Name: Yazar Gündemi: Superior Colliculus'ta Nöral Kodlamanın ve Görsel İşleme Mekanizmalarının Ortaya Çıkarılması
Uploaded: 2023-04-21T15:00:00
Description: Watch this Scientific Journal Video about Unveiling Neural Coding and Mechanisms of Visual Processing in the Superior Colliculus at JoVE.com

Bu çalışma Çin Ulusal Doğa Bilimleri Vakfı (32271060) tarafından desteklenmektedir. Y.-t.L. araştırmayı tasarladı, deneyi gerçekleştirdi, verileri analiz etti ve makaleyi yazdı. Deneyi Z.L. ve R.W. gerçekleştirdi.

Tüm deneysel prosedürler hayvan refahı yönergelerine uygun olarak gerçekleştirildi ve Pekin'deki Çin Beyin Araştırmaları Enstitüsü'ndeki IACUC tarafından onaylandı.
NOT: Bu protokolün zaman çizelgesi aşağıdaki gibidir: 1) vantuzu yapın; 2) virüsü enjekte etmek; 3) kafa plakasını implante edin; 4) 3 hafta sonra, fişi implante edin; 5) Koşu bandında ~ 3 günlük bir iyileşme ve alışkanlıktan sonra, iki foton / geniş alan görüntüleme yapın.
<p class="jove_t...

Superior Colliculus'ta İki Foton ve Geniş Alan Kalsiyum Görüntüleme

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L., Chen, H., Cang, J. <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+locomotion+on+visual+responses+in+the+mouse+superior+colliculus.">Effects of locomotion on visual responses in the mouse superior colliculus.</a> The Journal of Neuroscience. 39 (47), 9360-9368 (2019).</li><li>Schr&#246;der, S., 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=Arousal+modulates+retinal+output.">Arousal modulates retinal output.</a> Neuron. 107 (3), 487-495 (2020).</li><li>Ge, X., 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=Retinal+waves+prime+visual+motion+detection+by+simulating+future+optic+flow.">Retinal waves prime visual motion detection by simulating future optic flow.</a> Science. 373 (6553), (2021).</li><li>Chen, H., Savier, E. 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J., Cang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lack+of+evidence+for+stereotypical+direction+columns+in+the+mouse+superior+colliculus.">Lack of evidence for stereotypical direction columns in the mouse superior colliculus.</a> The Journal of Neuroscience. 41 (3), 461-473 (2021).</li><li>Kasai, M., Isa, T. <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+light+isoflurane+anesthesia+on+organization+of+direction+and+orientation+selectivity+in+the+superficial+layer+of+the+mouse+superior+colliculus.">Effects of light isoflurane anesthesia on organization of direction and orientation selectivity in the superficial layer of the mouse superior colliculus.</a> The Journal of Neuroscience. 42 (4), 619-630 (2022).</li><li>Kim, S., 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=The+apical+complex+couples+cell+fate+and+cell+survival+to+cerebral+cortical+development.">The apical complex couples cell fate and cell survival to cerebral cortical development.</a> Neuron. 66 (1), 69-84 (2010).</li><li>Kaifosh, P., Zaremba, J. D., Danielson, N. B., Losonczy, A. S. I. 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=Python+software+for+analysis+of+dynamic+fluorescence+imaging+data.">Python software for analysis of dynamic fluorescence imaging data.</a> Frontiers in Neuroinformatics. 8, 80 (2014).</li><li>Pnevmatikakis, E. A., Giovannucci, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NoRMCorre:+An+online+algorithm+for+piecewise+rigid+motion+correction+of+calcium+imaging+data.">NoRMCorre: An online algorithm for piecewise rigid motion correction of calcium imaging data.</a> Journal of Neuroscience Methods. 291, 83-94 (2017).</li><li>Kerlin, A. M., Andermann, M. L., Berezovskii, V. K., Reid, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Broadly+tuned+response+properties+of+diverse+inhibitory+neuron+subtypes+in+mouse+visual+cortex.">Broadly tuned response properties of diverse inhibitory neuron subtypes in mouse visual cortex.</a> Neuron. 67 (5), 858-871 (2010).</li><li>G&#246;bel, W., Helmchen, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+calcium+imaging+of+neural+network+function.">In vivo calcium imaging of neural network function.</a> Physiology. 22 (6), 358-365 (2007).</li><li>Dombeck, D. A., Khabbaz, A. N., Collman, F., Adelman, T. L., Tank, D. 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Protokoldeki kritik adımlar En kritik adım, 5.2 ve 5.3 adımlarındaki kraniyotomidir. İlk olarak, lambdanın 0,5 mm arkasındaki kemik kalındır ve içinde kan damarları vardır, bu da delme işlemi sırasında kanamaya neden olabilir. Kanamayı durdurmak için yeterli jel köpük hazırlanmalıdır. İkincisi, transvers sinüsün hemen üzerindeki kemiği çıkarırken iyi bir anjiorreksi olasılığı vardır. Sorun giderme için alternatif bir yaklaşım, ovalin içindeki kemiği inceltmek ve...

