Financiado pelo NIH P40 OD010952, a Fundação Korein, da Universidade de Miami Fellowship para SLC e uma bolsa Maytag a ATK. Os autores agradecem o pessoal da Resource Nacional de Aplysia, assim como Lauren Simonitis e Hannah Peck, que forneceu micrografias para a figura.

1. Preparação celular <ol><li> No dia 1, pesar e anestesiar animal. <ol><li> Pesar a 30 g-1 kg de animal. Anestesiar em 5-10 volumes de animais de 01:01 de água do mar: MgCl isotónica. 6H 2 0 durante 1 hora, com arejamento, tal como uma bomba de ar eléctrica de aquário com uma pedra difusora em anexo. </li></ol></li><li> Preparar material de dissecação. <ol><li> Montar bandeja de dissecação limpa com alfinetes de aço inoxidável, tais como pinos de tecido. Montar vários pratos de Petri contendo água do mar artificial (ASW, ver as Tabelas 1 e 3) + penicilina / estreptomicina (P / S). </li><li> Tenha pronto um microscópio de baixa potência. Ter instrumentos de dissecção limpo pronto, como nariz com nervuras e finas pinça cirúrgica, e multa e grandes tesouras cirúrgicas. Pulverizar os instrumentos com 70% de álcool isopropol antes da utilização e deixar secar. </li></ol></li><li> Posição animal na bandeja de dissecação. <ol><li> Posição animais lado ventral para baixo na bandeja de dissecação. Pin animaisatravés bordas da parede do corpo e fronteiras parapodial, mas evitar a cauda ea cabeça, para expor a superfície dorsal eo sulco genital </li><li> Enxaguar a superfície dorsal na água slow-running da torneira fria. Aplicar um fluxo de luz de 70% de álcool isopropol de um frasco de pressão ao longo do sulco genital e sobre a parte superior da cabeça. </li></ol></li><li> Fazer a incisão inicial. <ol><li> Usando um microscópio de baixa potência (veja a Tabela 2) e a luz reflectida para observar o ponto em que a ranhura genital origina a partir da margem anterior do invólucro, tautly segurar com nervuras-nose pinça uma dobra de tecido para o lado esquerdo desta origem, enquanto um recorte raso buraco todo o caminho através da, área lisa e plana de parede do corpo à direita do sulco genital com multa tesoura angulada. </li><li> Hemolinfa deve ser observado para derramar do buraco, às vezes levando consigo o gânglio abdominal e do estômago. </li></ol></li><li> Expanda a incisão. <ol><li> Use tesoura grande para expandir the incisão anterior a um ponto entre as rhinophoros, enquanto puxa para cima com a lâmina inferior, para evitar o entalhamento intestino. Os órgãos internos serão observados para derramar da incisão. </li></ol></li><li> Remover os gânglios. <ol><li> Reposicionar a bandeja e reorientar o microscópio sobre a região da cabeça. </li><li> Utilizando uma pinça limpa e tesouras finas, remove os gânglios cabeça, cortando em um ponto os nervos que formam gânglios cabeça em um anel ao redor do esôfago para remover pleural-pedal e cerebral gânglios como um grupo. </li><li> Remover o gânglio vestibular que adere ao lado ventral do esófago. </li><li> Retire o gânglio abdominal cortando os 4 grandes conectivos nervosas que emitem a partir deste gânglio. </li></ol></li><li> Isolar gânglios de interesse. <ol><li> Apare gânglios cabeça separados, deixando um comprimento de conectivos ligados uns aos gânglio de interesse, que é igual a, pelo menos, o diâmetro do gânglio, o que irá retardar a enzima sobre-digestãodas células de interesse no passo seguinte. </li><li> Coloque cada gânglio alvo através de duas lavagens de ASW + P / S, movendo-se entre as lavagens com uma pinça limpa. </li><li> Se alvo as células de PVC, deixe o hemiganglion pleural direito ligado à hemiganglion pedal direito, e da mesma forma deixar o hemiganglion pleural esquerdo ligado ao hemiganglion pedal esquerdo. </li><li> Descartar gânglios indesejada e o resto do animal de acordo com a prática da pesquisa aceite. </li></ol></li><li> Enzimaticamente digerir os gânglios. <ol><li> Para cada gânglio, preparar 1 ml de solução de enzima consistindo de dispase 3,75 mg, 1 mg e 0,3 g hialuronidase colagenase tipo XI por ml de ASW + P / S num tubo cónico de 15 ml de polipropileno. </li><li> Lugar lavado gânglios na solução enzimática e coloque a tampa firmemente. Colocar o tubo no seu lado num agitador rotativo (ver Tabela 2), a uma velocidade lenta para 13-5 hr durante a noite a cerca de 23 ° C (temperatura ambiente). </li></ol></li><li> Prepare oplacas de cultura. <ol><li> Antes de microdissecção (Dia 2), preparam poli-D-lisina (PDL) revestidos em placas de cultura de um capuz de cultura de tecidos. Adicionar 0,5 ml de PDL ~ (0,2 mg / ml de água esterilizada) ao centro de 35 mm de prato de ~ 25 min. </li><li> Lavar PDL 3x com água estéril. Deixe secar. UV-esterilizar as placas. </li></ol></li><li> Dia 2 Isolar os neurônios. <ol><li> Encher o centro de pratos de 35 mm que foram PDL revestido e UV esterilizadas com aproximadamente 0,5 ml de ASW + P / S para criar uma ilha de meios de comunicação dentro do prato de outro modo seca. Isto pode ser feito sobre a bancada, fora do capuz de cultura de tecidos. Um prato deve ser preparado para cada grupo de células provenientes de um hemiganglion. </li><li> Já imediata de 100 mm de diâmetro dissecção prato feito por Sylgard-revestimento e cura de uma superfície de dissecção 5 mm de profundidade, equipado com pinos de dissecação fina de diversos tamanhos para serem utilizados como pinos e as sondas (ver Tabela 3). Enxaguar este prato com 70% de álcool isopropol, em seguida, com ASW + P / S, e, finalmente, fill com ASW + P / S. </li></ol></li><li> Prepare microdissection de gânglios digerida. <ol><li> Despeje a solução de enzima que contém a pleural-pedal e bucal gânglios digerido no prato dissecção. </li><li> Colocar a cápsula na fase do microscópio sobre uma superfície preta sob luz reflectida. </li><li> Usando o tecido conjuntivo em anexo, o pino de cada lado dorsal hemiganglion pleural pedal-up. Os tecidos vão ser suave e intolerante de alongamento. </li></ol></li><li> Microdissect neurônios PVC. <ol><li> Usando dois pares de fórceps finas e limpas, e segurando um pino de dissecação muito bem em um par de fórceps como uma sonda, isolar as células de PVC a