Este trabalho foi financiado pelo NIH Grant EY17606 (APS).

1. Eletrodos preparar <ol><li> Preparar os eletrodos de registro e referência por imersão-los tanto em NaCl 1M e dirigir 15V entre eles usando uma onda senoidal 1 Hz ~ 20 para s. </li><li> Fazer a gravação usando eletrodos de um puxador de micropipeta (Sutter Instruments P-97). Para patch-pipetas usar um vidro de borosilicato com um diâmetro exterior de 1,2 mm e um diâmetro interno de 0,69 mm (Sutter Instruments, Cat # B120-69-10). Medir a resistência em série com a ponta do eletrodo. Com base no tamanho das células-alvo escolher uma ponteira de diâmetro, por corpos celulares ~ 20 mM em uso diâmetro ~ 5 mohms de corpos celulares ~ 5 mm de diâmetro em uso ~ 12 mohms. </li><li> Prepare solo / eletrodos de referência. Usando uma seringa encher um tubo de polietileno pequena seção (Intramedic, PE205) com 1 mM NaCl que inclui Agar 3,5% (Sigma; Cat # A7002) em NaCl 1M. Coloque esta ponte agar sobre o eletrodo de referência Ag / AgCl. </li></ol> 2. Soluções preparar <ol><li> Solução de banho externo, &quot;a mídia contendo bicarbonato (1 L): 1 garrafa de Ames &#39;Ames Médio (Sigma; Cat # A1420), 1,9 g de NaHCO 3, 7 mL de penicilina-estreptomicina (Sigma; Cat # P0781) para evitar bacteriana crescimento. Ajuste osmolaridade para ~ 280 mOsm. </li><li> Corte solução, &quot;a mídia contendo o HEPES pH tampão (1 L): 1 garrafa de Ames &#39;Ames Médio, 0,887 g de NaCl, 2,38 g de HEPES, 7 mL de penicilina-estreptomicina. Ajustar o pH a 7,4 com 1M ~ NaOH e / ou 1M HCl. Ajuste osmolaridade para ~ 280 mOsm. </li><li> Aspartato de potássio (K-Asp) pipeta solução interna (em mM): 125 K-aspartato, 10 KCl, 10 HEPES, 5 NMG-HEDTA, 0,5 CaCl 2, 1 ATP-Mg, 0,2 GTP-Mg, pH é ajustado para ~ 7.3 com NMG-OH, e osmolaridade é ajustada a ~ 280 mOsm. </li><li> Recuo Agar para estabilizar a temperatura baixa gelificação agarose contendo a retina (5% em peso), 7,5 g de Agar (Sigma; Cat # A7002) derretido em 150 ml de dH 2 O. </li></ol> 3. Dia da Experiência <ol><li> Descongelar ~ 1,5 mL de K-Asp Solução Interna e do fluoróforo de sua escolha a partir de freezer. Diluir o fluoróforo à concentração adequada, que deve ser determinada empiricamente. </li><li> Despeje media Ames &#39;contendo NaHCO 3 (~ 200 mL) para o recipiente de armazenamento à prova de luz e coloque em banho-maria (30-32 ° C) e equilibrar com 5% de CO 2 / 95% O 2 gás </li><li> Preencha frasco com 110 mL ~ dos meios de comunicação de Ames contendo HEPES, colocar no gelo e se equilibram com 100% de O 2. </li><li> Coloque o restante Ames &#39;mídia contendo NaHCO 3 em um reservatório aquecido em cima da gaiola de Faraday, e se equilibram com 5% de CO 2 / O 2 95% de gás. Parafilme podem ser usados ​​para prender o gás no espaço acima da solução. </li><li> Prepare a baixa temperatura de gelificação agarose (3%) pela adição de 0,75 g (Sigma; Cat # A0701) a 25 mL dos meios de comunicação de Ames com HEPES e aquecer a solução em ~ 115 ° C para derreter a agarose. Mexa até que a solução clara, sem bolhas, e armazenar em um banho de água (~ 42 ° C). </li><li> Preencha uma pipeta de gravação com a solução de K-Asp internos e verificar a resistência de ponta. </li></ol> 4. Experimente começar <ol><li> Euthanize o mouse e rapidamente remover os olhos com uma tesoura curva. Óculos infravermelhos deve ser usado para todos os procedimentos para prevenir branqueamento do pigmento visual. </li><li> Coloque os olhos em um pedaço de papel de filtro para os impedir de rolamento, e usando uma lâmina de dupla face fina, fazer uma fenda na córnea, mantendo o olho com a pinça. </li><li> Tão logo o globo ocular é perfurada, a transferência que olho em um prato cheio com a mídia de Ames. </li><li> Usando a régua na córnea como um ponto de entrada, tesoura pequena são usados ​​para cortar as porções restantes da córnea, após o qual a lente e vítreo pode ser removido. Tenha cuidado para que a retina permanece preso à ocular, e armazenar a ocular no escuro a 32 ° C nos meios de comunicação equilibrada com 5% de CO 2 / 95% O 2 Ames. </li></ol> 5. Corte <ol><li> Hemisect uma das oculares e dissociar a retina do epitélio pigmentar da retina. Retire