Superior colliculus (SC) tüm omurgalılarda önemli bir görme merkezidir. Memelilerde, retinadan ve görsel kortekstendoğrudan girdi alır 1. Optik kayıt, korteks 2,3,4,5'e yaygın olarak uygulanırken, SC'deki uygulaması zayıf optik erişimler tarafından engellenmektedir 6,7,8,9,10,11,12,13,14,15,16,17 ,18,19. Bu protokolün amacı, SC'deki nöral aktivitenin optik kaydı için iki tamamlayıcı yöntem hakkında ayrıntılı bilgi sağlamaktır.
SC, kolliküler nöronlara optik erişimi sınırlayan korteks ve transvers sinüsün altında bulunur. Bu sınırlamanın üstesinden gelmek için bir yaklaşım, üst üste binen korteksi aspire etmek ve ön-lateral SC 7,9,10,13,14,19'u ortaya çıkarmaktır. Bununla birlikte, SC kortikal girdiler aldığından, böyle bir işlem SC nöronlarının görsel uyaranlara nasıl tepki verdiğini etkileyebilir. Bu sınırlamanın üstesinden gelmek için, korteksi sağlam bırakırken posterior-medial SC'nin yüzeysel tabakasını silikon bir tıkaç ile görüntülemek için alternatif bir protokolü burada detaylandırıyoruz 8,11. Spesifik olarak, tek hücreli çözünürlük elde etmek için, vahşi tip farelerin posterior-medial SC'sindeki kalsiyum tepkilerini görüntülemek için iki foton mikroskobu uyguladık. Ek olarak, geniş kapsama alanı elde etmek için, posterior korteksigelişmemiş bir mutant farenin tüm SC'sini görüntülemek için geniş alan mikroskobu uyguladık 20.
Bu protokolde açıklanan iki yöntem birbirini tamamlayıcı niteliktedir. Korteks kesilmeden iki fotonlu kalsiyum görüntüleme, sağlam kortikal girdilerle tek hücre çözünürlüğünde nöral aktiviteyi kaydetmek için uygundur. Geniş alanlı kalsiyum görüntüleme, uzamsal çözünürlükten ödün verirken tüm SC'deki nöral aktiviteyi kaydetmek için uygundur.