partir de um hemiganglion pleural. Digestão enzimática irá ter removido ou partido para além da bainha do tecido conjuntivo que cobre o conjunto de PVC, no entanto, as células vão aderir um ao outro. </li><li> Utilização da sonda de separar estas células a partir do conjuntivo pedal 18 pleural, em seguida, deixar cair o grupo de células para a parte inferior da dissecçãoprato. </li></ol></li><li> Transferir neurônios prato de cultura. <ol><li> Transfira o grupo de células a um preparado 35 milímetros prato de cultura sugando suavemente o cluster na ponta de um pouco de fogo polido descartável vidro Pasteur pipeta, em seguida, dispensando-o lentamente na ilha de mídia em uma placa de cultura, tomando cuidado para evitar a introdução de bolhas de ar para a pipeta. Repita o isolamento do cluster PVC do outro hemiganglion e coloque em um prato de cultura distinta. </li></ol></li><li> Microdissect e transferir BSC neurônios. <ol><li> Pin o gânglio lado ventral bucal para cima, com cuidado para poupar as células de interesse. Repetir passo 1.12, com os dois conjuntos de células BSC do gânglio vestibular 10. </li><li> Isolamento de PVC e BSC neurônios irá produzir quatro placas de cultura contendo aglomerados de neurônios: 2 pratos que contenham grupos BSC e 2 pratos contendo aglomerados de PVC. Descartar o resto dos gânglios e anular o prato de 100 mm de dissecação. </li></ol></li><li> DissocIATE os grupos de células. <ol><li> Coloque um prato de cultura contendo células no estágio do microscópio de baixa potência e retire a tampa. </li><li> Dissociar o cluster PVC sacudindo suavemente a parte inferior da placa de cultura junto ao grupo de células com um pino de dissecação fina realizada em fórceps. Piparotear espetada a ponta do pino no plástico do fundo do prato, como se tentasse cavar uma mancha de plástico. Quando o atrito com o plástico libera o ponto de pino, uma onda de percussão é produzido através do meio que rompe a moita nas proximidades de células. </li><li> 5-10 súbitos podem ser necessários para quase dissociar completamente as células, mas é preferível deixar pequenos aglomerados de células, em vez de passe rapidamente demais para que as células sejam destruídos por pura mecânica. </li><li> Recoloque a tampa e repita com outros pratos da cultura. </li></ol></li><li> Armazenar culturas de células. <ol><li> Coloque as placas de cultura contendo ilhas de mídia em seus centros com células dissociadas emum grande recipiente, que permite a circulação de ar, tal como um x 25 mm de plástico redondos de Petri de 150, e em colocar este prato um conjunto incubadora a 17 ° C. </li><li> Instalar na câmara num prato aberto de água como fonte de humidade. Deixar repousar durante a noite. As células aderem ao revestimento de poli-D-lisina no centro do prato. </li></ol></li><li> Placas de cultura de inundação. <ol><li> No Dia 3, os pratos inundar suavemente com 2,5 ml de ASW + P / S. Examinar e contar as células usando um microscópio de cultura de células invertido. Loja no 17 ° C incubadora. </li></ol></li></ol> 2. Eletrofisiologia O método é o tampão padrão de aperto que tem sido descrito em numerosos documentos (por exemplo, Sakmann e Neher, 1995) 16. Este protocolo irá funcionar em células ≤ 100 pF de capacitância, ou células &lt;60 um de diâmetro durante os dias 3 e 4 do protocolo. Células sem processos são ideais para a gravação. A seguir CONSIDERAÇ especialíons se aplicam: <ol><li> Células maiores podem ser acomodados com a configuração do amplificador Axopatch 200B configurada para β = 0,1. Activação de grandes correntes pode levar as células a escapar fixador de tensão. Soluções ASW substituído por o teor de sal (por exemplo, uma fracção do NaCl substituo com cloreto de N-metil-D-glucamina impermeável) pode ser usado para reduzir toda a amplitude da corrente de células. </li><li> Fibra pipetas cheias de remendo borosilicato puxadas sobre um puxador de pipeta e reencheu meio com uma solução intracelular (ICS), constituído por 450 mM de KCl e outros sais (ver Tabela 1) são adequados, e deverá ter a resistência de cerca de 0,5-1 MOhms. Se o isolamento de correntes iónicas específicas é desejada, por exemplo, as correntes de Na +, na ausência de correntes de K, K + no presente solução pode ser substituído por outros iões tais como + Cs. Cl - substituição do ICS com um ânion impermeant também é justificada se a ICS mais natural é desejado9. </li><li> As células são robustos com&gt; 1 hr de duração gravações possíveis à temperatura ambiente. A gravação é ideal nos dias 3 e 4 do protocolo, correspondendo a 24-48 h em cultura. Após 48 horas, há dificuldade em formar vedações gigaohm, talvez devido à elaboração de um glicocálice na superfície da célula, e os problemas de fixação de espaço causados ​​pelo processo de desdobramento. As células são úteis, no entanto, para estudos de fixação não-correção, tais como toxicologia, que podem ser concluídos em &lt;14 d. </li><li> ASW e outras soluções para ser distribuído a partir do dispositivo de solução alimentada por gravidade, bem como a solução intracelular, deve ser filtrada através de uma seringa montada 0,2 um filtro Acrodisk (Tabela 3) para eliminar as partículas finas que interferem com a formação de selo gigaohm. </li><li> A dessensibilização ocorre quando se utiliza agonistas tais como D-aspartato (D-Asp), portanto, ~ 1-2 min entre as aplicações dos agonistas é recomendada. Inversamente, a potenciação é frequentemente observada com rápida aplicação repetidacatião de agonistas, tais como L-glutamato (L-Glu). </li><li> Agonist correntes activadas, tais como L-Glu, pode ser estudado através da aplicação de agonistas com o Picospritzer pipeta. Esta pipeta é puxado para a mesma que a pipeta patch e contém agonista ASW. Quando a ponta da pipeta este está posicionado abaixo do tubo de saída do dispositivo de solução alimentada por gravidade, e a um ângulo de 45 ° a partir do tubo de saída (Figura 2F), agonista será rapidamente lavados a partir da célula, e dessensibilização será minimizado. A pipeta agonista deve criar um ângulo de 90 ° ou mais em relação à pipeta patch. </li></ol>