as bordas da retina para permitir que o tecido para ficar na posição horizontal. </li><li> Use um pequeno vidro pipeta Pasteur com um bulbo de látex para preencher uma 35 milímetros placa de Petri com agar derretido, e arraste a pinça através através do ágar para testar a sua consistência. </li><li> Quando você pode começar a ver o ágar solidificar: <ol class="lalpha"><li> Transferência da retina para o topo do ágar. </li><li> Use um pedaço torcido de Kimwipe para absorver o excesso de solução em torno da retina. </li><li> Coloque 2-3 gotas de Agar diretamente na retina e rapidamente colocar um cilindro de plástico sobre a retina para formar uma parede em torno dela. Então por gotejamento agar derretido adicionais abaixo dos lados do cilindro de plástico, enquanto centrando a retina dentro do ágar. </li><li> Transferir o prato Petri to banho de água gelada para esfriar. </li></ol></li><li> Depois de ~ 45 segundo remover o tecido do banho-maria de gelo e use um êmbolo para expulsar o ágar bloco para fora do cilindro de plástico, empurrando a partir do lado mais distante da retina. </li><li> Use a lâmina de um lado para cortar um pequeno bloco de ágar contendo a retina e superglue o bloco no lugar contra o recuo de ágar no disco espécime. </li><li> Transferência do disco de amostra para a bandeja micrótomo vibrando e despeje HEPES gelada Ames na bandeja permitindo que o bloco com retina para ser totalmente submerso. </li><li> Fatias da retina com uma espessura de ~ 200 mM pode ser cortado à taxa máxima de lâmina de vibração e uma velocidade de lâmina para a frente esse conjunto que leva de 4 a 5 segundos para cortar a retina em cada fatia. </li><li> Use uma lâmina de bisturi n º 11 para remover cada uma fatia útil de cada vez </li><li> Fatias bom contendo retina são colocados em câmaras de gravação e são sobrecarregados com âncoras fatia com fios de nylon cruzá-los. Os fios de nylon mantenha o agar em torno da retina, deixando a retina desobstruídas para as gravações. </li><li> Transferência da câmara de gravação para o estágio do microscópio na posição vertical, fechar a cortina e ligar a fonte de luz infravermelha para ver a fatia em uma câmera infravermelha e minúsculas. </li></ol> 6. Gravação <ol><li> Uma vez que uma fatia boa da retina (com fotorreceptores intactas e do ângulo de corte adequado) é identificado começar a perfusão da retina a uma taxa superior a 5 mL / min com a mídia Ames aquecida &quot;, que é aquecida a 35 ° C e 37 equilibrada com 5% de CO 2 / 95% O 2. </li><li> Alguns danos na superfície pode ser aparente devido ao processo de corte. Esta camada fina de células geralmente pode ser removido com uma pipeta com uma ponta quebrada, e gentilmente sugando os corpos de células mortas. Este será tipicamente revelam células vivas embaixo. Identificar um corpo da célula saudável, cuja posição está localizado nos estratos de interesse. </li><li> Preencher uma micropipeta com a solução KAsp interna e aplicar pressão (para fora) positiva através da ponta da pipeta, e inferior a ponta da pipeta na câmara de gravação e para baixo ao nível da célula usando um micromanipulador. </li><li> Mova a ponta da pipeta de tal forma que as covinhas da membrana celular, e aplicar pressão suave (para dentro) negativa a fazer um selo de alta resistência. De célula inteira modo pode ser alcançado através da aplicação de pressão negativa para o eletrodo para invadir a célula. </li><li> Estimular o tecido da retina usando LEDs podem evocar respostas à luz. </li><li> Fotografia da célula a partir do qual a gravação foi feita evocando fluorescência do fluoróforo na solução da pipeta interna. </li></ol> 7. Resultados representante <img src="/files/ftp_upload/2107/2107fig1.jpg" alt="Figura 1" /> Figura 1. Aqui, a luz-potenciais evocados de um dark-adaptados neurônio da retina para flashes de luz de aumentar a força são mostrados. <img src="/files/ftp_upload/2107/2107fig2.jpg" alt="Figura 2" /> Figura 2. Imagem de fluorescência de uma fatia da retina onde as células foram preenchidas com o fluoróforo, Lucifer Yellow. Fluorescência evocado mostra a morfologia das células a partir do qual foram feitas as gravações de patch.

