Financial support for the experiments presented in the study was provided by the Marie Heim-V&#246;gtlin program of the Swiss National Science Foundation.
We thank Ms. Johanna Nyffeler for developing a set of modified MATLAB programs for screening for statistically significant differences in real-time cell analyzer&#8217;s data and Dr. Yama Abassi for helpful discussion.

1 Preparação <ol><li> Coloque a estação do analisador de células em tempo real num incubador de cultura de tecido fixado a 37 ° C e com 5% de CO 2. Realizar toda a manipulação de cultura de células e tratamentos farmacológicos em um capuz de cultura de tecidos em condições de esterilidade. </li><li> NOTA: Neuronal linhas celulares que requerem ajustes de temperatura diferentes em relação às condições normais de cultura, deve ser ajustada em conformidade. Para as linhas de células fracamente aderentes, utilizar agentes de revestimento para facilitar a interacção das células com os microeléctrodos de ouro no fundo dos poços da placa de E-96. </li><li> Preparar soluções 1000X ações dos compostos farmacológicos para o tratamento de cultura de células (agentes neuroprotetores ou inibidores vias de segundo mensageiro no solvente apropriado - dimetilsulfóxido ou água estéril) e armazená-los a -20 ° C. Use o solvente como veículo nos seguintes tratamentos. </li><li> Cultura de células de neuroblastoma humano SK-N-SH em DMEM / F12 suplementado com 10% soro fetal bovino (FBS) (meio de proliferação) em frascos de cultura de células com 175 cm 2, a densidade de superfície de cerca de 75%. Manter passagem número de células dentro de uma gama de (cerca de 10 passagens) para verificar a coerência entre as experiências em termos de taxa de proliferação celular e resposta a citotoxicidade. São preferidos os números de passagem inferior. </li><li> Lava-se a camada de células SK-N-SH aderente com PBS, e trypsinize com solução de tripsina-EDTA a 0,05% durante 5 min a 37 ° C. Centrifugar as células a 170 x g durante 5 minutos para remover a tripsina. Ressuspender as células em 10 ml de meio de proliferação. Contar as células com o contador de células Scepter e ajustar o número de células de 300.000 células / ml, diluindo as células com meio de proliferação. </li></ol> 2. Galvanização e proliferação de SK-N-SH Células <ol><li> Adicionar meio de proliferação de 100 ul a cada poço da placa de E-96 e deixá-lo por 30 minutos na capa de cultura de tecidos à temperatura ambiente para equilibrar. Insira o E-Plate 96 em tempo real a estação analisador de células na incubadora de CO 2 a 37 ° C. </li><li> Inicie o software em tempo real analisador de células. Na página de layout, selecione os poços incluídos no experimento e entrar nas caixas de edição a informação sobre o tipo de celular, número de células, nomes e concentrações de compostos químicos utilizados para o tratamento de células. NOTA: Para efeitos do presente protocolo, pelo menos, 4 repetições são recomendados para cada tratamento. </li><li> Na página de software Programação determinar &quot;Passos&quot; incluídos no experimento, selecionando o número de varreduras de medição Índice de celular eo intervalo entre as varreduras para cada etapa. Desde Passo 1 é pré-determinado para a medida de fundo, selecione &quot;Adicionar uma etapa&quot; e defina o Passo 2 para medir o Índice de celular a cada 15 minutos durante 96 horas. NOTA: Para os tratamentos, no qual são esperados efeitos com cinética rápida, definir varreduras em intervalos mais curtos. </li><li> Clique em Iniciar para iniciar a etapa pré-determinado automaticamente ume medir a impedância dos meios de fundo. Este valor é automaticamente subtraídos pelo programa em cada ponto de dados uma vez que as células são adicionadas aos poços. </li><li> Utilizar a suspensão de células previamente preparada no passo 1.5) de 300.000 células / ml em meio de proliferação. 30.000 células / poço de toxicidade celular / estudos de neuroproteção e 15.000 células / poço para estudos de proliferação celular. Retire o E-Plate e adicionar 100 mL de suspensão de células por poço para os estudos de toxicidade celular / neuroproteção e adicionar suspensão de células de 50 mL e meio de proliferação 50 ul por poço para os estudos de proliferação celular. O número de células plaqueadas por cavidade tem de ser optimizada para cada linha celular empiricamente. </li><li> Agite suavemente o E-Plate 96, mesmo para metalização das células. Deixar a placa de E-96 durante 30 minutos na capa de cultura de tecidos à temperatura ambiente para permitir que as células assentar uniformemente ao fundo dos poços. </li><li> Insira o E-Plate 96 no tempo real da estação analisador de células e começar Passo 2 no Cronograma pidade. Monitorar valores do Índice de celular em todo o experimento, exibindo as curvas de celulares na página Plot e os dados do Índice de celular matérias sobre o celular Index página do software. </li></ol> 3. Serum Privação <ol><li> 24 h após o plaqueamento das células, uma pausa na experiência, e remover a placa de E-96 a partir da estação em tempo real analisador de células. Dilui-se inibidores de segundo mensageiro de estoques 1000X com meio livre de soro / DMEM F12 - 200 × a concentração final. Tratar as células com 1 ul inibidores das vias de segundo mensageiro a ser testado para o seu envolvimento na neurotoxicidade / neuroprotecção 30 min antes de se iniciar a citotoxicidade, para inibir as respectivas vias. Retorne o E-Plate 96 para a estação e retomar as medições do Índice célula experimental. </li><li> Depois de uma pausa de 30 minutos novamente a experiência. Remova cuidadosamente meio de proliferação plenamente do E-placa de 96 poços com uma pipeta (ou multi-canal pipeta), tomando cuidado para não romper a camada de células aderentesdirigindo a extremidade da ponta da pipeta para o canto do poço. Adicione 200 ^ l / poço de DMEM isento de soro / meio F12 (meio privação de soro). Assegurar a troca rápida de meio de cultura de células, para minimizar a agitação mecânica das células. </li><li> Dilui-se os compostos a ser testados quanto aos seus efeitos neuroprotectores de 1000X estoque com meio DMEM / F12 isento de soro de 200 × a concentração final. Adicionar 1 ul compostos a ser testados quanto aos seus efeitos neuroprotectores e 1 ul inibidores das vias de segundo mensageiro em poços individuais de acordo com o plano experimental. </li><li> Em células para estudos de proliferação não mudam médio. Dilui-se os compostos a ensaiar a partir de estoque 1000X de 200 × a concentração final no meio de proliferação, trata-se com 1 ul por poço e continuar a cultura no meio de proliferação. </li><li> Retomar a experiência para continuar com celulares medições índice a cada 15 minutos durante 96 horas como definido anteriormente. </li></ol> 4 Dados Análise <ol><li> Para neurotoxicidade / dados de neuroproteção normalizar Índice celular para o último ponto de tempo antes do tratamento farmacológico ou mudança de meio para reduzir a variação entre os experimentos, selecionando &quot;Índice celular normalizado&quot; e &quot;normalizar Time&quot; na página Plot. </li><li> Destaque os poços na página Plot para as condições experimentais de interesse e clique em &quot;Adicionar&quot; para traçar as curvas de índice de celular normalizados. Observar a cinética do efeito neurotóxico / neuroprotectora, ou de inibição segundo mensageiros como curvas normalizadas Índice celular como uma função do tempo. </li><li> Observar as curvas Índice celular para os tratamentos com fármacos testados em meio de proliferação, como uma função do tempo para avaliar se um efeito sobre a proliferação está envolvido no efeito neuroprotector / neurotóxico. </li><li> Exportar a informação experimental para todos os pontos celular tempo Índice da página em software celular índice em um arquivo do Excel para iniciar a avaliação estatística dos resultados <br/&gt; NOTA: Como passo inicial na análise estatística de um conjunto de programas modificados MATLAB que usam o teste t de Welch, com o valor de p plotados semilogarithmically, utilizar eixo invertido contra a escala de tempo (fornecido como arquivos de código complementar). Estes programas permitem a detecção de valores de p ao longo do tempo de toda uma experiência em tempo real analisador de células e, assim, ajudar a seleção de pontos de tempo para a análise estatística mais detalhada. Veja o material suplementar para obter informações detalhadas sobre os programas. </li><li> Para a análise estatística das diferenças de valores do Índice de celulares em diferentes condições de tratamento em momentos específicos, selecione valores do Índice de celular em respectivos tempos de arquivo exportado Excel. Analisar os valores do Índice de celular para os pontos de tempo seleccionados com unidirecional ou bidirecional análise de variância (ANOVA) seguida do teste post-hoc usando o software estatístico. </li></ol>