<ol>
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As técnicas descritas aqui dissociação produzir culturas de neurônios sensoriais contendo 50-100 neurônios isolados intercaladas com um pequeno número de células gliais e outras células não identificados. Os passos mais críticos na protocolo são o momento em que o gânglio permanecem na solução enzimática, e sacudindo a dissociação dos grupos de células digeridos para quebrar o aglomerado em células individuais. Digestão enzimática (passo 1.8) tem de ser optimizada para a temperatura disponível. A 2...

O molusco opistobranch marinho Aplysia, tem sido um modelo neurobiológico útil para muitas décadas. Ele é mais conhecido como um modelo de habituação e condicionamento clássico 7, 8. Estudos sobre a aprendizagem e memória neste modelo ganhou o Prêmio Nobel de Fisiologia ou Medicina em 2000 por Eric R. Kandel, em um prêmio que ele compartilhou com Arvid Carlsson e Paul Greengard 10. Estudos envolvendo gravações eléctricos de preparações reduzidas, em que os elementos do sistema nervoso deste invertebrado são dissecados do animal com nervos e músculos permanecer ligados, ajudaram a elucidar os papéis de neurónios individuais na Aplysia. A identificação dos mecanismos moleculares precisos que constituem a aprendizagem em Aplysia no entanto, muitas vezes empregue uma outra técnica, a longo prazo co-culturas de um neurónio sensorial e uma neurónios motores, um por um, obtido a partir de animais dadores individuais e deixou-se formar uma sinapse no prato de cultura 21 . Nós e outros 1, 3, 6, 14, 15, 16 têm explorado a facilidade com a qual identificou neurônios pode ser alvo neste modelo, bem como a sua resistência em experimentos de longo prazo para fazer culturas de curto prazo dissociadas de aglomerados de neurônios nominalmente homogêneas em que estudamos correntes iônicas sob braçadeira de tensão na configuração de patch clamp. Muitos neurônios Aplysia enfrentar repetidas rodadas de remendo de fixação para dar tempo para manipulações experimentais de longa duração. A técnica é útil para os neurónios tais como as células do saco neurossecretoras do gânglio abdominal, e os neurónios sensoriais do gânglio da pleura e bucal cuja dissociação aqui descrita, mas não no caso de grandes neurónios&gt; 60 um de diâmetro, tal como L7 ou R2 gânglio abdominal. Não empregamos soro Aplysia em nossas culturas, ao contrário dos co-culturas sensório-motoneurônio descritos em outro lugar. A maioria dos neurônios obtidos através deste procedimento será sem processos de tele primeiras 48 h em cultura, facilitando a gravação voltagem da célula inteira, mas, em seguida germinar e elaborar axónios e outros processos para cerca de 14 dias antes da morte da falta de nutrientes e / ou factores de crescimento. Esta técnica produz culturas primárias de neurônios por 50-100 prato de regiões fisiologicamente documentados do gânglio vestibular e pleural. Este protocolo é útil para pesquisadores que estudam os aspectos da fisiologia da célula única em experimentos que requerem numerosos experimental repetições por animal. Ela produz um par correspondente de culturas devido à separação anatómica das células alvo em hemiganglia esquerda e direita, permitindo estudos que beneficiam com o tratamento combinado e as culturas de controlo. O protocolo visa bucais S cluster (BSC) neurônios do gânglio vestibular, e ventrocaudais (PVC) neurônios do gânglio pleural pleural. Estas células são um tamanho apropriado para as gravações de tensão de células inteiras e de exibição Robust respostas glutamatérgicos. A metodologia discutido é apropriado para a maioria dos gânglios do sistema nervoso Aplysia.

