

Research

JoVE Journal

Neuroscience

Complete Spinal Cord Injury and Brain Dissection Protocol for Subsequent Wholemount In Situ Hybridization in Larval Sea Lamprey

9.8K Görüntüleme.  University of Edinburgh.  Lamprey tam omurilik hasarı sonrası lokomosyonu kurtarmak. Ancak, bazı spinal çıkıntı nöronlar iyi rejeneratörler ve diğerleri değildir. Bu kağıt tam omurilik kesilerde üreten ve in situ hibridizasyon için Wholemount beyinleri ve omurilik hazırlama, konut deniz taşemen larvaları (ve son zamanlarda dönüştürülmüş yetişkinler) için teknikleri göstermektedir. 

Video: Complete Spinal Cord Injury and Brain Dissection Protocol for Subsequent Wholemount In Situ Hybridization in Larval Sea Lamprey

DiI-Labeling of DRG Neurons to Study Axonal Branching in a Whole Mount Preparation of Mouse Embryonic Spinal Cord

Here we present a technique to label the trajectories of small groups of DRG neurons into the embryonic spinal cord by diffusive staining using the lipophilic tracer 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI)1. The comparison of axonal pathways of wild-type with those of mouse lines in which genes are mutated allows testing for a functional role of candidate proteins in the control of axonal branching which is an essential mechanism in the wiring of the nervous system. Axonal branching enables an individual neuron to connect with multiple targets, thereby providing the physical basis for the parallel processing of information. Ramifications at intermediate target regions of axonal growth may be distinguished from terminal arborization. Furthermore, different modes of axonal branch formation may be classified depending on whether branching results from the activities of the growth cone (splitting or delayed branching) or from the budding of collaterals from the axon shaft in a process called interstitial branching2 (Fig. 1).
The central projections of neurons from the DRG offer a useful experimental system to study both types of axonal branching: when their afferent axons reach the dorsal root entry zone (DREZ) of the spinal cord between embryonic days 10 to 13 (E10 - E13) they display a stereotyped pattern of T- or Y-shaped bifurcation. The two resulting daughter axons then proceed in rostral or caudal directions, respectively, at the dorsolateral margin of the cord and only after a waiting period collaterals sprout from these stem axons to penetrate the gray matter (interstitial branching) and project to relay neurons in specific laminae of the spinal cord where they further arborize (terminal branching)3. DiI tracings have revealed growth cones at the dorsal root entry zone of the spinal cord that appeared to be in the process of splitting suggesting that bifurcation is caused by splitting of the growth cone itself4 (Fig. 2), however, other options have been discussed as well5.
This video demonstrates first how to dissect the spinal cord of E12.5 mice leaving the DRG attached. Following fixation of the specimen tiny amounts of DiI are applied to DRG using glass needles pulled from capillary tubes. After an incubation step, the labeled spinal cord is mounted as an inverted open-book preparation to analyze individual axons using fluorescence microscopy.

The stereotyped projections of sensory afferents into the rodent spinal cord offer an easily accessible experimental system to study axonal branching through the tracing of single axons.

Fare Embriyonik Omurilik Tüm Dağı Hazırlık aksonal dallanma Eğitim DRG Nöronlar DII-Etiketleme

Here we  present a technique to label the trajectories of small groups of DRG neurons  into the embryonic spinal cord by diffusive staining using the ...

Nörobilim

In ovo Electroporation of miRNA-based Plasmids in the Developing Neural Tube and Assessment of Phenotypes by DiI Injection in Open-book Preparations

