作者要感谢M. Steczkowski语音录音，M. Borczyk图纸，ATrąbczyńska病毒的产生，M.Ziókowska用于基因分型和A. Mirgos与拍摄援助。 KR承认钙调蛋白激酶子从K.戴瑟罗特控制下表达荧光蛋白mCherry重组腺相关病毒（腺相关病毒）的一种恩赐。该项目是在实验室的组织结构和功能，神经生物学，实验生物学Nencki研究所中心的动物模型和实验室的核心功能进行，利用概念的基础设施由欧洲联盟资助 - 在欧洲区域发展基金业务方案"创新经济"2007 - 2013年。这项工作是由国家科学中心的资金支持:索纳塔双2012/05 / E / NZ4 / 0299​​6，异色2013/08 / M / NZ3 / 00861，Symfonia 2013/08 / W / NZ24 / 00691为KR和索纳塔双2014 / 14 / E / NZ4 / 00172 RC

下述所有试验程序都通过实验生物学研究所Nencki，波兰科学院当地伦理委员会的批准。 注意:有些在相关视频的场景被加速。速度因子是在这些场景指示。 1.术前准备<ol><li>消毒在高压釜的液体和棉签所有工具，玻璃容器。使用可有可无的手套。清洁外科表中，立体定位架和所有用70％乙醇的周围区域。用无菌手术垫为所有消毒设备创建的无菌空间。切明胶海绵切成小块并在无菌盐水中浸泡其中。 注:根据指南实验动物的护理和使用，乙醇既不是消毒剂，也不是一个高层次的消毒剂。它应该只被用作灭菌面的清洗/脱脂剂。 </li><li>摆在第动物È感应腔室，并设置异氟烷水平到5％，氧流量为2升/分。这个过程大约需要3分钟。 </li><li>就拿动物出来的感应室。使用尾或脚趾捏以确保动物是完全镇静。 </li><li>使用精确的修剪剃从头部的背面（两耳之间）的毛发到眼睛。 </li><li>放置动物的立体框架，并与耳酒吧稳定的头部。 </li><li>设置麻醉水平1.5-2％异氟烷和0.3升/分钟的氧气。 </li><li>应用眼膏。 </li><li>注射用Tolfedine（4毫克/千克），Butomidor（2毫克/千克）和拜有利（5毫克/千克）动物皮下，以防止炎症，疼痛和感染，分别。 </li><li>注射地塞米松动物肌肉注射（0.2毫克/千克），以防止脑水肿。 注意:可以将注入塞米松皮下或腹膜内防止肌肉损伤。 </li><li>清洁使用S皮肤接着用70％乙醇terile棉签优碘。 </li><li>改变手套和用70％乙醇喷雾它们。 注意:使用一次性手套不要接触无菌区。触摸动物只用无菌手术器械和无菌棉签的提示。 </li></ol> 2.骨窗手术<ol><li>解除用钳子皮肤和使用微剪刀横向切开皮肤沿头部的基部，然后倾斜地眼睛之间的前点。取下皮瓣。 </li><li>应用利多卡因软膏与骨膜无菌棉签，防止出血过多和疼痛。 </li><li>用消毒棉签或手术刀去除骨膜。干用无菌棉签头骨。 </li><li>使用无菌针施加在皮肤上的边缘密氰基丙烯酸酯胶来固定它们，并从用牙科水泥接触，以防止。等待胶水干。 </li><li>躺在无菌3毫米玻璃罩超过Ť他的头骨前方的人字缝。中心RSC盖玻片坐标:AP，前囟门-2.8; ML，前囟门0马克盖玻片边缘用消毒针头刮伤颅骨表面。把玻璃罩回用70％乙醇消毒容器中。 </li><li>使用高速牙钻直径小毛刺勾勒出一个直径为3毫米的圆。清洗从骨粉尘用无菌生理盐水浸渍拭子钻井现场。使用明胶海绵和棉签停止偶尔出血和清洁骨。 </li><li>在钻孔之间通过轻触骨圈并检查其机动性检查骨厚度用细镊子。请记住，骨骼是在缝合的区域厚。停止钻井当骨圆是移动的，只有一个偶数，骨的薄层被留在圆周上。清理所有剩余的骨粉用生理盐水棉签蘸业务领域。 </li><li>滴在钻探领域的无菌生理盐水，覆盖钻CIRCLE。小心地撬起骨圈用细镊子，然后轻轻地但坚定地向上提起，取出骨头。要小心，不要歪斜骨圈，同时提起，以防止硬脑膜可能造成的损害。 </li><li>轻轻涂抹于硬脑膜在无菌盐水浸泡明胶海绵来帮助止血。等到所有的出血完全停止。小心取出明胶海绵不干扰凝血过程。 