<table border="1">
 <tbody>
 <tr>
 <td>Name of Reagent/Material</td>
 <td>Company</td>
 <td>Catalog Number</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>Artificial seawater ASW</td>
 <td>Sigma-Aldrich</td>
 <td>assorted</td>
 <td>(mM): 417 NaCl, 10 KCl, 10 CaCl2 (2 H2O), 5MgCl2 (6H2O), 15 HEPES-NaOH, pH 7.6</td>
 </tr>
 <tr>
 <td>Intracellular solution</td>
 <td>Sigma</td>
 <td>assorted</td>
 <td>(mM): 450 KCl, 2.9 CaCl2 (2 H2O), 2.5 MgCl2 (6 H2O), 5 Na2ATP, 10 EGTA, and 40 HEPES-KOH, pH 7.4</td>
 </tr>
 <tr>
 <td>Poly-D-lysine</td>
 <td>Sigma</td>
 <td>P6407</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>penicillin/streptomycin added to ASW at 1:100</td>
 <td>Lonzo Walkersville, Inc.</td>
 <td>17-603E</td>
 <td>5,000 Units/ml penicillin plus 5,000 mg/ml streptomycin</td>
 </tr>
 <tr>
 <td>Neutral dispase II</td>
 <td>Roche Diagnostics</td>
 <td>10165859001</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>hyaluronidase</td>
 <td>Sigma-Aldrich</td>
 <td>H4272</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>collagenase type XI</td>
 <td>Sigma-Aldrich</td>
 <td>C9407</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>L-Glutamate (L-Glu)</td>
 <td>Sigma-Aldrich</td>
 <td>49601-100G</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>D-Aspartate (D-Asp)</td>
 <td>Sigma-Aldrich</td>
 <td>11200-10G</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>N-methyl-D-aspartate (NMDA)</td>
 <td>Biomol</td>
 <td>100002-268</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>L-Asp</td>
 <td>Sigma</td>
 <td>A6683-25G</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionic acid (AMPA)</td>
 <td>Sigma</td>
 <td>A6816-5MG</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>L-Glu R antagonists</td>
 <td>various</td>
 <td>various</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>agar</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>kynurenate</td>
 <td>Sigma-Aldrich</td>
 <td>61250</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>APV</td>
 <td>Sigma-Aldrich</td>
 <td>A5282</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>DL-2-Amino-5-phosphonopentanoic acid (NMDAR antagonist)</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>2-propanol</td>
 <td>VWRSP</td>
 <td>BDH1133</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Chloriding solution</td>
 <td>Sigma</td>
 <td>assorted</td>
 <td>25 g FeCl3 + 25 ml concentrated HCl + 50 ml H2O</td>
 </tr>
 <tr>
 <td>Sylgard silicone 2-part polymer</td>
 <td>World Precision Instruments (WPI)</td>
 <td>SYL184</td>
 <td>Provides pin-out surface for small dissection dishes</td>
 </tr>
 <tr>
 <td>0-40x zoom magnification microscope for dissections</td>
 <td>Wild</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Techniquip 150 Watts Fiber Optic Illuminator</td>
 <td>Microoptics of Florida</td>
 <td>TQ FOI-150</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>RotoMix 50800 orbital mixer</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Nikon Diaphot inverted phase-contrast microscope with 4x, 20x (optional) &amp; 40x objectives</td>
 <td>SR Research Ltd.</td>
 <td>Eyelink II</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Tektronix digital oscilloscope</td>
 <td>SR Research Ltd.</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>pClamp 10 data acquisition and analysis software</td>
 <td>Molecular Devices</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>PC with Windows XP or higher operating system</td>
 <td>PC Solutions</td>
 <td>&nbsp;</td>
 <td>Thinkserver with solid state hard drives (80GB) and low noise monitors</td>
 </tr>
 <tr>
 <td>Flaming/Brown P87 micropipette puller</td>
 <td>Sutter Instruments, Novato, CA</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Axon Instruments Axopatch 200B clamp amplifier with a capacitance compensation range of 1-1000 pF; preamplifier</td>
 <td>Molecular Devices, Sunnyvale, CA</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Axon instruments electrode holder assembly for Axopatch 200B preamplifier</td>
 <td>Molecular Devices, Sunnyvale, CA</td>
 <td>CV203BU</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Digidata 1200 A/D converter</td>
 <td>Molecular Devices, Sunnyvale, CA</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Picospritzer, powered by N2 adjustable for pressure and duration</td>
 <td>Parker Hannifin, Cleveland, OH</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>TMC Micro-G Vibration isolation table</td>
 <td>Ametek</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Faraday cage</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>custom manufacture</td>
 </tr>
 <tr>
 <td>Burleigh Piezoelectric Clamshell Micromanipulators</td>
 <td>Burleigh Instruments; Thorlabs</td>
 <td>&nbsp;</td>
 <td>presently PCS-5000; -6000 series + mounts</td>
 </tr>
 <tr>
 <td>Narishige M-152 manual manipulators (for perfusion system and picospritzer)</td>
 <td>Narishige USA</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Filament pipette glass,1.5 mm OD, 0.84 mm ID -</td>
 <td>WPI</td>
 <td>1B150-3</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>3 inch length</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Ag/AgCl half cell</td>
 <td>WPI</td>
 <td>EP4</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>15 ml centrifuge tubes, 35-2097 BD Falcon* Centrifuge Tubes</td>
 <td>VWRSP</td>
 <td>21008-918</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Angled Scissors</td>
 <td>Fine Science Tools</td>
 <td>15006-09</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Dumostar Fine forceps</td>
 <td>Fine Science Tools</td>
 <td>11295-00</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>35 mm falcon tissue culture dishes</td>
 <td>VWRSP</td>
 <td>25382-064</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>falcon 150 x 25 mm tissue culture dishes; 1013</td>
 <td>VWRSP</td>
 <td>1013</td>
 <td>also can be made into small dissection dishes with sylgard</td>
 </tr>
 <tr>
 <td>sylgard</td>
 <td>WPI</td>
 <td>SYL184</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>animal dissection tray</td>
 <td>various</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>15 ml centrifuge tubes, 35-2097 BD Falcon</td>
 <td>VWRSP</td>
 <td>21008-918</td>
 <td>For 6-bore gravity-fed perfusion system</td>
 </tr>
 <tr>
 <td>Aluminum clips with screw hole ends</td>
 <td>hardware store</td>
 <td>&nbsp;</td>
 <td>For perfusion system</td>
 </tr>
 <tr>
 <td>23 gauge needles (manually file off points)</td>
 <td>VWRSP</td>
 <td>&nbsp;</td>
 <td>For perfusion system</td>
 </tr>
 <tr>
 <td>Polyethylene tubing 0.022"ID x 0.042"OD; 427411</td>
 <td>Becton-Dickinson</td>
 <td>&nbsp;</td>
 <td>For perfusion system</td>
 </tr>
 <tr>
 <td>H-7 pipette stand/holder for microcap perfusion array</td>
 <td>Narishige USA</td>
 <td>&nbsp;</td>
 <td>For perfusion system</td>
 </tr>
 <tr>
 <td>one-way valves</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>For perfusion system</td>
 </tr>
 <tr>
 <td>Drummond Microcaps 1 &mu;l</td>
 <td>VWRSP</td>
 <td>&nbsp;</td>
 <td>For perfusion system</td>
 </tr>
 <tr>
 <td>18 gauge needles for suction (filed off points)</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Polyethylene tubing</td>
 <td>Cole Parmer</td>
 <td>4.27436E+11</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>fine dissection pins</td>
 <td>Fine Science Tools</td>
 <td>26002-20</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>capillary tubes</td>
 <td>Kimble 71900-100</td>
 <td>&nbsp;</td>
 <td>fire-polished and U-shaped in a Bunsen burner flame and filled with 3% agar in ECS</td>
 </tr>
 <tr>
 <td>modeling clay</td>
 <td>craft store</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>dish holder for microscope stage with isolated ground bath</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>Custom manufacture</td>
 </tr>
 <tr>
 <td>pasteur pipettes</td>
 <td>VWRSP</td>
 <td>14672-412</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>pipette bulbs</td>
 <td>VWRSP</td>
 <td>53283-911</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>acrodisk syringe filters</td>
 <td>VWRSP</td>
 <td>28144-040</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>thick-walled 1.5 mm diameter borosilicate filament glass</td>
 <td>WPI</td>
 <td>1B150F-3</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>High purity nitrogen cylinder and bifurcating regulator</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 </tbody>
</table>
Tables 1-3. Lists of Reagents, Materials, and Equipment.

