Name: full-circle cauterization of limbal vascular plexus for surgically induced glaucoma in rodents
Uploaded: 2022-02-15T14:00:00
Description: Watch this Scientific Journal Video about Full-Circle Cauterization of Limbal Vascular Plexus for Surgically Induced Glaucoma in Rodents at JoVE.com

Laboratuvar teknisyenlerimiz José'ye; Nilson dos Santos, Daianne Mandarino Torres, José Francisco Tibúrcio, Gildo Brito de Souza ve Luciano Cavalcante Ferreira. Bu araştırma FAPERJ, CNPq ve CAPES tarafından finanse edilmiştir.

Tüm prosedürler, Görme ve Oftalmoloji Araştırmaları Derneği'nin (ARVO) Oftalmik ve Görsel Araştırmalarında Hayvanların Kullanımına İlişkin Bildiri'ye uygun olarak gerçekleştirildi ve Rio de Janeiro Federal Üniversitesi Sağlık Bilimleri Merkezi'nden Bilimsel Deneylerde Hayvanların Kullanımına İlişkin Etik Komite tarafından onaylandı (protokol 083/17). Bu çalışmada, her iki cinsiyetten 2-3 aylık ve 180-320 g ağırlığındaki Lister Hooded sıçanlar kullanıldı. Bununla birlikte, prosedü...

<ol>
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C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+rat+model+of+chronic+pressure-induced+optic+nerve+damage.">A rat model of chronic pressure-induced optic nerve damage.</a> Experimental Eye Research. 64 (1), 85-96 (1997).</li><li>Sappington, R. M., Carlson, B. J., Crish, S. D., Calkins, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+microbead+occlusion+model:+A+paradigm+for+induced+ocular+hypertension+in+rats+and+mice.">The microbead occlusion model: A paradigm for induced ocular hypertension in rats and mice.</a> Investigative Ophthalmology &amp; Visual Science. 51 (1), 207-216 (2010).</li><li>Zhu, M. D., Cai, F. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+experimental+chronic+intraocular+hypertension+in+the+rabbit.">Development of experimental chronic intraocular hypertension in the rabbit.</a> Australian and New Zealand Journal of Ophthalmology. 20 (3), 225-234 (1992).</li><li>Shareef, S. R., Garcia-Valenzuela, E., Salierno, A., Walsh, J., Sharma, 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=Chronic+ocular+hypertension+following+episcleral+venous+occlusion+in+rats.">Chronic ocular hypertension following episcleral venous occlusion in rats.</a> Experimental Eye Research. 61 (3), 379-382 (1995).</li><li>Levkovitch-Verbin, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Translimbal+laser+photocoagulation+to+the+trabecular+meshwork+as+a+model+of+glaucoma+in+rats.">Translimbal laser photocoagulation to the trabecular meshwork as a model of glaucoma in rats.</a> Investigative Ophthalmology &amp; Visual Science. 43 (2), 402-410 (2002).</li><li>Zhao, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+the+Circumlimbal+Suture+Model+of+Chronic+IOP+Elevation+in+Mice+and+Assessment+of+Changes+in+Gene+Expression+of+Stretch+Sensitive+Channels.">Characterization of the Circumlimbal Suture Model of Chronic IOP Elevation in Mice and Assessment of Changes in Gene Expression of Stretch Sensitive Channels.</a> Frontiers in Neuroscience. 11, (2017).</li><li>Biswas, S., Wan, K. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review+of+rodent+hypertensive+glaucoma+models.">Review of rodent hypertensive glaucoma models.</a> Acta Ophthalmologica. 97 (3), 331-340 (2019).</li><li>Pitha, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sustained+Dorzolamide+Release+Prevents+Axonal+and+Retinal+Ganglion+Cell+Loss+in+a+Rat+Model+of+IOP-Glaucoma.">Sustained Dorzolamide Release Prevents Axonal and Retinal Ganglion Cell Loss in a Rat Model of IOP-Glaucoma.</a> Translational Vision Science &amp; Technology. 7 (2), 13 (2018).</li><li>Grozdanic, S. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporary+elevation+of+the+intraocular+pressure+by+cauterization+of+vortex+and+episcleral+veins+in+rats+causes+functional+deficits+in+the+retina+and+optic+nerve.">Temporary elevation of the intraocular pressure by cauterization of vortex and episcleral veins in rats causes functional deficits in the retina and optic nerve.</a> Experimental Eye Research. 77 (1), 27-33 (2003).</li><li>Lani, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+subacute+model+of+glaucoma+based+on+limbal+plexus+cautery+in+pigmented+rats.">A subacute model of glaucoma based on limbal plexus cautery in pigmented rats.</a> Scientific Reports. 9 (1), 16286 (2019).</li><li>vander Merwe, E. L., Kidson, S. 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Limbal pleksus koterizasyonu (LPC), konjonktival veya zıvana diseksiyonu gerektirmeyen, kolay erişilebilir vasküler yapıları hedefleme avantajına sahip yeni bir trabeküler modeldir17,28. Koroid venöz drenajın cerrahi bozukluğuna dayanan ünlü bir OHT modeli olan vorteks venler koterizasyon modelinden farklı olarak, limbal venler sulu mizah çıkışında yukarı akışta yer aldığından, venöz tıkanıklığın LPC modelinde GİB artışını etkil...