<ol>
	<li>Weblin, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transmission+along+and+between+rods+in+the+tiger+salamander+retina.">Transmission along and between rods in the tiger salamander retina.</a> J Physiol. 280, 449-470 (1978).</li><li>Wu, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synaptic+connections+among+retina+neurons+in+living+slices.">Synaptic connections among retina neurons in living slices.</a> J Neurosci Methods. 20, 139-149 (1987).</li><li>Rieke, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal+contrast+adaptation+in+salamander+bipolar+cell.">Temporal contrast adaptation in salamander bipolar cell.</a> J Neurosci. 21, 9445-9454 (2001).</li><li>Armstrong-Gold, C., &amp;amp, R. i. e. k. e., F, . <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bandpass+filtering+at+the+rod+to+second-order+cell+synapse+in+salamander+(Ambystoma+tigrinum)+retina.">Bandpass filtering at the rod to second-order cell synapse in salamander (Ambystoma tigrinum) retina.</a> J Neurosci. 23, 3796-3806 (2003).</li><li>Masland, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+fundamental+plan+of+the+retina.">The fundamental plan of the retina.</a> Nat Neurosci. 4, 877-886 (2001).</li><li>Wassle, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Parallel+processing+in+the+mammalian+retina.">Parallel processing in the mammalian retina.</a> Nat Rev Neurosci. 5, 747-757 (2004).</li></ol>

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Gravação fatia de retinas vertebrados têm sido feitas há décadas 1,2, e têm sido bastante bem sucedidos em fornecer uma compreensão mais profunda de como o circuito da retina codifica luz incidente. As vantagens do corte em micrótomo vibrando em vez de diretamente com uma lâmina de barbear é que as fatias da retina incorrer menos danos na superfície. Com uma pipeta de sucção é fácil de remover esse dano e células-alvo saudável logo abaixo da superfície que possuem conectividade no circuito d...

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<td>Micropipette Puller</td>
<td>&nbsp;</td>
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<td>Low gelling temp agarose</td>
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<td>Ames' Medium</td>
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patch clamp recordings from mouse retinal neurons in a dark-adapted slice preparation

Nossa experiência visual é iniciada quando o pigmento visual em nossa fotorreceptores da retina absorve fótons de energia luminosa e inicia uma cascata de eventos intracelulares que levam ao encerramento do cíclica de nucleotídeo-gated canais na membrana da célula. A mudança resultante no potencial da membrana leva, por sua vez a redução na quantidade de liberação de neurotransmissores dos dois rod e terminais de cone sináptica. Para medir o quanto a mudança de luz evocada em fotorreceptoras potencial de membrana leva a atividade a jusante na retina, os cientistas fizeram gravações eletrofisiológicas das preparações fatia da retina para 1,2 décadas. No passado, essas fatias foram cortadas manualmente com uma lâmina de barbear no tecido da retina que é anexado ao papel de filtro; nos últimos anos um outro método de corte tem sido desenvolvida através do qual o tecido da retina é incorporado em agar baixa temperatura de gelificação e cortados em solução legal com um vibrando micrótomo 3,4. Esta preparação produz fatias da retina com menos danos superficiais e muito robusto respostas luz evocado. Aqui nós documento como esse procedimento pode ser feito sob a luz infravermelha para evitar a descoloração do pigmento visual.

