All animal experiments were performed in accordance with guidelines approved by the IACUC at the University of Nebraska Medical Center.
1. Before surgery
<ol>
	<li>Prepare pipettes for viral injections. Pull borosilicate glass capillaries using a pipette puller and bevel the pipette at a 20&#176; angle. Sterilize the pipettes overnight.</li>
	<li>Prepare fresh pieces of sterile gel foam by cutting them into small squares. Submerge the gel foam in a sterile microfuge tube containing 0.5 mL of...

<ol>
	<li>Cichon, 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=Branch-specific+dendritic+Ca2++spikes+cause+persistent+synaptic+plasticity.">Branch-specific dendritic Ca2+ spikes cause persistent synaptic plasticity.</a> Nature. 520 (7546), 180-185 (2015).</li><li>Goncalves, 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=Circuit+level+defects+in+the+developing+neocortex+of+Fragile+X+mice.">Circuit level defects in the developing neocortex of Fragile X mice.</a> Nature Neuroscience. 16 (7), 903-909 (2013).</li><li>Padmashri, 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=Altered+structural+and+functional+synaptic+plasticity+with+motor+skill+learning+in+a+mouse+model+of+fragile+X+syndrome.">Altered structural and functional synaptic plasticity with motor skill learning in a mouse model of fragile X syndrome.</a> Journal of Neuroscience. 33 (50), 19715-19723 (2013).</li><li>Peters, A. J., Chen, S. X., Komiyama, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Emergence+of+reproducible+spatiotemporal+activity+during+motor+learning.">Emergence of reproducible spatiotemporal activity during motor learning.</a> Nature. 510 (7504), 263-267 (2014).</li><li>Poskanzer, K. E., Yuste, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Astrocytes+regulate+cortical+state+switching+in+vivo.">Astrocytes regulate cortical state switching in vivo.</a> Proceedings of the National Academy of Sciences of the United States of America. 113 (19), 2675-2684 (2016).</li><li>Srinivasan, 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=Ca2++signaling+in+astrocytes+from+Ip3r2(-/-)+mice+in+brain+slices+and+during+startle+responses+in+vivo.">Ca2+ signaling in astrocytes from Ip3r2(-/-) mice in brain slices and during startle responses in vivo.</a> Nature Neuroscience. 18 (5), 708-717 (2015).</li><li>Takata, N., 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=Astrocyte+calcium+signaling+transforms+cholinergic+modulation+to+cortical+plasticity+in+vivo.">Astrocyte calcium signaling transforms cholinergic modulation to cortical plasticity in vivo.</a> Journal of Neuroscience. 31 (49), 18155-18165 (2011).</li><li>Yang, G., Pan, F., 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=Stably+maintained+dendritic+spines+are+associated+with+lifelong+memories.">Stably maintained dendritic spines are associated with lifelong memories.</a> Nature. 462 (7275), 920-924 (2009).</li><li>Zuo, Y., 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=Development+of+long-term+dendritic+spine+stability+in+diverse+regions+of+cerebral+cortex.">Development of long-term dendritic spine stability in diverse regions of cerebral cortex.</a> Neuron. 46 (2), 181-189 (2005).</li><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 (4), 489-496 (2006).</li><li>Isshiki, M., 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=Enhanced+synapse+remodelling+as+a+common+phenotype+in+mouse+models+of+autism.">Enhanced synapse remodelling as a common phenotype in mouse models of autism.</a> Nature Communications. 5, 4742 (2014).</li><li>Cruz-Martin, A., Crespo, M., Portera-Cailliau, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delayed+stabilization+of+dendritic+spines+in+fragile+X+mice.">Delayed stabilization of dendritic spines in fragile X mice.</a> Journal of Neuroscience. 30 (23), 7793-7803 (2010).</li><li>Mostany, 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=Altered+synaptic+dynamics+during+normal+brain+aging.">Altered synaptic dynamics during normal brain aging.</a> Journal of Neuroscience. 33 (9), 4094-4104 (2013).</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 (6917), 788-794 (2002).</li><li>Agarwal, 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=Transient+opening+of+the+mitochondrial+permeability+transition+pore+induces+microdomain+calcium+transients+in+astrocyte+processes.">Transient opening of the mitochondrial permeability transition pore induces microdomain calcium transients in astrocyte processes.