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			<td>16x objective</td>
			<td>Nikon</td>
			<td></td>
			<td></td>
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			<td>50-mm lens</td>
			<td>Computar</td>
			<td>M5018-MP2</td>
			<td></td>
		</tr>
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			<td>5-mm coverslip</td>
			<td>Warner instruments</td>
			<td>CS-5R</td>
			<td></td>
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			<td>bandpass filter</td>
			<td>Chroma Technology</td>
			<td>HQ575/250 m-2p</td>
			<td></td>
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			<td>butyl cyanoacrylate</td>
			<td>Vetbond, World Precision Instruments</td>
			<td></td>
			<td></td>
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			<td>camera for monitoring pupil</td>
			<td>FLIR</td>
			<td>BFS-U3-04S2M-CS</td>
			<td></td>
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			<td>camera for widefield imaging</td>
			<td>Basler</td>
			<td>acA2000-165&#181;m</td>
			<td></td>
		</tr>
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			<td>corona treater</td>
			<td>Electro-Technic Products</td>
			<td>BD-20AC</td>
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			<td>dichroic</td>
			<td>Chroma Technology</td>
			<td>T600/200dcrb&#160;</td>
			<td></td>
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			<td>galvanometers</td>
			<td>Cambridge Technology</td>
			<td></td>
			<td></td>
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			<td>glass bead sterilizer</td>
			<td>RWD</td>
			<td>RS1502</td>
			<td></td>
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			<td>microdrill</td>
			<td>RWD</td>
			<td>78001</td>
			<td></td>
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			<td>micromanipulator</td>
			<td>Sutter Instruments</td>
			<td>QUAD</td>
			<td></td>
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			<td>photomultiplier tube</td>
			<td>Hamamatsu</td>
			<td>R3896</td>
			<td></td>
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			<td>rotory encoder</td>
			<td>USdigital</td>
			<td>MA3-A10-125-N</td>
			<td></td>
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			<td>self-curing dental adhesive resin cement&#160;</td>
			<td>SuperBond C&#38;B, Sun Medical Co, Ltd. Moriyama, Japan</td>
			<td></td>
			<td></td>
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		<tr>
			<td>thermostatic heating pad&#160;</td>
			<td>RWD</td>
			<td>69020</td>
			<td></td>
		</tr>
		<tr>
			<td>Ti:Sapphire laser</td>
			<td>Spectra-Physics</td>
			<td>Mai Tai HP DeepSee</td>
			<td></td>
		</tr>
		<tr>
			<td>translucent silicone adhesive&#160;</td>
			<td>Kwik-Sil, World Precision Instruments</td>
			<td></td>
			<td></td>
		</tr>
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			<td>treadmill</td>
			<td>Xinglin Biology</td>
			<td></td>
			<td></td>
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		<tr>
			<td>Virus Strains</td>
			<td></td>
			<td></td>
			<td></td>
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			<td>rAAV2/9-hsyn-Gcamp6m</td>
			<td>Vector Core at Chinese Institute for Brain Research, Beijing</td>
			<td></td>
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			<td>Animals</td>
			<td></td>
			<td></td>
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			<td>C57BL/6J wild type</td>
			<td>Laboratory Animal Resource Center at Chinese Institute for Brain Research, Beijing</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Emx1-Cre</td>
			<td>The Jackson Laboratory&#160;</td>
			<td>5628</td>
			<td></td>
		</tr>
		<tr>
			<td>Pals1flox/wt</td>
			<td>Christopher A. Walsh Lab</td>
			<td></td>
			<td></td>
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			<td>Software</td>
			<td></td>
			<td></td>
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			<td>ImageJ</td>
			<td>NIH Image</td>
			<td></td>
			<td></td>
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			<td>Labview</td>
			<td>National Instruments</td>
			<td></td>
			<td></td>
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			<td>MATLAB</td>
			<td>Mathworks</td>
			<td></td>
			<td></td>
		</tr>
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</table>

calcium imaging in mouse superior colliculus

Tüm omurgalılarda evrimsel olarak korunmuş bir orta beyin yapısı olan superior colliculus (SC), serebral korteksin ortaya çıkmasından önceki en karmaşık görsel merkezdir. Her biri belirli bir görsel özelliği kodlayan ~30 tip retinal ganglion hücresinden (RGC'ler) doğrudan girdiler alır. SC'nin sadece retinal özellikleri miras alıp almadığı veya SC'de ek ve potansiyel olarak de novo işlemenin meydana gelip gelmediği belirsizliğini koruyor. SC'deki görsel bilginin nöral kodlamasını ortaya çıkarmak için, burada uyanık farelerde iki tamamlayıcı yöntemle görsel yanıtları optik olarak kaydetmek için ayrıntılı bir protokol sunuyoruz. Bir yöntem, üst üste binen korteksi kesmeden tek hücre çözünürlüğünde kalsiyum aktivitesini görüntülemek için iki foton mikroskobu kullanırken, diğeri korteksi büyük ölçüde gelişmemiş bir mutant farenin tüm SC'sini görüntülemek için geniş alan mikroskobu kullanır. Bu protokol, hayvan hazırlama, viral enjeksiyon, başlık plakası implantasyonu, fiş implantasyonu, veri toplama ve veri analizi dahil olmak üzere bu iki yöntemi detaylandırır. Temsili sonuçlar, iki fotonlu kalsiyum görüntülemenin, tek hücre çözünürlüğünde görsel olarak uyarılmış nöronal tepkileri ortaya çıkardığını ve geniş alanlı kalsiyum görüntülemenin tüm SC boyunca nöral aktiviteyi ortaya çıkardığını göstermektedir. Bu iki yöntem birleştirilerek SK'deki nöral kodlama farklı ölçeklerde ortaya çıkarılabilir ve bu kombinasyon beynin diğer bölgelerine de uygulanabilir.