注意:缝合区域是高度血管化的，所以在这一点上出血可能被证明是深远的。对于出血完全停止，必须等待足够的时间。它是有用的，以保持通过将它放置在冰上冷却的盐水浸泡的明胶海绵。 </li></ol> 3.病毒注射液<ol><li>连接输液泵的立体定向塔并连接控制器。 </li><li>将35G针头插入注射器。冲洗注射器10次用乙醇消毒，并用无菌生理盐水10次以除去电子商务痕迹thanol。从注射器除去气泡。将注射器进入泵内。 注意:考虑使用其他消毒剂。 </li><li>解冻的rAAV2 / 1 mCherry制剂的单次剂量（建议10 12 PFU），并保持在冰上。填与病毒溶液注射器。 </li><li>中心针上的前囟，然后使用以下坐标轻轻插入海马:AP -2，ML +/- 1.0，DV -1。这些坐标将位于靠近开颅的边缘。等待5分钟，使组织稳定。 </li><li>注入0.7微升的rAAV2 / 1 mCherry溶液以50升/分钟的速率。等待10分钟使病毒充分吸附。轻轻取出针。用明胶海绵吸干如果发生出血。与对侧部位重复。 </li></ol> 4.骨窗植入<ol><li>躺在在钻圆帧硬脑膜顶部的无菌干燥玻璃罩。拿住FORC玻璃罩EPS轻轻压平硬脑膜，并把玻璃罩"边缘靠近颅骨表面。 注意:这是可能的玻璃罩破坏凝块和出血的简历。如果是这样的情况下，解除玻璃罩，将其放置在醇，干燥并返回步骤2.9。 </li><li>用消毒针头敷在玻璃罩边缘茂密的氰基丙烯酸酯胶将其连接到颅骨。等待胶水干。 </li><li>放置在颅骨的前部的​​固定杆（M2螺母或者定制设计）。应用氰基丙烯酸酯胶在条的边缘。等待胶水干。 <ol><li>在广场将成像会议期间使颅窗口的水平定位位置的固定杆。把它作为遥远地从窗口。如果它被置于太靠近窗口，杆和螺钉将其与特制的保持器连接可能对作为在成像过程为目标的一个障碍。 </li></ol></li><l我&gt;准备牙科丙烯酸，并将其应用于玻璃周围的颅骨表面上。它是有用的，以形成在窗口周围的火山口状的形状。这将创造更高版本与水物镜成像应用水腔。 </li><li>创建具有牙科丙烯酸盖，覆盖业务领域，皮肤边缘，固定杆的其余部分，加强各地颅窗口的火山口。等待牙科水泥硬化。 </li><li>从立体框架中取出的动物，并把它放入回收室。 </li><li>等待动物从手术同时观察生理功能恢复。 </li><li> 48小时申请术后镇痛（卡洛芬，10毫克/千克）和抗生素治疗（拜有利，5毫克/千克）。 </li></ol> 5.成像<ol><li>启动钛宝石激光器，功率可达显微镜。在这个实验中使用的系统配备双光子激光，OPO系统和双磷砷化镓PMT。 </li><li>把动物的INDUC化室，诱导麻醉。 </li><li>从在显微镜下气体麻醉面罩感应腔和处取出动物。降低氧气流至0.3升/分和异氟醚浓度为1.5-2％。 </li><li>修复动物用M2螺丝（或其他定制系统）定制的显微镜机架。水平颅窗口。 注意:可以使用显微镜的制造商的头固定系统，虽然具体的定制帧给出更好的结果（改进的头部的稳定性，慢性实验期间在多个会话恒定定位）。 </li><li>上使用retrosplenial皮质的侧面之一的广角镜的设置和低倍率物镜中心视图并将其聚焦盖玻片表面上。 </li><li>适用的水的液滴进入火山口状丙烯酸系好。切换到长距离水浸物镜。移动目标对颅窗口，直到水半月板CONnects试样和目标。 </li><li>切换到双光子设置，并开始使用最低缩放扫描检体从上到下。硬膜的交叉将高达非特异性信号的眩光可见。 </li><li>调整中，根据从荧光细胞以覆盖整个动态范围的信号强度两个通道（GFP和mCherry）显微镜采集设置。 </li><li>找到合适的神经元（与来自其它细胞中分离的树突树）之后仅使用具有最低缩放和5微米的z距离的GFP filterset执行初始扫描。 </li><li>获取扫描栈的最大投影和（使用反色）打印的注释。 </li><li>设置变焦值，使图像所需的形态的细节。使用图像中最大的投影为导向的GFP和mCherry渠道整个树突树。 </li></ol>