Tıp literatürü glokomu, retinal ganglion hücrelerinin (RGC'ler), dendritlerin, soma ve aksonların ilerleyici dejenerasyonu ile karakterize heterojen bir optik nöropati grubu olarak anlamaktadır, bu da optik diskin yapısal çukurluğu (kazısı) ve optik sinirin fonksiyonel bozulması ile sonuçlanan, kontrolsüz vakalarda gözden beyne görsel bilgi iletimini kesintiye uğratarak amaurozise yol açmaktadır1. Glokom şu anda dünya çapında geri dönüşü olmayan körlüğün en yaygın nedenidir ve 2040 yılında yaklaşık 111,8 milyon kişiye ulaşacağı tahmin edilmektedir2, bu nedenle hastaların yaşam kalitesini (YK) derinden etkilemekte ve önemli sosyoekonomik kaygılara yol açmaktadır3.
Yüksek göz içi basıncı (GİB), glokomun gelişimi ve ilerlemesi için en önemli ve değiştirilebilir tek risk faktörlerinden biridir. Birden fazla glokom tipi arasında, normal tansiyonlu glokom (NTG) hariç tümü, hastalığın klinik öyküsünde bir süre yüksek GİB ile ilişkilidir. GİB'yi hedeflemek ve hastalığın ilerlemesini yavaşlatmak veya durdurmak için kayda değer klinik ve cerrahi gelişmelere rağmen, hastalar glokom nedeniyle hala görme yetisini kaybetmektedir 4,5. Bu nedenle, bu hastalığın karmaşık ve multifaktöriyel patofizyolojisinin tam olarak anlaşılması, özellikle RGC'lere nöroproteksiyon sağlamak için daha etkili tedavilerin geliştirilmesi için zorunludur.
Hastalık mekanizmalarının anlaşılmasına yönelik çeşitli deneysel yaklaşımlar arasında, oküler hipertansiyona (OHT) dayalı hayvan modelleri en çok insan glokomuna benzemektedir. Kemirgen modelleri, düşük maliyetli oldukları, kullanımı kolay oldukları, genetik olarak manipüle edilebildikleri, kısa ömürlü oldukları ve sulu mizah üretimi ve drenajı gibi insanlarla karşılaştırılabilir oküler anatomik ve fizyolojik özellikler sundukları için özellikle kullanışlıdır 6,7,8,9,10,11,12,13 . Şu anda kullanılan modeller arasında episkleral venlere 14 hipertonik salin enjeksiyonunu takiben trabeküler ağın sklerozu, mikroboncukların 15 veya viskoelastik maddelerin16 intrakameral enjeksiyonu, vorteks damarlarınınkoterizasyonu 17, trabeküler ağın argon lazer 18 ile fotokoagülasyonu, circumlimbal sütür 19 ve yaşa bağlı OHT'nin transgenik bir modelinin (DBA/2J fareler) kullanımı yer almaktadır8. Bununla birlikte, invazivlik, korneanın postoperatif opaklaşması, ön segment bozulması, kapsamlı öğrenme eğrileri, pahalı ekipman ve oldukça değişken postoperatif GİB'ler, mevcut modellerle ilişkili bildirilen tuzaklardan birkaçı arasındadır ve bu sorunların üstesinden gelmek için alternatif bir OHT modelinin geliştirilmesini talep etmektedir20,21,22.
Mevcut protokol, kemirgenlerde limbal pleksus koterizasyonuna (LPC) dayalı olarak glokoma vekil olarak OHT'yi indüklemek için yeni bir cerrahi prosedürü resmileştirmektedir23. Bu, benzersiz bir şekilde yüksek bir tam klinik iyileşme oranı ile ilişkili, yüksek verimlilik ve düşük GİB yükselmesi değişkenliği sağlayan, dolayısıyla her deneyde kullanılan daha az sayıda hayvanda in vivo fonksiyonel değerlendirme sağlayan kolay, tekrarlanabilir, erişilebilir ve invaziv olmayan bir modeldir. Cerrahi teknik, akut açı kapanması glokomunda görülen hipertansif atağı modelleyen, birkaç gün içinde başlangıç seviyelerine kademeli bir dönüş ile subakut OHT'yi indükler. Ayrıca, modeldeki GİB iyileşmesini, GİB'nin yeterli kontrolüne rağmen birkaç insan glokomu vakasında meydana gelen RGC'lerin sekonder dejenerasyonunun gelecekteki mekanik çalışmaları için yararlı olan sürekli glokomatöz nörodejenerasyon takip eder.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Acetone</td>
			<td>Isofar</td>
			<td>201</td>
			<td>Used for electron microscopy tissue preparation (step 5)</td>
		</tr>
		<tr>
			<td>Active electrode for electroretinography</td>
			<td>Hansol Medical Co</td>
			<td>-</td>
			<td>Stainless steel needle 0.25 mm &#215; 15 mm</td>
		</tr>
		<tr>
			<td>Anestalcon</td>
			<td>Novartis Bioci&#234;ncias S/A</td>
			<td>MS-1.0068.1087</td>
			<td>Proxymetacaine hydrochloride 0.5%</td>
		</tr>
		<tr>
			<td>Calcium chloride</td>
			<td>Vetec</td>
			<td>560</td>
			<td>Used for electron microscopy tissue preparation (step 5)</td>
		</tr>
		<tr>
			<td>Cautery Low Temp Fine Tip 10/bx</td>
			<td>Bovie Medical Corporation</td>
			<td>AA00</td>
			<td>Low-temperature ophthalmic cautery</td>
		</tr>
		<tr>
			<td>Cetamin</td>
			<td>Syntec do Brasil Ltda</td>
			<td>000200-3-000003</td>
			<td>Ketamine hydrochloride 10%</td>
		</tr>
		<tr>
			<td>DAKO</td>
			<td>Dako North America</td>
			<td>S3023</td>
			<td>Antifade mounting medium</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>Thermo Fisher Scientific</td>