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	<li>Cavallucci, V., D'Amelio, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Matter+of+life+and+death:+the+pharmacological+approaches+targeting+apoptosis+in+brain+diseases.">Matter of life and death: the pharmacological approaches targeting apoptosis in brain diseases.</a> Curr. Pharm. Des. 17 (3), 215-229 (2011).</li><li>Bull, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HPA+CHaPD+001:+Review+of+Environmental+Chemicals+and+Neurotoxicity.">HPA CHaPD 001: Review of Environmental Chemicals and Neurotoxicity.</a> Focus on Neurological Diseases. , (2007).</li><li>Ke, N., Wang, X., Xu, X., Abassi, Y. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+xCELLigence+system+for+real-time+and+label-free+monitoring+of+cell+viability.">The xCELLigence system for real-time and label-free monitoring of cell viability.</a> Methods Mol. Biol. 740, 33-43 (2011).</li><li>Limame, 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=Comparative+analysis+of+dynamic+cell+viability,+migration+and+invasion+assessments+by+novel+real-time+technology+and+classic+endpoint+assays.">Comparative analysis of dynamic cell viability, migration and invasion assessments by novel real-time technology and classic endpoint assays.</a> PLoS One. 7 (10), e46536 (2012).</li><li>Diemert, 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=Impedance+measurement+for+real-time+detection+of+neuronal+cell+death.">Impedance measurement for real-time detection of neuronal cell death.</a> J. Neurosci. Methods. 203 (1), 69-77 (2012).</li><li>Kustermann, 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=A+label-free,+impedance-based+real+time+assay+to+identify+drug-induced+toxicities+and+differentiate+cytostatic+from+cytotoxic+effects.">A label-free, impedance-based real time assay to identify drug-induced toxicities and differentiate cytostatic from cytotoxic effects.</a> Toxicol In Vitro. 27 (5), 1589-1595 (2013).</li><li>Marinova, Z., Walitza, S., Gr&#252;nblatt, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=5-HT2A+serotonin+receptor+agonist+DOI+alleviates+cytotoxicity+in+neuroblastoma+cells:+role+of+the+ERK+pathway.">5-HT2A serotonin receptor agonist DOI alleviates cytotoxicity in neuroblastoma cells: role of the ERK pathway.</a> Prog. Neuropsychopharmacol. Biol. Psychiatry. 44, 64-72 (2013).</li><li>Gonz&#225;lez-Maeso, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hallucinogens+recruit+specific+cortical+5-HT(2A)+receptor-mediated+signaling+pathways+to+affect+behavior.">Hallucinogens recruit specific cortical 5-HT(2A) receptor-mediated signaling pathways to affect behavior.</a> Neuron. 53 (3), 439-452 (2007).</li><li>Tsuchioka, M., Takebayashi, M., Hisaoka, K., Maeda, N., Nakata, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serotonin+(5-HT)+induces+glial+cell+line-derived+neurotrophic+factor+(GDNF)+mRNA+expression+via+the+transactivation+of+fibroblast+growth+factor+receptor+2+(FGFR2)+in+rat+C6+glioma+cells.">Serotonin (5-HT) induces glial cell line-derived neurotrophic factor (GDNF) mRNA expression via the transactivation of fibroblast growth factor receptor 2 (FGFR2) in rat C6 glioma cells.</a> J. Neurochem. 106 (1), 244-257 (2008).</li><li>Galante, 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=Differential+toxicity,+conformation+and+morphology+of+typical+initial+aggregation+states+of+A&#946;1-42+and+A&#946;py3-42+beta-amyloids.">Differential toxicity, conformation and morphology of typical initial aggregation states of A&#946;1-42 and A&#946;py3-42 beta-amyloids.</a> Int. J. Biochem. Cell. Biol. 44 (11), 2085-2093 (2012).</li><li>Sheline, C. T., Cai, A. L., Zhu, J., Shi, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serum+or+target+deprivation-induced+neuronal+death+causes+oxidative+neuronal+accumulation+of+Zn2+and+loss+of+NAD.">Serum or target deprivation-induced neuronal death causes oxidative neuronal accumulation of Zn2+and loss of NAD.</a> Eur. J. Neurosci. 32, 894-904 (2010).</li></ol>

