Esta pesquisa foi apoiada por doações da Fundação Alemã de Pesquisa (DFG) a MCS (FOR 1581, STU 544/1-1) e OG (FOR 1581, SFB 874). O site da DFG é http://www.dfg.de/en/index.jsp. Os financiadores não tiveram nenhum papel no desenho do estudo, coleta de dados e análise, decisão de publicar ou preparação dos autores manuscript.The agradecer Thomas Seidenbecher por nos fornecer o protocolo sobre-regulamentação, bem como Tobias Otto para obter ajuda com a configuração do eletrofisiológico equipamento de gravação.

<ol>
	<li>Bingman, V. P., Gasser, B. A., Colombo, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Responses+of+pigeon+(Columba+livia)+wulst+neurons+during+acquisition+and+reversal+of+a+visual+discrimination+task.">Responses of pigeon (Columba livia) wulst neurons during acquisition and reversal of a visual discrimination task.</a> Behav Neurosci. 122, 1139-1147 (2008).</li><li>Herry, C., Ciocchi, S., Senn, V., Demmou, L., M&#252;ller, C., L&#252;thi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Switching+on+and+off+fear+by+distinct+neuronal+circuits.">Switching on and off fear by distinct neuronal circuits.</a> Nature. 454, 600-606 (2008).</li><li>Quirk, G. J., Repa, C., LeDoux, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fear+conditioning+enhances+short-latency+auditory+responses+of+lateral+amygdala+neurons:+parallel+recordings+in+the+freely+behaving+rat.">Fear conditioning enhances short-latency auditory responses of lateral amygdala neurons: parallel recordings in the freely behaving rat.</a> Neuron. 15, 1029-1039 (1995).</li><li>Quirk, G. J., Armony, J. L., Ledoux, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Components+of+Tone-Evoked+Spike+Trains+in+Auditory+Cortex+and+Lateral+Amygdala.">Components of Tone-Evoked Spike Trains in Auditory Cortex and Lateral Amygdala.</a> Neuron. 19, 613-624 (1997).</li><li>Maren, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Auditory+fear+conditioning+increases+CS-elicited+spike+firing+in+lateral+amygdala+neurons+even+after+extensive+overtraining.">Auditory fear conditioning increases CS-elicited spike firing in lateral amygdala neurons even after extensive overtraining.</a> Eur J Neurosci. 12, 4047-4054 (2000).</li><li>Milad, M. R., Quirk, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurons+in+medial+prefrontal+cortex+signal+memory+for+fear+extinction.">Neurons in medial prefrontal cortex signal memory for fear extinction.</a> Nature. 420, 713-717 (2002).</li><li>Hobin, J. A., Goosens, K. A., Maren, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Context-dependent+neuronal+activity+in+the+lateral+amygdala+represents+fear+memories+after+extinction.">Context-dependent neuronal activity in the lateral amygdala represents fear memories after extinction.</a> J Neurosci. 23, 8410-8416 (2003).</li><li>Maren, S., Hobin, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hippocampal+regulation+of+context-dependent+neuronal+activity+in+the+lateral+amygdala.">Hippocampal regulation of context-dependent neuronal activity in the lateral amygdala.</a> Learn Mem. 14, 318-324 (2007).</li><li>Knapska, E., 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+involvement+of+the+central+amygdala+in+appetitive+versus+aversive+learning.">Differential involvement of the central amygdala in appetitive versus aversive learning.</a> Learn Mem. 13, 192-200 (2006).</li><li>Harloe, J. P., Thorpe, A. J., Lichtman, A. 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C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=34;Insight&amp;#34;+in+the+pigeon:+antecedents+and+determinants+of+an+intelligent+performance.">34;Insight&amp;#34; in the pigeon: antecedents and determinants of an intelligent performance.</a> Nature. 308, 61-62 (1984).</li><li>Mazur, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Varying+initial-link+and+terminal-link+durations+in+concurrent-chains+schedules:+a+comparison+of+three+models.">Varying initial-link and terminal-link durations in concurrent-chains schedules: a comparison of three models.</a> Behav Processes. 66, 189-200 (2004).</li><li>Herrnstein, R. J., Loveland, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complex+visual+concept+in+the+pigeon.">Complex visual concept in the pigeon.</a> Science. 146, 549-551 (1964).</li><li>St&#252;ttgen, M. C., Yildiz, A., G&#252;nt&#252;rk&#252;n, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adaptive+criterion+setting+in+perceptual+decision+making.">Adaptive criterion setting in perceptual decision making.</a> J Exp Anal Behav. 96, 155-176 (2011).</li><li>St&#252;ttgen, M. C., Kasties, N., Lengersdorf, D., Starosta, S., G&#252;nt&#252;rk&#252;n, O., J&#228;kel, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suboptimal+criterion+setting+in+a+perceptual+choice+task+with+asymmetric+reinforcement.">Suboptimal criterion setting in a perceptual choice task with asymmetric reinforcement.</a> Behav Processes. 96, 59-70 (2013).</li><li>Rose, J., Otto, T., Dittrich, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Biopsychology-Toolbox:+a+free,+open-source+Matlab-toolbox+for+the+control+of+behavioral+experiments.">The Biopsychology-Toolbox: a free, open-source Matlab-toolbox for the control of behavioral experiments.</a> J Neurosci Methods. 175, (2008).</li><li>Bilkey, D. K., Muir, G. 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Os autores não têm nada a revelar.