The superior colliculus (SC) is an important visual center in all vertebrates. In mammals, it receives direct inputs from the retina and the visual cortex1. While optical recording has been widely applied to the cortex2,3,4,5, its application in the SC is hindered by poor optical accesss6,7,8,9,10,11,12,13,14,15,16,17,18,19. The goal of this protocol is to provide details about two complementary methods for optical recording of the neural activity in the SC.
The SC is located beneath the cortex and transverse sinus, which limits optical access to the collicular neurons. One approach to overcome this limitation is to aspirate the overlaying cortex and expose the anterior-lateral SC7,9,10,13,14,19. However, because the SC receives cortical inputs, such an operation might affect how the SC neurons respond to visual stimuli. To overcome this limitation, we detail here an alternative protocol to image the superficial layer of the posterior-medial SC with a silicon plug, while leaving the cortex intact8,11. Specifically, to achieve single-cell resolution, we applied two-photon microscopy to image calcium responses in the posterior-medial SC of wild-type mice. In addition, to achieve broad coverage, we applied wide-field microscopy to image the entire SC of a mutant mouse whose posterior cortex has not developed20.
The two methods described in this protocol are complementary to each other. The two-photon calcium imaging without ablating the cortex is appropriate for recording neural activity at&#160;single-cell resolution with intact cortical inputs. The wide-field calcium imaging is appropriate for recording neural activity in the entire SC while sacrificing spatial resolution.

Yazar Gündemi: Superior Colliculus'ta Nöral Kodlamanın ve Görsel İşleme Mekanizmalarının Ortaya Çıkarılması 

Fare Superior Colliculus'ta Kalsiyum Görüntüleme

My research focuses on neural coding and mechanisms for visual processing. We are trying to answer how various information is encoded in the brain, especially in the superior colliculus under the underlying neuro-mechanisms. To understand visual processing, scientists combine various approaches, including neuronal morphology, antegrade and retrograde tracing, IL sequencing, neuro modeling, machine learning, is understood well.The challenge is to remove the skull over the SSA, cutting and left in the bone in one larger piece, is likely to fail because the bone is attached to the dura. By combining two photo on a wide field calcium image, our recent work revealed the function architecture of motion direction in the mouse SC at both single cell resolution and a global scale. We found that neurons with similar preference form patches up to 500 micrometer under global to the upward on the nasal motion.With our protocol, we are addressing two research gaps. First, researchers can perform long-term cast imaging in mouse SC at a single cell resolution without breaking the cortex. Secondly, researchers can record the neuroactivity across the entire SC using widefield microscoping.Our protocol provides a measure to image the posterior medial SC at single cell resolution with a intact cortex in mice. Also, we use a biocompatible plug to expose the SC, which reduces infection for chronic imaging. Our results provide a way to study the neural coding of visual information across a large visual field.Combined with optogenetics, one can study half inputs from different brain regions modulating the neuroactivity in SC.

Şekil 1A,B, sırasıyla vantuz ve tapaların nasıl yapılacağını göstermektedir. Şekil 2 , fişin nasıl başarılı bir şekilde implante edileceğini göstermektedir. Tıkaç implante edildikten sonra, Şekil 2D'de gösterildiği gibi posterior-medial SC ortaya çıkar. Şekil 3 , iki foton mikroskobu kullanılarak görüntülenen örnek bir vahşi tip fareden SC nöronlarını...

Watch this Scientific Journal Video about Unveiling Neural Coding and Mechanisms of Visual Processing in the Superior Colliculus at JoVE.com

Bu protokol, vahşi tip farelerde korteksi bozulmadan bırakırken iki foton mikroskobu ile tek nöron aktivitesinin görüntülenmesi ve kısmi korteks mutant farelerde geniş alan mikroskobu ile tüm SC'nin görüntülenmesi dahil olmak üzere, uyanık farelerin superior colliculus'unda (SC) kalsiyum yanıtlarını görüntüleme prosedürünü detaylandırır.

The superior colliculus (SC), an evolutionarily conserved midbrain structure in all vertebrates, is the most sophisticated visual center before the ...