Os custos de publicação para o atual vídeo-artigo foram patrocinados pela &quot;ACEA Biociências&quot;.

O protocolo atual apresenta a utilidade de um analisador de células em tempo real para avaliar de forma contínua e em condições livres de etiqueta os efeitos neuroprotetores / neurotóxicos de compostos em linhas de células neuronais e para obter insights sobre as segundas vias mensageiros envolvidos no efeito. Embora a utilidade do analisador de células em tempo real para estudar a toxicidade e efeitos das drogas sobre a proliferação celular é geralmente reconhecido, poucos estudos...

Morte das células neuronais desempenha um papel fundamental na fisiopatologia de várias doenças relacionadas com o cérebro 1. A disponibilidade de dados fiáveis ​​e de alto rendimento em ensaios de toxicidade in vitro é fundamental para obter uma melhor visão sobre os mecanismos de neurotoxicidade e ajudar a selecionar moléculas neuroprotetores como candidatos terapêuticas no desenvolvimento de medicamentos 2. No entanto, existem muitas limitações para mais amplamente utilizados em assays.They neurotoxicidade in vitro avaliar a neurotoxicidade / neuroprotecção a um único ponto de tempo, não permitindo resolução cinética; costumam usar etiqueta ou sonda que pode interferir com as vias de sinalização e limitar estudos adicionais na mesma população de células, e muitas vezes são de trabalho intensivo, e em muitos casos não fornecem uma visão mecanicista. No presente estudo demonstram a utilidade de um analisador de células à base de impedância em tempo real para determinar a neurotoxicidade e neuroprotecção em uma linha de células neuronais em tempo real e sob livre de marcadorcondições e fornecer informações sobre os mecanismos a jusante, através da análise das vias de segundos mensageiros envolvidos no efeito. Estudos anteriores confirmaram a validade do analisador de células em tempo real para determinar a citotoxicidade, bem como os efeitos sobre a proliferação de células nas linhas de células em comparação com as técnicas convencionais 3,4,5,6. Por exemplo, observou-se uma boa correlação entre as leituras do ensaio padrão de viabilidade celular WST-1 e valores de índice de células em vários pontos de tempo, sob condições de proliferação basal e após dois paradigmas diferentes tóxicos em células HeLa 3. Em A549 e MDA-MB-231 células de proliferação e de citotoxicidade provocada com o paclitaxel microtúbulos estabilizador mostrou valores muito semelhantes, quando avaliada através de medições de índice celular e utilizado de forma padrão a sulforodamina B (SRB) 4. Na linha de célula neuronal de neurônios do hipocampo imortalizados HT-22 Celulares medições do Índice foram validados por sua capacidade to detectar a proliferação de células, a citotoxicidade do glutamato e citoprotecção contra a amplamente utilizado 3 (4,5-dimetiltiazol-2-il) 2,5-difenil-brometo (MTT) 5. No mesmo estudo os resultados do ensaio de MTT e medições de índice celular também se correlacionou bem na medição neuronal proliferação de células progenitoras, citotoxicidade após privação de fatores de crescimento e resgate de citotoxicidade pelo pan-caspase inibidor QVD 5. A citotoxicidade induzida em células NIH 3T3 por Vandetanib (crescimento endotelial vascular receptor do factor inibidor e do receptor do factor de crescimento epidérmico), mostrou resultados semelhantes medidos com os valores de índice celular ou ensaio de incorporação de vermelho neutro 6. Usámos recentemente o sistema analisador de células em tempo real para avaliar os efeitos neuroprotectores da serotonina 2A (5-HT 2A) agonista do receptor de cloridrato de (±) -2,5-dimetoxi-4-iodoamphetamine (DOI), em uma linha de células neuronais ( células SK-N-SH) e selecionados para o envolvimento de secoª vias Messenger através monitorar o efeito da sua inibição química sobre a neuroproteção observada 7. Curiosamente, o receptor 5-HT 2A tem agonistas tanto alucinógenas e nonhallucinogenic (como o DOI e lisuride, respectivamente), o que pode ativar ambas as segundas vias comuns de mensagem e distintas 8. As vantagens da técnica apresentada é que ela permite a coleta de informações em tempo real sobre a sobrevivência das células no decorrer do dia, para delinear as vias de segundo mensageiro envolvido, para avaliar a possível contribuição de efeitos de proliferação de neuroproteção, e para selecionar um tempo ideal para estudos adicionais de ponto final sobre a mesma população de células. Um diagrama esquemático do fluxo no protocolo actual é apresentado na Figura 1.

