Name: visualization of thalamocortical axon branching and synapse formation in organotypic cocultures
Uploaded: 2018-03-28T12:30:00
Description: Watch this Scientific Journal Video about Visualization of Thalamocortical Axon Branching and Synapse Formation in Organotypic Cocultures at JoVE.com

This work was supported by MEXT KAKENHI on Innovative Areas Mesoscopic Neurocircuitry 23115102 and Dynamic Regulation of Brain Function by Scrap and Build System 16H06460 to N.Y.&#160;We also thank Gabriel Hand for critical reading.

All experiments were performed according to the guidelines established by the animal welfare committees of Osaka University and the Japan Neuroscience Society.
1. Organotypic cocultures of the thalamus and cerebral cortex
Note: For the detailed procedure, refer to the original publications7,8,13. All procedures should be performed under sterile conditions. Sprague-Dawley (SD)...

<ol>
	<li>Kageyama, G. H., Robertson, R. T. <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+geniculocortical+projections+to+visual+cortex+in+rat:+evidence+early+ingrowth+and+synaptogenesis.">Development of geniculocortical projections to visual cortex in rat: evidence early ingrowth and synaptogenesis.</a> J. Comp. Neurol. 335 (1), 123-148 (1993).</li><li>Lopez-Bendito, G., Molnar, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thalamocortical+development:+how+are+we+going+to+get+there.">Thalamocortical development: how are we going to get there.</a> Nat. Rev. Neurosci. 4 (4), 276-289 (2003).</li><li>Espinosa, J. S., Stryker, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+plasticity+of+the+primary+visual+cortex.">Development and plasticity of the primary visual cortex.</a> Neuron. 75 (2), 230-249 (2012).</li><li>Portera-Cailliau, C., Weimer, R. M., De Paola, V., Caroni, P., Svoboda, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diverse+modes+of+axon+elaboration+in+the+developing+neocortex.">Diverse modes of axon elaboration in the developing neocortex.</a> PLoS Biol. 3 (8), 272 (2005).</li><li>Holtmaat, A., Svoboda, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experience-dependent+structural+synaptic+plasticity+in+the+mammalian+brain.">Experience-dependent structural synaptic plasticity in the mammalian brain.</a> Nat. Rev. Neurosci. 10 (9), 647-658 (2009).</li><li>Bhatt, D. H., Zhang, S., 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=Dendritic+spine+dynamics.">Dendritic spine dynamics.</a> Annu Rev Physiol. 71, 261-282 (2009).</li><li>Yamamoto, N., Kurotani, T., Toyama, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+connections+between+the+lateral+geniculate+nucleus+and+visual+cortex+in+vitro.">Neural connections between the lateral geniculate nucleus and visual cortex in vitro.</a> Science. 245 (4914), 192-194 (1989).</li><li>Yamamoto, N., Yamada, K., Kurotani, T., Toyama, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laminar+specificity+of+extrinsic+cortical+connections+studied+in+coculture+preparations.">Laminar specificity of extrinsic cortical connections studied in coculture preparations.</a> Neuron. 9 (2), 217-228 (1992).</li><li>Uesaka, N., Hirai, S., Maruyama, T., Ruthazer, E. S., Yamamoto, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activity+dependence+of+cortical+axon+branch+formation:+a+morphological+and+electrophysiological+study+using+organotypic+slice+cultures.">Activity dependence of cortical axon branch formation: a morphological and electrophysiological study using organotypic slice cultures.</a> J. Neurosci. 25 (1), 1-9 (2005).</li><li>Uesaka, N., Hayano, Y., Yamada, A., Yamamoto, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interplay+between+laminar+specificity+and+activity-dependent+mechanisms+of+thalamocortical+axon+branching.">Interplay between laminar specificity and activity-dependent mechanisms of thalamocortical axon branching.</a> J. Neurosci. 27 (19), 5215-5223 (2007).</li><li>Uesaka, N., Nishiwaki, M., Yamamoto, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single+cell+electroporation+method+for+axon+tracing+in+cultured+slices.">Single cell electroporation method for axon tracing in cultured slices.</a> Dev. Growth Differ. 50 (6), 475-477 (2008).</li><li>Matsumoto, N., Hoshiko, M., Sugo, N., Fukazawa, Y., Yamamoto, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synapse-dependent+and+independent+mechanisms+of+thalamocortical+axon+branching+are+regulated+by+neuronal+activity.">Synapse-dependent and independent mechanisms of thalamocortical axon branching are regulated by neuronal activity.</a> Dev Neurobiol. 76 (3), 323-336 (2016).</li><li>Matsumoto, N., Sasaki, K., Yamamoto, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electroporation+Method+for+Mammalian+CNS+Neurons+in+Organotypic+Slice+Cultures.">Electroporation Method for Mammalian CNS Neurons in Organotypic Slice Cultures.</a> Electroporation Methods in Neuroscience. , 159-168 (2015).</li><li>Molnar, Z., Blakemore, C. <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+regional+specificity+for+connections+formed+between+thalamus+and+cortex+in+coculture.">Lack of regional specificity for connections formed between thalamus and cortex in coculture.</a> Nature. 351 (6326), 475-477 (1991).</li><li>Bolz, J., Novak, N., Staiger, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+specific+afferent+connections+in+organotypic+slice+cultures+from+rat+visual+cortex+cocultured+with+lateral+geniculate+nucleus.">Formation of specific afferent connections in organotypic slice cultures from rat visual cortex cocultured with lateral geniculate nucleus.</a> J. Neurosci. 12 (8), 3054-3070 (1992).</li><li>Yamamoto, 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=Inhibitory+mechanism+by+polysialic+acid+for+lamina-specific+branch+formation+of+thalamocortical+axons.">Inhibitory mechanism by polysialic acid for lamina-specific branch formation of thalamocortical axons.</a> J. Neurosci. 20 (24), 9145-9151 (2000).</li><li>Yamamoto, 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=Characterization+of+factors+regulating+lamina-specific+growth+of+thalamocortical+axons.">Characterization of factors regulating lamina-specific growth of thalamocortical axons.</a> J Neurobiol. 42 (1), 56-68 (2000).</li><li>Ohnami, 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=Role+of+RhoA+in+activity-dependent+cortical+axon+branching.">Role of RhoA in activity-dependent cortical axon branching.</a> J. Neurosci. 28 (37), 9117-9121 (2008).</li><li>Yamada, 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=Role+of+pre-+and+postsynaptic+activity+in+thalamocortical+axon+branching.">Role of pre- and postsynaptic activity in thalamocortical axon branching.</a> Proc Natl Acad Sci U S A. 107 (16), 7562-7567 (2010).</li></ol>