			<td>28718-90-3</td>
			<td>diamidino-2-phenylindole; blue fluorescent nuclear counterstain; emission at 452&#177;3 nm</td>
		</tr>
		<tr>
			<td>Ecofilm</td>
			<td>Crist&#225;lia Produtos Qu&#237;micos Farmac&#234;uticos Ltda</td>
			<td>MS-1.0298.0487</td>
			<td>Carmellose sodium 0.5%</td>
		</tr>
		<tr>
			<td>EPON Resin</td>
			<td>Polysciences, Inc.</td>
			<td>-</td>
			<td>Epoxy resin used for electron microscopy, composed of a mixture of four reagents: Poly/Bed 812 Resin (CAT#08791); DDSA - Dodecenylsuccinic Anhydride (CAT#00563); NMA - Nadic Methyl Anhydride (CAT#00886); DMP-30 - 2,4,6-tris(dimethylaminomethyl)phenol (CAT#00553)</td>
		</tr>
		<tr>
			<td>Glutaraldehyde</td>
			<td>Electron Microscopy Sciences</td>
			<td>16110</td>
			<td>Used for electron microscopy tissue preparation (step 5)</td>
		</tr>
		<tr>
			<td>Hyabak</td>
			<td>Uni&#227;o Qu&#237;mica Farmac&#234;utica Nacional S/A</td>
			<td>MS-8042140002</td>
			<td>Sodium hyaluronate 0.15%</td>
		</tr>
		<tr>
			<td>Icare Tonolab</td>
			<td>Icare Finland Oy</td>
			<td>TV02 (model number)</td>
			<td>Rebound handheld tonometer</td>
		</tr>
		<tr>
			<td>IgG donkey anti-mouse antibody + Alexa Fluor 555</td>
			<td>Thermo Fisher Scientific</td>
			<td>A31570</td>
			<td>Secondary antibody solution</td>
		</tr>
		<tr>
			<td>LCD monitor 23 inches</td>
			<td>Samsung Electronics Co. Ltd.</td>
			<td>S23B550</td>
			<td>Model LS23B550, for electroretinogram recording</td>
		</tr>
		<tr>
			<td>LSM 510 Meta</td>
			<td>Carl Zeiss</td>
			<td>-</td>
			<td>Confocal epifluorescence microscope</td>
		</tr>
		<tr>
			<td>Maxiflox</td>
			<td>Crist&#225;lia Produtos Qu&#237;micos Farmac&#234;uticos Ltda</td>
			<td>MS-1.0298.0489</td>
			<td>Ciprofloxacin 3.5 mg/g</td>
		</tr>
		<tr>
			<td>MEB-9400K</td>
			<td>Nihon Kohden Corporation</td>
			<td>-</td>
			<td>System for electroretinogram recording</td>
		</tr>
		<tr>
			<td>monoclonal IgG1 mouse anti-Brn3a</td>
			<td>MilliporeSigma</td>
			<td>MAB-1585</td>
			<td>Brn3a primary antibody solution</td>
		</tr>
		<tr>
			<td>Neuropack Manager v08.33</td>
			<td>Nihon Kohden Corporation</td>
			<td>-</td>
			<td>Software for electroretinogram signal processing</td>
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		<tr>
			<td>Optomotry</td>
			<td>CerebralMechanics</td>
			<td>-</td>
			<td>System for optomotor response analysis</td>
		</tr>
		<tr>
			<td>Osmium tetroxide</td>
			<td>Electron Microscopy Sciences</td>
			<td>19100</td>
			<td>Used for electron microscopy tissue preparation (step 5)</td>
		</tr>
		<tr>
			<td>Potassium ferrocyanide</td>
			<td>Electron Microscopy Sciences</td>
			<td>20150</td>
			<td>Used for electron microscopy tissue preparation (step 5)</td>
		</tr>
		<tr>
			<td>Reference and ground electrodes for electroretinography</td>
			<td>Chalgren Enterprises</td>
			<td>110-63</td>
			<td>Stainless steel needles 0.4 mm &#215; 37 mm</td>
		</tr>
		<tr>
			<td>Sodium cacodylate buffer</td>
			<td>Electron Microscopy Sciences</td>
			<td>12300</td>
			<td>Used for electron microscopy tissue preparation (step 5)</td>
		</tr>
		<tr>
			<td>Ster MD</td>
			<td>Uni&#227;o Qu&#237;mica Farmac&#234;utica Nacional S/A</td>
			<td>MS-1.0497.1287</td>
			<td>Prednisolone acetate 0.12%</td>
		</tr>
		<tr>
			<td>Terolac</td>
			<td>Crist&#225;lia Produtos Qu&#237;micos Farmac&#234;uticos Ltda</td>
			<td>MS-1.0497.1286</td>
			<td>Ketorolac trometamol 0.5%</td>
		</tr>
		<tr>
			<td>Terramicina</td>
			<td>Laborat&#243;rios Pfizer Ltda</td>
			<td>MS-1.0216.0024</td>
			<td>Oxytetracycline hydrochloride 30 mg/g + polymyxin B 10,000 U/g</td>
		</tr>
		<tr>
			<td>Tono-Pen XL</td>
			<td>Reichert Technologies</td>
			<td>230635</td>
			<td>Digital applanation handheld tonometer</td>
		</tr>
		<tr>
			<td>TO-PRO-3</td>
			<td>Thermo Fisher Scientific</td>
			<td>T3605</td>
			<td>Far red-fluorescent nuclear counterstain; emission at 661 nm</td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma-Aldrich</td>
			<td>9036-19-5</td>
			<td>Non-ionic surfactant</td>
		</tr>
		<tr>
			<td>Uranyl acetate</td>
			<td>Electron Microscopy Sciences</td>
			<td>22400</td>
			<td>Used for electron microscopy tissue preparation (step 5)</td>
		</tr>
		<tr>
			<td>Xilazin</td>
			<td>Syntec do Brasil Ltda</td>
			<td>7899</td>
			<td>Xylazine hydrochloride 2%</td>
		</tr>
		<tr>
			<td></td>
			<td>Carl Zeiss</td>
			<td>-</td>
			<td>Stereo microscope for surgery and retinal dissection</td>
		</tr>
	</tbody>
</table>