<table border="0" cellpadding="0" cellspacing="0" width="1015">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Name of Material/ Equipment</td>
			<td style="width:161px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:457px;">Comments/Description</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:279px;">xCELLigence&#160; RTCA SP system bundle</td>
			<td style="width:161px;">ACEA Biosciences</td>
			<td style="width:119px;">No: 00380601030</td>
			<td>consists of RTCA Analyzer, RTCA SP Station and RTCA Control Unit</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:279px;">E-plate 96</td>
			<td style="width:161px;">ACEA Biosciences</td>
			<td style="width:119px;">No: 05232368001</td>
			<td>for culturing the cells, inserted in the RTCA SP Station</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:279px;">SK-N-SH cells</td>
			<td style="width:161px;">ATCC - (in partnership with LGC Standards)</td>
			<td style="width:119px;">HTB-11</td>
			<td>can be replaced by another adherent neuronal cell line of interest</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">DMEM/F12&#160;</td>
			<td style="width:161px;">Sigma-Aldrich</td>
			<td style="width:119px;">D8437</td>
			<td>cell culture medium</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">fetal bovine serum</td>
			<td style="width:161px;">Life Technologies</td>
			<td style="width:119px;">16140-063</td>
			<td>supplements proliferation, but not serum deprivation medium</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">tisue culture flask T175</td>
			<td style="width:161px;">Sarstedt</td>
			<td style="width:119px;">83.1812.302&#160;</td>
			<td>for culturing cells, which will be later plated on the E-Plate 96</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">0.05% Trypsin-EDTA</td>
			<td style="width:161px;">Life Technologies</td>
			<td style="width:119px;">25300-054</td>
			<td>for trypsinization of cells cultured in tissue culture flasks</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Scepter 2.0 cell counter</td>
			<td style="width:161px;">Merck Millipore</td>
			<td style="width:119px;">PHCC20060</td>
			<td>automated cell counter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">phosphate-buffered saline</td>
			<td style="width:161px;">Life Technologies</td>
			<td style="width:119px;">10010-015</td>
			<td>for washing the cells</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">(&#177;)-DOI hydrochloride</td>
			<td style="width:161px;">Sigma-Aldrich</td>
			<td style="width:119px;">D101</td>
			<td>5-HT2A agonist for cell culture treatment</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">LY-294,002 hydrochloride</td>
			<td style="width:161px;">Sigma-Aldrich</td>
			<td style="width:119px;">L9908</td>
			<td>PI3-K inhibitor for cell culture treatment&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">lisuride maleate</td>
			<td style="width:161px;">Tocris Bioscience</td>
			<td align="right" style="width:119px;">4052</td>
			<td>compound with 5-HT2A agonistic activity for cell culture treatment</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">dimethyl sulfoxide</td>
			<td style="width:161px;">Sigma-Aldrich</td>
			<td style="width:119px;">D4540</td>
			<td>for dissolving LY-294,002 and lisuride maleate</td>
		</tr>
	</tbody>
</table>

real-time impedance-based cell analyzer as a tool to delineate molecular pathways involved in neurotoxicity and neuroprotection in a neuronal cell line

Muitas doenças relacionadas com o cérebro tem a morte celular neuronal envolvida na sua fisiopatologia. Melhoria em modelos in vitro para estudar os efeitos neuroprotetores ou neurotóxicos das drogas e vias a jusante envolvidos ajudaria a obter insights sobre os mecanismos moleculares de neuroproteção / neurotoxicidade e, potencialmente, poderia facilitar o desenvolvimento de drogas. No entanto, muitos ensaios in vitro de toxicidade existentes têm limitações importantes - mais avaliar a neurotoxicidade e neuroprotecção num único ponto de tempo, não permitindo observar o decurso do tempo e a cinética do efeito. Além disso, a oportunidade de coletar informações sobre as vias de sinalização a jusante envolvidos na neuroproteção em tempo real seria de grande importância. No protocolo corrente que descrevem a utilização de um analisador de células à base de impedância em tempo real para determinar os efeitos neuroprotectores da serotonina 2A (5-HT 2A) agonistas do receptor numa linha de células neuronais sob livre de marcador e em tempo real Conditíons, utilizando medidas de impedância. Além disso, demonstra-se que os inibidores das vias de segundo mensageiro podem ser utilizados para delinear as moléculas jusante envolvidos no efeito neuroprotector. Os requerentes também descrevem a utilidade desta técnica para determinar se um efeito sobre a proliferação celular, contribui para um efeito neuroprotector observada. O sistema utiliza placas de microeletrônica especiais referidas como E-placas que contêm alternando matrizes de microeletrodos de ouro na superfície inferior dos poços, que servem como sensores celulares. A leitura da impedância é modificada pelo número de células aderentes, a viabilidade celular, a morfologia e a adesão. Um parâmetro adimensional chamado Índice celular é derivada das medições de impedância eléctrica e é usado para representar o estado da célula. Em geral, o analisador de células à base de impedância em tempo real permite em tempo real, livre de marcador de avaliação de neuroprotecção e neurotoxicidade, e a avaliação do envolvimento das vias de segundo mensageiro, contribuindo para maisavaliação detalhada e de alto rendimento de potenciais compostos neuroprotetores em vitro, para a seleção de candidatos terapêuticos.