Este protocolo descreve uma tarefa comportamental complexa adequada para gravações a única unidade simultâneas. Descrevemos a tarefa SIFC para pombos, mas pode ser facilmente adaptado para roedores, exigindo puxões nariz ou a pressão da alavanca, em vez de chave bica, e substituindo visual olfativo, auditivo, ou estímulos tácteis. Talvez os passos mais críticos durante o processo de formação são: 1) redução gradual da probabilidade de recompensa e 2) aumento no número de julga...

Aprender novas associações estímulo-resposta para os resultados envolve uma ampla gama de processos de plasticidade neural. Estes processos são, em última análise reflete na saída pico mudando de neurônios individuais. Indiscutivelmente, um dos paradigmas mais utilizadas de aprendizagem é o medo condicionamento pavloviano realizado com roedores. Neste cenário, a aquisição e extinção de uma resposta condicionada ocorrer dentro de algumas dezenas de ensaios 2. O desenvolvimento rápido de medo condicionado pode ser vantajoso porque permite que a execução de um grande número de animais dentro de um curto espaço de tempo. Além disso, a aquisição ea extinção pode ser observado dentro de algumas dezenas de ensaios em um único dia em animais ingênuos 3,4 ou espalhados por 2 ou 3 dias 2,5-8. No entanto, os conhecimentos adquiridos sobre as mudanças de atividade neural durante a aprendizagem nesses experimentos não se aplicam necessariamente fora do domínio do medo condicionado. Por exemplo, o comportamento alvo-dirigida impulsionado pela posiçãoreforço tiva é mais adequadamente modelada por operante em vez de procedimentos de Pavlov condicionado, e pode, em parte, dependem de diferentes substratos neurais 9,10. Além disso, o condicionamento do medo se desenvolve tão rapidamente que as respostas neurais para o CS só pode ser observado por algumas dezenas de ensaios, colocando limites severos na análise das mudanças de atividade neural durante a aprendizagem. Infelizmente, a aquisição e extinção do responder operante normalmente leva vários dias. Isto é prejudicial para as investigações neurofisiológicos, porque é notoriamente difícil de gravar a actividade de células individuais ao longo de mais do que algumas horas. Devido à alta similaridade das formas de onda de potenciais de ação extracelular gravados, é problemático afirmar que picos registrados no primeiro dia são gerados a partir da mesma célula como picos com ondas semelhantes gravado no próximo 11,12, especialmente em áreas com alta densidade de células, tais como o hipocampo. <p class=&quot;Jove_content&quot;&gt; Para tratar dessas questões, foi desenvolvido um paradigma comportamental romance utilizando três condições de aprendizagem dentro de uma sessão experimental em um único dia. Isto requer que o animal experimental é disposto para realizar centenas de ensaios em diferentes condições de uma programação fina de reforço. Pombos-correio (Columbia livia domestica forma) são organismos modelo clássicos em psicologia experimental 13-17. Estas aves são capazes de realizar discriminações visuais complexas 18, pode se adaptar com flexibilidade às mudanças de comportamento contingências de reforçamento 19,20, e são trabalhadores exclusivamente ávidos, realizando 1.000 ensaios com uma quantidade mínima de reforço. Estas características tornam especialmente adequado para as experiências descritas abaixo.