isolation of sensory neurons of aplysia californica for patch clamp recordings of glutamatergic currents

O molusco gastrópode marinho Aplysia californica tem uma história venerável como um modelo de funcionamento do sistema nervoso, com particular importância em estudos de aprendizagem e memória. As preparações típicas para esses estudos são aquelas em que o sensorial e motoneurónios são deixadas intactas num animal minimamente dissecados, ou uma técnica elaborada neuronal co-cultura de motoneurónios e sensorial indivíduo. Menos comum é o isolado preparação neuronal em que pequenos grupos de neurônios nominalmente homogêneos são dissociados em células isoladas em cultura de curto prazo. Tais células isoladas são úteis para a caracterização biofísica das correntes de iões utilizando técnicas de patch clamp, e modulação específica destas condutâncias. Um protocolo para a preparação de tais culturas é descrito. O protocolo aproveita os facilmente identificáveis ​​neurônios sensoriais glutamatérgicos do gânglio pleural e bucal, e descreve a sua dissociação e manutenção mínima in cultura durante vários dias, sem soro.

As localizações dos neurónios sensoriais dos gânglios dentro que são orientados neste protocolo, os neurónios do BSC e PVC são mostrados na Figura 1. Os neurónios BSC estão localizados em dois conjuntos ovais simétricos no lado ventral do gânglio vestibular, a superfície que fica virado para fora a partir da massa no gânglio vestibular intacta (Figura 1A). Os neurónios do PVC formam aglomerados bilaterais, em forma de V que envolvem a superfície dorsal do gânglio pleural...

Watch this Scientific Journal Video about Isolation of Sensory Neurons of Aplysia californica for Patch Clamp Recordings of Glutamatergic Currents at JoVE.com

Isolation of Sensory Neurons of Aplysia californica for Patch Clamp Recordings of Glutamatergic Currents

Nós descrevemos a dissecação do sistema nervoso do mar marinho lebre<em&gt; Aplysia</em&gt; Após a anestesia, o isolamento de neurônios para a cultura de tecidos de curto prazo e gravações de correntes iônicas única célula através da técnica de patch clamp.

Isolamento de neurônios sensoriais de<em&gt; Aplysia californica</em&gt; Para Remendo Recordings Grampo de Correntes glutamatérgicos

The marine gastropod mollusk Aplysia californica has a venerable  history as a model of nervous system function, with particular significance in  studies ...

isolation-sensory-neurons-aplysia-californica-for-patch-clamp

Research

JoVE Journal

Neuroscience

Isolation of Sensory Neurons of Aplysia californica for Patch Clamp Recordings of Glutamatergic Currents

12.2K visualizações.  University of Miami. Nós descrevemos a dissecação do sistema nervoso do mar marinho lebre Aplysia Após a anestesia, o isolamento de neurônios para a cultura de tecidos de curto prazo e gravações de correntes iônicas única célula através da técnica de patch clamp.

Vídeo: Isolation of Sensory Neurons of Aplysia californica for Patch Clamp Recordings of Glutamatergic Currents

Electrode Fabrication and Implantation in Aplysia californica for Multi-channel Neural and Muscular Recordings in Intact, Freely Behaving Animals

Recording from key nerves and muscles of Aplysia during feeding behavior allows us to study the patterns of neural control in an intact animal. Simultaneously recording from multiple nerves and muscles gives us precise information about the timing of neural activity. Previous recording methods have worked for two electrodes, but the study of additional nerves or muscles required combining and averaging the recordings of multiple animals, which made it difficult to determine fine details of timing and phasing, because of variability from response to response, and from animal to animal. Implanting four individual electrodes has a very low success rate due to the formation of adhesions that prevent animals from performing normal feeding movements. We developed a new method of electrode fabrication that reduces the bulk of the electrodes inside the animal allowing for normal feeding movements. Using a combination of glues to attach the electrodes results in a more reliable insulation of the electrode which lasts longer, making it possible to record for periods as long as a week. The fabrication technique that we describe could be extended to incorporate several additional electrodes, and would be applicable to vertebrate animals.