<html> Privação de soro leva à diminuição nos valores de índice de células, que podem ser monitorados continuamente com o analisador de células em tempo real Neurotóxicos estímulos para as células de levar a uma redução nos valores do índice de células, o que pode ser monitorado em tempo real com a técnica apresentada e a dinâmica dos quais é dependente do estímulo neurotóxico específico e do tipo de célula estudada. Figura 2 mostra o au...

Watch this Scientific Journal Video about Real-Time Impedance-based Cell Analyzer as a Tool to Delineate Molecular Pathways Involved in Neurotoxicity and Neuroprotection in a Neuronal Cell Line at JoV

Real-Time Impedance-based Cell Analyzer as a Tool to Delineate Molecular Pathways Involved in Neurotoxicity and Neuroprotection in a Neuronal Cell Line

Improved in vitro neurotoxicity assays would aid the identification of new neuroprotective compounds. The utility of a real-time impedance-based cell analyzer to determine cytotoxicity and cytoprotection in neuronal cell lines and to delineate the involvement of second messenger pathways, thus gaining insight in the mechanism of neuroprotection is presented.

Analyzer celular baseado em impedância Real-Time como uma ferramenta para delinear vias moleculares envolvidas na neurotoxicidade e neuroproteção em uma linha de células neuronais

Many brain-related disorders have neuronal cell death involved in their pathophysiology. Improved in vitro models to study neuroprotective or neurotoxic ...

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Research

JoVE Journal

Neuroscience

11.3K visualizações.  University of Zürich. Improved in vitro neurotoxicity assays would aid the identification of new neuroprotective compounds. The utility of a real-time impedance-based cell analyzer to determine cytotoxicity and cytoprotection in neuronal cell lines and to delineate the involvement of second messenger pathways, thus gaining insight in the mechanism of neuroprotection is presented.

Vídeo: Real-Time Impedance-based Cell Analyzer as a Tool to Delineate Molecular Pathways Involved in Neurotoxicity and Neuroprotection in a Neuronal Cell Line

Automated Sholl Analysis of Digitized Neuronal Morphology at Multiple Scales

Neuronal morphology plays a significant role in determining how neurons function and communicate1-3. Specifically, it affects the ability of neurons to receive inputs from other cells2 and contributes to the propagation of action potentials4,5. The morphology of the neurites also affects how information is processed. The diversity of dendrite morphologies facilitate local and long range signaling and allow individual neurons or groups of neurons to carry out specialized functions within the neuronal network6,7. Alterations in dendrite morphology, including fragmentation of dendrites and changes in branching patterns, have been observed in a number of disease states, including Alzheimer's disease8, schizophrenia9,10, and mental retardation11. The ability to both understand the factors that shape dendrite morphologies and to identify changes in dendrite morphologies is essential in the understanding of nervous system function and dysfunction.
Neurite morphology is often analyzed by Sholl analysis and by counting the number of neurites and the number of branch tips. This analysis is generally applied to dendrites, but it can also be applied to axons. Performing this analysis by hand is both time consuming and inevitably introduces variability due to experimenter bias and inconsistency. The Bonfire program is a semi-automated approach to the analysis of dendrite and axon morphology that builds upon available open-source morphological analysis tools. Our program enables the detection of local changes in dendrite and axon branching behaviors by performing Sholl analysis on subregions of the neuritic arbor. For example, Sholl analysis is performed on both the neuron as a whole as well as on each subset of processes (primary, secondary, terminal, root, etc.) Dendrite and axon patterning is influenced by a number of intracellular and extracellular factors, many acting locally. Thus, the resulting arbor morphology is a result of specific processes acting on specific neurites, making it necessary to perform morphological analysis on a smaller scale in order to observe these local variations12.
The Bonfire program requires the use of two open-source analysis tools, the NeuronJ plugin to ImageJ and NeuronStudio. Neurons are traced in ImageJ, and NeuronStudio is used to define the connectivity between neurites. Bonfire contains a number of custom scripts written in MATLAB (MathWorks) that are used to convert the data into the appropriate format for further analysis, check for user errors, and ultimately perform Sholl analysis. Finally, data are exported into Excel for statistical analysis. A flow chart of the Bonfire program is shown in Figure 1.

We have developed a computer program to analyze neuronal morphology. In combination with two existing open source analysis tools, our program performs Sholl analysis and determines the number of neurites, branch points, and neurite tips. The analyses are performed so that local changes in neurite morphology can be observed.

Análise Sholl automatizado de Morfologia Neuronal Digitized em múltiplas escalas

Neuronal morphology plays a significant role in determining how neurons function and communicate1-3.  Specifically, it affects the ability of neurons to ...

