Agradecemos também o Gabriel Hand para leitura crítica.

Todos os experimentos foram realizados de acordo com as diretrizes estabelecidas pelos comités de bem-estar animal da Universidade de Osaka e da sociedade de neurociência do Japão.
1. Organotypic cocultures do tálamo e córtex cerebral
Nota: Para o procedimento detalhado, consulte o original publicações7,8,13. Todos os procedimentos devem ser executados sob condições estéreis. Ratos Sprague-Dawley (SD) são utilizados para culturas neuronal.
<ol><li>
Preparação dos reagentes Nota: Volumes dos seguintes reagentes são para o cérebro de um rato.<ol>
<li>
Prepare-se 10 x modificado N2 suplemento 13: insulina (50 μg/mL), progesterona (200 nM), hidrocortisona (200 nM), Selenito de sódio (300 nM), transferrina (1 mg/mL), putrescina (1 mM), glicose (60 mg/mL)</li>
		<li>
Prepare soro contendo meio de cultura (10 mL): 85% DMEM/F12, suplemento de N2 10 x modificado 10%, 5% de soro fetal bovino (FBS)</li>
		<li>
Preparar meio de cultura livre de soro (20 mL): 90% DMEM/F12, 10% x 10 modificado N2 suplemento</li>
		<li>Prepare a solução de colágeno de cauda de rato (0,5 mL). Em breve, tomar fibras concursos de um rabo de rato em condições estéreis e incubar durante uma noite em solução de ácido acético. Após a centrifugação, recolher o sobrenadante (alguns mg/mL) e armazenar em um refrigerador13.</li>
	</ol>
</li>
	<li>
Preparação de pratos de cultura
	<ol>
<li>Coloque uma inserção da membrana em uma placa de Petri de 35mm.</li>
		<li>Adicionar 40-50 μL de solução de colágeno de cauda de rato para a membrana e espalhe a solução de colágeno em torno do centro.</li>
		<li>Ar seco a membrana completamente em uma bancada limpa.</li>
		<li>Colocar 1,5-2 mL do meio de cultura contendo soro para o prato, para que a membrana é encharcada com o meio.</li>
		<li>Coloque o prato de cultura numa incubadora (37 ° C, ar umidificado 95% e 5% CO2) antes do chapeamento.</li>
	</ol>
</li>
	<li>
Preparação de fatias corticais
	<ol>
<li>Esterilize todos os instrumentos cirúrgicos com etanol a 70% durante 10 min ou mais.</li>
		<li>Dissecar o cérebro todo rapidamente de um dia pós-natal (P) 2 rato sob anestesia gelada (imergido em lascas de gelo por alguns minutos).</li>
		<li>Lugar do cérebro em uma placa de Petri contendo 100 mL de frio Hanks de 100mm equilibrada solução salina.</li>
		<li>Remover o problema de pia do cérebro com pinça fina e cortar fatias corticais (300-400 μm de espessura) do córtex visual e somatossensorial com tesoura microcirúrgica (para detalhes, veja a Figura 1). Nota: Estima-se aproximadamente a espessura das fatias corticais pela escala de grades sob um microscópio binocular. Nota: Alternativamente, fatias corticais podem ser feitas com um vibratome sob condições estéreis.</li>
		<li>Transferi algumas fatias corticais para a inserção de membrana com uma pipeta descartável de plástico.</li>
		<li>Ajustar as posições das fatias perto do centro da inserção da cultura, com uma pipeta Pasteur fogo-polido (para obter detalhes, consulte8,13) e remover o excesso de meio da inserção. Nota: Ajuste o nível do meio ligeiramente abaixo da superfície das fatias para que as fatias podem receber uma oferta suficiente do gás e do médio. Isto é crucial para a viabilidade celular.</li>
		<li>Manter as fatias em meio de cultura contendo soro a 37 ° C, em um ambiente de umidificado 95% ar e 5% de CO2e cultura sozinha por um dia antes de um bloco talâmica é levado e colocado ao lado.</li>
	</ol>
</li>
	<li>
Preparação dos blocos talâmicos
	<ol>
<li>Esterilize todos os instrumentos cirúrgicos com etanol a 70% durante 10 min ou mais.</li>
		<li>Anestesia um rato grávido (embrionário dia 15) por injeção intraperitoneal de pentobarbital (50 mg/kg) contendo anestésico.</li>
		<li>Dissecar cada embrião partir os cornos uterinos e colocar os embriões em uma placa de Petri contendo 100 mL de solução salina balanceada de Hanks frio de 100mm.</li>
		<li>Sob um microscópio binocular, remover o cérebro de cada embrião e cortar blocos talâmicos que contêm principalmente o núcleo geniculado lateral e complexo (aproximadamente 0,5 mm x 3) ventrobasal7 usando tesoura microcirúrgica (ver Figura 1).</li>
	</ol>
</li>
	<li>
Cultura e manter organotypic cocultures
	<ol>