</a> Neuron. 93 (3), 587-605 (2017).</li><li>Bindocci, E., 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=Three-dimensional+Ca2++imaging+advances+understanding+of+astrocyte+biology.">Three-dimensional Ca2+ imaging advances understanding of astrocyte biology.</a> Science. 356 (6339), (2017).</li><li>Dana, 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=High-performance+calcium+sensors+for+imaging+activity+in+neuronal+populations+and+microcompartments.">High-performance calcium sensors for imaging activity in neuronal populations and microcompartments.</a> Nature Methods. 16 (7), 649-657 (2019).</li><li>Han, S., Yang, W., Yuste, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-color+volumetric+imaging+of+neuronal+activity+of+cortical+columns.">Two-color volumetric imaging of neuronal activity of cortical columns.</a> Cell Reports. 27 (7), 2229-2240 (2019).</li><li>Nimmerjahn, A., Kirchhoff, F., 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=Resting+microglial+cells+are+highly+dynamic+surveillants+of+brain+parenchyma+in+vivo.">Resting microglial cells are highly dynamic surveillants of brain parenchyma in vivo.</a> Science. 308 (5726), 1314-1318 (2005).</li><li>Stowell, R. 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=Noradrenergic+signaling+in+the+wakeful+state+inhibits+microglial+surveillance+and+synaptic+plasticity+in+the+mouse+visual+cortex.">Noradrenergic signaling in the wakeful state inhibits microglial surveillance and synaptic plasticity in the mouse visual cortex.</a> Nature Neuroscience. 22 (11), 1782-1792 (2019).</li><li>Madisen, L., 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+robust+and+high-throughput+Cre+reporting+and+characterization+system+for+the+whole+mouse+brain.">A robust and high-throughput Cre reporting and characterization system for the whole mouse brain.</a> Nature Neuroscience. 13 (1), 133-140 (2010).</li><li>Chen, S. 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=Subtype-specific+plasticity+of+inhibitory+circuits+in+motor+cortex+during+motor+learning.">Subtype-specific plasticity of inhibitory circuits in motor cortex during motor learning.</a> Nature Neuroscience. 18 (8), 1109-1115 (2015).</li><li>Stobart, J. L., 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=Cortical+circuit+activity+evokes+rapid+astrocyte+calcium+signals+on+a+similar+timescale+to+neurons.">Cortical circuit activity evokes rapid astrocyte calcium signals on a similar timescale to neurons.</a> Neuron. 98 (4), 726-735 (2018).</li><li>Matsui, 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=Mouse+in+utero+electroporation:+controlled+spatiotemporal+gene+transfection.">Mouse in utero electroporation: controlled spatiotemporal gene transfection.</a> Journal of Visualized Experiments: JoVE. (54), e3024 (2011).</li><li>Roth, R. 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=Cortical+synaptic+AMPA+receptor+plasticity+during+motor+learning.">Cortical synaptic AMPA receptor plasticity during motor learning.</a> Neuron. 105 (5), 895-908 (2020).</li><li>Stogsdill, J. 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=Astrocytic+neuroligins+control+astrocyte+morphogenesis+and+synaptogenesis.">Astrocytic neuroligins control astrocyte morphogenesis and synaptogenesis.</a> Nature. 551 (7679), 192-197 (2017).</li><li>Suresh, A., Dunaevsky, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relationship+between+synaptic+AMPAR+and+spine+dynamics:+impairments+in+the+FXS+mouse.">Relationship between synaptic AMPAR and spine dynamics: impairments in the FXS mouse.</a> Cerebral Cortex. 27 (8), 4244-4256 (2017).</li><li>Yang, 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=Transcranial+two-photon+imaging+of+synaptic+structures+in+the+cortex+of+awake+head-restrained+mice.">Transcranial two-photon imaging of synaptic structures in the cortex of awake head-restrained mice.</a> Methods in Molecular Biology. 1010, 35-43 (2013).</li><li>Dombeck, D. 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+large-scale+neural+activity+with+cellular+resolution+in+awake,+mobile+mice.">Imaging large-scale neural activity with cellular resolution in awake, mobile mice.</a> Neuron. 56 (1), 43-57 (2007).