<table border="0" cellpadding="0" cellspacing="0" style="width:1379px;" width="1377">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:277px;">Name of Material/ Equipment</td>
			<td style="width:305px;">Company</td>
			<td style="width:325px;">Catalog Number</td>
			<td style="width:471px;">Comments/Description</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Resistance wire (for use as electrodes)</td>
			<td style="width:305px;">California Fine Wire, Grover Beach (CA), USA</td>
			<td></td>
			<td>Stablohm 675; formvar-coated nichrome wires (outer diameter 25 &#181;m)</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Microconnectors</td>
			<td style="width:305px;">Ginder Scientific, Nepean, Ontario, Canada</td>
			<td style="width:325px;"></td>
			<td>GS18PLG-220 (plug) &#38; GS18SKT-220 (socket to build headstage)</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Cannulae</td>
			<td style="width:305px;">Henke Sass Wolf, Tuttlingen, Germany</td>
			<td style="width:325px;"></td>
			<td>0.4x20mm/ 27Gx3/4&#34;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Gold solution for plating</td>
			<td style="width:305px;">Neuralynx, Bozeman (MT), USA</td>
			<td style="width:325px;"></td>
			<td>SIFCO Process Gold Non-Cyanide, Code 5355</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Solution for ultrasonic bath</td>
			<td style="width:305px;">Alconox, Inc., New York, USA</td>
			<td style="width:325px;">1304</td>
			<td>Tergazyme</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Conductive glue</td>
			<td style="width:305px;">Henkel Loctite</td>
			<td></td>
			<td>LOCTITE 3888 Silver filled, conductive, adhesive</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Stainless steel screws</td>
			<td style="width:305px;">J.I. Morris, Southbridge (MA), USA</td>
			<td style="width:325px;"></td>
			<td>F0CE125 self-tapping miniature screws, body length 1/8 inches</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Light-curing dental cement</td>
			<td style="width:305px;">van der Ven Dental, Duisburg, Germany</td>
			<td style="width:325px;"></td>
			<td>Omniceram Evo Flow A2</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Light-curing unit</td>
			<td style="width:305px;">van der Ven Dental, Duisburg, Germany</td>
			<td style="width:325px;"></td>
			<td>Jovident Excelled 215 Curing Light (wireless LED light curing unit)</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Filter amplifiers</td>
			<td style="width:305px;">npi electronic GmbH, Germany</td>
			<td>DPA-2FS</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">A/D converter</td>
			<td style="width:305px;">Cambridge Electronic Design, Cambridge, UK</td>
			<td>power 1401</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Spike2 software</td>
			<td style="width:305px;">Cambridge Electronic Design, Cambridge, UK</td>
			<td style="width:325px;"></td>
			<td>Version 7.06a</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:277px;">Matlab</td>
			<td style="width:305px;">The Mathworks, Natick (MA), USA</td>
			<td style="width:325px;"></td>
			<td>R2012a</td>
		</tr>
	</tbody>
</table>

recording single neurons' action potentials from freely moving pigeons across three stages of learning