<li>Usando uma pipeta Pasteur, coloque o bloco talâmica junto a superfície ventricular da fatia cortical que foi colocada no filtro de membrana.</li>
		<li>Manter os cocultures em meio de cultura contendo soro a 37 ° C, em um ambiente de ar umidificado 95% e 5% de CO2.</li>
		<li>Troca metade do médio com meio de cultura livre de soro depois de dois dias em cultura. Depois disso, troca o meio de cada 2-3 dias. Nota: O nível de médio porte deve ser verificado após o câmbio médio, como é importante para a sobrevivência da pilha.</li>
	</ol>
</li>
</ol>2. eletroporação
Todos os procedimentos devem ser executados sob condições estéreis.
Nota: Execute electroporation um dia após o preparo dos blocos talâmicos para evitar o desprendimento dos blocos.
<ol><li>
Plasmídeos
	<ol>
<li>Fazer uma mistura de plasmídeos da seguinte forma: pCAGGS-DsRed 2 μg/μL; pCAG-SYP-EGFP 3,5 μg/μL. Nota: Purificar os ambos Plasmideos usando um kit de Maxiprep livre de endotoxinas e dissolver numa solução salina balanceada de Hanks.</li>
	</ol>
</li>
	<li>
Instalação de equipamento de eletroporação Os instrumentos elétricos como um estimulador e um isolador devem ser conectados conforme mostrado na Figura 2.<ol>
<li>Conecte o estimulador do isolador bifásico.</li>
		<li>Conecte um eletrodo (um fio de prata 0,2 mm de diâmetro) para o terminal negativo do isolador.</li>
		<li>Conecte um eletrodo (um fio de prata 1 mm de diâmetro) em série com um resistor Ω a 100 e o terminal positivo do isolador.</li>
		<li>Ligar o amplificador ao osciloscópio para monitorar se correntes elétricas são passadas através do resistor, medindo a tensão com o amplificador.</li>
	</ol>
</li>
	<li>
Preparação de pipetas de vidro Nota: Dois tipos de pipetas de vidro são utilizados para ejeção da solução do plasmídeo e a aplicação de pulsos elétricos.<ol>
<li>Fazer as pipetas de capilares de vidro com um extrator de eletrodo.</li>
		<li>Quebre a ponta para a pipeta de ejeção (o diâmetro da ponta deve ser de 20-50 μm).</li>
		<li>Moer e polir a ponta da pipeta eletrodo com lixa seguida de fogo-polimento (o diâmetro interno deve ser de 50-200 μm). Nota: Ponta do eletrodo deve ser plana e Lisa, como que toca diretamente o tecido.</li>
	</ol>
</li>
	<li>
Procedimento de eletroporação
	<ol>
<li>Conecte as ejeção e eletrodo pipetas para os manipuladores.</li>
		<li>Introduza um fio de prata (0,2 mm de diâmetro) dentro da pipeta de eletrodo.</li>
		<li>Anexe a pipeta de ejeção de uma seringa de 1 mL com um tubo de plástico.</li>
		<li>Ocupam > 5 μL de solução de plasmídeo dentro da pipeta de ejeção por sucção da seringa.</li>
		<li>Colocar o coculture no palco electroporation e inserir o eletrodo de diâmetro de 1 mm no meio de cultura.</li>
		<li>Coloque a pipeta de ejeção do explante talâmica.</li>
		<li>Empurre a seringa manualmente após a ponta toca a superfície do bloco talâmica. Nota: Sobre 0,5 μL do plasmídeo solução geralmente é usada por um bloco talâmica.</li>
		<li>Coloca a pipeta do eletrodo no bloco talâmica imediatamente depois da retração da pipeta ejeção.</li>
		<li>Entrega os pulsos elétricos (50-400 μA, trens de 3 a 5 de 200 pulsos quadrados de 1 ms duração a 200 Hz). Monitore a amplitude e o número de trens no osciloscópio. Nota: A amplitude das correntes elétricas depende do diâmetro interno de um eletrodo pipeta13.</li>
		<li>Retire a pipeta do eletrodo e devolver o prato para a incubadora.</li>
	</ol>
</li>
	<li>
Observação microscópica
	<ol>
<li>Coloque o prato de cultura num palco microscópica de um microscópio confocal vertical equipado com dois conjuntos de filtro para EGFP (excitação, 488 nm; emissão, 515 nm) e DsRed (excitação, 514 nm; emissão, 565 nm).</li>
		<li>Com imagens de 10-25 seções óticas em tamanhos de 1-7 µm-passo com uma lente objetiva distância de long-trabalho X 20. Selecione individualmente distinguíveis rotulados axônios que expressam tanto DsRed e SYP-EGFP. Nota: A área observada é aproximadamente 0,7 x 0,7 mm (correspondente a 1024 x 1024 pixels, ou seja, 0,68 μm/pixel).</li>
		<li>Capture imagens cada 24 h para a geração de imagens diária. Concluída dentro de 10 min à temperatura ambiente e retornar as culturas para a incubadora. Para a imagem latente de lapso de tempo curto intervalo, manter a cultura em uma câmara de cultura, que mantém que o ambiente de humedecido 95% ar e 5% CO2 a 37 ° C.</li>
	</ol>
</li>
</ol>