</li><li>Kislin, M., 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=Flat-floored+air-lifted+platform:+a+new+method+for+combining+behavior+with+microscopy+or+electrophysiology+on+awake+freely+moving+rodents.">Flat-floored air-lifted platform: a new method for combining behavior with microscopy or electrophysiology on awake freely moving rodents.</a> Journal of Visualized Experiments: JoVE. (88), e51869 (2014).</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=high-resolution+imaging+in+the+mouse+neocortex+through+a+chronic+cranial+window.">high-resolution imaging in the mouse neocortex through a chronic cranial window.</a> Nature Protocols. 4 (8), 1128-1144 (2009).</li><li>Hauglund, N. L., 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=Meningeal+lymphangiogenesis+and+enhanced+glymphatic+activity+in+mice+with+chronically+implanted+EEG+electrodes.">Meningeal lymphangiogenesis and enhanced glymphatic activity in mice with chronically implanted EEG electrodes.</a> Journal of Neuroscience. 40 (11), 2371-2380 (2020).</li><li>De Paola, V., 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=Cell+type-specific+structural+plasticity+of+axonal+branches+and+boutons+in+the+adult+neocortex.">Cell type-specific structural plasticity of axonal branches and boutons in the adult neocortex.</a> Neuron. 49 (6), 861-875 (2006).</li><li>Cheng, 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=Simultaneous+two-photon+calcium+imaging+at+different+depths+with+spatiotemporal+multiplexing.">Simultaneous two-photon calcium imaging at different depths with spatiotemporal multiplexing.</a> Nature Methods. 8 (2), 139-142 (2011).</li><li>Yang, 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=Thinned-skull+cranial+window+technique+for+long-term+imaging+of+the+cortex+in+live+mice.">Thinned-skull cranial window technique for long-term imaging of the cortex in live mice.</a> Nature Protocols. 5 (2), 201-208 (2010).</li><li>Shih, A. Y., 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+polished+and+reinforced+thinned-skull+window+for+long-term+imaging+of+the+mouse+brain.">A polished and reinforced thinned-skull window for long-term imaging of the mouse brain.</a> Journal of Visualized Experiments: JoVE. (61), e3742 (2012).</li><li>Helm, P. J., Ottersen, O. P., Nase, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+optical+properties+of+the+mouse+cranium--implications+for+in+vivo+multi+photon+laser+scanning+microscopy.">Analysis of optical properties of the mouse cranium--implications for in vivo multi photon laser scanning microscopy.</a> Journal of Neuroscience Methods. 178 (2), 316-322 (2009).</li><li>Stobart, J. L., 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+calcium+imaging+of+astrocytes+reveals+distinct+cellular+compartment+responses+to+sensory+stimulation.">Long-term in vivo calcium imaging of astrocytes reveals distinct cellular compartment responses to sensory stimulation.</a> Cerebral Cortex. 28 (1), 184-198 (2018).</li><li>Pryazhnikov, E., 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=Longitudinal+two-photon+imaging+in+somatosensory+cortex+of+behaving+mice+reveals+dendritic+spine+formation+enhancement+by+subchronic+administration+of+low-dose+ketamine.">Longitudinal two-photon imaging in somatosensory cortex of behaving mice reveals dendritic spine formation enhancement by subchronic administration of low-dose ketamine.</a> Scientific Reports. 8 (1), 6464 (2018).</li><li>Thrane, A. 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=General+anesthesia+selectively+disrupts+astrocyte+calcium+signaling+in+the+awake+mouse+cortex.">General anesthesia selectively disrupts astrocyte calcium signaling in the awake mouse cortex.</a> Proceedings of the National Academy of Sciences of the United States of America. 109 (46), 18974-18979 (2012).</li><li>Paukert, M., 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=Norepinephrine+controls+astroglial+responsiveness+to+local+circuit+activity.">Norepinephrine controls astroglial responsiveness to local circuit activity.</a> Neuron. 82 (6), 1263-1270 (2014).</li><li>Delekate, 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=Metabotropic+P2Y1+receptor+signalling+mediates+astrocytic+hyperactivity+in+vivo+in+an+Alzheimer's+disease+mouse+model.">Metabotropic P2Y1 receptor signalling mediates astrocytic hyperactivity in vivo in an Alzheimer's disease mouse model.</a> Nature Communications. 5, 5422 (2014).</li></ol>