full-circle cauterization of limbal vascular plexus for surgically induced glaucoma in rodents

Dünya çapında körlüğün ikinci önde gelen nedeni olan glokom, optik sinirde yapısal hasar ve retina ganglion hücresi (RGC) dejenerasyonu ile karakterize, gözden beyne görsel bilgi iletimini kesintiye uğratarak görsel işlev bozukluğuna neden olan heterojen bir oküler bozukluk grubudur. Göz içi basıncının yükselmesi en önemli risk faktörüdür; Bu nedenle, hastalığın nedenlerini ve etkilerini araştırmak için genetik veya deneysel yaklaşımlarla kemirgenlerde çeşitli oküler hipertansiyon modelleri geliştirilmiştir. Bunlar arasında cerrahi invazivlik, yetersiz fonksiyonel değerlendirme, kapsamlı eğitim gereksinimi ve retina hasarının oldukça değişken uzantısı gibi bazı sınırlamalar bildirilmiştir. Bu çalışma, sulu mizah drenajının önemli bir bileşeni olan limbal vasküler pleksusun düşük sıcaklıkta, tam daire koterizasyonuna dayalı olarak kemirgenlerde oküler hipertansiyonu indüklemek için basit, düşük maliyetli ve etkili bir yöntemi karakterize etmektedir. Yeni model, ilerleyici RGC ve optik sinir dejenerasyonu ile ilişkili, teknik olarak kolay, noninvaziv ve tekrarlanabilir bir subakut oküler hipertansiyon ve hem elektrofizyolojik hem de davranışsal yöntemlerle in vivo fonksiyonel çalışmalara izin veren benzersiz bir postoperatif klinik iyileşme oranı sağlar.

Kantitatif değişkenler ortalama ± ortalamanın standart hatası (SEM) olarak ifade edilir. OHT ve kontrol grupları arasındaki GİB dinamiklerinin karşılaştırılması dışında (Şekil 1F), istatistiksel analiz iki yönlü ANOVA ve ardından Sidak'ın çoklu karşılaştırma testi kullanılarak yapıldı. p değerinin 0.05< olması istatistiksel olarak anlamlı kabul edildi.
Şekil 1 , limbal damarların 360° termal kaynakl...

Watch this Scientific Journal Video about Full-Circle Cauterization of Limbal Vascular Plexus for Surgically Induced Glaucoma in Rodents at JoVE.com

Full-Circle Cauterization of Limbal Vascular Plexus for Surgically Induced Glaucoma in Rodents

Bu protokolün amacı, subakut oküler hipertansiyonu indükleyen limbal vasküler pleksusun 360° termik koterizasyonuna dayanan yeni bir glokomatöz nörodejenerasyon modelini karakterize etmektir.

Kemirgenlerde Cerrahi Olarak İndüklenen Glokom için Limbal Vasküler Pleksusun Tam Daire Koterizasyonu

Glaucoma, the second leading cause of blindness worldwide, is a heterogeneous group of ocular disorders characterized by structural damage to the optic ...