<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>

Os autores não têm nada para divulgar.

O protocolo atual também é uma ferramenta poderosa para estudar aspectos do desenvolvimento do crescimento de axônios, além do TC projeção11. Por exemplo, uma combinação de cultura fatia cortical e a técnica de eletroporação permite visualizar a morfologia axonal individual de neurônios corticais e observação de longo prazo9,18.
Usando o protocolo atual, os papéis de genes interessantes na formaç...

A projeção thalamocortical (TC) do cérebro de mamíferos é um sistema adequado para investigar a orientação do axônio e mecanismos de direcionamento. Durante o desenvolvimento, axônios sensoriais do TC crescem na placa cortical e ramos de formulário e sinapses preferencialmente em camada IV das áreas sensoriais primárias no córtex cerebral1,2. Mesmo após o estabelecimento de conexões fundamentais, mandris axonal e terminais sinápticos são remodelados dependendo de mudanças ambientais3,4. No entanto, como morfologia do axônio TC é alterada dinamicamente é mal compreendida. Uma das principais razões é a falta de uma técnica adequada para observar mudanças estruturais a nível uma única célula. Embora os desenvolvimentos recentes na microscopia, tais como a microscopia de dois fotões, permitiram a observação directa da vida neurônios corticais na vivo, existem limitações ainda técnicas para capturar o global TC trajetórias5, 6. portanto, em vitro métodos para geração de imagens ao vivo de axônios de TC que fornece ferramentas poderosas para análises estruturais de formação de ramificação e sinapse do axônio.
Nosso grupo pela primeira vez estabeleceu um método de cultura estático fatia com membrana permeável7. Usando este método, uma fatia de cortical do rato foi cocultured com um bloco talâmica sensorial, e conexões de TC de lâmina específica foram recapituladas neste organotypic cocultures7,8. Etiquetando esparsas com uma proteína fluorescente ainda mais nos permitiu observar crescimento do axônio TC e ramo formação9,10,11. Recentemente, temos desenvolvido um novo método para tratamento de imagens simultâneo de ramificação e formação de sinapse de axônios individuais de TC no organotypic cocultures12. Para visualizar sites pré-sináptica e axônios TC simultaneamente, DsRed e EGFP-tag Sinaptofisina (SYP-EGFP) foram co transfectadas em um pequeno número de neurônios talâmicos por eletroporação de coculture o organotypic. O método atual facilita a análise morfológica de axônios de TC e permite a observação a longo prazo, que pode ser usada para mostrar a relação causal entre a formação de ramificação e sinapse do axônio.