Watch this Scientific Journal Video about Patch Clamp Recordings from Mouse Retinal Neurons in a Dark-adapted Slice Preparation at JoVE.com

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

Aqui nós descrevemos um procedimento para a geração de adaptação ao escuro fatias da retina do rato para gravações eletrofisiológicas.

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 ...

patch-clamp-recordings-from-mouse-retinal-neurons-dark-adapted-slice

Research

JoVE Journal

Neuroscience

14.3K visualizações.  University of Southern California. Aqui nós descrevemos um procedimento para a geração de adaptação ao escuro fatias da retina do rato para gravações eletrofisiológicas.

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

Paired Patch Clamp Recordings from Motor-neuron and Target Skeletal Muscle in Zebrafish

Larval zebrafish represent the first vertebrate model system to allow simultaneous patch clamp recording from a spinal motor-neuron and target muscle. This is a direct consequence of the accessibility to both cell types and ability to visually distinguish the single segmental CaP motor-neuron on the basis of morphology and location. This video demonstrates the microscopic methods used to identify a CaP motor-neuron and target muscle cells as well as the methodologies for recording from each cell type. Identification of the CaP motor-neuron type is confirmed by either dye filling or by the biophysical features such as action potential waveform and cell input resistance. Motor-neuron recordings routinely last for one hour permitting long-term recordings from multiple different target muscle cells. Control over the motor-neuron firing pattern enables measurements of the frequency-dependence of synaptic transmission at the neuromuscular junction. Owing to a large quantal size and the low noise provided by whole cell voltage clamp, all of the unitary events can be resolved in muscle. This feature permits study of basic synaptic properties such as release properties, vesicle recycling, as well as synaptic depression and facilitation. The advantages offered by this in vivo preparation eclipse previous neuromuscular model systems studied wherein the motor-neurons are usually stimulated by extracellular electrodes and the muscles are too large for whole cell patch clamp. The zebrafish preparation is amenable to combining electrophysiological analysis with a wide range of approaches including transgenic lines, morpholino knockdown, pharmacological intervention and in vivo imaging. These approaches, coupled with the growing number of neuromuscular disease models provided by mutant lines of zebrafish, open the door for new understanding of human neuromuscular disorders.

Larval zebrafish represent the first vertebrate model system to allow simultaneous patch clamp recording from a spinal motor-neuron and target skeletal muscle. This video demonstrates the microscopic methods used to identify a segmental CaP motor-neuron and target muscle cells as well as the methodologies for recording from each cell type.

Gravações patch emparelhado Grampo da Motor-neurônio e músculo alvo ósseas em Zebrafish

Larval zebrafish represent the first vertebrate model system to allow simultaneous patch clamp recording from a spinal motor-neuron and target muscle.  ...

Neurociência

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  ...

F1FO ATPase Vesicle Preparation and Technique for Performing Patch Clamp Recordings of Submitochondrial Vesicle Membranes