Enquanto o sujeito da aprendizagem atraiu imenso interesse dos cientistas, tanto comportamentais e neurais, apenas relativamente poucos pesquisadores observaram a atividade de um único neurônio enquanto os animais estão adquirindo uma resposta operantly condicionado, ou quando essa resposta é extinto. Mas, mesmo nestes casos, períodos de observação geralmente abrangem apenas uma única fase de aprendizagem, ou seja, aquisição ou extinção, mas não ambos (exceções incluem protocolos que empregam aprendizagem reversa; ver Bingman et al 1 para um exemplo.). No entanto, a aquisição e extinção implicam diferentes mecanismos de aprendizagem e, portanto, deverão ser acompanhados por diferentes tipos e / ou loci de plasticidade neural. Nesse sentido, desenvolvemos um paradigma comportamental que institui três estágios de aprendizagem em uma única sessão comportamental e que é bem adequado para a gravação simultânea de potenciais de ação dos neurônios individuais. Animais umre treinados em uma tarefa de escolha forçada intervalo único que requer mapeamento cada uma das duas respostas de escolha possíveis para a apresentação de diferentes estímulos visuais inovadores (aquisição). Depois de ter atingido um critério de desempenho pré-definida, uma das duas respostas de escolha já não é reforçada (extinção). Após um certo decréscimo no nível de desempenho, respostas corretas são reforçadas novamente (reaquisição). Ao utilizar um novo conjunto de estímulos em cada sessão, os animais podem sofrer o processo de aquisição de extinção-reaquisição repetidamente. Porque todas as três fases de aprendizagem ocorrem numa única sessão de comportamento, o paradigma é ideal para a observação simultânea da saída de cravação de múltiplos neurónios individuais. Usamos pombos como sistemas modelo, mas a tarefa pode ser facilmente adaptada para outras espécies capazes de aprendizagem discriminação condicionado.

Comportamento A Figura 4A mostra o desempenho comportamental de um animal em uma sessão de exemplo. O nível do desempenho animal atinge critério para NS 2 em 180 tentativas (45 apresentações de estímulo) e está perto de 100% para o NS 1 desde o início. Esta estratégia - a primeira resposta para a mesma chave tanto para novos estímulos, e, em seguida, ajustar as respostas para um dos estímulos - é quase tão freqüentemente observada como inicial aleatória responden...

Watch this Scientific Journal Video about Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning at JoVE.com

Recording Single Neurons&#039; Action Potentials from Freely Moving Pigeons Across Three Stages of Learning

Aprender novas associações estímulo-resposta envolve uma ampla gama de processos neurais que são em última análise, refletem na mudança de pico de saída de neurônios individuais. Aqui nós descrevemos um protocolo de comportamento que permite o registro contínuo da atividade de um único neurônio enquanto que os animais adquirem, extinguir, e readquirir uma resposta condicionada em uma única sessão experimental.

Registro do potencial de ação simples Neurônios &#39;de livremente mover Pombos em três estágios da aprendizagem

While the subject of learning has attracted immense interest from both behavioral and neural scientists, only relatively few investigators have observed ...

recording-single-neurons-action-potentials-from-freely-moving-pigeons

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Neuroscience

Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning

11.9K visualizações.  Ruhr-University Bochum.  Aprender novas associações estímulo-resposta envolve uma ampla gama de processos neurais que são em última análise, refletem na mudança de pico de saída de neurônios individuais. Aqui nós descrevemos um protocolo de comportamento que permite o registro contínuo da atividade de um único neurônio enquanto que os animais adquirem, extinguir, e readquirir uma resposta condicionada em uma única sessão experimental. 