Araştırmam nöral kodlama ve görsel işleme mekanizmalarına odaklanıyor. Beyinde, özellikle de altta yatan nöro-mekanizmaların altındaki superior colliculus'ta çeşitli bilgilerin nasıl kodlandığını cevaplamaya çalışıyoruz. Görsel işlemeyi anlamak için bilim adamları, nöronal morfoloji, antegrad ve retrograd izleme, IL dizileme, nöro modelleme, makine öğrenimi gibi çeşitli yaklaşımları birleştirir, iyi anlaşılır.Buradaki zorluk, kafatasını SSA'nın üzerinden çıkarmak, kesmek ve kemikte daha büyük bir parça halinde bırakmaktır, çünkü kemik duraya bağlı olduğu için başarısız olması muhtemeldir. İki fotoğrafı geniş alanlı bir kalsiyum görüntüsünde birleştirerek, son çalışmamız fare SC'sinde hem tek hücre çözünürlüğünde hem de küresel ölçekte hareket yönünün fonksiyon mimarisini ortaya çıkardı. Benzer tercihe sahip nöronların, burun hareketinde yukarı doğru küreselin altında 500 mikrometreye kadar yamalar oluşturduğunu bulduk.Protokolümüzle iki araştırma boşluğunu ele alıyoruz. İlk olarak, araştırmacılar korteksi kırmadan tek bir hücre çözünürlüğünde fare SC'de uzun süreli döküm görüntüleme yapabilirler. İkinci olarak, araştırmacılar geniş alan mikroskobu kullanarak tüm SC boyunca nöroaktiviteyi kaydedebilirler.Protokolümüz, farelerde sağlam bir korteks ile posterior medial SC'yi tek hücre çözünürlüğünde görüntülemek için bir ölçü sağlar. Ayrıca, kronik görüntüleme için enfeksiyonu azaltan SC'yi ortaya çıkarmak için biyouyumlu bir fiş kullanıyoruz. Sonuçlarımız, geniş bir görsel alanda görsel bilginin sinirsel kodlamasını incelemek için bir yol sağlar.Optogenetik ile birlikte, SC'deki nöroaktiviteyi modüle eden farklı beyin bölgelerinden gelen yarı girdiler incelenebilir.

calcium-imaging-in-mouse-superior-colliculus

Research

JoVE Journal

Neuroscience

Calcium Imaging in Mouse Superior Colliculus

The superior colliculus (SC), an evolutionarily conserved midbrain structure in all vertebrates, is the most sophisticated visual center before the emergence of the cerebral cortex. It receives direct inputs from ~30 types of retinal ganglion cells (RGCs), with each encoding a specific visual feature. It remains elusive whether the SC simply inherits retinal features or if additional and potentially de novo processing occurs in the SC. To reveal the neural coding of visual information in the SC, we provide here a detailed protocol to optically record visual responses with two complementary methods in awake mice. One method uses two-photon microscopy to image calcium activity at single-cell resolution without ablating the overlaying cortex, while the other uses wide-field microscopy to image the whole SC of a mutant mouse whose cortex is largely undeveloped. This protocol details these two methods, including animal preparation, viral injection, headplate implantation, plug implantation, data acquisition, and data analysis. The representative results show that the two-photon calcium imaging reveals visually evoked neuronal responses at single-cell resolution, and the wide-field calcium imaging reveals&#160;neural activity across the entire SC. By combining these two methods, one can reveal the neural coding in the SC at different scales, and such combination can also be applied to other brain regions.

This protocol details the procedure for imaging calcium responses in the superior colliculus (SC) of awake mice, including imaging single-neuron activity with two-photon microscopy while leaving the cortex intact in wild-type mice, and imaging the entire SC with wide-field microscopy in partial-cortex mutant mice.

Nörobilim

Preparation of a Suction Cup and Plugs for Calcium Imaging in Mouse

Begin the process of creating a suction cup by depositing a drop of PBS in an acrylic dish. Use a 21 gauge flat needle to fill the tip of the needle with PBS by capillarity. Cover the tip of the needle with a translucent silicone adhesive, and set it for approximately 10 minutes.Cut the silicone adhesive with scissors to a disc with a two millimeter diameter. To prepare the plugs, take a 0.75 millimeter thick plastic shim stock and cut out a one by one centimeter square in the center. Clean the shim stock and two acrylic blocks with alcohol, and wipe them with lens paper.Place the shim stock on one acrylic block, and deposit silicone adhesive into the center to fill 90%of the opening. Add another acrylic block. Apply approximately one kilogram of force, and wait 20 minutes.Under a surgical microscope, cut the silicone adhesive with a scalpel into one by 1.5 millimeter triangular prisms. Remove any dust from the triangular prisms with sticky plastic tape, and place them on a glass cover slip. Place the cover slip with the triangular prisms under a corona treater and turn it on.Bring the corona treater closer to the cover slip until lightning appears, and hold it in that position for a few minutes until the prisms and cover slip are attached. After placing the plugs in a Petri dish, incubate at 70 degrees Celsius overnight.