Mitochondria are involved in many important cellular functions including metabolism, survival1, development and, calcium signaling2. Two of the most important mitochondrial functions are related to the efficient production of ATP, the energy currency of the cell, by oxidative phosphorylation, and the mediation of signals for programmed cell death3.
The enzyme primarily responsible for the production of ATP is the F1FO-ATP synthase, also called ATP synthase4-5. In recent years, the role of mitochondria in apoptotic and necrotic cell death has received considerable attention. In apoptotic cell death, BCL-2 family proteins such as Bax enter the mitochondrial outer membrane, oligomerize and permeabilize the outer membrane, releasing pro-apoptotic factors into the cytosol6. In classic necrotic cell death, such as that produced by ischemia or excitotoxicity in neurons, a large, poorly regulated increase in matrix calcium contributes to the opening of an inner membrane pore, the mitochondrial permeability transition pore or mPTP. This depolarizes the inner membrane and causes osmotic shifts, contributing to outer membrane rupture, release of pro-apoptotic factors, and metabolic dysfunction. Many proteins including Bcl-xL7 interact with F1FO ATP synthase, modulating its function. Bcl-xL interacts directly with the beta subunit of F1FO ATP synthase, and this interaction decreases a leak conductance within the F1FOATPasecomplex, increasing the net transport of H+ by F1FO during F1FO ATPase activity8 and thereby increasing mitochondrial efficiency. To study the activity and modulation of the ATP synthase, we isolated from rodent brain submitochondrial vesicles (SMVs) containing F1FO ATPase. The SMVs retain the structural and functional integrity of the F1FO ATPase as shown in Alavian et al. Here, we describe a method that we have used successfully for the isolation of SMVs from rat brain and we delineate the patch clamp technique to analyze channel activity (ion leak conductance) of the SMVs.

F1FO ATPase Vesicle Preparation and Technique for Performing Patch Clamp Recordings of Submitochondrial Vesicle Membranes

A method to isolate submitochondrial vesicles enriched in F1FO ATP synthase complexes from rat brain is described. These vesicles allow the study of the activity of F1FO ATPase complex and its modulation using the technique of patch clamp recording.

<sub&gt; 1</sub&gt; F<sub&gt; Ó</sub&gt; ATPase Vesicle Preparação e Técnica para Execução de Remendo Recordings Grampo de membranas de vesículas submitocondriais

Mitochondria are involved in many important cellular  functions including metabolism, survival1, development and, calcium signaling2. Two of the most ...

Simultaneous Whole-cell Recordings from Photoreceptors and Second-order Neurons in an Amphibian Retinal Slice Preparation

One of the central tasks in retinal neuroscience is to understand the circuitry of retinal neurons and how those connections are responsible for shaping the signals transmitted to the brain. Photons are detected in the retina by rod and cone photoreceptors, which convert that energy into an electrical signal, transmitting it to other retinal neurons, where it is processed and communicated to central targets in the brain via the optic nerve. Important early insights into retinal circuitry and visual processing came from the histological studies of Cajal1,2 and, later, from electrophysiological recordings of the spiking activity of retinal ganglion cells - the output cells of the retina3,4.
A detailed understanding of visual processing in the retina requires an understanding of the signaling at each step in the pathway from photoreceptor to retinal ganglion cell. However, many retinal cell types are buried deep in the tissue and therefore relatively inaccessible for electrophysiological recording. This limitation can be overcome by working with vertical slices, in which cells residing within each of the retinal layers are clearly visible and accessible for electrophysiological recording.
Here, we describe a method for making vertical sections of retinas from larval tiger salamanders (Ambystoma tigrinum). While this preparation was originally developed for recordings with sharp microelectrodes5,6, we describe a method for dual whole-cell voltage clamp recordings from photoreceptors and second-order horizontal and bipolar cells in which we manipulate the photoreceptor's membrane potential while simultaneously recording post-synaptic responses in horizontal or bipolar cells. The photoreceptors of the tiger salamander are considerably larger than those of mammalian species, making this an ideal preparation in which to undertake this technically challenging experimental approach. These experiments are described with an eye toward probing the signaling properties of the synaptic ribbon - a specialized synaptic structure found in a only a handful of neurons, including rod and cone photoreceptors, that is well suited for maintaining a high rate of tonic neurotransmitter release7,8 - and how it contributes to the unique signaling properties of this first retinal synapse.

We describe the preparation of thin retinal slices from aquatic tiger salamanders (Ambystoma tigrinum) and explain how we use these slices to study synaptic processing in the retina by obtaining dual whole-cell voltage clamp recordings from photoreceptors and second-order horizontal and bipolar cells.

Gravações Whole-cell simultâneas de fotorreceptores e os neurônios de segunda ordem em um anfíbio Retinal Slice Preparação

One of the central tasks in retinal neuroscience  is to understand the circuitry of retinal neurons and how those connections are  responsible for shaping ...