Electrode Fabrication and Implantation in Aplysia californica for Multi-channel Neural and Muscular Recordings in Intact, Freely Behaving Animals

A technique is described for implanting four in vivo electrodes to monitor the neuromuscular control of feeding behavior in Aplysia californica.

Fabricação de eletrodos e Implantação de Aplysia californica Para gravações multi-canal neural e muscular na Intact, Animais Livremente Behaving

Recording from key nerves and muscles of Aplysia during feeding behavior allows us to study the patterns of neural control in an intact animal.  ...

Neurociência

Patch Clamp Recordings from Mouse Retinal Neurons in a Dark-adapted Slice Preparation

Our visual experience is initiated when the visual pigment in our retinal photoreceptors absorbs photons of light energy and initiates a cascade of intracellular events that lead to closure of cyclic-nucleotide-gated channels in the cell membrane. The resulting change in membrane potential leads in turn to reductions in the amount of neurotransmitter release from both rod and cone synaptic terminals. To measure how the light-evoked change in photoreceptor membrane potential leads to downstream activity in the retina, scientists have made electrophysiological recordings from retinal slice preparations for decades1,2. In the past these slices have been cut manually with a razor blade on retinal tissue that is attached to filter paper; in recent years another method of slicing has been developed whereby retinal tissue is embedded in low gelling temperature agar and sliced in cool solution with a vibrating microtome3,4. This preparation produces retinal slices with less surface damage and very robust light-evoked responses. Here we document how this procedure can be done under infrared light to avoid bleaching the visual pigment.

Here we describe a procedure for generating dark-adapted slices of the mouse retina for electrophysiological recordings.

Remendo Recordings Grampo de neurônios da retina do rato em um Preparação Slice Dark-adaptados

Our visual experience is initiated when the visual pigment in our retinal photoreceptors absorbs photons of light energy and initiates a cascade of ...

Live-imaging of PKC Translocation in Sf9 Cells and in Aplysia Sensory Neurons

Protein kinase Cs (PKCs) are serine threonine kinases that play a central role in regulating a wide variety of cellular processes such as cell growth and learning and memory. There are four known families of PKC isoforms in vertebrates: classical PKCs (&alpha;, &beta;I, &beta;II and &gamma;), novel type I PKCs (&#949; and &eta;), novel type II PKCs (&delta; and &theta;), and atypical PKCs (&zeta; and &iota;). The classical PKCs are activated by Ca2+ and diacylclycerol (DAG), while the novel PKCs are activated by DAG, but are Ca2+-independent. The atypical PKCs are activated by neither Ca2+ nor DAG. In Aplysia californica, our model system to study memory formation, there are three nervous system specific PKC isoforms one from each major class, namely the conventional PKC Apl I, the novel type I PKC Apl II and the atypical PKC Apl III. PKCs are lipid-activated kinases and thus activation of classical and novel PKCs in response to extracellular signals has been frequently correlated with PKC translocation from the cytoplasm to the plasma membrane. Therefore, visualizing PKC translocation in real time in live cells has become an invaluable tool for elucidating the signal transduction pathways that lead to PKC activation. For instance, this technique has allowed for us to establish that different isoforms of PKC translocate under different conditions to mediate distinct types of synaptic plasticity and that serotonin (5HT) activation of PKC Apl II requires production of both DAG and phosphatidic acid (PA) for translocation 1-2. Importantly, the ability to visualize the same neuron repeatedly has allowed us, for example, to measure desensitization of the PKC response in exquisite detail 3. In this video, we demonstrate each step of preparing Sf9 cell cultures, cultures of Aplysia sensory neurons have been described in another video article 4, expressing fluorescently tagged PKCs in Sf9 cells and in Aplysia sensory neurons and live-imaging of PKC translocation in response to different activators using laser-scanning microscopy.

In this video, we demonstrate visualization of PKC translocation in living cells using fluorescently tagged PKCs.

Live-imagem de translocação da PKC em células Sf9 e em neurônios sensoriais Aplysia

Protein kinase Cs (PKCs) are serine threonine kinases that play a central role in regulating a wide variety of cellular processes such as cell growth and ...

Patch Clamp Recordings in Inner Ear Hair Cells Isolated from Zebrafish

Patch clamp analyses of the voltage-gated channels in sensory hair cells isolated from a variety of species have been described previously1-4 but this video represents the first application of those techniques to hair cells from zebrafish. Here we demonstrate a method to isolate healthy, intact hair cells from all of the inner ear end-organs: saccule, lagena, utricle and semicircular canals. Further, we demonstrate the diversity in hair cell size and morphology and give an example of the kinds of patch clamp recordings that can be obtained. The advantage of the use of this zebrafish model system over others stems from the availability of zebrafish mutants that affect both hearing and balance. In combination with the use of transgenic lines and other techniques that utilize genetic analysis and manipulation, the cell isolation and electrophysiological methods introduced here should facilitate greater insight into the roles hair cells play in mediating these sensory modalities.

The purpose of this video is to demonstrate procedures for obtaining healthy, intact hair cells from the inner ear organs of adult zebrafish and then using them for patch clamp studies aimed at characterizing the biophysical properties of their voltage-gated channels.

Gravações patch clamp em células ciliadas da orelha interna Isolado de Zebrafish

Patch  clamp analyses of the voltage-gated channels in sensory hair cells isolated  from a variety of species have been described previously1-4 but this  ...

Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica

In animals with large identified neurons (e.g. mollusks), analysis of motor pools is done using intracellular techniques1,2,3,4. Recently, we developed a technique to extracellularly stimulate and record individual neurons in Aplysia californica5. We now describe a protocol for using this technique to uniquely identify and characterize motor neurons within a motor pool.
This extracellular technique has advantages. First, extracellular electrodes can stimulate and record neurons through the sheath5, so it does not need to be removed. Thus, neurons will be healthier in extracellular experiments than in intracellular ones. Second, if ganglia are rotated by appropriate pinning of the sheath, extracellular electrodes can access neurons on both sides of the ganglion, which makes it easier and more efficient to identify multiple neurons in the same preparation. Third, extracellular electrodes do not need to penetrate cells, and thus can be easily moved back and forth among neurons, causing less damage to them. This is especially useful when one tries to record multiple neurons during repeating motor patterns that may only persist for minutes. Fourth, extracellular electrodes are more flexible than intracellular ones during muscle movements. Intracellular electrodes may pull out and damage neurons during muscle contractions. In contrast, since extracellular electrodes are gently pressed onto the sheath above neurons, they usually stay above the same neuron during muscle contractions, and thus can be used in more intact preparations.
To uniquely identify motor neurons for a motor pool (in particular, the I1/I3 muscle in Aplysia) using extracellular electrodes, one can use features that do not require intracellular measurements as criteria: soma size and location, axonal projection, and muscle innervation4,6,7. For the particular motor pool used to illustrate the technique, we recorded from buccal nerves 2 and 3 to measure axonal projections, and measured the contraction forces of the I1/I3 muscle to determine the pattern of muscle innervation for the individual motor neurons.
We demonstrate the complete process of first identifying motor neurons using muscle innervation, then characterizing their timing during motor patterns, creating a simplified diagnostic method for rapid identification. The simplified and more rapid diagnostic method is superior for more intact preparations, e.g. in the suspended buccal mass preparation8 or in vivo9. This process can also be applied in other motor pools10,11,12 in Aplysia or in other animal systems2,3,13,14.

Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica

In animals with large identified neurons (e.g. mollusks), analysis of motor pools is done using intracellular techniques1,2,3,4. Recently, we developed a technique to extracellularly stimulate and record individual neurons in Aplysia californica5. We now describe a protocol for using this technique to uniquely identify and characterize motor neurons within a motor pool.

Extracelularmente Identificar os neurônios motores de um pool do motor muscular em<em&gt; Aplysia californica</em

In animals with large  identified neurons (e.g. mollusks), analysis of motor pools is done using  intracellular techniques1,2,3,4. Recently,  we developed ...

Patch Clamp Recordings from Embryonic Zebrafish Mauthner Cells

Mauthner cells (M-cells) are large reticulospinal neurons located in the hindbrain of teleost fish. They are key neurons involved in a characteristic behavior known as the C-start or escape response that occurs when the organism perceives a threat. The M-cell has been extensively studied in adult goldfish where it has been shown to receive a wide range of excitatory, inhibitory and neuromodulatory signals1. We have been examining M-cell activity in embryonic zebrafish in order to study aspects of synaptic development in a vertebrate preparation. In the late 1990s Ali and colleagues developed a preparation for patch clamp recording from M-cells in zebrafish embryos, in which the CNS was largely intact2,3,4. The objective at that time was to record synaptic activity from hindbrain neurons, spinal cord neurons and trunk skeletal muscle while maintaining functional synaptic connections within an intact brain-spinal cord preparation. This preparation is still used in our laboratory today. To examine the mechanisms underlying developmental synaptic plasticity, we record excitatory (AMPA and NMDA-mediated)5,6 and inhibitory (GABA and glycine) synaptic currents from developing M-cells. Importantly, this unique preparation allows us to return to the same cell (M-cell) from preparation to preparation to carefully examine synaptic plasticity and neuro-development in an embryonic organism. The benefits provided by this preparation include 1) intact, functional synaptic connections onto the M-cell, 2) relatively inexpensive preparations, 3) a large supply of readily available embryos 4) the ability to return to the same cell type (i.e. M-cell) in every preparation, so that synaptic development at the level of an individual cell can be examined from fish to fish, and 5) imaging of whole preparations due to the transparent nature of the embryos.

We have developed an intact brain-spinal cord preparation to record and monitor electrical activity via patch clamp recording from the Mauthner neurons and other reticulospinal cells in zebrafish embryos. Thus, we are able to record excitatory and inhibitory synaptic currents, voltage-gated channel activity and action potentials from key neurons in a developing embryo.

Grampo patch Gravações de Embryonic Cells Zebrafish Mauthner

Mauthner cells (M-cells) are large  reticulospinal neurons located in the hindbrain of teleost fish. They are key  neurons involved in a characteristic ...

Perforated Patch-clamp Recording of Mouse Olfactory Sensory Neurons in Intact Neuroepithelium: Functional Analysis of Neurons Expressing an Identified Odorant Receptor

Analyzing the physiological responses of olfactory sensory neurons (OSN) when stimulated with specific ligands is critical to understand the basis of olfactory-driven behaviors and their modulation. These coding properties depend heavily on the initial interaction between odor molecules and the olfactory receptor (OR) expressed in the OSNs. The identity, specificity and ligand spectrum of the expressed OR are critical. The probability to find the ligand of the OR expressed in an OSN chosen randomly within the epithelium is very low. To address this challenge, this protocol uses genetically tagged mice expressing the fluorescent protein GFP under the control of the promoter of defined ORs. OSNs are located in a tight and organized epithelium lining the nasal cavity, with neighboring cells influencing their maturation and function. Here we describe a method to isolate an intact olfactory epithelium and record through patch-clamp recordings the properties of OSNs expressing defined odorant receptors. The protocol allows one to characterize OSN membrane properties while keeping the influence of the neighboring tissue. Analysis of patch-clamp results yields&#160;a precise quantification of ligand/OR interactions, transduction pathways and pharmacology, OSNs&#39; coding properties and their modulation at the membrane level.&#160;

Analyzing the physiological properties of olfactory sensory neurons still faces technical limitations. Here we record them through perforated patch-clamp in an intact preparation of the olfactory epithelium in gene-targeted mice. This technique allows the characterization of membrane properties and responses to specific ligands of neurons expressing defined olfactory receptors.