<ol>
	<li>Grutzendler, J., Gan, W. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-photon+imaging+of+synaptic+plasticity+and+pathology+in+the+living+mouse+brain.">Two-photon imaging of synaptic plasticity and pathology in the living mouse brain.</a> NeuroRx. 3, 489-496 (2006).</li><li>Svoboda, K., Yasuda, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Principles+of+two-photon+excitation+microscopy+and+its+applications+to+neuroscience.">Principles of two-photon excitation microscopy and its applications to neuroscience.</a> Neuron. 50, 823-839 (2006).</li><li>Trachtenberg, J. T., 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=Long-term+in+vivo+imaging+of+experience-dependent+synaptic+plasticity+in+adult+cortex.">Long-term in vivo imaging of experience-dependent synaptic plasticity in adult cortex.</a> Nature. 420, 788-794 (2002).</li><li>Holtmaat, A., 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=Imaging+neocortical+neurons+through+a+chronic+cranial+window.">Imaging neocortical neurons through a chronic cranial window.</a> Cold Spring Harb Protoc. 2012, 694-701 (2012).</li><li>Chow, D. K., 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=Laminar+and+compartmental+regulation+of+dendritic+growth+in+mature+cortex.">Laminar and compartmental regulation of dendritic growth in mature cortex.</a> Nat Neurosci. 12, 116-118 (2009).</li><li>Czajkowski, 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=Encoding+and+storage+of+spatial+information+in+the+retrosplenial+cortex.">Encoding and storage of spatial information in the retrosplenial cortex.</a> Proc Natl Acad Sci U S A. 111, 8661-8666 (2014).</li><li>Czajkowski, 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=Superficially+projecting+principal+neurons+in+layer+V+of+medial+entorhinal+cortex+in+the+rat+receive+excitatory+retrosplenial+input.">Superficially projecting principal neurons in layer V of medial entorhinal cortex in the rat receive excitatory retrosplenial input.</a> J Neurosci. 33, 15779-15792 (2013).</li><li>Feng, G., 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=Imaging+neuronal+subsets+in+transgenic+mice+expressing+multiple+spectral+variants+of+GFP.">Imaging neuronal subsets in transgenic mice expressing multiple spectral variants of GFP.</a> Neuron. 28, 41-51 (2000).</li><li>Couey, J. J., 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=Recurrent+inhibitory+circuitry+as+a+mechanism+for+grid+formation.">Recurrent inhibitory circuitry as a mechanism for grid formation.</a> Nat Neurosci. 16, 318-324 (2013).</li><li>Miyashita, T., Rockland, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GABAergic+projections+from+the+hippocampus+to+the+retrosplenial+cortex+in+the+rat.">GABAergic projections from the hippocampus to the retrosplenial cortex in the rat.</a> European Journal of Neuroscience. 26, 1193-1204 (2007).</li></ol>

作者（KL，MR，KR）拥有专利本条座架待定（PL410001）的权利。

在当前的论文中，我们提出在在RSC突触输入和突触后的目标体内成像同时双光子的协议通过颅窗口。植入程序包括几个关键步骤。首先，将动物深度麻醉并固定在立体定位框架，然后经RSC颅骨变薄沿标出圆形线的钻头和圆形骨除去。出血停止之后，所述的rAAV2 / 1 mCherry注入海马，及玻璃盖被固定到颅骨上钻孔区。最后的固定杆被固定在头部和动物放置在回收室48小时。后所需?...