Vídeo: Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from individual neurons are critical for understanding how neural circuits function under natural conditions. Traditionally, these recordings have been performed 'blind', meaning the identity of the recorded cell is unknown at the start of the recording. Cellular identity can be subsequently determined via intracellular1, juxtacellular2 or loose-patch3 iontophoresis of dye, but these recordings cannot be pre-targeted to specific neurons in regions with functionally heterogeneous cell types. Fluorescent proteins can be expressed in a cell-type specific manner permitting visually-guided single-cell electrophysiology4-6. However, there are many model systems for which these genetic tools are not available. Even in genetically accessible model systems, the desired promoter may be unknown or genetically homogenous neurons may have varying projection patterns. Similarly, viral vectors have been used to label specific subgroups of projection neurons7, but use of this method is limited by toxicity and lack of trans-synaptic specificity. Thus, additional techniques that offer specific pre-visualization to record from identified single neurons in vivo are needed. Pre-visualization of the target neuron is particularly useful for challenging recording conditions, for which classical single-cell recordings are often prohibitively difficult8-11. The novel technique described in this paper uses retrograde transport of a fluorescent dye applied using tungsten needles to rapidly and selectively label a specific subset of cells within a particular brain region based on their unique axonal projections, thereby providing a visual cue to obtain targeted electrophysiological recordings from identified neurons in an intact circuit within a vertebrate CNS.
The most significant novel advancement of our method is the use of fluorescent labeling to target specific cell types in a non-genetically accessible model system. Weakly electric fish are an excellent model system for studying neural circuits in awake, behaving animals12. We utilized this technique to study sensory processing by "small cells" in the anterior exterolateral nucleus (ELa) of weakly electric mormyrid fish. "Small cells" are hypothesized to be time comparator neurons important for detecting submillisecond differences in the arrival times of presynaptic spikes13. However, anatomical features such as dense myelin, engulfing synapses, and small cell bodies have made it extremely difficult to record from these cells using traditional methods11, 14. Here we demonstrate that our novel method selectively labels these cells in 28% of preparations, allowing for reliable, robust recordings and characterization of responses to electrosensory stimulation.

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

Retrograde transport of fluorescent dye labels a sub-population of neurons based on anatomical projection. Labeled axons can be visually targeted in vivo, permitting extracellular recording from identified axons. This technique facilitates recording when neurons cannot be labeled through genetic manipulation or are difficult to isolate using 'blind' in vivo approaches.

Labeling fluorescentes retrógrada Permite alvejado Extracelular Gravação Single-unidade dos neurônios identificados<em&gt; In vivo</em

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from ...

Neurociência

Optical Recording of Suprathreshold Neural Activity with Single-cell and Single-spike Resolution

Signaling of information in the vertebrate central nervous system is often carried by populations of neurons rather than individual neurons. Also propagation of suprathreshold spiking activity involves populations of neurons. Empirical studies addressing cortical function directly thus require recordings from populations of neurons with high resolution. Here we describe an optical method and a deconvolution algorithm to record neural activity from up to 100 neurons with single-cell and single-spike resolution. This method relies on detection of the transient increases in intracellular somatic calcium concentration associated with suprathreshold electrical spikes (action potentials) in cortical neurons. High temporal resolution of the optical recordings is achieved by a fast random-access scanning technique using acousto-optical deflectors (AODs)1. Two-photon excitation of the calcium-sensitive dye results in high spatial resolution in opaque brain tissue2. Reconstruction of spikes from the fluorescence calcium recordings is achieved by a maximum-likelihood method. Simultaneous electrophysiological and optical recordings indicate that our method reliably detects spikes (&gt;97% spike detection efficiency), has a low rate of false positive spike detection (&lt; 0.003 spikes/sec), and a high temporal precision (about 3 msec) 3. This optical method of spike detection can be used to record neural activity in vitro and in anesthetized animals in vivo3,4.

Understanding the function of the vertebrate central nervous system requires recordings from many neurons because cortical function arises on the level of populations of neurons. Here we describe an optical method to record suprathreshold neural activity with single-cell and single-spike resolution, dithered random-access scanning. This method records somatic fluorescence calcium signals from up to 100 neurons with high temporal resolution. A maximum-likelihood algorithm deconvolves the underlying suprathreshold neural activity from the somatic fluorescence calcium signals. This method reliably detects spikes with high detection efficiency and a low rate of false positives and can be used to study neural populations in vitro and in vivo.

A gravação ótica da atividade neural supraliminares com resolução de uma única célula e um único pico

Signaling of information in the vertebrate central nervous system is often carried by populations of neurons rather than individual neurons. Also ...

