Puncta Analyzer Plug-in para o Image J foi escrito por Barry Wark (endereço atual: Consultoria Physion) no laboratório de Ben A. Barres (Stanford University). Financiamento; <ul><li> Alfred P. Sloan Foundation </li><li> O A. Esther e José Klingenstein Fund, Inc. </li><li> Fundação de Pesquisa Biomédica ampla </li><li> Cura para a Iniciativa de Huntington s Disease </li></ul>

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Não há conflitos de interesse declarados.

O ensaio sinapse descrito acima é baseado no contexto de nossos objetivos experimental, no qual nos concentramos principalmente em projeções excitatórias do RGCs, seja na cultura ou purificada na seção cérebro. Nós fornecemos uma referência anticorpos tabela listando que funcionam bem para rotulagem sinapses excitatórias (Tabela 1). Este ensaio sinapse pode ser adaptado para a quantificação do número sinapse de uma população neuronal ou qualquer outro subtipo sináptico para o...

<table border="1" cellpadding="0" cellspacing="0"><tbody><tr><td></td><td> Antígeno </td><td> Espécies </td><td> Monoclonais / policlonais </td><td> Vendedor </td><td> Número de catálogo </td><td> Diluição </td><td> Trabalha em Cultura </td><td> Obras nas Seções </td></tr><tr><td rowspan="10"> Pré-sináptica </td><td> Sinapsina </td><td> Coelho </td><td> Policlonal </td><td> Sistemas Synaptic </td><td> 106004 </td><td> 1:750 </td><td> Y </td><td> ND </td></tr><tr><td> Sinapsina </td><td> Mouse </td><td> Monoclonal </td><td> Sistemas Synaptic </td><td> 106001 </td><td> 1:500 </td><td> Y </td><td> Y </td></tr><tr><td> Fagote </td><td> Mouse </td><td> Monoclonal </td><td> Designs ensaio </td><td> VAM-PS003F </td><td> 1:500 </td><td> Y </td><td> Y </td></tr><tr><td> Fagote </td><td> Cobaia </td><td> Policlonal </td><td> Sistemas Synaptic </td><td> 141004 </td><td> 1:1000 </td><td> Y </td><td> ND </td></tr><tr><td> Sinaptotagmina 1 </td><td> Coelho </td><td> Policlonal </td><td> Sistemas Synaptic </td><td> 105002 </td><td> 1:750 </td><td> Y </td><td> N </td></tr><tr><td> Sinaptobrevina 2 (C1.69.1) </td><td> Mouse </td><td> Monoclonal </td><td> Sistemas Synaptic </td><td> 104211 </td><td> 1:500 </td><td> Y </td><td> Y </td></tr><tr><td> Sinaptofisina (C1.7.2) </td><td> Mouse </td><td> Monoclonal </td><td> Sistemas Synaptic </td><td> 101011 </td><td> 1:500 </td><td> Y </td><td> Y </td></tr><tr><td> VGlut1 </td><td> Mouse </td><td> Monoclonal </td><td> Millipore </td><td> MAB5502 </td><td> 1:2500 </td><td> N </td><td> Y </td></tr><tr><td> VGlut1 </td><td> Cobaia </td><td> Policlonal </td><td> Millipore </td><td> AB5905 </td><td> 1:2500 </td><td> N </td><td> Y </td></tr><tr><td> VGlut2 </td><td> Cobaia </td><td> Policlonal </td><td> Millipore </td><td> AB2251 </td><td> 1:2500 </td><td> N </td><td> Y </td></tr><tr><td rowspan="6"> Pós-sinápticos </td><td> PSD-95 (6G6 1C9-clone) </td><td> Mouse </td><td> Monoclonal </td><td> Afinidade Bio Reagentes </td><td> MA1-045 </td><td> 1:750 </td><td> Y </td><td> N </td></tr><tr><td> PSD-95 </td><td> Coelho </td><td> Policlonal </td><td> Zymed </td><td> 51-6900 </td><td> 1:500 </td><td> N </td><td> Y </td></tr><tr><td> Pombo-correio </td><td> Mouse </td><td> Monoclonal </td><td> Sistemas Synaptic </td><td> 160011 </td><td> 1:500 </td><td> Y </td><td> ND </td></tr><tr><td> Pombo-correio </td><td> Rato </td><td> Policlonal </td><td> Millipore </td><td> AB5875 </td><td> 1:500 </td><td> Y </td><td> Y </td></tr><tr><td> Gephyrin </td><td> Coelho </td><td> Policlonal </td><td> Sistemas Synaptic </td><td> 147003 </td><td> 1:500 </td><td> Y </td><td> Y </td></tr><tr><td> Gephyrin </td><td> Mouse </td><td> Monoclonal </td><td> Sistemas Synaptic </td><td> 147 </td><td> 1:200 </td><td> Y </td><td> Y </td></tr></tbody></table> Tabela 1: Lista de exemplos de bons marcadores pré-e pós-sinápticos que temos utilizado com sucesso em nosso ensaio sinapse. Estar ciente de que esta não é uma lista exaustiva de todos os marcadores disponíveis. Y = Sim, N = Não, ND = não determinado. <table border="1" cellpadding="0" cellspacing="0"><tbody><tr><td> Reagente </td><td> Companhia </td><td> Gato. Não. </td></tr><tr><td> PBS </td><td> Invitrogen </td><td> 20012-027 </td></tr><tr><td> poli-d-lisina </td><td> Sigma </td><td> P6407 </td></tr><tr><td> Laminina </td><td> Cultrex </td><td> 3400-010-01 </td></tr><tr><td> Triton X-100 </td><td> Roche Diagnostics Gmbh </td><td> 9002-93-1 </td></tr><tr><td> Soro normal de cabra </td><td> Gibco </td><td> 16210 </td></tr><tr><td> VectaShield com DAPI </td><td> Vector Laboratories </td><td> H-1200 </td></tr><tr><td> Outubro </td><td> Tissue-Tek </td><td> 4583 </td></tr><tr><td> Tris-Base (50 mM) </td><td> Pescador </td><td> BP152-5 </td></tr><tr><td> Albumina de soro bovino </td><td> Sigma </td><td> A2153 </td></tr><tr><td> l-lisina </td><td> Sigma </td><td> L-1137 </td></tr><tr><td> 16% de solução PFA </td><td> Microscopia Eletrônica de Ciências </td><td> 15711 </td></tr><tr><td> PFA granular </td><td> Microscopia Eletrônica de Ciências </td><td> 19210 </td></tr><tr><td> 24 poços placa de cultura </td><td> Falcão </td><td> 35-3047 </td></tr><tr><td> Anticorpos de cabra anti-camundongo conjugado Alexa </td><td> Invitrogen </td><td> --- </td></tr><tr><td> Fornecimento </td><td> Companhia </td><td> Gato. Não. </td></tr><tr><td> 12mm, n º 0 lamínulas de vidro </td><td> Karl Hecht Gmbh </td><td> 1105209 </td></tr><tr><td> No. 1,5 vidro lamela (para fatias) </td><td> VWR Scientific </td><td> 48393241 </td></tr><tr><td> Lâminas de vidro </td><td> VWR Scientific </td><td> 48311-703 </td></tr></tbody></table>