Commissural dI1 neurons have been extensively studied to elucidate the mechanisms underlying axon guidance during development1,2. These neurons are located in the dorsal spinal cord and send their axons along stereotyped trajectories. Commissural axons initially project ventrally towards and then across the floorplate. After crossing the midline, these axons make a sharp rostral turn and project longitudinally towards the brain. Each of these steps is regulated by the coordinated activities of attractive and repulsive guidance cues. The correct interpretation of these cues is crucial to the guidance of axons along their demarcated pathway. Thus, the physiological contribution of a particular molecule to commissural axon guidance is ideally investigated in the context of the living embryo. Accordingly, gene knockdown in vivo must be precisely controlled in order to carefully distinguish axon guidance activities of genes that may play multiple roles during development.
Here, we describe a method to knockdown gene expression in the chicken neural tube in a cell type-specific, traceable manner. We use novel plasmid vectors3 harboring cell type-specific promoters/enhancers that drive the expression of a fluorescent protein marker, followed directly by a miR30-RNAi transcript4 (located within the 3'-UTR of the cDNA encoding the fluorescent protein) (Figure 1). When electroporated into the developing neural tube, these vectors elicit efficient downregulation of gene expression and express bright fluorescent marker proteins to enable direct tracing of the cells experiencing knockdown3. Mixing different RNAi vectors prior to electroporation allows the simultaneous knockdown of two or more genes in independent regions of the spinal cord. This permits complex cellular and molecular interactions to be examined during development, in a manner that is fast, simple, precise and inexpensive. In combination with DiI tracing of commissural axon trajectories in open-book preparations5, this method is a useful tool for in vivo studies of the cellular and molecular mechanisms of commissural axon growth and guidance. In principle, any promoter/enhancer could be used, potentially making the technique more widely applicable for in vivo studies of gene function during development6.
This video first demonstrates how to handle and window eggs, the injection of DNA plasmids into the neural tube and the electroporation procedure. To investigate commissural axon guidance, the spinal cord is removed from the embryo as an open-book preparation, fixed, and injected with DiI to enable axon pathways to be traced. The spinal cord is mounted between coverslips and visualized using confocal microscopy.

In ovo Electroporation of miRNA-based Plasmids in the Developing Neural Tube and Assessment of Phenotypes by DiI Injection in Open-book Preparations

A method by which gene expression in the neural tube can be downregulated in a cell type-specific, traceable manner is described. We demonstrate how in ovo electroporation of microRNA-based plasmids that elicit spatiotemporally controlled RNA interference can be used to investigate commissural axon guidance in the developing neural tube.

Open-kitap Hazırlıklarında Dii Enjeksiyon tarafından geliştirilmesi Nöral Tüp ve fenotipleri Değerlendirilmesinde miRNA tabanlı Plazmidler arasında ovo Elektroporasyon yılında

Commissural dI1 neurons have been extensively studied to elucidate the mechanisms underlying axon guidance during development1,2. These neurons are ...

Dissection and Lateral Mounting of Zebrafish Embryos: Analysis of Spinal Cord Development

The zebrafish spinal cord is an effective investigative model for nervous system research for several reasons. First, genetic, transgenic and gene knockdown approaches can be utilized to examine the molecular mechanisms underlying nervous system development. Second, large clutches of developmentally synchronized embryos provide large experimental sample sizes. Third, the optical clarity of the zebrafish embryo permits researchers to visualize progenitor, glial, and neuronal populations. Although zebrafish embryos are transparent, specimen thickness can impede effective microscopic visualization. One reason for this is the tandem development of the spinal cord and overlying somite tissue. Another reason is the large yolk ball, which is still present during periods of early neurogenesis. In this article, we demonstrate microdissection and removal of the yolk in fixed embryos, which allows microscopic visualization while preserving surrounding somite tissue. We also demonstrate semipermanent mounting of zebrafish embryos. This permits observation of neurodevelopment in the dorso-ventral and anterior-posterior axes, as it preserves the three-dimensionality of the tissue.

Developmental processes such as proliferation, patterning, differentiation, and axon guidance can be readily modeled in the zebrafish spinal cord. In this article, we describe a mounting procedure for zebrafish embryos, which optimizes visualization of these events.

Diseksiyon ve Zebra balığı Embriyolar Yanal Montaj: Omurilik Kalkınma Analizi

The zebrafish spinal cord is an effective investigative model for nervous system research for several reasons. First, genetic, transgenic and gene ...