Here, we have presented a protocol for the implantation of chronic cranial windows for in vivo imaging of cortical astrocytes and neurons in awake, head-restrained mice on an air-lifted home cage. Specific examples have been provided of the cranial window application for imaging astrocytes that express GECIs and neuronal synaptic structures. With the use of multiphoton microscopy, astrocytic calcium signaling dynamics and structural synaptic dynamics can be recorded repeatedly over days.
<p class="jove_conte...

The ability to perform in vivo multiphoton fluorescence microscopy in the cortex of mice is paramount to the study of cellular signaling and structure1,2,3,4,5,6,7,8,9, disease pathology10,11, and cellular development12,13. With the implantation of chronic cranial windows, longitudinal imaging is possible, allowing for repeated imaging of cortical areas for days, weeks, or months13,14 in live animals. Multiphoton microscopy is ideal for in vivo, repeated imaging because of improved depth probing and reduced photodamage associated with the infrared laser used. This allows for the study of molecular and cellular dynamics of specific cells in various cortical regions.
Multiphoton microscopy has been used for in vivo imaging of neuronal and glial cells in mice15,16,17,18,19,20. Various strategies can be implemented to label particular cell types and areas of interest. One common approach is to drive the expression of genetically encoded fluorescent proteins in a cell-specific manner using the Cre-Lox recombination system. This can be performed with genetically modified mice, e.g., crossing tdTomato &#34;floxed&#34; mouse (Ai14) with a mouse expressing Cre-recombinase under a promoter of interest21. Alternatively, cell- and site-specific labeling can be achieved with viral injections. Here, a virus encoding Cre recombinase under a cell-specific promotor and a virus encoding a floxed gene of interest are injected into a defined region. Appropriate cell types receiving both viral vectors will then express the desired gene(s). These genes can be structural markers, such as tdTomato, to view changes in cellular morphology22 or genetically encoded calcium indicators (GECIs), such as GCaMP and/or RCaMP, to examine calcium dynamics23. Methods of genetic recombination can be applied individually or in combination to label one or more cell types. A third approach, not requiring transgenic mice or viral constructs (which have limited packaging capacity), is in utero electroporation of DNA constructs24. Depending on the timing of the electroporation, different cell types can be targeted25,26,27.
When performing multiphoton imaging, mice can be imaged while awake or anesthetized. Imaging of awake mice can be performed by securing the mouse via an attached head plate28. This approach is made less stressful by allowing relatively free movement of the animal using methods, such as free-floating, air-supported Styrofoam balls29, free-floating treadmills1, or an air-lifted home cage system where mice are fastened by an attached head plate and allowed to move in an open chamber30. For each of these imaging conditions, it will first be necessary to habituate the mice to the imaging setup. This paper describes the habituation and imaging procedure using an air-lifted home cage system.
This protocol describes the implantation of a chronic cranial window for longitudinal in vivo imaging in the cortex. Here, we will use mice that conditionally express GCaMP6f in astrocytes to monitor calcium signaling dynamics. Further, this paper describes the procedure for viral injections using tdTomato as a label for neurons. This allows the determination of changes in neuronal synaptic structure and/or the availability as a structural marker that enables repeated imaging of the same astrocyte. Throughout the protocol, crucial steps will be highlighted to ensure the best possible quality of images obtained from multiphoton microscopy.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>15o Pointed Blade</td>
			<td>Surgistar</td>
			<td>6500</td>
			<td>Surgery Tools</td>
		</tr>
		<tr>
			<td>19 G Needles</td>
			<td>BD</td>
			<td>305186</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>AAV1-CAG-FLEX-tdTomato</td>
			<td>Addgene</td>
			<td>28306-AAV1</td>
			<td>Viral Vector</td>
		</tr>
		<tr>
			<td>AAV1-CaMKII-0-4-Cre</td>
			<td>Addgene</td>
			<td>105558-AAV1</td>
			<td>Viral Vector</td>
		</tr>
		<tr>
			<td>Acteone</td>
			<td>Fisher Scientific</td>
			<td>A16P4</td>
			<td>Reagent</td>
		</tr>
		<tr>
			<td>Alcohol Prep Pads</td>
			<td>Fisher Scientific</td>
			<td>Covidien 5750</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Beveler</td>
			<td>Narishige</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Borosilicate Glass</td>
			<td>World Precision Instruments</td>
			<td>TW100F-4</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Carbide Burs</td>
			<td>SS White Dental</td>
			<td>14717</td>
			<td>Surgery Tools</td>
		</tr>
		<tr>
			<td>Carprofen (Rimadyl), 50 mg/mL</td>
			<td>Zoetis Mylan Institutional, LLC.</td>
			<td></td>
			<td>Drug</td>
		</tr>
		<tr>
			<td>Compressed Air</td>
			<td>Fisher Scientific</td>
			<td>23-022-523</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Cotton Tip Applicators</td>