Geçici göz içi basıncı yükselmesine dayalı sağlam ve ilerleyici glokom dejenerasyonunu indüklemek için basit bir yöntem geliştirdik. Bu, glokom patofizyolojisinin kilit noktalarını incelemek için eşsiz bir fırsattır. Bu, her deney için daha az sayıda hayvan kullanarak in vivo fonksiyon analizine ve kısa vadeli deneysel tasarımlara olanak tanıyan, öğrenmesi kolay, invaziv olmayan, düşük maliyetli ve yüksek oranda tekrarlanabilir bir modeldir.Retina ve optik sinir, merkezi sinir sisteminin değerlendirilebilir parçalarıdır, bu nedenle bu yapıların ilerleyici bozukluğunun modellenmesi, diğer nörodejeneratif bozukluklar hakkında değerli bilgiler sağlayabilir. Hem deneysel hem de kontralateral kontrol gözlerinin başlangıç göz içi basıncını veya GİB'sini ölçmek için, anestezi uygulanmış sıçanı, kornea yüzeyine tonometrenin ucuna kolayca erişilebilecek şekilde tezgah üstünde ventral dekübit pozisyonuna yerleştirin. Tonometre ucunu, merkezi kornea bölgesine dik olarak hafifçe dokunacak şekilde konumlandırın.Ardından, ölçüm düğmesine basarak ölçümü alın. Daha sonra, fareyi stereo mikroskop altında hafif bir yanal dekübit pozisyonuna yerleştirin ve deney gözünü 40 kat büyütmede inceleyin. İşlem sırasında, bir damla karmeloz sodyum veya sodyum hiyalüronat damlatılarak kontralateral kontrol gözünü yağlayın.Daha sonra, kavisli forseps kullanarak, limbusun 360 derecesini çevreleyen damar sistemini ortaya çıkarmak için deneysel göz küresini hafifçe ileri doğru itin. Daha sonra, diğer elinizle, düşük sıcaklıkta bir oftalmik koter kullanarak, korneanın etrafındaki damarları nazikçe dağlayın. Kornea çevresini dağlamamaya dikkat edin.Ameliyat edilen gözde skleral limbusta küçük dairesel koterizasyon izlerinin ortaya çıkışını, limbal vaskülatürün obliterasyonunu ve pupil genişlemesini gözlemleyerek cerrahi prosedürün başarısını doğrulayın. Ameliyattan sonra, daha önce gösterildiği gibi her iki gözde de ameliyat sonrası GİB'yi kontrol edin. Ardından, deneysel gözün ön yüzeyine bir damla oftalmik prednizolon asetat uygulayın.40 saniye sonra, oftalmik bir antibiyotik merhem ile değiştirin. Steroid olmayan bir antienflamatuar ilaç ve antibiyotik merhemden oluşan topikal ilaçlarla deneysel gözün günlük klinik takibini uygulayın. Optomotor tepki analizi için, fareyi dörtgende dört bilgisayar monitörü ile oluşturulmuş bir platforma alıştırma için yerleştirin.Sanal silindirin merkezini gösterdiğinden, video karesindeki kırmızı artı imlecini serbestçe hareket eden farenin gözleri arasında tutun. Dönen derecelendirmeler tarafından ortaya çıkarılan sıçan başının ve boynunun refleksif bir takibinden oluşan optomotor tepkiyi gözlemleyin. Başlangıçta, düşük uzamsal frekansa sahip bir uyaran tanıtın, ardından izleme hareketi fark edilmeyene kadar frekansı kademeli olarak artırın.Model elektroretinogramını kaydetmek için, sıçanı uyuşturduktan sonra, aktif elektrodu korneanın temporal çevresine dikkatlice yerleştirin. Ek olarak, referans elektrodu ipsilateral temporal kantusun deri altı dokusuna ve toprak elektrodunu arka bacaklardan birine yerleştirin. Ardından fareyi uyaran ekranından 20 santimetre uzağa konumlandırın, sinyal taban çizgisini izleyin ve toplama sistemindeki Analiz düğmesine basarak alımı başlatın.Retinaları izole ettikten sonra, iç retinayı yukarı bakacak şekilde bir mililitre PBS içeren 24 oyuklu bir kültür plakasına aktarın. PBS ile seyreltilmiş% 0.5 iyonik olmayan bir yüzey aktif madde ile yıkayarak dokuyu geçirgenleştirin. Daha sonra, dokuyu ve bloke edici çözeltiyi oda sıcaklığında bir saat boyunca hafifçe çalkalayarak inkübe edin.İnkübasyon sırasında, Brn-3a birincil antikor çözeltisini hazırlayın ve dört santigrat derecede saklayın. Doku blokajından sonra, retinaları 200 mikrolitre primer antikor çözeltisinde dört santigrat derecede 72 saat boyunca hafifçe çalkalayarak inkübe edin. Sonra, mendili PBS ile yıkayın.Dokuyu 200 mikrolitre ikincil antikor çözeltisinde oda sıcaklığında iki saat inkübe edin ve daha sonra floresan çekirdeklerin boyanması için 10 dakika boyunca nükleer karşı boyama çözeltisi ile inkübe edin. Üç PBS yıkamasından sonra, retinayı vitreus tarafı yukarı bakacak şekilde iki küçük fırça kullanarak bir cam mikroskop lamına aktarın. Dorsal retinal kadranı mikroskop lamı üzerinde yukarı doğru konumlandırın.Son olarak, 200 mikrolitre antifade montaj ortamını bir cam kapak kızağı üzerine uygulayın ve mikroskobik analiz için düz monte edilmiş retinaya yerleştirin. Konfokal epifloresan mikroskobu altında, 40 kat büyütücü bir objektif kullanarak, retinal ganglion hücrelerini tahmin etmek için düz bağlantıları inceleyin. Göz küresi enükleasyonundan sonra, göz içi kısmın bir kısmı da dahil olmak üzere optik sinirin intraorbital kısmının proksimal segmentini çıkarın.Ardından, numuneleri hemen 200 ila 300 mikrolitre soğuk fiksatif içeren şişelere veya tüplere yerleştirin. İki saat sonra, dokuyu soğuk 100 mikromolar sodyum kakodilat tamponu ile yıkayın. Daha sonra, dokuyu bir saat boyunca% 1 osmiyum tetroksit ve beş nanomolar kalsiyum klorür içinde dört santigrat derecede hafifçe çalkalayın.Soğuk sodyum kakodilat tamponu ile üç yıkamadan sonra, optik sinir parçalarını gece boyunca inkübe etmeden önce soğuk damıtılmış su ve dört santigrat derecede% 1 pisuar asetat ile yıkayın. Ertesi gün, suyla üç yıkamadan sonra, artan aseton konsantrasyonlarında dokuyu kademeli olarak kurutun. Ardından, dokuyu 24 saat boyunca saf epoksi reçineye gömmeden önce üç tur gömme ve epoksi reçine aseton solüsyonu gerçekleştirin.Ertesi gün, numuneleri numune taşıyıcıdan çıkarın ve 60 santigrat derecede 48 saat boyunca gömme kalıplarına aktarın. Polimerizasyondan sonra, optik sinir parçalarının enine yarı ince kesitlerini kesmek için bir ultra mikrotom kullanın. Ardından, bölümleri toplayın ve bir mikroskop cam lamına aktarın.Bölümleri toluidin mavisi ile boyayın ve 100 kat büyütmede optik mikroskop kullanarak görüntüleyin. Ultra yapısal analiz için, ultra ince kesitler yapın ve bunları bakır bir ızgara üzerinde toplayın. Ardından, transmisyon elektron mikroskobik incelemesi için bölümleri pisuar asetat ve kurşun sitrat ile boyayın.Tam daire koterizasyon, kontrol gözlerine kıyasla ameliyattan hemen sonra GİB yükselmesine neden oldu. Postoperatif GİB için pik birinci günde gözlendi ve altıncı günde kademeli olarak başlangıç seviyelerine düştü. Ayrıca, retina fonksiyonu sırasıyla optomotor refleks ve patern elektroretinogram kullanılarak hem davranışsal hem de elektrofizyolojik olarak değerlendirildi.Ameliyattan sonra, her iki parametre de iki farklı bozulma fazı gösterdi: üçüncü günde oküler hipertansiyon akut fazı ve 30. günde sekonder dejenerasyon fazı. Kontrol optik sinirleri ile karşılaştırıldığında, aksonal sayılar ve yarı ince transversal optik sinir kesitleri ameliyattan sonra progresif olarak azaldı. Kontrol gözünden optik sinirlerin transmisyon elektron mikrografları, ince glial hücre süreçleri ve belirgin aksonal mikrotübüller ve nörofilamentler ile ayrılmış yoğun paketlenmiş miyelinli lifler gösterdi.Buna karşılık, üç günlük oküler hipertansiyondan sonra, birkaç dejenere lif, glial hücre süreçlerinde sitoplazmik vakuolasyon ve glial hücre çekirdeklerinde yoğunlaştırılmış kromatin gözlendi. Yedi gün sonra, dejenere aksonal liflerde ve hipertonik glial hücre süreçlerinde bir artış oldu. Ve 14 gün sonra, aksonlar arasında glial hücre süreçlerinin istilası ile ilişkili optik sinir liflerinde daha fazla düzensizlik gözlendi.Ayrıca, retinal ganglion hücrelerinin yoğunluğu zamanla özellikle dorsal ve temporal retinal kadranlarda azalmıştır. Bu işlemi gerçekleştirirken, kord çevresini koruyarak ve skleral limbusun her yerinde sürekli koterizasyon izlerinin görülmesini sağlamak için koter ucu ile limbal damarlara hafifçe dokunmaya çalışın. Bu işlemi takiben göz yapılarının fonksiyonel biyokimyasal ve immünohistokimyasal değerlendirilmesi ve glokom fizyopatolojisi üzerine geçerli olabilecek diğer yöntemler gibi çeşitli yöntemler uygulanabilir.