Recording EEG in Freely Moving Neonatal Rats Using a Novel Method

EEG is a useful method to detect electrical activity in the brain. Moreover, it is a widely used diagnostic tool for various neurological conditions, such as epilepsy and neurodegenerative disorders. However, it is technically difficult to obtain EEG recordings in neonates as it requires specialized handling and great care. Here, we present a novel method to record EEG in neonatal rat pups (P8-P15). We designed a simple and reliable electrode using computer pin loci; it can be easily implanted into the skull of a rat pup to record high-quality EEG signals in the normal and epileptic brain. Pups were given an intraperitoneal (i.p.) injection of the neurotoxin kainic acid (KA) to induce epileptic seizures. The surgical implantation performed in this procedure is less expensive than other EEG procedures for neonates. This method allows one to record high-quality and stable EEG signals for more than 1 week. Furthermore, this procedure can also be applied to adult rats and mice to study epilepsy or other neurological disorders.

Here, we introduce a novel technique designed to record electroencephalography (EEG) in freely moving neonatal epileptic pups and describe its procedures, features, and applications. This method allows one to record EEG for more than 1 week.

Gravação de EEG em Ratos Neonatais de Movimentação Livre Usando um Novo Método

EEG is a useful method to detect electrical activity in the brain. Moreover, it is a widely used diagnostic tool for various neurological conditions, such ...

Simultaneous Recordings of Cortical Local Field Potentials, Electrocardiogram, Electromyogram, and Breathing Rhythm from a Freely Moving Rat

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls body functions and internal organ rhythms when animals are exposed to emotional challenges and changes in their living environments. In general experiments, signals from different organs, such as the brain and the heart, are recorded by independent recording systems that require multiple recording devices and different procedures for processing the data files. This study describes a new method that can simultaneously monitor electrical biosignals, including tens of local field potentials in multiple brain regions, electrocardiograms that represent the cardiac rhythm, electromyograms that represent awake/sleep-related muscle contraction, and breathing signals, in a freely moving rat. The recording configuration of this method is based on a conventional micro-drive array for cortical local field potential recordings in which tens of electrodes are accommodated, and the signals obtained from these electrodes are integrated into a single electrical board mounted on the animal's head. Here, this recording system was improved so that signals from the peripheral organs are also transferred to an electrical interface board. In a single surgery, electrodes are first separately implanted into the appropriate body parts and the target brain areas. The open ends of all of these electrodes are then soldered to individual channels of the electrical board above the animal's head so that all of the signals can be integrated into the single electrical board. Connecting this board to a recording device allows for the collection of all of the signals into a single device, which reduces experimental costs and simplifies data processing, because all data can be handled in the same data file. This technique will aid the understanding of the neurophysiological correlates of the associations between central and peripheral organs.

This study introduces a method for the simultaneous recording of local field potentials in the brain, electrocardiograms, electromyograms, and breathing signals of a freely moving rat. This technique, which reduces experimental costs and simplifies data analysis, will contribute to the understanding of the interactions between the brain and peripheral organs.

Gravações simultâneas de potenciais de campo corticais Local, eletrocardiograma, eletromiograma e respirar o ritmo de um rato andando livremente

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls ...

Noninvasive EEG Recordings from Freely Moving Piglets

The method allows the recording of high-quality electroencephalograms (EEGs) from freely moving piglets directly in the pigpen. We use a one-channel telemetric electroencephalography system in combination with standard self-adhesive hydrogel electrodes. The piglets are calmed down without the use of sedatives. After their release into the pigpen, the piglets behave normally&#8212;they drink and sleep in the same cycle as their siblings. Their sleep phases are used for the EEG recordings.

Here, we present a protocol to record telemetric electroencephalograms (EEGs) from freely moving piglets directly in the pigpen without the use of a sedative, making it possible to record typical EEG patterns during non-REM sleep, like spindle bursts.