双光子显微镜彻底改变了大脑活动的观察生活和行为的动物。自1990年推出它迅速得到普及，现在实现为对体内 1,2大脑活动的许多方面考核最有趣和创新的方法之一。这些应用包括血流测量，神经元激活（ 例如 ，使用钙离子浓度指标或立即早期基因表达）和神经细胞的形态。越来越多的实验室使用双光子显微镜，实现在整个科学界的技术，因为体内脑成像的新标准。 标准方法涉及颅窗口植入在桶或小鼠脑3的视觉皮层（在覆盖有盖玻璃的头盖骨的圆孔）。接着，根据不同的实验方案，在谋本身经历一系列可视化和行为训练会话，允许在一段时间4,5-监视在大脑活动和神经元形态的变化。在两种情况下，开颅仅影响顶骨，而不穿过缝线。它主要是认为该技术的主要缺点是其应用受到限制，以方便皮质诸如桶或视觉皮层。在其他地区颅窗口植入带来了很大的困难，因失血过多和/或空间阻碍。 在本文中，我们提出了retrosplenial皮层（RSC）作为用于体内显微镜6双光子兴趣另一可能的区域上方颅窗口的注入。 RSC负责空间记忆形成脑电路的一个重要因素。解剖学上，RSC是连接皮质，海马，丘脑和区域7神经元网络的一部分。它是积极参与各种行为，如空间学习和灭绝以及空间导航6。 为了可视化神经元的形态学变化，我们使用表达该THY1启动子下的绿色荧光蛋白（GFP）的转基因小鼠品系。在这些小鼠中，绿色荧光蛋白是在用双光子显微镜8在大脑中的神经元，允许皮质轴突和树突的清晰的可视化的大约10％来表示。我们提出另一个创新是重组腺相关病毒血清型2/1（的rAAV2 / 1）特定的神经元的CaMKII子9下编码红色荧光蛋白（mCherry）进入脑的突出到RSC更深结构的注射，如海马。的rAAV2 / 1 mCherry的Thy1肾炎-GFP小鼠海马的表达允许hippocampo-cortica的前和突触后元素的同时进行可视化升突触10。 mCherry的重组腺相关病毒驱动的表达需要两到三周的蛋白质在终末达到足够的水平。这一时期是从开颅手术恢复所需的通常时间是一致的。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Drug</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Baxter</td>
			<td>AErrane 8DG9623</td>
			<td>5-2% pre-operative</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Baxter</td>
			<td>AErrane 8DG9623</td>
			<td>1.5-2% during surgery</td>
		</tr>
		<tr>
			<td>Dexametasone</td>
			<td>Scan Vet</td>
			<td>Dexasone 2mg/ml</td>
			<td>0.2 mg/kg intramuscular</td>
		</tr>
		<tr>
			<td>Baytril</td>
			<td>Bayer</td>
			<td>2.50%</td>
			<td>5 mg/kg subcutaneously</td>
		</tr>
		<tr>
			<td>Tolfedine</td>
			<td>Vetoquinol</td>
			<td>4%</td>
			<td>4 mg/kg subcutaneously</td>
		</tr>
		<tr>
			<td>Butomidor</td>
			<td>Richter Pharma</td>
			<td>10 mg/ml</td>
			<td>2 mg/kg subcutaneously</td>
		</tr>
		<tr>
			<td>Carprofen</td>
			<td>KRKA-Polska</td>
			<td>Rycarfa 50mg/ml</td>
			<td>10 mg/kg subcutaneously</td>
		</tr>
		<tr>
			<td>Lidocaine</td>
			<td>Jelfa</td>
			<td>Lignocainum</td>
			<td>topically</td>
		</tr>
		<tr>
			<td>Lidocaine</td>
			<td>Jelfa</td>
			<td>20 mg/g</td>
			<td>topically</td>
		</tr>
		<tr>
			<td>Surgery</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Gelfoam</td>
			<td>Ethicon</td>
			<td>Spongostan dental; REF MS0005</td>
			<td></td>
		</tr>
		<tr>
			<td>Eye ointment</td>
			<td>Dedra</td>
			<td>Lubrithal</td>
			<td>topically</td>
		</tr>
		<tr>
			<td>CA glue</td>
			<td>Pelikan Daniel</td>
			<td>20G Huste</td>
			<td></td>
		</tr>
		<tr>
			<td>Dental acrylic</td>
			<td>SpofaDental</td>
			<td>Duracryl Plus</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereotaxic frame</td>
			<td>Stoelting</td>
			<td>51500D</td>
			<td></td>
		</tr>
		<tr>
			<td>Tool</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Coverglass</td>
			<td>Harvard Apparatus</td>
			<td>HSE-64-0720</td>
			<td>3 mm diameter</td>
		</tr>
		<tr>
			<td>Dental drill</td>
			<td>Sigmed</td>
			<td>Keystone KVet</td>
			<td></td>
		</tr>
		<tr>
			<td>Fixation bar</td>
			<td>Custom made</td>
			<td>N/A</td>
			<td>M2 or M3 screw nuts could be used</td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>Renex</td>
			<td>PN-7B-SA</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro scissors</td>
			<td>Falcon</td>
			<td>BM.183.180</td>
			<td></td>
		</tr>
		<tr>
			<td>Dissection microscope</td>
			<td>KOZO</td>
			<td>XTL6445T</td>
			<td></td>
		</tr>
		<tr>
			<td>Imaging</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Holder frame</td>
			<td>Custom made</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Two-photon microscope</td>
			<td>Zeiss</td>
			<td>Upright Axio Examiner Z1</td>
			<td>Laser unit: Coherent Chameleon 690-1040nm with Optical Parametric Oscillator 1050-1300nm. Objectives: EC-PLAN-NEUFLUAR 10x/0.1 and LD Plan-APOCHROMAT 20x/1.0. Detection: Zeiss bandpass filters BP 500-550 (GFP) and BP 570-610 (mCherry) separated by beam splitter at 560nm and coupled to two GaAsP photodetectors.&#160;</td>
		</tr>
		<tr>
			<td>Reagent</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Virus</td>
			<td>gift from K. Deisseroth</td>
			<td></td>
			<td>Recombinant adeno-associated virus (rAAV) expressing fluorescent protein mCherry under the control of CaMK promoter</td>
		</tr>
	</tbody>
</table>

simultaneous two-photon in vivo imaging of synaptic inputs and postsynaptic targets in the mouse retrosplenial cortex

This video shows the craniotomy procedure that allows chronic imaging of neurons in the mouse retrosplenial cortex (RSC) using in vivo two-photon microscopy in Thy1-GFP transgenic mouse line. This approach creates a possibility to investigate the correlation of behavioural manipulations with changes in neuronal morphology in vivo.
The cranial window implantation procedure was considered to be limited only to the easily accessible cortex regions such as the barrel field. Our approach allows visualization of neurons in the highly vascularized RSC. RSC is an important element of the brain circuit responsible for spatial memory, previously deemed to be problematic for in vivo two-photon imaging.
The cranial window implantation over the RSC is combined with an injection of mCherry-expressing recombinant adeno-associated virus (rAAVmCherry) into the dorsal hippocampus. The expressed mCherry spreads out to axonal projections from the hippocampus to RSC, enabling the visualization of changes in both presynaptic axonal boutons and postsynaptic dendritic spines in the cortex. 
This technique allows long-term monitoring of experience-dependent structural plasticity in RSC.