full-circle-cauterization-limbal-vascular-plexus-for-surgically

Research

JoVE Journal

Neuroscience

Preparing Undercut Model of Posttraumatic Epileptogenesis in Rodents

Partially isolated cortex ("undercut") is an animal model of posttraumatic epileptogenesis. The surgical procedure involves cutting through the sensorimotor cortex and the underneath white matter (undercut) so that a specific region of the cerebral cortex is largely isolated from the neighboring cortex and subcortical regions1-3. After a latency of two or more weeks following the surgery, epileptiform discharges can be recorded in brain slices from rodents1; and electrical or behavior seizures can be observed in vivo from other species such as cat and monkey4-6. This well established animal model is efficient to generate and mimics several important characteristics of traumatic brain injury. However, it is technically challenging attempting to make precise cortical lesions in the small rodent brain with a free hand. Based on the procedure initially established in Dr. David Prince's lab at the Stanford University1, here we present an improved technique to perform a surgery for the preparation of this model in mice and rats. We demonstrate how to make a simple surgical device and use it to gain a better control of cutting depth and angle to generate more precise and consistent results. The device is easy to make, and the procedure is quick to learn. The generation of this animal model provides an efficient system for study on the mechanisms of posttraumatic epileptogenesis.

Partially isolated cortex (&#x201C;undercut&#x201D;) is an efficient animal model of posttraumatic epileptogenesis. Here we demonstrate how to make a novel surgical device and use it to make more precise and consistent lesions to generate this model.

Kemirgenler Travma Sonrası epileptogenezisin Alt kesilme Model hazırlanması

Partially isolated cortex ("undercut") is an animal model of posttraumatic epileptogenesis. The surgical procedure involves cutting through the ...

Nörobilim

Whole Animal Perfusion Fixation for Rodents

The goal of fixation is to rapidly and uniformly preserve tissue in a life-like state. While placing tissue directly in fixative works well for small pieces of tissue, larger specimens like the intact brain pose a problem for immersion fixation because the fixative does not reach all regions of the tissue at the same rate 5,7. Often, changes in response to hypoxia begin before the tissue can be preserved 12. The advantage of directly perfusing fixative through the circulatory system is that the chemical can quickly reach every corner of the organism using the natural vascular network. In order to utilize the circulatory system most effectively, care must be taken to match physiological pressures 3. It is important to note that physiological pressures are dependent on the species used. Techniques for perfusion fixation vary depending on the tissue to be fixed and how the tissue will be processed following fixation. In this video, we describe a low-cost, rapid, controlled and uniform fixation procedure using 4% paraformaldehyde perfused via the vascular system: through the heart of the rat to obtain the best possible preservation of the brain for immunohistochemistry. The main advantage of this technique (vs. gravity-fed systems) is that the circulatory system is utilized most effectively.

Here we describe a low-cost, rapid, controlled and uniform fixation procedure using 4% paraformaldehyde perfused via the vascular system: through the heart of the rat to obtain the best possible preservation of the brain.

Kemirgenler için Tüm Hayvan Perfüzyon Fiksasyon

The goal of fixation is to rapidly and uniformly preserve tissue in a life-like state. While placing tissue directly in fixative works well for small ...

Large-scale Recording of Neurons by Movable Silicon Probes in Behaving Rodents

A major challenge in neuroscience is linking behavior to the collective activity of neural assemblies. Understanding of input-output relationships of neurons and circuits requires methods with the spatial selectivity and temporal resolution appropriate for mechanistic analysis of neural ensembles in the behaving animal, i.e. recording of representatively large samples of isolated single neurons. Ensemble monitoring of neuronal activity has progressed remarkably in the past decade in both small and large-brained animals, including human subjects1-11. Multiple-site recording with silicon-based devices are particularly effective because of their scalability, small volume and geometric design.
Here, we describe methods for recording multiple single neurons and local field potential in behaving rodents, using commercially available micro-machined silicon probes with custom-made accessory components. There are two basic options for interfacing silicon probes to preamplifiers: printed circuit boards and flexible cables. Probe supplying companies (<a href="http://www.neuronexustech.com/" >http://www.neuronexustech.com/</a>; <a href="http://www.sbmicrosystems.com/">http://www.sbmicrosystems.com/</a>; <a href="http://www.acreo.se/">http://www.acreo.se/</a>) usually provide the bonding service and deliver probes bonded to printed circuit boards or flexible cables. Here, we describe the implantation of a 4-shank, 32-site probe attached to flexible polyimide cable, and mounted on a movable microdrive. Each step of the probe preparation, microdrive construction and surgery is illustrated so that the end user can easily replicate the process.

We describe methods for large-scale recording of multiple single units and local field potential in behaving rodents with silicon probes. Drive fabrication, probe attachment to the drive and probe implantation processes are illustrated in sufficient details for easy replication.

Kemirgenler davranmak yılında Hareketli Silikon Problar tarafından Nöronlar Büyük ölçekli Kaydı

A major challenge in neuroscience is linking behavior to the collective activity of neural assemblies. Understanding of input-output relationships of ...