Neurociência

Efficient Derivation of Human Neuronal Progenitors and Neurons from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system (CNS) structure and circuitry in today's healthcare industry. Cell-based therapies hold great promise to restore the lost nerve tissue and function for CNS disorders. However, cell therapies based on CNS-derived neural stem cells have encountered supply restriction and difficulty to use in the clinical setting due to their limited expansion ability in culture and failing plasticity after extensive passaging1-3. Despite some beneficial outcomes, the CNS-derived human neural stem cells (hNSCs) appear to exert their therapeutic effects primarily by their non-neuronal progenies through producing trophic and neuroprotective molecules to rescue the endogenous cells1-3. Alternatively, pluripotent human embryonic stem cells (hESCs) proffer cures for a wide range of neurological disorders by supplying the diversity of human neuronal cell types in the developing CNS for regeneration1,4-7. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity7-10. In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic11-13. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules14 (please see a schematic in Fig. 1). Retinoic acid (RA) does not induce neuronal differentiation of undifferentiated hESCs maintained on feeders1, 14. And unlike mouse ESCs, treating hESC-differentiated embryoid bodies (EBs) only slightly increases the low yield of neurons1, 14, 15. However, after screening a variety of small molecules and growth factors, we found that such defined conditions rendered retinoic acid (RA) sufficient to induce the specification of neuroectoderm direct from pluripotent hESCs that further progressed to neuroblasts that generated human neuronal progenitors and neurons in the developing CNS with high efficiency (Fig. 2). We defined conditions for induction of neuroblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human neuronal cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of neuroblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human neuronal progenitors and neuronal cell types in the developing CNS for neural repair.

Derivação eficiente dos recursos humanos Progenitores Neuronal e Neurônios de pluripotentes células estaminais embrionárias humanas com a indução de moléculas pequenas

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system ...

Simultaneous Electroencephalography, Real-time Measurement of Lactate Concentration and Optogenetic Manipulation of Neuronal Activity in the Rodent Cerebral Cortex

Although the brain represents less than 5% of the body by mass, it utilizes approximately one quarter of the glucose used by the body at rest1. The function of non rapid eye movement sleep (NREMS), the largest portion of sleep by time, is uncertain. However, one salient feature of NREMS is a significant reduction in the rate of cerebral glucose utilization relative to wakefulness2-4. This and other findings have led to the widely held belief that sleep serves a function related to cerebral metabolism. Yet, the mechanisms underlying the reduction in cerebral glucose metabolism during NREMS remain to be elucidated.
	One phenomenon associated with NREMS that might impact cerebral metabolic rate is the occurrence of slow waves, oscillations at frequencies less than 4 Hz, in the electroencephalogram5,6. These slow waves detected at the level of the skull or cerebral cortical surface reflect the oscillations of underlying neurons between a depolarized/up state and a hyperpolarized/down state7. During the down state, cells do not undergo action potentials for intervals of up to several hundred milliseconds. Restoration of ionic concentration gradients subsequent to action potentials represents a significant metabolic load on the cell8; absence of action potentials during down states associated with NREMS may contribute to reduced metabolism relative to wake.
	Two technical challenges had to be addressed in order for this hypothetical relationship to be tested. First, it was necessary to measure cerebral glycolytic metabolism with a temporal resolution reflective of the dynamics of the cerebral EEG (that is, over seconds rather than minutes). To do so, we measured the concentration of lactate, the product of aerobic glycolysis, and therefore a readout of the rate of glucose metabolism in the brains of mice. Lactate was measured using a lactate oxidase based real time sensor embedded in the frontal cortex. The sensing mechanism consists of a platinum-iridium electrode surrounded by a layer of lactate oxidase molecules. Metabolism of lactate by lactate oxidase produces hydrogen peroxide, which produces a current in the platinum-iridium electrode. So a ramping up of cerebral glycolysis provides an increase in the concentration of substrate for lactate oxidase, which then is reflected in increased current at the sensing electrode. It was additionally necessary to measure these variables while manipulating the excitability of the cerebral cortex, in order to isolate this variable from other facets of NREMS.
	We devised an experimental system for simultaneous measurement of neuronal activity via the elecetroencephalogram, measurement of glycolytic flux via a lactate biosensor, and manipulation of cerebral cortical neuronal activity via optogenetic activation of pyramidal neurons. We have utilized this system to document the relationship between sleep-related electroencephalographic waveforms and the moment-to-moment dynamics of lactate concentration in the cerebral cortex. The protocol may be useful for any individual interested in studying, in freely behaving rodents, the relationship between neuronal activity measured at the electroencephalographic level and cellular energetics within the brain.

A procedure is described for manipulating the activity of cerebral cortical pyramidal neurons optogenetically while the electroencephalogram, electromyogram, and cerebral lactate concentration are monitored. Experimental recordings are performed on cable-tethered mice while they undergo spontaneous sleep/wake cycles. Optogenetic equipment is assembled in our laboratory; recording equipment is commercially available.

Eletroencefalografia simultânea, em tempo real de medição da concentração de lactato e Manipulação optogenética da atividade neuronal do córtex cerebral de roedores

Although the brain represents less than 5% of the body  by mass, it utilizes approximately one quarter of the glucose used by the body  at rest1. The ...