GFP的神经元在大鼠Thy1-GFP报道小鼠的子集的表达允许在皮质树突和在RSC局部轴突突起的体内成像。 图1A示出了用可见光多个GFP阳性树突图像的堆叠的最大投影。细胞体通过动脉遮蔽。 图1B示出了在图1A所示的树枝状分支的单一平面的缩放图像（数字变焦3×）。树突形态（棘，丝状伪足）的细节都清晰可见。 GFP的通道是通过使用带通发...

Watch this Scientific Journal Video about Simultaneous Two-photon In Vivo Imaging of Synaptic Inputs and Postsynaptic Targets in the Mouse Retrosplenial Cortex at JoVE.com

Simultaneous Two-photon In Vivo Imaging of Synaptic Inputs and Postsynaptic Targets in the Mouse Retrosplenial Cortex

This video shows the craniotomy procedure that allows chronic imaging of neurons in mouse retrosplenial cortex using in vivo two photon microscopy in Thy1-GFP transgenic line. This approach is combined with injection of mCherry-expressing adeno-associated virus into dorsal hippocampus. These techniques allow long-term monitoring of experience-dependent structural plasticity in RSC.

同时双光子<em&gt;在体内</em&gt;突触输入的影像和突触后目标中的鼠标Retrosplenial的Cortex

This video shows the craniotomy procedure that allows chronic imaging of neurons in the mouse retrosplenial cortex (RSC) using in vivo two-photon ...

simultaneous-two-photon-vivo-imaging-synaptic-inputs-postsynaptic

Research

JoVE Journal

Neuroscience

Simultaneous Two-photon In Vivo Imaging of Synaptic Inputs and Postsynaptic Targets in the Mouse Retrosplenial Cortex

11.4K 次观看.  Nencki Institute of Experimental Biology. This video shows the craniotomy procedure that allows chronic imaging of neurons in mouse retrosplenial cortex using in vivo two photon microscopy in Thy1-GFP transgenic line. This approach is combined with injection of mCherry-expressing adeno-associated virus into dorsal hippocampus. These techniques allow long-term monitoring of experience-dependent structural plasticity in RSC.

视频: Simultaneous Two-photon In Vivo Imaging of Synaptic Inputs and Postsynaptic Targets in the Mouse Retrosplenial Cortex

In vivo Imaging of the Mouse Spinal Cord Using Two-photon Microscopy

In vivo imaging using two-photon microscopy 1 in mice that have been genetically engineered to express fluorescent proteins in specific cell types 2-3 has significantly broadened our knowledge of physiological and pathological processes in numerous tissues in vivo 4-7. In studies of the central nervous system (CNS), there has been a broad application of in vivo imaging in the brain, which has produced a plethora of novel and often unexpected findings about the behavior of cells such as neurons, astrocytes, microglia, under physiological or pathological conditions 8-17. However, mostly technical complications have limited the implementation of in vivo imaging in studies of the living mouse spinal cord. In particular, the anatomical proximity of the spinal cord to the lungs and heart generates significant movement artifact that makes imaging the living spinal cord a challenging task.
We developed a novel method that overcomes the inherent limitations of spinal cord imaging by stabilizing the spinal column, reducing respiratory-induced movements and thereby facilitating the use of two-photon microscopy to image the mouse spinal cord in vivo. This is achieved by combining a customized spinal stabilization device with a method of deep anesthesia, resulting in a significant reduction of respiratory-induced movements. This video protocol shows how to expose a small area of the living spinal cord that can be maintained under stable physiological conditions over extended periods of time by keeping tissue injury and bleeding to a minimum. Representative raw images acquired in vivo detail in high resolution the close relationship between microglia and the vasculature. A timelapse sequence shows the dynamic behavior of microglial processes in the living mouse spinal cord. Moreover, a continuous scan of the same z-frame demonstrates the outstanding stability that this method can achieve to generate stacks of images and/or timelapse movies that do not require image alignment post-acquisition. Finally, we show how this method can be used to revisit and reimage the same area of the spinal cord at later timepoints, allowing for longitudinal studies of ongoing physiological or pathological processes in vivo.

In vivo Imaging of the Mouse Spinal Cord Using Two-photon Microscopy

A minimally invasive protocol to stabilize the mouse spinal column and perform repetitive in vivo spinal cord imaging using two-photon microscopy is described. This method combines a spinal stabilization device and an anesthetic regimen to minimize respiratory-induced movements and produce raw imaging data that require no alignment or other post-processing.

在体内脊髓的鼠标线使用双光子显微镜成像

In vivo imaging using two-photon microscopy 1 in mice that have been genetically engineered to express fluorescent proteins in specific cell types 2-3 has ...