			<td>Puritan</td>
			<td>836-WC NO BINDER</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Cover Glass, No. 1 thickness, 3 mm/5 mm</td>
			<td>Warner Instruments</td>
			<td>64-0720, 64-0700</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Dental Drill</td>
			<td>Aseptico</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Dexamethasone, 4 mg/mL</td>
			<td>Mylan Institutional, LLC.</td>
			<td></td>
			<td>Drug</td>
		</tr>
		<tr>
			<td>Dissecting Microscope</td>
			<td>Nikon</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Duralay Liquid&#160; (dental cement liquid)</td>
			<td>Patterson Dental</td>
			<td>602-8518</td>
			<td>Reagent</td>
		</tr>
		<tr>
			<td>Duralay Powder&#160; (dental cement powder)</td>
			<td>Patterson Dental</td>
			<td>602-7932</td>
			<td>Reagent</td>
		</tr>
		<tr>
			<td>Enrofloxacin, 2.27%</td>
			<td>Bayer</td>
			<td></td>
			<td>Drug</td>
		</tr>
		<tr>
			<td>Eye Ointment</td>
			<td>Dechra</td>
			<td>17033-211-38</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Fiber Lite High Intensity Illuminator</td>
			<td>Dolan-Jenner Industries</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Forceps (Large)</td>
			<td>World Precision Instruments</td>
			<td>14099</td>
			<td>Surgery Tools</td>
		</tr>
		<tr>
			<td>Forceps (Small)</td>
			<td>World Precision Instruments</td>
			<td>501764</td>
			<td>Surgery Tools</td>
		</tr>
		<tr>
			<td>GCaMP6f B6; 129S-Gt(ROSA)26Sortm95.1(CAGGCaMP6f)Hze/J</td>
			<td>The Jackson Laboratory</td>
			<td>Stock No: 024105</td>
			<td>Mouse line</td>
		</tr>
		<tr>
			<td>Germinator</td>
			<td>Fisher Scientific</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>GLAST-CreER Tg(Slc1a3-cre/ERT) 1Nat/J</td>
			<td>The Jackson Laboratory</td>
			<td>Stock No: 012586</td>
			<td>Mouse Line</td>
		</tr>
		<tr>
			<td>Headplate</td>
			<td>Neurotar</td>
			<td>Model 1, Model 3</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Hemostatic forceps</td>
			<td>World Precision Instruments</td>
			<td>501705</td>
			<td>Surgery Tools</td>
		</tr>
		<tr>
			<td>Holder for 15o Pointed Blade</td>
			<td>World Precision Instruments</td>
			<td>501247</td>
			<td>Surgery Tools</td>
		</tr>
		<tr>
			<td>Holder for Scalpel Blades</td>
			<td>World Precision Instruments</td>
			<td>500236</td>
			<td>Surgery Tools</td>
		</tr>
		<tr>
			<td>Iodine Prep Pads</td>
			<td>Avantor</td>
			<td>15648-926</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Piramal</td>
			<td></td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Isoflurane table top system with Induction Box</td>
			<td>Harvard Apparatus</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Isoflurane Vaporizer</td>
			<td>SurgiVet</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Krazy Glue</td>
			<td>Office Depot</td>
			<td>KG517</td>
			<td>Reagent</td>
		</tr>
		<tr>
			<td>Loctite 401</td>
			<td>Henkel</td>
			<td>40140</td>
			<td>fast-curing instant adhesive</td>
		</tr>
		<tr>
			<td>Loctite 454</td>
			<td>Fisher Scientific</td>
			<td>NC9194415</td>
			<td>cyanoacrylate adhesive gel</td>
		</tr>
		<tr>
			<td>Micropipette Puller</td>
			<td>Sutter Instruments</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Multiphoton Microscope</td>
			<td></td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Nitrogen</td>
			<td>Matheson</td>
			<td>NI M200</td>
			<td>Gas</td>
		</tr>
		<tr>
			<td>Oxygen</td>
			<td>Matheson</td>
			<td>OX M250</td>
			<td>Gas</td>
		</tr>
		<tr>
			<td>Picospritzer</td>
			<td>Parker</td>
			<td></td>
			<td>intracellular microinjection dispense system</td>
		</tr>
		<tr>
			<td>Pipette Tips</td>
			<td>Rainin</td>
			<td>17014340</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Rodent Hair Trimmer</td>
			<td>Wahl</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Saline (0.9% Sodium Chloride)</td>
			<td>Med Vet International</td>
			<td>RX0.9NACL-30BAC</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Scalpel Blades, Size 11</td>
			<td>Integra</td>
			<td>4-111</td>
			<td>Surgery Tools</td>
		</tr>
		<tr>
			<td>Scissors</td>
			<td>World Precision Instruments</td>
			<td>503667</td>
			<td>Surgery Tools</td>
		</tr>
		<tr>
			<td>Stereotaxic Instrument</td>
			<td>Stoelting</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Sugi Sponge Strips (sponge strips)</td>
			<td>Kettenbach Dental</td>
			<td>31002</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>SURGIFOAM (gel foam)</td>
			<td>Ethicon</td>
			<td>1972</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Syringe with 26 G Needle</td>
			<td>BD</td>
			<td>309625</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Tamoxifen</td>
			<td>Sigma Aldrich</td>
			<td>T5648-1G</td>
			<td>Reagent</td>
		</tr>
		<tr>
			<td>Ti:Sapphire Laser</td>
			<td>Coherent</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Transfer Pipettes</td>
			<td>Fisher Scientific</td>
			<td>13-711-9AM</td>
			<td>Surgery Supply</td>
		</tr>
		<tr>
			<td>Water Blanket</td>
			<td>Fisher Scientific</td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Xylocaine MPF with Epinephrine (1:200,000), 10 mg/mL</td>
			<td>Fresenius Kabi USA</td>
			<td></td>
			<td>Drug</td>
		</tr>
	</tbody>
</table>