Perfurado gravação patch-clamp de rato Olfactory neurônios sensoriais na Intact neuroepitélio: Análise Funcional do Neurônios Expressando uma Odorant Receptor Identificados

Analyzing the physiological responses of olfactory sensory neurons (OSN) when stimulated with specific ligands is critical to understand the basis of ...

Whole-cell Patch-clamp Recordings in Brain Slices

Whole-cell patch-clamp recording is an electrophysiological technique that allows the study of the&#160;electrical properties of a substantial part of the neuron. In this configuration, the micropipette is in tight contact with the cell membrane, which prevents current leakage and thereby provides more accurate ionic current measurements than the previously used intracellular sharp electrode recording method. Classically, whole-cell recording can be performed on neurons in various types of preparations, including cell culture models, dissociated neurons, neurons in brain slices, and in intact anesthetized or awake animals. In summary, this technique has immensely contributed to the understanding of passive and active biophysical properties of excitable cells. A major advantage of this technique is that it provides information on how specific manipulations (e.g., pharmacological, experimenter-induced plasticity) may alter specific neuronal functions or channels in real-time. Additionally, significant opening of the plasma membrane allows the internal pipette solution to freely diffuse into the cytoplasm, providing means for introducing drugs, e.g., agonists or antagonists of specific intracellular proteins, and manipulating these targets without altering their functions in neighboring cells. This article will focus on whole-cell recording performed on neurons in brain slices,&#160;a preparation that has the advantage of recording neurons in relatively well preserved brain circuits, i.e., in a physiologically relevant context. In particular,&#160;when combined with appropriate pharmacology, this technique is a powerful tool allowing identification of specific neuroadaptations that occurred following any type of experiences, such as learning, exposure to drugs of abuse, and stress. In summary, whole-cell patch-clamp recordings in brain slices provide means to measure in ex vivo preparation long-lasting changes in neuronal functions that have developed in intact awake animals.

This protocol describes basic procedural steps for performing whole-cell patch-clamp recordings. This technique allows the study of&#160;the electrical behavior of neurons, and when performed in brain slices, allows the assessment of various neuronal functions from neurons that are still integrated in relatively well preserved brain circuits.

Gravações de células inteiras de patch-clamp em Brain Slices

Whole-cell patch-clamp recording is an electrophysiological technique that allows the study of the&#160;electrical properties of a substantial part of the ...

Subcellular Patch-clamp Recordings from the Somatodendritic Domain of Nigral Dopamine Neurons

Dendrites of dopaminergic neurons receive and convey synaptic input, support action potential back-propagation and neurotransmitter release. Understanding these fundamental functions will shed light on the information transfer in these neurons. Dendritic patch-clamp recordings provide the possibility to directly examine the electrical properties of dendrites and underlying voltage-gated ion channels. However, these fine structures are not easily accessible to patch pipettes because of their small diameter. This report describes a step-by-step procedure to collect stable and reliable recordings from the dendrites of dopaminergic neurons in acute slices. Electrophysiological measurements are combined with post hoc recovery of cell morphology. Successful experiments rely on improved preparation of slices, solutions and pipettes, adequate adjustment of the optics and stability of the pipette in contact with the recorded structure. Standard principles of somatic patch-clamp recording are applied to dendrites but with a gentler approach of the pipette. These versatile techniques can be implemented to address various questions concerning the excitable properties of dendrites.

Subcellular patch-clamp recordings offer the possibility to investigate the functional properties of dendrites. However these fine structures are not easily accessible due to their small diameter. The protocol described here aims to facilitate the collection of stable and reliable recordings from the dendrites of dopamine neurons in slices in vitro.

Subcelulares Gravações patch-clamp do domínio somatodendrítico da substância negra dopamina Neurônios

Dendrites of dopaminergic neurons receive and convey synaptic input, support action potential back-propagation and neurotransmitter release. Understanding ...

Whole-cell Patch-clamp Recordings for Electrophysiological Determination of Ion Selectivity in Channelrhodopsins

Over the past decade, channelrhodopsins became indispensable in neuroscientific research where they are used as tools to non-invasively manipulate electrical processes in target cells. In this context, ion selectivity of a channelrhodopsin is of particular importance. This article describes the investigation of chloride selectivity for a recently identified anion-conducting channelrhodopsin of Proteomonas sulcata via electrophysiological patch-clamp recordings on HEK293 cells. The experimental procedure for measuring light-gated photocurrents demands a fast switchable &#8211; ideally monochromatic &#8211; light source coupled into the microscope of an otherwise conventional patch-clamp setup. Preparative procedures prior to the experiment are outlined involving preparation of buffered solutions, considerations on liquid junction potentials, seeding and transfection of cells, and pulling of patch pipettes. The actual recording of current-voltage relations to determine the reversal potentials for different chloride concentrations takes place 24 h to 48 h after transfection. Finally, electrophysiological data are analyzed with respect to theoretical considerations of chloride conduction.

This article describes how the ion selectivity of channelrhodopsin is determined with electrophysiological whole-cell patch-clamp recordings using HEK293 cells. Here, the experimental procedure for investigating chloride selectivity of an anion-selective channelrhodopsin is demonstrated. However, the procedure is transferable to other channelrhodopsins of distinct selectivity.