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		<col style="width:113pt" width="151" />
		<col style="width:89pt" width="119" />
		<col style="width:84pt" width="112" />
		<col style="width:58pt" width="77" />
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	<tbody>
		<tr height="40" style="height:30.0pt">
			<td class="xl20" height="40" style="width:113pt;height:30.0pt" width="151">DMEM/F12</td>
			<td class="xl20" style="width:89pt" width="119">GIBCO</td>
			<td class="xl20" style="width:84pt" width="112">11320-033</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">Hanks&#8217; balanced salt solution (HBSS)</td>
			<td class="xl20" style="width:89pt" width="119">Nissui</td>
			<td class="xl21" style="width:84pt" width="112">5905</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">Fetal bovine serum (FBS)</td>
			<td class="xl20" style="width:89pt" width="119">Thermo Scientific</td>
			<td class="xl20" style="width:84pt" width="112">SH30396-03</td>
			<td class="xl20" style="width:58pt" width="77">Hyclone</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">Insulin</td>
			<td class="xl20" style="width:89pt" width="119">Sigma</td>
			<td class="xl20" style="width:84pt" width="112">I6634</td>
			<td class="xl20" style="width:58pt" width="77"></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">Progesterone</td>
			<td class="xl20" style="width:89pt" width="119">Sigma</td>
			<td class="xl20" style="width:84pt" width="112">P8783</td>
			<td class="xl20" style="width:58pt" width="77"></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">Hydrocortisone</td>
			<td class="xl20" style="width:89pt" width="119">Sigma&#160;</td>
			<td class="xl20" style="width:84pt" width="112">H0888</td>
			<td class="xl20" style="width:58pt" width="77"></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">Sodium selenite</td>
			<td class="xl20" style="width:89pt" width="119">Wako Pure 
			Chemical Industries</td>
			<td class="xl20" style="width:84pt" width="112">192-10843</td>
			<td class="xl20" style="width:58pt" width="77"></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">Transferrin&#160;</td>
			<td class="xl20" style="width:89pt" width="119">Sigma</td>
			<td class="xl20" style="width:84pt" width="112">T1147</td>
			<td class="xl20" style="width:58pt" width="77"></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">Putrescine&#160;</td>
			<td class="xl20" style="width:89pt" width="119">Sigma</td>
			<td class="xl20" style="width:84pt" width="112">P5780</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">Glucose</td>
			<td class="xl20" style="width:89pt" width="119">Wako 
			Pure Chemical Industries</td>
			<td class="xl20" style="width:84pt" width="112">16806-25</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">35 mm petri dishes</td>
			<td class="xl20" style="width:89pt" width="119">Falcon</td>
			<td class="xl21" style="width:84pt" width="112">351008</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">Millicell-CM insert</td>
			<td class="xl20" style="width:89pt" width="119">Millipore</td>
			<td class="xl20" style="width:84pt" width="112">PICMORG50</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">100 mm petri dishes</td>
			<td class="xl20" style="width:89pt" width="119">BIO-BIK</td>
			<td class="xl20" style="width:84pt" width="112">I-90-20</td>
			<td class="xl20" style="width:58pt" width="77">petri dish sterrile</td>
		</tr>
		<tr height="40" style="height:30.0pt">
			<td class="xl20" height="40" style="width:113pt;height:30.0pt" width="151">HiPure Plasmid Maxiprep Kit</td>
			<td class="xl20" style="width:89pt" width="119">Invitrogen</td>
			<td class="xl20" style="width:84pt" width="112">K210006</td>
			<td class="xl23" style="width:58pt" width="77"></td>
		</tr>
		<tr height="59" style="height:44.25pt">
			<td class="xl20" height="59" style="width:113pt;height:44.25pt" width="151">Disposable sterile plastic pipettes</td>
			<td class="xl20" style="width:89pt" width="119"></td>
			<td class="xl20" style="width:84pt" width="112">202-IS</td>
			<td class="xl20" style="width:58pt" width="77">transfer pipets sterile</td>
		</tr>
		<tr height="54" style="height:40.5pt">
			<td class="xl20" height="54" style="width:113pt;height:40.5pt" width="151">Glass capillary: OD 1.2 mm</td>
			<td class="xl20" style="width:89pt" width="119">Narishige</td>
			<td class="xl20" style="width:84pt" width="112">&#160;G-1.2</td>
			<td class="xl20" style="width:58pt" width="77">inner diameter, 1.2 mm</td>
		</tr>
		<tr height="53" style="height:39.75pt">
			<td class="xl20" height="53" style="width:113pt;height:39.75pt" width="151">Silver wire: 0.2 and 1 mm&#160;</td>
			<td class="xl20" style="width:89pt" width="119">Nilaco</td>
			<td class="xl20" style="width:84pt" width="112">AG-401265 (diameter, 0.2 mm), AG-401485 (diameter, 1.0 mm)</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">1 mL syringe</td>
			<td class="xl20" style="width:89pt" width="119">Terumo</td>
			<td class="xl20" style="width:84pt" width="112">SS-01T</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">Stimulator&#160;</td>
			<td class="xl20" style="width:89pt" width="119">A.M.P.I</td>
			<td class="xl20" style="width:84pt" width="112">Master 8</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">Biphasic isolator&#160;</td>
			<td class="xl20" style="width:89pt" width="119">BAK ELECTRONICS</td>
			<td class="xl20" style="width:84pt" width="112">BSI-2</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">Amplifier&#160;</td>
			<td class="xl20" style="width:89pt" width="119">A-M Systems</td>
			<td class="xl20" style="width:84pt" width="112">Model 1800</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">Oscilloscope</td>
			<td class="xl20" style="width:89pt" width="119">Hitachi</td>
			<td class="xl20" style="width:84pt" width="112">VC-6723</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">Manipulator</td>
			<td class="xl20" style="width:89pt" width="119">Narishige</td>
			<td class="xl20" style="width:84pt" width="112">SM-15</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">Micromanipulator</td>
			<td class="xl20" style="width:89pt" width="119">Narishige</td>
			<td class="xl20" style="width:84pt" width="112">MO-10</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">Stereomicroscope&#160;</td>
			<td class="xl20" style="width:89pt" width="119">Olympus</td>
			<td class="xl20" style="width:84pt" width="112">SZ40</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">Universal stand&#160;</td>
			<td class="xl20" style="width:89pt" width="119">Olympus</td>
			<td class="xl20" style="width:84pt" width="112">SZ-STU2</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">Light illumination system&#160;</td>
			<td class="xl20" style="width:89pt" width="119">Olympus</td>
			<td class="xl20" style="width:84pt" width="112">LG-PS2, LG-DI, HLL301</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">Electrode puller&#160;</td>
			<td class="xl20" style="width:89pt" width="119">Narishige</td>
			<td class="xl20" style="width:84pt" width="112">PC-10</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">Confocal microscope</td>
			<td class="xl20" style="width:89pt" width="119">Nikon</td>
			<td class="xl20" style="width:84pt" width="112">Digital eclipse C1 laser</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">x20 objective</td>
			<td class="xl20" style="width:89pt" width="119">Nikon</td>
			<td class="xl20" style="width:84pt" width="112">ELWD 20x/0.45</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">Culture chamber</td>
			<td class="xl20" style="width:89pt" width="119">Tokai Hit</td>
			<td class="xl20" style="width:84pt" width="112">UK A16-U</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">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

Formação de ramificação e sinapse do axônio são processos cruciais para o estabelecimento de circuitos neuronais precisos. Durante o desenvolvimento, axônios sensoriais thalamocortical (TC) formam ramos e sinapses em camadas específicas do córtex cerebral. Apesar da óbvia correlação espacial entre formação de ramificação e sinapse do axônio, a relação causal entre eles é mal compreendida. Para resolver esse problema, recentemente desenvolvemos um método para tratamento de imagens simultâneo de ramificação e sinapse formação de axônios individuais de TC em organotypic cocultures.
Este protocolo descreve um método que consiste em uma combinação de um organotypic coculture e eletroporação. Organotypic cocultures do tálamo e córtex cerebral facilitam a observação dos processos axonal, preservando estruturas características tais como a configuração laminar e manipulação genética. Dois plasmídeos distintos codificação DsRed e Sinaptofisina com tag EGFP (SYP-EGFP) foram co transfectados em um pequeno número de neurônios talâmicos técnica de eletroporação. Este método permitiu-nos Visualizar morfologias axonal individuais dos neurônios de TC e seus sites pré-sináptica simultaneamente. O método permitiu também a observação a longo prazo, que revelou a relação causal entre formação de ramificação e sinapse do axônio.