科研

神经科学

Detection of Microregional Hypoxia in Mouse Cerebral Cortex by Two-photon Imaging of Endogenous NADH Fluorescence

The brain's ability to function at high levels of metabolic demand depends on continuous oxygen supply through blood flow and tissue oxygen diffusion. Here we present a visualized experimental and methodological protocol to directly visualize microregional tissue hypoxia and to infer perivascular oxygen gradients in the mouse cortex. It is based on the non-linear relationship between nicotinamide adenine dinucleotide (NADH) endogenous fluorescence intensity and oxygen partial pressure in the tissue, where observed tissue NADH fluorescence abruptly increases at tissue oxygen levels below 10 mmHg1. We use two-photon excitation at 740 nm which allows for concurrent excitation of intrinsic NADH tissue fluorescence and blood plasma contrasted with Texas-Red dextran. The advantages of this method over existing approaches include the following: it takes advantage of an intrinsic tissue signal and can be performed using standard two-photon in vivo imaging equipment; it permits continuous monitoring in the whole field of view with a depth resolution of ~50 &mu;m. We demonstrate that brain tissue areas furthest from cerebral blood vessels correspond to vulnerable watershed areas which are the first to become functionally hypoxic following a decline in vascular oxygen supply. This method allows one to image microregional cortical oxygenation and is therefore useful for examining the role of inadequate or restricted tissue oxygen supply in neurovascular diseases and stroke.

Here we describe a method to directly visualize microregional tissue hypoxia in the mouse cortex in vivo. It is based on concurrent two-photon imaging of nicotinamide adenine dinucleotide (NADH) and the cortical microcirculation. This method is useful for high resolution analysis of tissue oxygen supply.

检测内源NADH的荧光双光子成像的小鼠大脑皮层Microregional缺氧

The brain's ability to function at high levels of metabolic demand depends on continuous oxygen supply through blood flow and tissue oxygen diffusion. ...

In Vivo Two-photon Imaging Of Experience-dependent Molecular Changes In Cortical Neurons

The brain's ability to change in response to experience is essential for healthy brain function, and abnormalities in this process contribute to a variety of brain disorders1,2. To better understand the mechanisms by which brain circuits react to an animal's experience requires the ability to monitor the experience-dependent molecular changes in a given set of neurons, over a prolonged period of time, in the live animal. While experience and associated neural activity is known to trigger gene expression changes in neurons1,2, most of the methods to detect such changes do not allow repeated observation of the same neurons over multiple days or do not have sufficient resolution to observe individual neurons3,4. Here, we describe a method that combines in vivo two-photon microscopy with a genetically encoded fluorescent reporter to track experience-dependent gene expression changes in individual cortical neurons over the course of day-to-day experience. 
One of the well-established experience-dependent genes is Activity-regulated cytoskeletal associated protein (Arc)5,6. The transcription of Arc is rapidly and highly induced by intensified neuronal activity3, and its protein product regulates the endocytosis of glutamate receptors and long-term synaptic plasticity7. The expression of Arc has been widely used as a molecular marker to map neuronal circuits involved in specific behaviors3. In most of those studies, Arc expression was detected by in situ hybridization or immunohistochemistry in fixed brain sections. Although those methods revealed that the expression of Arc was localized to a subset of excitatory neurons after behavioral experience, how the cellular patterns of Arc expression might change with multiple episodes of repeated or distinctive experiences over days was not investigated. 
In vivo two-photon microscopy offers a powerful way to examine experience-dependent cellular changes in the living brain8,9. To enable the examination of Arc expression in live neurons by two-photon microscopy, we previously generated a knock-in mouse line in which a GFP reporter is placed under the control of the endogenous Arc promoter10. This protocol describes the surgical preparations and imaging procedures for tracking experience-dependent Arc-GFP expression patterns in neuronal ensembles in the live animal. In this method, chronic cranial windows were first implanted in Arc-GFP mice over the cortical regions of interest. Those animals were then repeatedly imaged by two-photon microscopy after desired behavioral paradigms over the course of several days. This method may be generally applicable to animals carrying other fluorescent reporters of experience-dependent molecular changes4.

In Vivo Two-photon Imaging Of Experience-dependent Molecular Changes In Cortical Neurons

Experience-dependent molecular changes in neurons are essential for the brain's ability to adapt in response to behavioral challenges. An in vivo two-photon imaging method is described here that allows the tracking of such molecular changes in individual cortical neurons through genetically encoded reporters.

在体内双光子成像的经验依赖的分子在大脑皮质神经元的变化

The brain's ability to change in response to experience is essential for healthy brain function, and abnormalities in this process contribute to a variety ...

In Vivo Two-Photon Microscopy of Single Nerve Endings in Skin

Nerve endings in skin are involved in physiological processes such as sensing1 as well as in pathological processes such as neuropathic pain2. Their close-to-surface positioning facilitates microscopic imaging of skin nerve endings in living intact animal. Using multiphoton microscopy, it is possible to obtain fine images overcoming the problem of strong light scattering of the skin tissue. Reporter transgenic mice that express EYFP under the control of Thy-1 promoter in neurons (including periphery sensory neurons) are well suited for the longitudinal studies of individual nerve endings over extended periods of time up to several months or even life-long. Furthermore, using the same femtosecond laser as for the imaging, it is possible to produce highly selective lesions of nerve fibers for the studies of the nerve fiber restructuring. Here, we present a simple and reliable protocol for longitudinal multiphoton in vivo imaging and laser-based microsurgery on mouse skin nerve endings.