Deciphering Axonal Pathways of Genetically Defined Groups of Neurons in the Chick Neural Tube Utilizing in ovo Electroporation

Employment of enhancer elements to drive expression of reporter genes in neurons is a widely used paradigm for tracking axonal projection. For tracking axonal projection of spinal interneurons in vertebrates, germ line-targeted reporter genes yield bilaterally symmetric labeling. Therefore, it is hard to distinguish between the ipsi- and contra-laterally projecting axons. Unilateral electroporation into the chick neural tube provides a useful means to restrict expression of a reporter gene to one side of the central nervous system, and to follow axonal projection on both sides 1 ,2-5. This video demonstrates first how to handle the eggs prior to injection. At HH stage 18-20, DNA is injected into the sacral level of the neural tube, then tungsten electrodes are placed parallel to the embryo and short electrical pulses are administered with a pulse generator. The egg is sealed with tape and placed back into an incubator for further development. Three days later (E6) the spinal cord is removed as an open book preparation from embryo, fixed, and processed for whole mount antibody staining. The stained spinal cord is mounted on slide and visualized using confocal microscopy.

Deciphering Axonal Pathways of Genetically Defined Groups of Neurons in the Chick Neural Tube Utilizing in ovo Electroporation

This video demonstrates how to visualize axonal pathways of genetically defined groups of neurons in the embryonic chick spinal cord utilizing in ovo electroporation of reporter genes under the control of specific enhancer elements.

Nöronlar, Genetik Tanımlı Gruplar Aksonal tanımında kullanılması Civciv Nöral Tüp Deşifre Ovo Elektroporasyon

Employment of enhancer elements to drive expression of reporter genes in neurons is a widely used paradigm for tracking axonal projection. For tracking ...

Biyoloji

Stab Wound Injury of the Zebrafish Adult Telencephalon: A Method to Investigate Vertebrate Brain Neurogenesis and Regeneration

Adult zebrafish have an amazing capacity to regenerate their central nervous system after injury. To investigate the cellular response and the molecular mechanisms involved in zebrafish adult central nervous system (CNS) regeneration and repair, we developed a zebrafish model of adult telencephalic injury.
In this approach, we manually generate an injury by pushing an insulin syringe needle into the zebrafish adult telencephalon. At different post injury days, fish are sacrificed, their brains are dissected out and stained by immunohistochemistry and/or in situ hybridization (ISH) with appropriate markers to observe cell proliferation, gliogenesis, and neurogenesis. The contralateral unlesioned hemisphere serves as an internal control. This method combined for example with RNA deep sequencing can help to screen for new genes with a role in zebrafish adult telencephalon neurogenesis, regeneration, and repair.

To shed light on the cellular and molecular mechanisms of zebrafish adult neurogenesis and regeneration, we developed a protocol for invasive surgery causing mechanical injuries in the zebrafish adult telencephalon and subsequent monitoring of changes in the stabbed hemisphere by immunohistochemistry or in situ hybridization.

Zebra balığı Yetişkin telencephalon stab Yara Yaralanma: Omurgalı Beyin nöron ve Rejenerasyon Soruşturma Bir Yöntem

Adult zebrafish have an amazing capacity to regenerate their central nervous system after injury. To investigate the cellular response and the molecular ...

Acute Dissociation of Lamprey Reticulospinal Axons to Enable Recording from the Release Face Membrane of Individual Functional Presynaptic Terminals

Synaptic transmission is an extremely rapid process. Action potential driven influx of Ca2+&#160;into the presynaptic terminal, through voltage-gated calcium channels (VGCCs) located in the release face membrane, is the trigger for vesicle fusion and neurotransmitter release. Crucial to the rapidity of synaptic transmission is the spatial and temporal synchrony between the arrival of the action potential, VGCCs and the neurotransmitter release machinery. The ability to directly record Ca2+&#160;currents from the release face membrane of individual presynaptic terminals is imperative for a precise understanding of the relationship between presynaptic Ca2+&#160;and neurotransmitter release. Access to the presynaptic release face membrane for electrophysiological recording is not available in most preparations and presynaptic Ca2+&#160;entry has been characterized using imaging techniques and macroscopic current measurements &#8211; techniques that do not have sufficient temporal resolution to visualize Ca2+ entry. The characterization of VGCCs directly at single presynaptic terminals has not been possible in central synapses and has thus far been successfully achieved only in the calyx-type synapse of the chick ciliary ganglion and in rat calyces. We have successfully addressed this problem in the giant reticulospinal synapse of the lamprey spinal cord by developing an acutely dissociated preparation of the spinal cord that yields isolated reticulospinal axons with functional presynaptic terminals devoid of postsynaptic structures. We can fluorescently label and identify individual presynaptic terminals and target them for recording. Using this preparation, we have characterized VGCCs directly at the release face of individual presynaptic terminals using immunohistochemistry and electrophysiology approaches. Ca2+ currents have been recorded directly at the release face membrane of individual presynaptic terminals, the first such recording to be carried out at central synapses.