O experimento aqui descrito destina-se a revelar a relação entre formação de ramificação e sinapse de axônio de TC. Para visualizar simultaneamente trajetórias axonal e locais de sites pré-sináptica, única ou poucas células talâmicos em organotypic cocultures foram transfectadas com dois plasmídeos codificação SYP-EGFP e DsRed usando eletroporação. Durante a segunda semana de cultura, axônios individualmente distinguíveis do TC foram claramente rotulados por DsRed (<st...

Watch this Scientific Journal Video about Visualization of Thalamocortical Axon Branching and Synapse Formation in Organotypic Cocultures at JoVE.com

Visualization of Thalamocortical Axon Branching and Synapse Formation in Organotypic Cocultures

Este protocolo descreve um método para tratamento de imagens simultâneo de thalamocortical axônio ramificação e sinapse formação em cocultures de organotypic do tálamo e córtex cerebral. Axônios de thalamocortical individuais e seus terminais pré-sináptica são visualizados pela técnica de eletroporação única célula com DsRed e Sinaptofisina GFP-etiquetado.

Visualização do axônio Thalamocortical ramificação e sinapse formação em Organotypic Cocultures

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

visualization-thalamocortical-axon-branching-synapse-formation

Research

JoVE Journal

Neuroscience

6.4K visualizações.  Kanazawa University. Este protocolo descreve um método para tratamento de imagens simultâneo de thalamocortical axônio ramificação e sinapse formação em cocultures de organotypic do tálamo e córtex cerebral. Axônios de thalamocortical individuais e seus terminais pré-sináptica são visualizados pela técnica de eletroporação única célula com DsRed e Sinaptofisina GFP-etiquetado.

Vídeo: Visualization of Thalamocortical Axon Branching and Synapse Formation in Organotypic Cocultures

Automated Interactive Video Playback for Studies of Animal Communication

Video playback is a widely-used technique for the controlled manipulation and presentation of visual signals in animal communication. In particular, parameter-based computer animation offers the opportunity to independently manipulate any number of behavioral, morphological, or spectral characteristics in the context of realistic, moving images of animals on screen. A major limitation of conventional playback, however, is that the visual stimulus lacks the ability to interact with the live animal. Borrowing from video-game technology, we have created an automated, interactive system for video playback that controls animations in response to real-time signals from a video tracking system. We demonstrated this method by conducting mate-choice trials on female swordtail fish, Xiphophorus birchmanni. Females were given a simultaneous choice between a courting male conspecific and a courting male heterospecific (X. malinche) on opposite sides of an aquarium. The virtual male stimulus was programmed to track the horizontal position of the female, as courting males do in the wild. Mate-choice trials on wild-caught X. birchmanni females were used to validate the prototype's ability to effectively generate a realistic visual stimulus.

Video playback is a widely used technique in animal behavior. We created and evaluated a program that applies rules-based, interactive playback of 3-D computer animations in response to real-time, automated data on subject behavior.

Reprodução de vídeo automatizada interativo para estudos da comunicação animal

Video playback is a widely-used technique for the controlled manipulation and presentation of visual signals in animal communication. In particular, ...

Neurociência

Visualization of Proprioceptors in Drosophila Larvae and Pupae

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other insects proprioception is provided by specialized sensory organs termed chordotonal organs (ChOs) 2. Like many other organs in Drosophila, ChOs develop twice during the life cycle of the fly. First, the larval ChOs develop during embryogenesis. Then, the adult ChOs start to develop in the larval imaginal discs and continue to differentiate during metamorphosis.
The development of larval ChOs during embryogenesis has been studied extensively 10,11,13,15,16. The centerpiece of each ChO is a sensory unit composed of a neuron and a scolopale cell. The sensory unit is stretched between two types of accessory cells that attach to the cuticle via specialized epidermal attachment cells 1,9,14. When a fly larva moves, the relative displacement of the epidermal attachment cells leads to stretching of the sensory unit and consequent opening of specific transient receptor potential vanilloid (TRPV) channels at the outer segment of the dendrite 8,12. The elicited signal is then transferred to the locomotor central pattern generator circuit in the central nervous system.
Multiple ChOs have been described in the adult fly 7. These are located near the joints of the adult fly appendages (legs, wings and halters) and in the thorax and abdomen. In addition, several hundreds of ChOs collectively form the Johnston's organ in the adult antenna that transduce acoustic to mechanical energy 3,5,17,4.
In contrast to the extensive knowledge about the development of ChOs in embryonic stages, very little is known about the morphology of these organs during larval stages. Moreover, with the exception of femoral ChOs 18 and Johnston's organ, our knowledge about the development and structure of ChOs in the adult fly is very fragmentary.
Here we describe a method for staining and visualizing ChOs in third instar larvae and pupae. This method can be applied together with genetic tools to better characterize the morphology and understand the development of the various ChOs in the fly.