Farede Kalsiyum Görüntüleme için Vantuz ve Tıkaçların Hazırlanması

Viral Construct (AAV) Injection in Mouse Superior Colliculus for Calcium Imaging

Begin by securing the anesthetized mouse onto a stereotaxic frame with ear bars. Apply ophthalmic ointment on the mouse's eyes to prevent drying, and maintain the body temperature of the mouse at 37 degrees Celsius with a thermostatic heating pad. After shaving the fur and sterilizing the surgical site, inject lidocaine, tilidine, and meloxicam.Once the skin over the SC is removed, clean the skull with a cotton swab. Adjust the stereotaxic frame until the skull surface is flat. Using a drill, create a whole 0.5 millimeter lateral, and 0.42 millimeter anterior to the lambda, until the dura is exposed.Inject an adeno-associated virus, or AAV, expressing GCaMP6m, at depths of one millimeter and 1.6 millimeters from the Lambda using a beveled glass micro-pipette. After the injection, slowly withdraw the injector and proceed with the implantation of the head plate.

Kalsiyum Görüntüleme için Fare Superior Colliculus'ta Viral Yapı (AAV) Enjeksiyonu

Implantation of the Headplate in Mouse for Calcium Imaging 

After injecting the viral construct into the mouse brain, clean the muscles and tissues over the skull, and scratch the skull with a blade. Prepare the dental adhesive resin cement by mixing 3/4 spoonful of polymer, three drops of monomer, and one drop of catalyst in a ceramic bowl on ice. Apply the mixture to the head plate and the skull.Attach them and wait for the adhesive to set for five minutes. Finally, inject antibiotics to prevent infections. After removing the mouse from the stereotaxic frame, place it on a heating pad for recovery, and return it to the home cage after recovering from anesthesia.

Kalsiyum görüntüleme için farede kafa plakasının implantasyonu 

Implanting the Plug in the Mouse for Calcium Imaging

Three weeks after the viral infection, anesthetize and fix the mouse with a head plate on a stereotaxic frame. Soak a gel foam in saline to stop potential bleeding. Use a micro-drill to create a three by two millimeter oval, centered at 0.5 millimeter posterior to the lambda.Thin the boundary of the oval until it cracks, then thin the skull before the oval recording window to close the cover slip to the SC.Using fine forceps, take off the bone flaps. Make a cut down the dura, posterior to the transverse sinus and remove the piece of dura. Dry the skull and the recording window with gel foam and cotton swabs.Then deposit a drop of silicone adhesive into the recording window. Use the suction cup to hold the plug with negative pressure, and use a motorized micro-manipulator to move the suction cup and lower the plug into the silicone adhesive until the cover slip touches the skull. Once the head plate is cleaned, apply butyl cyanoacrylate and resin cement around the boundary of the plug to fix it to the head plate and proceed with imaging.

Kalsiyum görüntüleme için fareye fişin implante edilmesi

Two-Photon Calcium Imaging of Mouse Superior Colliculus Neurons

After implanting the head plate and plug, secure the animal on a rotating treadmill with its head plate. Place the treadmill beneath the two-photon microscope and adjust the height to an appropriate position. Place a black aluminum cone between the objective and the head plate to prevent light contamination from the monitor for visual stimulation.To perform two-photon imaging, adjust the laser power at the sample plane between 20 and 80 milliwatts. Scan a 600-by-600 micrometer field of view at 4.8 hertz with a spatial resolution of 2.4 micrometers per pixel and image neural activity up to 350 micrometers in depth. Using a rotary encoder, record the mouse's locomotion on the treadmill.Use a camera with a 50 millimeter lens to record its pupil size and position. Lastly, synchronize these recordings, and image acquisitions to visual stimulation by recording triggers sent by the stimulation computer. The calcium responses of SC neurons from a wild type mouse and the standard deviation projection of the fluorescence across images are presented.

Fare Superior Colliculus Nöronlarının İki Fotonlu Kalsiyum Görüntülemesi

Wide-Field Calcium Imaging of Mouse Superior Colliculus Neurons

To begin, inject 100 nanoliters of AAV expressing GCaMP6m at a depth of 200 micrometers at the center of each side of the SC to the mutant mouse whose posterior cortex has failed to develop. After approximately three weeks, implant a five millimeter diameter cover slip over the SC.After fixing the cover slip, acquire images using a CMOA camera after passing an emission filter at 10 hertz. The calcium responses of SC neurons from a partial cortex mutant mouse were imaged using wide-field microscopy.The acquired image was down sampled to one quarter of the original size, and visually evoked calcium responses are shown.