implantation of a cranial window for repeated in vivo imaging in awake mice

To fully understand the cellular physiology of neurons and glia in behaving animals, it is necessary to visualize their morphology and record their activity in vivo in behaving mice. This paper describes a method for the implantation of a chronic cranial window to allow for the longitudinal imaging of brain cells in awake, head-restrained mice. In combination with genetic strategies and viral injections, it is possible to label specific cells and regions of interest with structural or physiological markers. This protocol demonstrates how to combine viral injections to label neurons in the vicinity of GCaMP6-expressing astrocytes in the cortex for simultaneous imaging of both cells through a cranial window. Multiphoton imaging of the same cells can be performed for days, weeks, or months in awake, behaving animals. This approach provides researchers with a method for viewing cellular dynamics in real time and can be applied to answer a number of questions in neuroscience.

The quality of the cranial window can be assessed by how crisp the neuronal structures appear. In a good window, dendritic spines are clearly visible (Figure 1). With the structural and positional data stored, the same animal can be imaged repeatedly for days, weeks, or months to examine the same cells (Figure 1). The images in Figure 1 were obtained from the forelimb region of the primary motor cortex (in a 5 mm window). A variety ...

Watch this Scientific Journal Video about Implantation of a Cranial Window for Repeated In Vivo Imaging in Awake Mice at JoVE.com

Implantation of a Cranial Window for Repeated In Vivo Imaging in Awake Mice

Presented here is a protocol for the implantation of a chronic cranial window for the longitudinal imaging of brain cells in awake, head-restrained mice.

Implantation of a Cranial Window for Repeated In Vivo Imaging in Awake Mice

To fully understand the cellular physiology of neurons and glia in behaving animals, it is necessary to visualize their morphology and record their ...