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

The marine gastropod mollusk Aplysia californica has a venerable history as a model of nervous system function, with particular significance in studies of learning and memory. The typical preparations for such studies are ones in which the sensory and motoneurons are left intact in a minimally dissected animal, or a technically elaborate neuronal co-culture of individual sensory and motoneurons. Less common is the isolated neuronal preparation in which small clusters of nominally homogeneous neurons are dissociated into single cells in short term culture. Such isolated cells are useful for the biophysical characterization of ion currents using patch clamp techniques, and targeted modulation of these conductances. A protocol for preparing such cultures is described. The protocol takes advantage of the easily identifiable glutamatergic sensory neurons of the pleural and buccal ganglia, and describes their dissociation and minimal maintenance in culture for several days without serum.

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

We describe the dissection of the nervous system of the marine sea hare Aplysia after anesthesia, the isolation of neurons for short term-tissue culture, and recordings of single cell ion currents via the patch clamp technique.

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 ...

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 ...

Whole-cell Patch-clamp Recordings from Morphologically- and Neurochemically-identified Hippocampal Interneurons

GABAergic inhibitory interneurons play a central role within neuronal circuits of the brain. Interneurons comprise a small subset of the neuronal population (10-20%), but show a high level of physiological, morphological, and neurochemical heterogeneity, reflecting their diverse functions. Therefore, investigation of interneurons provides important insights into the organization principles and function of neuronal circuits. This, however, requires an integrated physiological and neuroanatomical approach for the selection and identification of individual interneuron types. Whole-cell patch-clamp recording from acute brain slices of transgenic animals, expressing fluorescent proteins under the promoters of interneuron-specific markers, provides an efficient method to target and electrophysiologically characterize intrinsic and synaptic properties of specific interneuron types. Combined with intracellular dye labeling, this approach can be extended with post-hoc morphological and immunocytochemical analysis, enabling systematic identification of recorded neurons. These methods can be tailored to suit a broad range of scientific questions regarding functional properties of diverse types of cortical neurons.

Cortical networks are controlled by a small, but diverse set of inhibitory interneurons. Functional investigation of interneurons therefore requires targeted recording and rigorous identification. Described here is a combined approach involving whole-cell recordings from single or synaptically-coupled pairs of neurons with intracellular labeling, post-hoc morphological and immunocytochemical analysis.

Whole-cell Recordings patch-clamp de Morphologically- e identificados Neuroquimicamente hipocampo Interneurônios

GABAergic inhibitory interneurons play a central role within neuronal circuits of the brain. Interneurons comprise a small subset of the neuronal ...

Recording Light-evoked Postsynaptic Responses in Neurons in Dark-adapted, Mouse Retinal Slice Preparations Using Patch Clamp Techniques

The retina is the gateway to the visual system. To understand visual signal processing mechanisms, we investigate retinal neural network functions. Retinal neurons in the network comprise of numerous subtypes. More than 10 subtypes of bipolar cells, ganglion cells, and amacrine cells have been identified by morphological studies. Multiple subtypes of retinal neurons are thought to encode distinct features of visual signaling, such as motion and color, and form multiple neural pathways. However, the functional roles of each neuron in visual signal processing are not fully understood. The patch clamp method is useful to address this fundamental question. Here, a protocol to record light-evoked synaptic responses in mouse retinal neurons using patch clamp recordings in dark-adapted conditions is provided. The mouse eyes are dark-adapted O/N, and retinal slice preparations are dissected in a dark room using infrared illumination and viewers. Infrared light does not activate mouse photoreceptors and thus preserves their light responsiveness. Patch clamp is used to record light-evoked responses in retinal neurons. A fluorescent dye is injected during recordings to characterize neuronal morphological subtypes. This procedure enables us to determine the physiological functions of each neuron in the mouse retina.

We will demonstrate how to prepare retinal slices from the mouse eye and record light responses in retinal neurons. The entire procedure is conducted in dark-adapted conditions.

Gravação Light-provocou respostas pós-sinápticos nos neurônios em Dark-adaptados, Preparações da retina do rato fatia usando técnicas Grampo patch

The retina is the gateway to the visual system. To understand visual signal processing mechanisms, we investigate retinal neural network functions. ...

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 ...