The current protocol is also a powerful tool to study developmental aspects of growing axons other than of the TC projection11. For instance, a combination of cortical slice culture and the electroporation technique allows visualizing individual axonal morphology of cortical neurons and long term observation9,18.
By using the current protocol, the roles of interesting genes in axon branching and synapse formatio...

The thalamocortical (TC) projection in the mammalian brain is a suitable system to investigate axon guidance and targeting mechanisms. During development, sensory TC axons grow in the cortical plate, and form branches and synapses preferentially in layer IV of the primary sensory areas in the cerebral cortex1,2. Even after establishment of fundamental connections, axonal arbors and synaptic terminals are remodeled depending on environmental changes3,4. However, how TC axon morphology is dynamically altered is poorly understood. One of the main reasons is the lack of an adequate technique to observe structural changes at a single cell level. Although recent developments in microscopy, such as two-photon microscopy, have allowed direct observation of living cortical neurons in vivo, there are still technical limitations for capturing the overall TC trajectories5,6. Therefore, in vitro methods for live imaging of TC axons would provide powerful tools for structural analyses of axon branching and synapse formation.
Our group for the first time established a static slice culture method with permeable membrane7. Using this method, a rat cortical slice was cocultured with a sensory thalamic block, and lamina-specific TC connections were recapitulated in this organotypic cocultures7,8. Sparse labeling with a fluorescent protein further allowed us to observe TC axon growth and branch formation9,10,11. Recently, we have developed a novel method for simultaneous imaging of branching and synapse formation of individual TC axons in the organotypic cocultures12. To visualize TC axons and presynaptic sites simultaneously, DsRed and EGFP-tagged synaptophysin (SYP-EGFP) were co-transfected into a small number of thalamic neurons by electroporation of the organotypic coculture. The current method facilitates morphological analysis of TC axons and allows for long-term observation, which can be used to show the causal relationship between axon branching and synapse formation.