Gravações de EEG não invasiva de leitões movimentando-se livremente

The method allows the recording of high-quality electroencephalograms (EEGs) from freely moving piglets directly in the pigpen. We use a one-channel ...

Microdialysis of Excitatory Amino Acids During EEG Recordings in Freely Moving Rats

Microdialysis is a well-established neuroscience technique that correlates the changes of neurologically active substances diffusing into the brain interstitial space with the behavior and/or with the specific outcome of a pathology (e.g., seizures for epilepsy). When studying epilepsy, the microdialysis technique is often combined with short-term or even long-term video-electroencephalography (EEG) monitoring to assess spontaneous seizure frequency, severity, progression and clustering. The combined microdialysis-EEG is based on the use of several methods and instruments. Here, we performed in vivo microdialysis and continuous video-EEG recording to monitor glutamate and aspartate outflow over time, in different phases of the natural history of epilepsy in a rat model. This combined approach allows the pairing of changes in the neurotransmitter release with specific stages of the disease development and progression. The amino acid concentration in the dialysate was determined by liquid chromatography. Here, we describe the methods and outline the principal precautionary measures one should take during in vivo microdialysis-EEG, with particular attention to the stereotaxic surgery, basal and high potassium stimulation during microdialysis, depth electrode EEG recording and high-performance liquid chromatography analysis of aspartate and glutamate in the dialysate. This approach may be adapted to test a variety of drug or disease induced changes of the physiological concentrations of aspartate and glutamate in the brain. Depending on the availability of an appropriate analytical assay, it may be further used to test different soluble molecules when employing EEG recording at the same time.

Here, we describe a method for in vivo microdialysis to analyze aspartate and glutamate release in the ventral hippocampus of epileptic and non-epileptic rats, in combination with EEG recordings. Extracellular concentrations of aspartate and glutamate may be correlated with the different phases of the disease.

Microdialysis de aminoácidos excitatórios durante as gravações de EEG em ratos movimentando-se livremente

Microdialysis is a well-established neuroscience technique that correlates the changes of neurologically active substances diffusing into the brain ...

Hybrid Microdrive System with Recoverable Opto-Silicon Probe and Tetrode for Dual-Site High Density Recording in Freely Moving Mice

Multi-regional neural recordings can provide crucial information to understanding fine-timescale interactions between multiple brain regions. However, conventional microdrive designs often only allow use of one type of electrode to record from single or multiple regions, limiting the yield of single-unit or depth profile recordings. It also often limits the ability to combine electrode recordings with optogenetic tools to target pathway and/or cell type specific activity. Presented here is a hybrid microdrive array for freely moving mice to optimize yield and a description of its fabrication and reuse of the microdrive array. The current design employs nine tetrodes and one opto-silicon probe implanted in two different brain areas simultaneously in freely moving mice. The tetrodes and the opto-silicon probe are independently adjustable along the dorsoventral axis in the brain to maximize the yield of unit and oscillatory activities. This microdrive array also incorporates a set-up for light, mediating optogenetic manipulation to investigate the regional- or cell type-specific responses and functions of long-range neural circuits. In addition, the opto-silicon probe can be safely recovered and reused after each experiment. Because the microdrive array consists of 3D-printed parts, the design of microdrives can be easily modified to accommodate various settings. First described is the design of the microdrive array and how to attach the optical fiber to a silicon probe for optogenetics experiments, followed by fabrication of the tetrode bundle and implantation of the array into a mouse brain. The recording of local field potentials and unit spiking combined with optogenetic stimulation also demonstrate feasibility of the microdrive array system in freely moving mice.

This protocol describes the construction of a hybrid microdrive array that allows implantation of nine independently adjustable tetrodes and one adjustable opto-silicon probe in two brain regions in freely moving mice. Also demonstrated is a method for safely recovering and reusing the opto-silicon probe for multiple purposes.

Sistema híbrido do Microdrive com a ponta de prova recuperável do opto-silicone e tetrode para a gravação high-density do duplo-local em ratos livremente moventes

Multi-regional neural recordings can provide crucial information to understanding fine-timescale interactions between multiple brain regions. However, ...