quantifying synapses: an immunocytochemistry-based assay to quantify synapse number

Um dos objetivos mais importantes da neurociência é entender os sinais moleculares que instruem estágios iniciais da formação de sinapses. Como tal, tornou-se imperativo para desenvolver abordagens objetivo de quantificar alterações na conectividade sináptica. A partir de fixação da amostra, este protocolo detalhes como quantificar o número sinapse neuronal tanto na cultura dissociada e nas seções do cérebro utilizando imunocitoquímica. Usando compartimento de anticorpos específicos, nós rótulo terminais pré-sinápticos, bem como sites de especialização pós-sináptica. Nós definimos sinapses como pontos de co-localização entre os sinais gerados por estes marcadores. O número dessas colocalizations é quantificado através de um plug in puncta Analyzer (escrito por Bary Wark, disponível mediante solicitação, c.eroglu cellbio.duke.edu @), sob a plataforma de software de análise de ImageJ. O ensaio sinapse descritos neste protocolo pode ser aplicado a qualquer preparação de tecidos e cultura neural para o qual você tem seletiva marcadores pré-e pós-sináptica. Este ensaio sinapse é uma ferramenta valiosa que pode ser amplamente utilizada no estudo do desenvolvimento sináptica.

Watch this Scientific Journal Video about Quantifying Synapses: an Immunocytochemistry-based Assay to Quantify Synapse Number at JoVE.com

Quantifying Synapses: an Immunocytochemistry-based Assay to Quantify Synapse Number

Este protocolo detalhes como quantificar o número sinapse neuronal tanto na cultura dissociada e nas seções do cérebro utilizando imunocitoquímica. Usando compartimento de anticorpos específicos, nós rótulo terminais pré-sinápticos, bem como sites de especialização pós-sináptica. Nós definimos sinapses como pontos de co-localização entre os sinais gerados por estes marcadores.