In Vivo Two-Photon Microscopy of Single Nerve Endings in Skin

The protocol for dynamic longitudinal imaging and selective laser lesion of nerve endings in reporter transgenic mice is presented.&#160;

在皮肤中的单神经末梢体内双光子显微镜

Nerve endings in skin are involved in physiological processes such as sensing1 as well as in pathological processes such as neuropathic pain2. Their ...

Live Imaging of Mitosis in the Developing Mouse Embryonic Cortex

Although of short duration, mitosis is a complex and dynamic multi-step process fundamental for development of organs including the brain. In the developing cerebral cortex, abnormal mitosis of neural progenitors can cause defects in brain size and function. Hence, there is a critical need for tools to understand the mechanisms of neural progenitor mitosis. Cortical development in rodents is an outstanding model for studying this process. Neural progenitor mitosis is commonly examined in fixed brain sections. This protocol will describe in detail an approach for live imaging of mitosis in ex vivo embryonic brain slices. We will describe the critical steps for this procedure, which include: brain extraction, brain embedding, vibratome sectioning of brain slices, staining and culturing of slices, and time-lapse imaging. We will then demonstrate and describe in detail how to perform post-acquisition analysis of mitosis. We include representative results from this assay using the vital dye Syto11, transgenic mice (histone H2B-EGFP and centrin-EGFP), and in utero electroporation (mCherry-&#945;-tubulin). We will discuss how this procedure can be best optimized and how it can be modified for study of genetic regulation of mitosis. Live imaging of mitosis in brain slices is a flexible approach to assess the impact of age, anatomy, and genetic perturbation in a controlled environment, and to generate a large amount of data with high temporal and spatial resolution. Hence this protocol will complement existing tools for analysis of neural progenitor mitosis.

Neural progenitor mitosis is a critical parameter of neurogenesis. Much of our understanding of neural progenitor mitosis is based on analysis of fixed tissue. Live imaging in embryonic brain slices is a versatile technique to assess mitosis with high temporal and spatial resolution in a controlled environment.

有丝分裂中的不同发育阶段小鼠胚胎皮层实时成像

Although of short duration, mitosis is a complex and dynamic multi-step process fundamental for development of organs including the brain. In the ...

Two-Photon in vivo Imaging of Dendritic Spines in the Mouse Cortex Using a Thinned-skull Preparation

In the mammalian cortex, neurons form extremely complicated networks and exchange information at synapses. Changes in synaptic strength, as well as addition/removal of synapses, occur in an experience-dependent manner, providing the structural foundation of neuronal plasticity. As postsynaptic components of the most excitatory synapses in the cortex, dendritic spines are considered to be a good proxy of synapses. Taking advantages of mouse genetics and fluorescent labeling techniques, individual neurons and their synaptic structures can be labeled in the intact brain. Here we introduce a transcranial imaging protocol using two-photon laser scanning microscopy to follow fluorescently labeled postsynaptic dendritic spines over time in vivo. This protocol utilizes a thinned-skull preparation, which keeps the skull intact and avoids inflammatory effects caused by exposure of the meninges and the cortex. Therefore, images can be acquired immediately after surgery is performed. The experimental procedure can be performed repetitively over various time intervals ranging from hours to years. The application of this preparation can also be expanded to investigate different cortical regions and layers, as well as other cell types, under physiological and pathological conditions.

Two-Photon in vivo Imaging of Dendritic Spines in the Mouse Cortex Using a Thinned-skull Preparation

Time-lapse imaging in the living animal provides valuable information on structural reorganization in the intact brain. Here, we introduce a thinned-skull preparation that allows transcranial imaging of fluorescently labeled synaptic structures in the living mouse cortex by two-photon microscopy.

双光子<em&gt;在体内</em&gt;树突棘中的鼠标皮质用稀疏的头颅成像准备

In the mammalian cortex, neurons form extremely complicated networks and exchange information at synapses. Changes in synaptic strength, as well as ...

Two-photon Imaging of Cellular Dynamics in the Mouse Spinal Cord

Two-photon (2P) microscopy is utilized to reveal cellular dynamics and interactions deep within living, intact tissues. Here, we present a method for live-cell imaging in the murine spinal cord. This technique is uniquely suited to analyze neural precursor cell (NPC) dynamics following transplantation into spinal cords undergoing neuroinflammatory demyelinating disorders. NPCs migrate to sites of axonal damage, proliferate, differentiate into oligodendrocytes, and participate in direct remyelination. NPCs are thereby a promising therapeutic treatment to ameliorate chronic demyelinating diseases. Because transplanted NPCs migrate to the damaged areas on the ventral side of the spinal cord, traditional intravital 2P imaging is impossible, and only information on static interactions was previously available using histochemical staining approaches. Although this method was generated to image transplanted NPCs in the ventral spinal cord, it can be applied to numerous studies of transplanted and endogenous cells throughout the entire spinal cord. In this article, we demonstrate the preparation and imaging of a spinal cord with enhanced yellow fluorescent protein-expressing axons and enhanced green fluorescent protein-expressing transplanted NPCs.