Recording Ca2+ currents at the presynaptic release face membrane is key to a precise understanding of Ca2+ entry and neurotransmitter release. We present an acute dissociation of the lamprey spinal cord that yields functional isolated reticulospinal axons, permitting recording directly from the release face membrane of individual presynaptic terminals.

Lamprey Reticulospinal Aksonlar Akut Ayrılma Bireysel Fonksiyonel Presinaptik Terminalleri Yayın Yüz Membranından Kayıt Enable

Synaptic transmission is an extremely rapid process. Action potential driven influx of Ca2+&#160;into the presynaptic terminal, through voltage-gated ...

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal degeneration. Lack of growth cone formation, regeneration, and loss of additional myelinated axonal projections within the spinal cord greatly limits neurological recovery following injury. To assess how central myelinated axons of the spinal cord respond to injury, we developed an ex vivo living spinal cord model utilizing transgenic mice that express yellow fluorescent protein in axons and a focal and highly reproducible laser-induced spinal cord injury to document the fate of axons and myelin (lipophilic fluorescent dye Nile Red) over time using two-photon excitation time-lapse microscopy. Dynamic processes such as acute axonal injury, axonal retraction, and myelin degeneration are best studied in real-time. However, the non-focal nature of contusion-based injuries and movement artifacts encountered during in vivo spinal cord imaging make differentiating primary and secondary axonal injury responses using high resolution microscopy challenging. The ex vivo spinal cord model described here mimics several aspects of clinically relevant contusion/compression-induced axonal pathologies including axonal swelling, spheroid formation, axonal transection, and peri-axonal swelling providing a useful model to study these dynamic processes in real-time. Major advantages of this model are excellent spatiotemporal resolution that allows differentiation between the primary insult that directly injures axons and secondary injury mechanisms; controlled infusion of reagents directly to the perfusate bathing the cord; precise alterations of the environmental milieu (e.g., calcium, sodium ions, known contributors to axonal injury, but near impossible to manipulate in vivo); and murine models also offer an advantage as they provide an opportunity to visualize and manipulate genetically identified cell populations and subcellular structures. Here, we describe how to isolate and image the living spinal cord from mice to capture dynamics of acute axonal injury.

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

We present a protocol utilizing two-photon excitation time-lapse microscopy to simultaneously visualize the dynamics of axon and myelin injuries in real time. This proposed protocol permits studies of both intrinsic and extrinsic factors which can influence central myelinated axon fate after injury and contribute to permanent clinical disability.

Bir<em&gt; Ex vivo</em&gt; Lazer kaynaklı Omurilik Felçlileri Modeli Gerçek zamanlı aksonal Dejenerasyon mekanizmaları değerlendirmek için

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal ...

Zebrafish In Situ Spinal Cord Preparation for Electrophysiological Recordings from Spinal Sensory and Motor Neurons

Zebrafish, first introduced as a developmental model, have gained popularity in many other fields. The ease of rearing large numbers of rapidly developing organisms, combined with the embryonic optical clarity, served as initial compelling attributes of this model. Over the past two decades, the success of this model has been further propelled by its amenability to large-scale mutagenesis screens and by the ease of transgenesis. More recently, gene-editing approaches have extended the power of the model.
For neurodevelopmental studies, the zebrafish embryo and larva provide a model to which multiple methods can be applied. Here, we focus on methods that allow the study of an essential property of neurons, electrical excitability. Our preparation for the electrophysiological study of zebrafish spinal neurons involves the use of veterinarian suture glue to secure the preparation to a recording chamber. Alternative methods for recording from zebrafish embryos and larvae involve the attachment of the preparation to the chamber using a fine tungsten pin1,2,3,4,5. A tungsten pin is most often used to mount the preparation in a lateral orientation, although it has been used to mount larvae dorsal-side up4. The suture glue has been used to mount embryos and larvae in both orientations. Using the glue, a minimal dissection can be performed, allowing access to spinal neurons without the use of an enzymatic treatment, thereby avoiding any resultant damage. However, for larvae, it is necessary to apply a brief enzyme treatment to remove the muscle tissue surrounding the spinal cord. The methods described here have been used to study the intrinsic electrical properties of motor neurons, interneurons, and sensory neurons at several developmental stages6,7,8,9.