The protocol describes how to perform viral injections and implant a cranial window for imaging of brain cells in awake, head-restrained mice. The advantage of this method is that structure and activity of neurons and astrocytes can be imaged repeatedly over multiple sessions. This approach can be used to determine how neural cells are altered in models of neurodevelopmental, or neurodegenerative disorders, or whether experience-dependent plasticity is impaired.Begin by securing an anesthetized mouse to a stereotaxic frame using the snout clamp and ear bars. Using sterile surgical tools, cut and remove the skin from the frontal sutures anterior to the bregma to posteriorly to lambda. Using a sterile size 11 carbon steel surgical blade, gently scrape all the connective tissue from the skull.With the help of a dental drill, gradually drill the skull bone along the outline of the opening in concentric circles to facilitate even thinning of the bone. After each concentric pass, add a drop, or two of saline to the drilled area, and allow the saline to sit for at least 10 seconds before resuming the drilling. Gently push on the central area of the skull bone with fine forceps to check that the skull is adequately thinned and moves.Ensure that the underlying vasculature where the drilling occurred is intact, and that the bone is not cracked. Carefully insert a miniature 15-degree pointed blade into the thinned bone and cut and use the gel foam soaked in saline to stop any bleeds that may occur. Using forceps, carefully lift and remove the bone, taking care to not damage the dura mater.For the injection, fill a sterile beveled glass pipette with a 20-micrometer tip with the virus mixture. Then lower the pipette to touch the surface of the brain, and continue to lower for an additional 200 to 300 micrometers for layer 2/3 injections. Using an intracellular microinjection dispense system, pressure inject the system 12 to 15 times over two minutes.For the cranial window implantation, place the cover glass over the opening in the skull. Use forceps to ensure that the glass is flush over the opening. To seal the edges of the glass window to the skull, apply cyanoacrylate adhesive gel around the perimeter of the glass surface.Over the adhesive gel, apply a layer of glue. Then add a layer of dental cement liquid. When dental cement hardens, apply a thin layer of glue around the central opening of the helicopter type head plate, and place the helicopter type head plate of the appropriate size over the cover glass.Allow the glue to dry. Add dental cement powder in a 1.5-milliliter microfuge tube up to the 0.1 milliliter mark. Mix seven to eight drops of fast-curing instant adhesive into the powder, and draw the resultant mixture into a one-milliliter syringe with a 19 gauge needle that has been cut to create a larger opening.Inject the powder mixture through the lateral holes of the helicopter bar until it seeps from either side. Apply the dental cement adhesive mixture to the rest of the exposed skull to fasten the head plate to the skull. Wrap the mouse in cloth, and secure it via its head plate to the head fixation arm of the airlifted home cage, then leave the home cage exposed to light.After a habituation time of 15 minutes, remove the mouse from the home cage. Using the wide field mode of the microscope, select two to three positions of easily identifiable vasculature. Save the images of the blood vessels, and record the x and y-coordinates that appear on the motor controller.Image the synaptic structures of neurons, and GCaMP6f activity in astrocytes. In the representative analysis, the quality of the cranial window was evaluated with repeated imaging of dendrites and GCaMP6f-expressing astrocytes over days. In a good window, the neuronal structures appeared crisp with clearly visible dendritic spines.Two new spines appeared on day two of imaging. Only one spine persisted and was visible on day five. Calcium activity was studied in astrocytes expressing GCaMP6f at different time points.A global event encompassing the entire cell was witnessed during a locomotion bout. The two critical steps of this protocol are that the bone needs to be adequately thinned prior to removal of the bone, and the proper placement of the cover glass over the opening. Imaging can be combined with behavioral analysis, either during imaging, or post-behavior, such as learning a new motor skill, to determine how neuronal and astrocyte structure and function is modulated by learning.

implantation-cranial-window-for-repeated-vivo-imaging-awake

Research

JoVE Journal

Neuroscience

6.6K Görüntüleme.  University of Nebraska Medical Center. Protokol, viral enjeksiyonların nasıl gerçekleştirileceğini ve uyanık, kafa kısıtlamalı farelerde beyin hücrelerinin görüntülenmesi için bir kafatası penceresinin nasıl implante edileceğini açıklar. Bu yöntemin avantajı, nöronların ve astrositlerin yapısının ve aktivitesinin birden fazla seansta tekrar tekrar görüntülenebilmesidir. Bu yaklaşım, nörogelişimsel veya nörodejeneratif bozukluk modellerinde sinir hücrelerinin nasıl değiştirildiğini veya deneyi...