A new ex vivo preparation for imaging the mouse spinal cord. This protocol allows for two-photon imaging of live cellular interactions throughout the spinal cord.

细胞动力学在小鼠脊髓双光子成像

Two-photon (2P) microscopy is utilized to reveal cellular dynamics and interactions deep within living, intact tissues. Here, we present a method for ...

Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System

An In vivo electroretinogram (ERG) signal is composed of several overlapping components originating from different retinal cell types, as well as noise from extra-retinal sources. Ex vivo ERG provides an efficient method to dissect the function of retinal cells directly from an intact isolated retina of animals or donor eyes. In addition, ex vivo ERG can be used to test the efficacy and safety of potential therapeutic agents on retina tissue from animals or humans. We show here how commercially available in vivo ERG systems can be used to conduct ex vivo ERG recordings from isolated mouse retinas. We combine the light stimulation, electronic and heating units of a standard in vivo system with custom-designed specimen holder, gravity-controlled perfusion system and electromagnetic noise shielding to record low-noise ex vivo ERG signals simultaneously from two retinas with the acquisition software included in commercial in vivo systems. Further, we demonstrate how to use this method in combination with pharmacological treatments that remove specific ERG components in order to dissect the function of certain retinal cell types.

Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System

Ex vivo ERG can be used to record electrical activity of retinal cells directly from isolated intact retinas of animals or humans. We demonstrate here how common in vivo ERG systems can be adapted for ex vivo ERG recordings in order to dissect the electrical activity of retinal cells.

同时<em&gt;体外</em两个由视网膜&gt;功能测试<em&gt;在体内</em&gt;电图系统

An In vivo electroretinogram (ERG) signal is composed of several overlapping components originating from different retinal cell types, as well as noise ...

Two-photon Calcium Imaging in Neuronal Dendrites in Brain Slices

Calcium (Ca2+) imaging is a powerful tool to investigate the spatiotemporal dynamics of intracellular Ca2+ signals in neuronal dendrites. Ca2+ fluctuations can occur through a variety of membrane and intracellular mechanisms and play a crucial role in the induction of synaptic plasticity and regulation of dendritic excitability. Hence, the ability to record different types of Ca2+ signals in dendritic branches is valuable for groups studying how dendrites integrate information. The advent of two-photon microscopy has made such studies significantly easier by solving the problems inherent to imaging in live tissue, such as light scattering and photodamage. Moreover, through combination of conventional electrophysiological techniques with two-photon Ca2+ imaging, it is possible to investigate local Ca2+ fluctuations in neuronal dendrites in parallel with recordings of synaptic activity in soma. Here, we describe how to use this method to study the dynamics of local Ca2+ transients (CaTs) in dendrites of GABAergic inhibitory interneurons. The method can be also applied to studying dendritic Ca2+ signaling in different neuronal types in acute brain slices.

We present a method combining whole-cell patch-clamp recordings and two-photon imaging to record Ca2+ transients in neuronal dendrites in acute brain slices.

脑切片神经元树突的双光子钙成像

Calcium (Ca2+) imaging is a powerful tool to investigate the spatiotemporal dynamics of intracellular Ca2+ signals in neuronal dendrites. Ca2+ ...

In Vivo Two-photon Imaging of Cortical Neurons in Neonatal Mice

Two-photon imaging is a powerful tool for the in vivo analysis of neuronal circuits in the mammalian brain. However, a limited number of in vivo imaging methods exist for examining the brain tissue of live newborn mammals. Herein we summarize a protocol for imaging individual cortical neurons in living neonatal mice. This protocol includes the following two methodologies: (1) the Supernova system for sparse and bright labeling of cortical neurons in the developing brain, and (2) a surgical procedure for the fragile neonatal skull. This protocol allows the observation of temporal changes of individual cortical neurites during neonatal stages with a high signal-to-noise ratio. Labeled cell-specific gene silencing and knockout can also be achieved by combining the Supernova with RNA interference and CRISPR/Cas9 gene editing systems. This protocol can, thus, be used for analyzing the developmental dynamics of cortical neurons, molecular mechanisms that control the neuronal dynamics, and changes in neuronal dynamics in disease models.

In Vivo Two-photon Imaging of Cortical Neurons in Neonatal Mice

We present an in vivo two-photon imaging protocol for imaging the cerebral cortex of neonatal mice. This method is suitable for analyzing the developmental dynamics of cortical neurons, the molecular mechanisms that control the neuronal dynamics, and the changes in neuronal dynamics in disease models.

体内新生小鼠皮层神经元的双光子成像

Two-photon imaging is a powerful tool for the in vivo analysis of neuronal circuits in the mammalian brain. However, a limited number of in vivo imaging ...