A Low Cost Setup for Behavioral Audiometry in Rodents

In auditory animal research it is crucial to have precise information about basic hearing parameters of the animal subjects that are involved in the experiments. Such parameters may be physiological response characteristics of the auditory pathway, e.g. via brainstem audiometry (BERA). But these methods allow only indirect and uncertain extrapolations about the auditory percept that corresponds to these physiological parameters. To assess the perceptual level of hearing, behavioral methods have to be used. A potential problem with the use of behavioral methods for the description of perception in animal models is the fact that most of these methods involve some kind of learning paradigm before the subjects can be behaviorally tested, e.g. animals may have to learn to press a lever in response to a sound. As these learning paradigms change perception itself 1,2 they consequently will influence any result about perception obtained with these methods and therefore have to be interpreted with caution. Exceptions are paradigms that make use of reflex responses, because here no learning paradigms have to be carried out prior to perceptual testing. One such reflex response is the acoustic startle response (ASR) that can highly reproducibly be elicited with unexpected loud sounds in na&iuml;ve animals. This ASR in turn can be influenced by preceding sounds depending on the perceptibility of this preceding stimulus: Sounds well above hearing threshold will completely inhibit the amplitude of the ASR; sounds close to threshold will only slightly inhibit the ASR. This phenomenon is called pre-pulse inhibition (PPI) 3,4, and the amount of PPI on the ASR gradually depends on the perceptibility of the pre-pulse. PPI of the ASR is therefore well suited to determine behavioral audiograms in na&iuml;ve, non-trained animals, to determine hearing impairments or even to detect possible subjective tinnitus percepts in these animals. In this paper we demonstrate the use of this method in a rodent model (cf. also ref. 5), the Mongolian gerbil (Meriones unguiculatus), which is a well know model species for startle response research within the normal human hearing range (e.g. 6).

A fast and inexpensive method for the behavioral determination of hearing parameters like hearing thresholds, hearing impairments or phantom perceptions (subjective tinnitus) is described. It uses pre-pulse inhibition of the acoustic startle response and can be easily implemented in a personal computer using a programmable AD/DA-converter and a piezo sensor.

Kemirgenler Davranış Odyometri için Düşük Maliyetli Kurulum

In auditory animal research it is crucial to have precise information about basic hearing parameters of the animal subjects that are involved in the ...

Recording and Analysis of Circadian Rhythms in Running-wheel Activity in Rodents

When rodents have free access to a running wheel in their home cage, voluntary use of this wheel will depend on the time of day1-5. Nocturnal rodents, including rats, hamsters, and mice, are active during the night and relatively inactive during the day. Many other behavioral and physiological measures also exhibit daily rhythms, but in rodents, running-wheel activity serves as a particularly reliable and convenient measure of the output of the master circadian clock, the suprachiasmatic nucleus (SCN) of the hypothalamus. In general, through a process called entrainment, the daily pattern of running-wheel activity will naturally align with the environmental light-dark cycle (LD cycle; e.g. 12 hr-light:12 hr-dark). However circadian rhythms are endogenously generated patterns in behavior that exhibit a ~24 hr period, and persist in constant darkness. Thus, in the absence of an LD cycle, the recording and analysis of running-wheel activity can be used to determine the subjective time-of-day. Because these rhythms are directed by the circadian clock the subjective time-of-day is referred to as the circadian time (CT). In contrast, when an LD cycle is present, the time-of-day that is determined by the environmental LD cycle is called the zeitgeber time (ZT).
Although circadian rhythms in running-wheel activity are typically linked to the SCN clock6-8, circadian oscillators in many other regions of the brain and body9-14 could also be involved in the regulation of daily activity rhythms. For instance, daily rhythms in food-anticipatory activity do not require the SCN15,16 and instead, are correlated with changes in the activity of extra-SCN oscillators17-20. Thus, running-wheel activity recordings can provide important behavioral information not only about the output of the master SCN clock, but also on the activity of extra-SCN oscillators. Below we describe the equipment and methods used to record, analyze and display circadian locomotor activity rhythms in laboratory rodents.

Circadian rhythms in voluntary wheel-running activity in mammals are tightly coupled to the molecular oscillations of a master clock in the brain. As such, these daily rhythms in behavior can be used to study the influence of genetic, pharmacological, and environmental factors on the functioning of this circadian clock.

Kemirgenler Faaliyet teker Running kayıt ve Sirkadiyen Rhythms Analizi

When rodents have free access to a running wheel in their home cage, voluntary use of this wheel will depend on the time of day1-5. Nocturnal rodents, ...

Deep Brain Stimulation with Simultaneous fMRI in Rodents

In order to visualize the global and downstream neuronal responses to deep brain stimulation (DBS) at various targets, we have developed a protocol for using blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) to image rodents with simultaneous DBS. DBS fMRI presents a number of technical challenges, including accuracy of electrode implantation, MR artifacts created by the electrode, choice of anesthesia and paralytic to minimize any neuronal effects while simultaneously eliminating animal motion, and maintenance of physiological parameters, deviation from which can confound the BOLD signal.&#160;Our laboratory has developed a set of procedures that are capable of overcoming most of these possible issues. For electrical stimulation, a homemade tungsten bipolar microelectrode is used, inserted stereotactically at the stimulation site in the anesthetized subject. In preparation for imaging, rodents are fixed on a plastic headpiece and transferred to the magnet bore. For sedation and paralysis during scanning, a cocktail of dexmedetomidine and pancuronium is continuously infused, along with a minimal dose of isoflurane; this preparation minimizes the BOLD ceiling effect of volatile anesthetics. In this example experiment, stimulation of the subthalamic nucleus (STN) produces BOLD responses which are observed primarily in ipsilateral cortical regions, centered in motor cortex. Simultaneous DBS and fMRI allows the unambiguous modulation of neural circuits dependent on stimulation location and stimulation parameters, and permits observation of neuronal modulations free of regional bias. This technique may be used to explore the downstream effects of modulating neural circuitry at nearly any brain region, with implications for both experimental and clinical DBS.

This protocol describes a standard method for simultaneous functional magnetic resonance imaging and deep brain stimulation in the rodent. The combined use of these experimental tools allows for the exploration of global downstream activity in response to electrical stimulation at virtually any brain target.

Kemirgenler Eşzamanlı fMRI ile derin beyin stimülasyonu

In order to visualize the global and downstream neuronal responses to deep brain stimulation (DBS) at various targets, we have developed a protocol for ...