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			<td class="xl20" height="40" style="width:113pt;height:30.0pt" width="151">35 mm petri dishes</td>
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			<td class="xl20" height="40" style="width:113pt;height:30.0pt" width="151">Millicell-CM insert</td>
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			<td class="xl20" height="40" style="width:113pt;height:30.0pt" width="151">100 mm petri dishes</td>
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			<td class="xl20" height="59" style="width:113pt;height:44.25pt" width="151">Disposable sterile plastic pipettes</td>
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			<td class="xl20" height="54" style="width:113pt;height:40.5pt" width="151">Glass capillary: OD 1.2 mm</td>
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			<td class="xl20" height="40" style="width:113pt;height:30.0pt" width="151">1 mL syringe</td>
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			<td class="xl20" height="40" style="width:113pt;height:30.0pt" width="151">Confocal microscope</td>
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		<tr height="40" style="height:30.0pt">
			<td class="xl20" height="40" style="width:113pt;height:30.0pt" width="151">Sprague-Dawley (SD) rat</td>
			<td class="xl20" style="width:89pt" width="119">Japan SLC and Nihon-Dobutsu</td>
			<td class="xl20" style="width:84pt" width="112"></td>
			<td class="xl20" style="width:58pt" width="77"></td>
		</tr>
		<tr height="40" style="height:30.0pt">
			<td class="xl20" height="40" style="width:113pt;height:30.0pt" width="151">Microsurgery scissors</td>
			<td class="xl20" style="width:89pt" width="119">Natsume&#160;</td>
			<td class="xl20" style="width:84pt" width="112">MB-54-1</td>
			<td class="xl20" style="width:58pt" width="77"></td>
		</tr>
	</tbody>
</table>

visualization of thalamocortical axon branching and synapse formation in organotypic cocultures

Axon branching and synapse formation are crucial processes for establishing precise neuronal circuits. During development, sensory thalamocortical (TC) axons form branches and synapses in specific layers of the cerebral cortex. Despite the obvious spatial correlation between axon branching and synapse formation, the causal relationship between them is poorly understood. To address this issue, we recently developed a method for simultaneous imaging of branching and synapse formation of individual TC axons in organotypic cocultures.
This protocol describes a method which consists of a combination of an organotypic coculture and electroporation. Organotypic cocultures of the thalamus and cerebral cortex facilitate gene manipulation and observation of axonal processes, preserving characteristic structures such as laminar configuration. Two distinct plasmids encoding DsRed and EGFP-tagged synaptophysin (SYP-EGFP) were co-transfected into a small number of thalamic neurons by an electroporation technique. This method allowed us to visualize individual axonal morphologies of TC neurons and their presynaptic sites simultaneously. The method also enabled long-term observation which revealed the causal relationship between axon branching and synapse formation.

The experiment described here aims to reveal the relationship between TC axon branching and synapse formation. To simultaneously visualize axonal trajectories and locations of presynaptic sites, single or a few thalamic cells in organotypic cocultures were transfected with two plasmids encoding SYP-EGFP and DsRed using electroporation. During the second week in culture, individually distinguishable TC axons were clearly labeled by DsRed (Figure 3). Only the a...

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Visualization of Thalamocortical Axon Branching and Synapse Formation in Organotypic Cocultures

This protocol describes a method for simultaneous imaging of thalamocortical axon branching and synapse formation in organotypic cocultures of the thalamus and cerebral cortex. Individual thalamocortical axons and their presynaptic terminals are visualized by a single cell electroporation technique with DsRed and GFP-tagged synaptophysin.

Axon branching and synapse formation are crucial processes for establishing precise neuronal circuits. During development, sensory thalamocortical (TC) ...

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Neuroscience

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