Multi-Fiber Photometry to Record Neural Activity in Freely-Moving Animals

Recording the activity of a group of neurons in a freely-moving animal is a challenging undertaking. Moreover, as the brain is dissected into smaller and smaller functional subgroups, it becomes paramount to record from projections and/or genetically-defined subpopulations of neurons. Fiber photometry is an accessible and powerful approach that can overcome these challenges. By combining optical and genetic methodologies, neural activity can be measured in deep brain structures by expressing genetically-encoded calcium indicators, which translate neural activity into an optical signal that can be easily measured. The current protocol details the components of a multi-fiber photometry system, how to access deep brain structures to deliver and collect light, a method to account for motion artifacts, and how to process and analyze fluorescent signals. The protocol details experimental considerations when performing single and dual color imaging, from either single or multiple implanted optic fibers.

This protocol details how to implement and perform multi-fiber photometry recordings, how to correct for calcium-independent artifacts, and important considerations for dual-color photometry imaging.

Fotometria de múltiplas fibras para gravar atividade neural em animais em movimento livre

Recording the activity of a group of neurons in a freely-moving animal is a challenging undertaking. Moreover, as the brain is dissected into smaller and ...

Wireless Electrophysiological Recording of Neurons by Movable Tetrodes in Freely Swimming Fish

The neural mechanisms governing fish behavior remain mostly unknown, although fish constitute the majority of all vertebrates. The ability to record brain activity from freely moving fish would advance research on the neural basis of fish behavior considerably. Moreover, precise control of the recording location in the brain is critical to studying coordinated neural activity across regions in fish brain. Here, we present a technique that records wirelessly from the brain of freely swimming fish while controlling for the depth of the recording location. The system is based on a neural logger associated with a novel water-compatible implant that can adjust the recording location by microdrive-controlled tetrodes. The capabilities of the system are illustrated through recordings from the telencephalon of goldfish.

A novel wireless technique for recording extracellular neural signals from the brain of freely swimming goldfish is presented. The recording device is composed of two tetrodes, a microdrive, a neural data logger, and a waterproof case. All parts are custom-made except for the data logger and its connector.

Gravação eletrofisiológica sem fio dos neurônios por tetrodes móveis em peixes livremente da natação

The neural mechanisms governing fish behavior remain mostly unknown, although fish constitute the majority of all vertebrates. The ability to record brain ...

Single-Cell Electroporation across Different Organotypic Slice Culture of Mouse Hippocampal Excitatory and Class-Specific Inhibitory Neurons

Electroporation has established itself as a critical method for transferring specific genes into cells to understand their function. Here, we describe a single-cell electroporation technique that maximizes the efficiency (~80%) of in vitro gene transfection in excitatory and class-specific inhibitory neurons in mouse organotypic hippocampal slice culture. Using large glass electrodes, tetrodotoxin-containing artificial cerebrospinal fluid and mild electrical pulses, we delivered a gene of interest into cultured hippocampal CA1 pyramidal neurons and inhibitory interneurons. Moreover, electroporation could be carried out in cultured hippocampal slices up to 21 days in vitro with no reduction in transfection efficiency, allowing for the study of varying slice culture developmental stages. With interest growing in examining the molecular functions of genes across a diverse range of cell types, our method demonstrates a reliable and straightforward approach to in vitro gene transfection in mouse brain tissue that can be performed with existing electrophysiology equipment and techniques.

Presented here is a protocol for single-cell electroporation that can deliver genes in both excitatory and inhibitory neurons across a range of in vitro hippocampal slice culture ages. Our approach provides precise and efficient expression of genes in individual cells, which can be used to examine cell-autonomous and intercellular functions.

Eletroporação unicelular em diferentes culturas organotipápicas de neurônios inibitórios hipocampais e inibidores específicos de classe

Electroporation has established itself as a critical method for transferring specific genes into cells to understand their function. Here, we describe a ...