Visualization of Proprioceptors in Drosophila Larvae and Pupae

A method to immunostain and visualize chordotonal organs in larvae and pupae of Drosophila melanogaster is described.

Visualização de Propriocepção em<em&gt; Drosophila</em&gt; As larvas e pupas

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other ...

Paired Whole Cell Recordings in Organotypic Hippocampal Slices

Pair recordings involve simultaneous whole cell patch clamp recordings from two synaptically connected neurons, enabling not only direct electrophysiological characterization of the synaptic connections between individual neurons, but also pharmacological manipulation of either the presynaptic or the postsynaptic neuron. When carried out in organotypic hippocampal slice cultures, the probability that two neurons are synaptically connected is significantly increased. This preparation readily enables identification of cell types, and the neurons maintain their morphology and properties of synaptic function similar to that in native brain tissue. A major advantage of paired whole cell recordings is the highly precise information it can provide on the properties of synaptic transmission and plasticity that are not possible with other more crude techniques utilizing extracellular axonal stimulation. Paired whole cell recordings are often perceived as too challenging to perform. While there are challenging aspects to this technique, paired recordings can be performed by anyone trained in whole cell patch clamping provided specific hardware and methodological criteria are followed. The probability of attaining synaptically connected paired recordings significantly increases with healthy organotypic slices and stable micromanipulation allowing independent attainment of pre- and postsynaptic whole cell recordings. While CA3-CA3 pyramidal cell pairs are most widely used in the organotypic slice hippocampal preparation, this technique has also been successful in CA3-CA1 pairs and can be adapted to any neurons that are synaptically connected in the same slice preparation. In this manuscript we provide the detailed methodology and requirements for establishing this technique in any laboratory equipped for electrophysiology.

Pair recordings are simultaneous whole cell patch clamp recordings from two synaptically connected neurons, enabling precise electrophysiological and pharmacological characterization of the synapses between individual neurons. Here we describe the detailed methodology and requirements for establishing this technique in organotypic hippocampal slice cultures in any laboratory equipped for electrophysiology.

Emparelhados Recordings células inteiras em organotï¿½icas fatias do hipocampo

Pair recordings involve simultaneous whole cell patch clamp recordings from two synaptically connected neurons, enabling not only direct ...

Inhibitory Synapse Formation in a Co-culture Model Incorporating GABAergic Medium Spiny Neurons and HEK293 Cells Stably Expressing GABAA Receptors

Inhibitory neurons act in the central nervous system to regulate the dynamics and spatio-temporal co-ordination of neuronal networks. GABA (&#947;-aminobutyric acid) is the predominant inhibitory neurotransmitter in the brain. It is released from the presynaptic terminals of inhibitory neurons within highly specialized intercellular junctions known as synapses, where it binds to GABAA receptors (GABAARs) present at the plasma membrane of the synapse-receiving, postsynaptic neurons. Activation of these GABA-gated ion channels leads to influx of chloride resulting in postsynaptic potential changes that decrease the probability that these neurons will generate action potentials. 
During development, diverse types of inhibitory neurons with distinct morphological, electrophysiological and neurochemical characteristics have the ability to recognize their target neurons and form synapses which incorporate specific GABAARs subtypes. This principle of selective innervation of neuronal targets raises the question as to how the appropriate synaptic partners identify each other. 
To elucidate the underlying molecular mechanisms, a novel in vitro co-culture model system was established, in which medium spiny GABAergic neurons, a highly homogenous population of neurons isolated from the embryonic striatum, were cultured with stably transfected HEK293 cell lines that express different GABAAR subtypes. Synapses form rapidly, efficiently and selectively in this system, and are easily accessible for quantification. Our results indicate that various GABAAR subtypes differ in their ability to promote synapse formation, suggesting that this reduced in vitro model system can be used to reproduce, at least in part, the in vivo conditions required for the recognition of the appropriate synaptic partners and formation of specific synapses. Here the protocols for culturing the medium spiny neurons and generating HEK293 cells lines expressing GABAARs are first described, followed by detailed instructions on how to combine these two cell types in co-culture and analyze the formation of synaptic contacts.

Inhibitory Synapse Formation in a Co-culture Model Incorporating GABAergic Medium Spiny Neurons and HEK293 Cells Stably Expressing GABAA Receptors

The molecular mechanisms that co-ordinate the formation of inhibitory GABAergic synapses during ontogeny are largely unknown. To study these processes,we have developed a co-culture model system which incorporates embryonic medium spiny GABAergic neurons cultured together with stably transfected human embryonic kidney 293 (HEK293) cells expressing functional GABAA receptors.