Fast Micro-iontophoresis of Glutamate and GABA: A Useful Tool to Investigate Synaptic Integration

One of the fundamental interests in neuroscience is to understand the integration of excitatory and inhibitory inputs along the very complex structure of the dendritic tree, which eventually leads to neuronal output of action potentials at the axon. The influence of diverse spatial and temporal parameters of specific synaptic input on neuronal output is currently under investigation, e.g. the distance-dependent attenuation of dendritic inputs, the location-dependent interaction of spatially segregated inputs, the influence of GABAergig inhibition on excitatory integration, linear and non-linear integration modes, and many more.
With fast micro-iontophoresis of glutamate and GABA it is possible to precisely investigate the spatial and temporal integration of glutamatergic excitation and GABAergic inhibition. Critical technical requirements are either a triggered fluorescent lamp, light-emitting diode (LED), or a two-photon scanning microscope to visualize dendritic branches without introducing significant photo-damage of the tissue. Furthermore, it is very important to have a micro-iontophoresis amplifier that allows for fast capacitance compensation of high resistance pipettes. Another crucial point is that no transmitter is involuntarily released by the pipette during the experiment.
Once established, this technique will give reliable and reproducible signals with a high neurotransmitter and location specificity. Compared to glutamate and GABA uncaging, fast iontophoresis allows using both transmitters at the same time but at very distant locations without limitation to the field of view. There are also advantages compared to focal electrical stimulation of axons: with micro-iontophoresis the location of the input site is definitely known and it is sure that only the neurotransmitter of interest is released. However it has to be considered that with micro-iontophoresis only the postsynapse is activated and presynaptic aspects of neurotransmitter release are not resolved. In this article we demonstrate how to set up micro-iontophoresis in brain slice experiments.

In this article we introduce fast micro-iontophoresis of neurotransmitters as a technique to investigate integration of postsynaptic signals with high spatial and temporal precision.

Rápido Micro-iontoforese de glutamato e GABA: uma ferramenta útil para investigar Integração Synaptic

One of the fundamental interests in neuroscience is to understand the integration of excitatory and inhibitory inputs along the very complex structure of ...

Sex Stratified Neuronal Cultures to Study Ischemic Cell Death Pathways

Sex differences in neuronal susceptibility to ischemic injury and neurodegenerative disease have long been observed, but the signaling mechanisms responsible for those differences remain unclear. Primary disassociated embryonic neuronal culture provides a simplified experimental model with which to investigate the neuronal cell signaling involved in cell death as a result of ischemia or disease; however, most neuronal cultures used in research today are mixed sex. Researchers can and do test the effects of sex steroid treatment in mixed sex neuronal cultures in models of neuronal injury and disease, but accumulating evidence suggests that the female brain responds to androgens, estrogens, and progesterone differently than the male brain. Furthermore, neonate male and female rodents respond differently to ischemic injury, with males experiencing greater injury following cerebral ischemia than females. Thus, mixed sex neuronal cultures might obscure and confound the experimental results; important information might be missed. For this reason, the Herson Lab at the University of Colorado School of Medicine routinely prepares sex-stratified primary disassociated embryonic neuronal cultures from both hippocampus and cortex. Embryos are sexed before harvesting of brain tissue and male and female tissue are disassociated separately, plated separately, and maintained separately. Using this method, the Herson Lab has demonstrated a male-specific role for the ion channel TRPM2 in ischemic cell death. In this manuscript, we share and discuss our protocol for sexing embryonic mice and preparing sex-stratified hippocampal primary disassociated neuron cultures. This method can be adapted to prepare sex-stratified cortical cultures and the method for embryo sexing can be used in conjunction with other protocols for any study in which sex is thought to be an important determinant of outcome.

Primary disassociated embryonic hippocampal neuronal cultures are useful for investigating the signaling mechanisms involved in neuron death. Sexing the embryos before the isolation and dissociation of the hippocampus allows the preparation of separate male and female cultures, which enables the researcher to identify and investigate sex-specific cell signaling.

Sex differences in neuronal susceptibility to ischemic injury and neurodegenerative disease have long been observed, but the signaling mechanisms ...

Inducing Plasticity of Astrocytic Receptors by Manipulation of Neuronal Firing Rates

Close to two decades of research has established that astrocytes in situ and in vivo express numerous G protein-coupled receptors (GPCRs) that can be stimulated by neuronally-released transmitter. However, the ability of astrocytic receptors to exhibit plasticity in response to changes in neuronal activity has received little attention. Here we describe a model system that can be used to globally scale up or down astrocytic group I metabotropic glutamate receptors (mGluRs) in acute brain slices. Included are methods on how to prepare parasagittal hippocampal slices, construct chambers suitable for long-term slice incubation, bidirectionally manipulate neuronal action potential frequency, load astrocytes and astrocyte processes with fluorescent Ca2+ indicator, and measure changes in astrocytic Gq GPCR activity by recording spontaneous and evoked astrocyte Ca2+ events using confocal microscopy. In essence, a &#8220;calcium roadmap&#8221; is provided for how to measure plasticity of astrocytic Gq GPCRs. Applications of the technique for study of astrocytes are discussed. Having an understanding of how astrocytic receptor signaling is affected by changes in neuronal activity has important implications for both normal synaptic function as well as processes underlying neurological disorders and neurodegenerative disease.

Here we describe an adaptation of protocols used to induce homeostatic plasticity in neurons for the study of plasticity of astrocytic G protein-coupled receptors. Recently used to examine changes in astrocytic group I mGluRs in juvenile mice, the method can be applied to measure scaling of various astrocytic GPCRs, in tissue from adult mice in situ and in vivo, and to gain a better appreciation of the sensitivity of astrocytic receptors to changes in neuronal activity.

Induzir Plasticidade de astrocítica Receptores de Manipulação de Neuronal queima de moeda

Close to two decades of research has established that astrocytes in situ and in vivo express numerous G protein-coupled receptors (GPCRs) that can be ...

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 ...