Zebrafish In Situ Spinal Cord Preparation for Electrophysiological Recordings from Spinal Sensory and Motor Neurons

This manuscript describes methods for electrophysiological recordings from spinal neurons of zebrafish embryos and larvae. The preparation maintains neurons in situ and often involves minimum dissection. These methods allow for the electrophysiological study of a variety of spinal neurons, from the initial electrical excitability acquisition through the early larval stages.

Zebra balığı<em&gt; Situ</em&gt; Omurilik Omurilik duyusal ve motor nöronlar gelen Elektrofizyolojik Recordings Hazırlık

Zebrafish, first introduced as a developmental model, have gained popularity in many other fields. The ease of rearing large numbers of rapidly developing ...

Stereotactic Atlas-Guided Laser Capture Microdissection of Brain Regions Affected by Traumatic Injury

The ability to isolate specific brain regions of interest can be impeded in tissue disassociation techniques that do not preserve their spatial distribution. Such techniques also potentially skew gene expression analysis because the process itself can alter expression patterns in individual cells. Here we describe a laser capture microdissection (LCM) method to selectively collect specific brain regions affected by traumatic brain injury (TBI) by using a modified Nissl (cresyl violet) staining protocol and the guidance of a rat brain atlas. LCM provides access to brain regions in their native positions and the ability to use anatomical landmarks for identification of each specific region. To this end, LCM has been used previously to examine brain region specific gene expression in TBI. This protocol allows examination of TBI-induced alterations in gene and microRNA expression in distinct brain areas within the same animal. The principles of this protocol can be amended and applied to a wide range of studies examining genomic expression in other disease and/or animal models.

We describe the use of laser capture microdissection to obtain samples of distinct cell populations from different brain regions for gene and microRNA analysis. This technique allows the study of differential effects of traumatic brain injury in specific regions of the rat brain.

Stereotaksik Atlas güdümlü lazer yakalama mikrodiseksiyon travma yaralanma tarafından etkilenen beyin bölgeleri

The ability to isolate specific brain regions of interest can be impeded in tissue disassociation techniques that do not preserve their spatial ...

Controlled Semi-Automated Laser-Induced Injuries for Studying Spinal Cord Regeneration in Zebrafish Larvae

Zebrafish larvae possess a fully functional central nervous system (CNS) with a high regenerative capacity only a few days after fertilization. This makes this animal model very useful for studying spinal cord injury and regeneration. The standard protocol for inducing such lesions is to transect the dorsal part of the trunk manually. However, this technique requires extensive training and damages additional tissues. A protocol was developed for laser-induced lesions to circumvent these limitations, allowing for high reproducibility and completeness of spinal cord transection over many animals and between different sessions, even for an untrained operator. Furthermore, tissue damage is mainly limited to the spinal cord itself, reducing confounding effects from injuring different tissues, e.g., skin, muscle, and CNS. Moreover, hemi-lesions of the spinal cord are possible. Improved preservation of tissue integrity after laser injury facilitates further dissections needed for additional analyses, such as electrophysiology. Hence, this method offers precise control of the injury extent that is unachievable manually. This allows for new experimental paradigms in this powerful model in the future.

The present protocol describes a method to induce tissue-specific and highly reproducible injuries in zebrafish larvae using a laser lesion system combined with an automated microfluidic platform for larvae handling.

Zebra Balığı Larvalarında Omurilik Rejenerasyonunu İncelemek için Kontrollü Yarı Otomatik Lazer Kaynaklı Yaralanmalar

Zebrafish larvae possess a fully functional central nervous system (CNS) with a high regenerative capacity only a few days after fertilization. This makes ...

Sonradan wholemount için komple Omurilik Yaralanmalı ve Beyin Diseksiyon Protokolü

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