Formação Sinapse Inibitória em uma co-cultura-tipo que comportem GABAérgicos espinhosos médios neurônios e células HEK293 expressando estavelmente GABA<sub&gt; A</sub&gt; Receptores

Inhibitory neurons act in the central nervous system to regulate the dynamics and spatio-temporal co-ordination of neuronal networks. GABA ...

Whole-mount Imaging of Mouse Embryo Sensory Axon Projections

The visualization of full-length neuronal projections in embryos is essential to gain an understanding of how mammalian neuronal networks develop. Here we describe a method to label in situ a subset of dorsal root ganglion (DRG) axon projections to assess their phenotypic characteristics using several genetically manipulated mouse lines. The TrkA-positive neurons are nociceptor neurons, dedicated to the transmission of pain signals. We utilize a TrkAtaulacZ mouse line to label the trajectories of all TrkA-positive peripheral axons in the intact mouse embryo. We further breed the TrkAtaulacZ line onto a Bax null background, which essentially abolishes neuronal apoptosis, in order to assess growth-related questions independently of possible effects of genetic manipulations on neuronal survival. Subsequently, genetically modified mice of interest are bred with the TrkAtaulacZ/Bax null line and are then ready for study using the techniques described herein. This presentation includes detailed information on mouse breeding plans, genotyping at the time of dissection, tissue preparation, staining and clearing to allow for visualization of full-length axonal trajectories in whole-mount preparation.

We present here an optimized protocol to genotype, stain and prepare fetal mice for the imaging of peripheral nociceptor axon projections in the whole animal, as an effective method to assess sensory axon growth phenotypes in developing genetically engineered mice.

Todo-mount imagem de embrião de rato Projeções Sensorial Axon

The visualization of full-length neuronal projections in embryos is essential to gain an understanding of how mammalian neuronal networks develop. Here we ...

Utilizing Combined Methodologies to Define the Role of Plasma Membrane Delivery During Axon Branching and Neuronal Morphogenesis

During neural development, growing axons extend to multiple synaptic partners by elaborating axonal branches. Axon branching is promoted by extracellular guidance cues like netrin-1 and results in dramatic increases to the surface area of the axonal plasma membrane. Netrin-1-dependent axon branching likely involves temporal and spatial control of plasma membrane expansion, the components of which are supplied through exocytic vesicle fusion. These fusion events are preceded by formation of SNARE complexes, comprising a v-SNARE, such as VAMP2 (vesicle-associated membrane protein 2), and plasma membrane t-SNAREs, syntaxin-1 and SNAP25 (synaptosomal-associated protein 25). Detailed herein isa multi-pronged approach used to examine the role of SNARE mediated exocytosis in axon branching. The strength of the combined approach is data acquisition at a range of spatial and temporal resolutions, spanning from the dynamics of single vesicle fusion events in individual neurons to SNARE complex formation and axon branching in populations of cultured neurons. This protocol takes advantage of established biochemical approaches to assay levels of endogenous SNARE complexes and Total Internal Reflection Fluorescence (TIRF) microscopy of cortical neurons expressing VAMP2 tagged with a pH-sensitive GFP (VAMP2-pHlourin) to identify netrin-1 dependent changes in exocytic activity in individual neurons. To elucidate the timing of netrin-1-dependent branching, time-lapse differential interference contrast (DIC) microscopy of single neurons over the order of hours is utilized. Fixed cell immunofluorescence paired with botulinum neurotoxins that cleave SNARE machinery and block exocytosis demonstrates that netrin-1 dependent axon branching requires SNARE-mediated exocytic activity.

Light microscopy techniques coupled with biochemical assays elucidate the involvement of SNARE-mediated exocytosis in netrin-dependent axon branching. This combination of techniques permits identification of molecular mechanisms controlling axon branching and cell shape change.

Utilizando metodologias combinadas para definir o papel do Plasma Membrane entrega durante Axon Ramificação e Neuronal morfogênese

During neural development, growing axons extend to multiple synaptic partners by elaborating axonal branches. Axon branching is promoted by extracellular ...

Quadruple Immunostaining of the Olfactory Bulb for Visualization of Olfactory Sensory Axon Molecular Identity Codes

The mouse olfactory system is often used to study mechanisms of neural circuit formation&#12288;because of its simple anatomical structure. An Olfactory Sensory Neuron (OSN) is a bipolar cell with a single dendrite and a single unbranched axon. An OSN expresses only one Olfactory Receptor (OR) gene, OSNs expressing a given type of OR converge their axons to a few sets of invariant glomeruli in the Olfactory Bulb (OB). A remarkable feature of OSN projection is that the expressed ORs play instructive roles in axonal projection. ORs regulate the expression of multiple axon-sorting molecules and generate the combinatorial molecular code of axon-sorting molecules at the OSN axon termini. Thus, to understand the molecular mechanisms of OR-specific axon guidance mechanisms, it is vital to characterize their expression profiles at the OSN axon termini within the same glomerulus. The aim of this article was to introduce methods for collecting as many glomeruli as possible on a single OB section and for performing immunostaining using multiple antibodies. This would allow the comparison and analysis of the expression patterns of axon-sorting molecules without staining variation between OB sections.