Microglia as a Surrogate Biosensor to Determine Nanoparticle Neurotoxicity

Nanoparticles found in air pollutants can alter neurotransmitter profiles, increase neuroinflammation, and alter brain function. Therefore, the assay described here will aid in elucidating the role of microglia in neuroinflammation and neurodegenerative diseases. The use of microglia, resident immune cells of the brain, as a surrogate biosensor provides novel insight into how inflammatory responses mediate neuronal insults. Here, we utilize an immortalized murine microglial cell line, designated BV2, and describe a method for nanoparticle exposure using silver nanoparticles (AgNPs) as a standard. We describe how to expose microglia to nanoparticles, how to remove nanoparticles from supernatant, and how to use supernatant from activated microglia to determine toxicity, using hypothalamic cell survival as a measure. Following AgNP exposure, BV2 microglial activation was validated using a tumor necrosis factor alpha (TNF-&#945;) enzyme linked immunosorbent assay (ELISA). The supernatant was filtered to remove the AgNP and to allow cytokines and other secreted factors to remain in the conditioned media. Hypothalamic cells were then exposed to supernatant from AgNP activated microglia and survival of neurons was determined using a resazurin-based fluorescent assay. This technique is useful for utilizing microglia as a surrogate biomarker of neuroinflammation and determining the effect of neuroinflammation on other cell types.

Microglia (immune cells of the brain), are used as a surrogate biosensor to determine how nanoparticles influence neurotoxicity. We describe a series of experiments designed to assay microglial response to nanoparticles and exposure of hypothalamic neurons to supernatant from activated microglia to determine neurotoxicity.

Microglia como um Biosensor Surrogate determinar nanopartículas neurotoxicidade

Nanoparticles found in air pollutants can alter neurotransmitter profiles, increase neuroinflammation, and alter brain function. Therefore, the assay ...

In Utero Electroporation Approaches to Study the Excitability of Neuronal Subpopulations and Single-cell Connectivity

The nervous system is composed of an enormous range of distinct neuronal types. These neuronal subpopulations are characterized by, among other features, their distinct dendritic morphologies, their specific patterns of axonal connectivity, and their selective firing responses. The molecular and cellular mechanisms responsible for these aspects of differentiation during development are still poorly understood.
Here, we describe combined protocols for labeling and characterizing the structural connectivity and excitability of cortical neurons. Modification of the in utero electroporation (IUE) protocol allows the labeling of a sparse population of neurons. This, in turn, enables the identification and tracking of the dendrites and axons of individual neurons, the precise characterization of the laminar location of axonal projections, and morphometric analysis. IUE can also be used to investigate changes in the excitability of wild-type (WT) or genetically modified neurons by combining it with whole-cell recording from acute slices of electroporated brains. These two techniques contribute to a better understanding of the coupling of structural and functional connectivity and of the molecular mechanisms controlling neuronal diversity during development. These developmental processes have important implications on axonal wiring, the functional diversity of neurons, and the biology of cognitive disorders.

In Utero Electroporation Approaches to Study the Excitability of Neuronal Subpopulations and Single-cell Connectivity

This manuscript provides protocols that use in utero electroporation (IUE) to describe the structural connectivity of neurons at the single-cell level and the excitability of fluorescently labeled neurons. Histology is used to characterize dendritic and axonal projections. Whole-cell recording in acute slices is used to investigate excitability.

In Utero Eletroporação Abordagens para estudar a excitabilidade neuronal subpopulações e Conectividade uma única célula

The nervous system is composed of an enormous range of distinct neuronal types. These neuronal subpopulations are characterized by, among other features, ...

Organotypic Hippocampal Slice Cultures As a Model to Study Neuroprotection and Invasiveness of Tumor Cells

In organotypic hippocampal slice cultures (OHSC), the morphological and functional characteristics of both neurons and glial cells are well preserved. This model is suitable for addressing different research questions that involve studies on neuroprotection, electrophysiological experiments on neurons, neuronal networks or tumor invasion. The hippocampal architecture and neuronal activity in multisynaptic circuits are well conserved in OHSC, even though the slicing procedure itself initially lesions and leads to formation of a glial scar. The scar formation alters presumably the mechanical properties and diffusive behavior of small molecules, etc. Slices allow the monitoring of time dependent processes after brain injury without animal surgery, and studies on interactions between various brain-derived cell types, namely astrocytes, microglia and neurons under both physiological and pathological conditions. An ambivalent aspect of this model is the absence of blood flow and immune blood cells. During the progression of the neuronal injury, migrating immune cells from the blood play an important role. As those cells are missing in slices, the intrinsic processes in the culture may be observed without external interference. Moreover, in OHSC the composition of the medium-external environment is precisely controlled. A further advantage of this method is the lower number of sacrificed animals compared to standard preparations. Several OHSC can be obtained from one animal making simultaneous studies with multiple treatments in one animal possible. For these reasons, OHSC are well suited to analyze the effects of new protective therapeutics after tissue damage or during tumor invasion. 
The protocol presented here describes a preparation method of OHSC that allows generating highly reproducible, well preserved slices that can be used for a variety of experimental research, like neuroprotection or tumor invasion studies.

Organotypic hippocampal slice cultures (OHSC) represent an in vitro model that simulates the in vivo situation very well. Here we describe a vibratome-based improved slicing protocol to obtain high quality slices for use in assessing the neuroprotective potential of novel substances or the biological behavior of tumor cells.

Organotypic fatias Hippocampal culturas como um modelo para estudo neuroproteção e invasão de células tumorais

In organotypic hippocampal slice cultures (OHSC), the morphological and functional characteristics of both neurons and glial cells are well preserved. ...