Quantification of Cerebral Vascular Architecture using Two-photon Microscopy in a Mouse Model of HIV-induced Neuroinflammation

Human Immunodeficiency Virus 1 (HIV-1) infection frequently results in HIV-1 Associated Neurocognitive Disorders (HAND), and is characterized by a chronic neuroinflammatory state within the central nervous system (CNS), thought to be driven principally by virally-mediated activation of microglia and brain resident macrophages. HIV-1 infection is also accompanied by changes in cerebrovascular blood flow (CBF), raising the possibility that HIV-associated chronic neuroinflammation may lead to changes in CBF and/or in cerebral vascular architecture. To address this question, we have used a mouse model for HIV-induced neuroinflammation, and we have tested whether long-term exposure to this inflammatory environment may damage brain vasculature and result in rarefaction of capillary networks. In this paper we describe a method to quantify changes in cortical capillary density in a mouse model of neuroinflammatory disease (HIV-1 Tat transgenic mice). This generalizable approach employs in vivo two-photon imaging of cortical capillaries through a thin-skull cortical window, as well as ex vivo two-photon imaging of cortical capillaries in mouse brain sections. These procedures produce images and z-stack files of capillary networks, respectively, which can be then subjected to quantitative analysis in order to assess changes in cerebral vascular architecture.

This paper describes a method by which the vascular architecture in the brain can be quantified using in vivo and ex vivo two-photon microscopy.

HIV kaynaklı Nöroinflamasyondan bir Fare Modeli İki foton Mikroskop kullanarak Serebral Vasküler Mimarlık Niceleme

Human Immunodeficiency Virus 1 (HIV-1) infection frequently results in HIV-1 Associated Neurocognitive Disorders (HAND), and is characterized by a chronic ...

Cannula Implantation into the Cisterna Magna of Rodents

Cisterna magna cannulation (CMc) is a straightforward procedure that enables direct access to the cerebrospinal fluid (CSF) without operative damage to the skull or the brain parenchyma. In anesthetized rodents, the exposure of the dura mater by blunt dissection of the neck muscles allows the insertion of a cannula into the cisterna magna (CM). The cannula, composed either by a fine beveled needle or borosilicate capillary, is attached via a polyethylene (PE) tube to a syringe. Using a syringe pump, molecules can then be injected at controlled rates directly into the CM, which is continuous with the subarachnoid space. From the subarachnoid space, we can trace CSF fluxes by convective flow into the perivascular space around penetrating arterioles, where solute exchange with the interstitial fluid (ISF) occurs. CMc can be performed for acute injections immediately following the surgery, or for chronic implantation, with later injection in anesthetized or awake, freely moving rodents. Quantitation of tracer distribution in the brain parenchyma can be performed by epifluorescence, 2-photon microscopy, and magnetic resonance imaging (MRI), depending on the physico-chemical properties of the injected molecules. Thus, CMc in conjunction with various imaging techniques offers a powerful tool for assessment of the glymphatic system and CSF dynamics and function. Furthermore, CMc can be utilized as a conduit for fast, brain-wide delivery of signaling molecules and metabolic substrates that could not otherwise cross the blood brain barrier (BBB).

Here we describe a protocol to perform cisterna magna cannulation (CMc), a minimally invasive way to deliver tracers, substrates and signaling molecules into the cerebrospinal fluid (CSF). Combined with different imaging modalities, CMc enables glymphatic system and CSF dynamics assessment, as well as brain-wide delivery of various compounds.

Kanül implantasyon Sisterna Magna kemirgenler içine

Cisterna magna cannulation (CMc) is a straightforward procedure that enables direct access to the cerebrospinal fluid (CSF) without operative damage to ...

Intracranial Pharmacotherapy and Pain Assays in Rodents

Pain is a salient sensory experience with affective and cognitive dimensions. However, central mechanisms for pain remain poorly understood, hindering the development of effective therapeutics. Intracranial pharmacology presents an important tool for understanding the molecular and cellular mechanisms of pain in the brain, as well as for novel treatments. Here we present a protocol that integrates intracranial pharmacology with pain behavior testing. Specifically, we show how to infuse analgesic drugs into a select brain region, which may be responsible for pain modulation. Furthermore, to determine the effect of the candidate drug in the central nerve system, pain assays are performed after intracranial treatment. Our results demonstrate that intracranial administration of analgesic drugs in a targeted region can provide relief of pain in rodents. Thus, our protocol successfully demonstrates that intracranial pharmacology, combined with pain behavior testing, can be a powerful tool for the study of pain mechanisms in the brain.

Here we present a protocol to perform intracranial pharmacological experiments followed by pain behavior assays in rodents. This protocol allows researchers to deliver molecular and cellular targets in the brain, for pharmacologic agents in the treatment of pain.

Kafa içi farmakoterapi ve ağrı deneyleri Rodents

Pain is a salient sensory experience with affective and cognitive dimensions. However, central mechanisms for pain remain poorly understood, hindering the ...

The Power of Interstimulus Interval for the Assessment of Temporal Processing in Rodents

Temporal processing deficits have been implicated as a potential elemental dimension of higher-level cognitive processes, commonly observed in neurocognitive disorders. Despite the popularization of prepulse inhibition (PPI) in recent years, many current protocols promote using a percent of control measure, thereby precluding the assessment of temporal processing. The present study used cross-modal PPI and gap prepulse inhibition (gap-PPI) to demonstrate the benefits of employing a range of interstimulus intervals (ISIs) to delineate effects of sensory modality, psychostimulant exposure, and age. Assessment of sensory modality, psychostimulant exposure, and age reveals the utility of an approach varying the interstimulus interval (ISI) to establish the shape of the ISI function, including increases (sharper curve inflections) or decreases (flattening of the response amplitude curve) in startle amplitude. Additionally, shifts in peak response inhibition, suggestive of a differential sensitivity to the manipulation of ISI, are often revealed. Thus, the systematic manipulation of ISI affords a critical opportunity to evaluate temporal processing, which may reveal the underlying neural mechanisms involved in neurocognitive disorders.

Temporal processing, a preattentive process, may underlie deficits in higher-level cognitive processes, including attention, commonly observed in neurocognitive disorders. Using prepulse inhibition as an exemplar paradigm, we present a protocol for manipulating interstimulus interval (ISI) to establish the shape of the ISI function to provide an assessment of temporal processing.