Olfactory sensory neurons express a wide variety of axon-sorting molecules to establish proper neural circuitry. This protocol describes an immunohistochemical staining method to visualize combinatorial expressions of axon-sorting molecules at the axon termini of olfactory sensory neurons.

Imunossinção Quadruple da Lâmpada Olfativa para Visualização de Códigos de Identidade Molecular de Axon Sensorial Olfativo

The mouse olfactory system is often used to study mechanisms of neural circuit formation&#12288;because of its simple anatomical structure. An Olfactory ...

Improving the Application of High Molecular Weight Biotinylated Dextran Amine for Thalamocortical Projection Tracing in the Rat

High molecular weight biotinylated dextran amine (BDA) has been used as a highly sensitive neuroanatomical tracer for many decades. Since the quality of its labeling was affected by various factors, here, we provide a refined protocol for the application of high molecular weight BDA for studying optimal neural labeling in the central nervous system. After stereotactic injection of BDA into the ventral posteromedial nucleus (VPM) of the thalamus in the rat through a delicate glass pipette, BDA was stained with fluorescent streptavidin-Alexa (AF) 594 and counterstained with fluorescent Nissl stain AF500/525. On the background of green Nissl staining, the red BDA labeling, including neuronal cell bodies and axonal terminals, was more distinctly demonstrated in the somatosensory cortex. Furthermore, double fluorescent staining for BDA and the calcium-binding protein parvalbumin (PV) was carried out to observe the correlation of BDA labeling and PV-positive interneurons in the cortical target, providing the opportunity to study the local neural circuits and their chemical characteristics. Thus, this refined method is not only suitable for visualizing high quality neural labeling with the high molecular weight BDA through reciprocal neural pathways between the thalamus and cerebral cortex, but also will permit the simultaneous demonstration of other neural markers with fluorescent histochemistry or immunochemistry.

Here, we present a refined protocol to effectively reveal biotinylated dextran amine (BDA) labeling with a fluorescent staining method through a reciprocal neural pathway. It is suitable for analyzing the fine structure of BDA labeling and distinguishing it from other neural elements under a confocal laser scanning microscope.

Melhorar a aplicação de alto Peso Molecular Biotinylated dextrano amina para projeção Thalamocortical rastreamento em ratos

High molecular weight biotinylated dextran amine (BDA) has been used as a highly sensitive neuroanatomical tracer for many decades. Since the quality of ...

Evaluation of Synapse Density in Hippocampal Rodent Brain Slices

In the brain, synapses are specialized junctions between neurons, determining the strength and spread of neuronal signaling. The number of synapses is tightly regulated during development and neuronal maturation. Importantly, deficits in synapse number can lead to cognitive dysfunction. Therefore, the evaluation of synapse number is an integral part of neurobiology. However, as synapses are small and highly compact in the intact brain, the assessment of absolute number is challenging. This protocol describes a method to easily identify and evaluate synapses in hippocampal rodent slices using immunofluorescence microscopy. It includes a three-step procedure to evaluate synapses in high-quality confocal microscopy images by analyzing the co-localization of pre- and postsynaptic proteins in hippocampal slices. It also explains how the analysis is performed and gives representative examples from both excitatory and inhibitory synapses. This protocol provides a solid foundation for the analysis of synapses and can be applied to any research investigating the structure and function of the brain.

A protocol for accurately identifying and analyzing synapses in hippocampal slices using immunofluorescence is outlined in this article.

Avaliação da densidade de sinapse em fatias Hippocampal cérebro de roedor

In the brain, synapses are specialized junctions between neurons, determining the strength and spread of neuronal signaling. The number of synapses is ...

Visualization and Live Imaging of Oligodendrocyte Organelles in Organotypic Brain Slices Using Adeno-associated Virus and Confocal Microscopy

Neurons rely on the electric insulation and trophic support of myelinating oligodendrocytes. Despite the importance of oligodendrocytes, the advanced tools currently used to study neurons, have only partly been taken on by oligodendrocyte researchers. Cell type-specific staining by viral transduction is a useful approach to study live organelle dynamics. This paper describes a protocol for visualizing oligodendrocyte mitochondria in organotypic brain slices by transduction with adeno-associated virus (AAV) carrying genes for mitochondrial targeted fluorescent proteins under the transcriptional control of the myelin basic protein promoter. It includes the protocol for making organotypic coronal mouse brain slices. A procedure for time-lapse imaging of mitochondria then follows. These methods can be transferred to other organelles and may be particularly useful for studying organelles in the myelin sheath. Finally, we describe a readily available technique for visualization of unstained myelin in living slices by Confocal Reflectance microscopy (CoRe). CoRe requires no extra equipment and can be useful to identify the myelin sheath during live imaging.

Myelinating oligodendrocytes promote rapid action potential propagation and neuronal survival. Described here is a protocol for oligodendrocyte-specific expression of fluorescent proteins in organotypic brain slices with subsequent time-lapse imaging. Further, a simple procedure for visualizing unstained myelin is presented.

Visualização e imagem ao vivo do Oligodendrocyte organelas em fatias Organotypic cérebro usando microscopia Confocal e vírus Adeno-associado

Neurons rely on the electric insulation and trophic support of myelinating oligodendrocytes. Despite the importance of oligodendrocytes, the advanced ...