Sinapses quantificar: um ensaio baseado em Imunocitoquímica para a quantificação do número Synapse

One of the most important goals in neuroscience is to understand the molecular cues that instruct early stages of synapse formation. As such it has become ...

quantifying-synapses-an-immunocytochemistry-based-assay-to-quantify

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

35.6K visualizações.  Duke University. Este protocolo detalhes como quantificar o número sinapse neuronal tanto na cultura dissociada e nas seções do cérebro utilizando imunocitoquímica. Usando compartimento de anticorpos específicos, nós rótulo terminais pré-sinápticos, bem como sites de especialização pós-sináptica. Nós definimos sinapses como pontos de co-localização entre os sinais gerados por estes marcadores.

Vídeo: Quantifying Synapses: an Immunocytochemistry-based Assay to Quantify Synapse Number

Automated Quantification of Synaptic Fluorescence in C. elegans

Synapse strength refers to the amplitude of postsynaptic responses to presynaptic neurotransmitter release events, and has a major impact on overall neural circuit function. Synapse strength critically depends on the abundance of neurotransmitter receptors clustered at synaptic sites on the postsynaptic membrane. Receptor levels are established developmentally, and can be altered by receptor trafficking between surface-localized, subsynaptic, and intracellular pools, representing important mechanisms of synaptic plasticity and neuromodulation. Rigorous methods to quantify synaptically-localized neurotransmitter receptor abundance are essential to study synaptic development and plasticity. Fluorescence microscopy is an optimal approach because it preserves spatial information, distinguishing synaptic from non-synaptic pools, and discriminating among receptor populations localized to different types of synapses. The genetic model organism Caenorhabditis elegans is particularly well suited for these studies due to the small size and relative simplicity of its nervous system, its transparency, and the availability of powerful genetic techniques, allowing examination of native synapses in intact animals.
Here we present a method for quantifying fluorescently-labeled synaptic neurotransmitter receptors in C. elegans. Its key feature is the automated identification and analysis of individual synapses in three dimensions in multi-plane confocal microscope output files, tabulating position, volume, fluorescence intensity, and total fluorescence for each synapse. This approach has two principal advantages over manual analysis of z-plane projections of confocal data. First, because every plane of the confocal data set is included, no data are lost through z-plane projection, typically based on pixel intensity averages or maxima. Second, identification of synapses is automated, but can be inspected by the experimenter as the data analysis proceeds, allowing fast and accurate extraction of data from large numbers of synapses. Hundreds to thousands of synapses per sample can easily be obtained, producing large data sets to maximize statistical power. Considerations for preparing C. elegans for analysis, and performing confocal imaging to minimize variability between animals within treatment groups are also discussed. Although developed to analyze C. elegans postsynaptic receptors, this method is generally useful for any type of synaptically-localized protein, or indeed, any fluorescence signal that is localized to discrete clusters, puncta, or organelles.
The procedure is performed in three steps: 1) preparation of samples, 2) confocal imaging, and 3) image analysis. Steps 1 and 2 are specific to C. elegans, while step 3 is generally applicable to any punctate fluorescence signal in confocal micrographs.

Automated Quantification of Synaptic Fluorescence in C. elegans

The abundance of neurotransmitter receptors clustered at synapses strongly influences synaptic strength. This method quantifies fluorescently-labeled neurotransmitter receptors in three dimensions with single-synapse resolution in C. elegans, allowing hundreds of synapses to be rapidly characterized within a single sample without distortions introduced by z-plane projection.

Quantificação automatizada de fluorescência em Synaptic<em&gt; C. elegans</em

Synapse strength refers to the amplitude of postsynaptic responses to presynaptic neurotransmitter release events, and has a major impact on overall ...

Neurociência

DetectSyn: A Rapid, Unbiased Fluorescent Method to Detect Changes in Synapse Density

Synapses are the site of communication between neurons. Neuronal circuit strength is related to synaptic density, and the breakdown of synapses is characteristic of disease states like major depressive disorder (MDD) and Alzheimer's disease. Traditional techniques to investigate synapse numbers include genetic expression of fluorescent markers (e.g., green fluorescent protein (GFP)), dyes that fill a neuron (e.g., carbocyanine dye, DiI), and immunofluorescent detection of spine markers (e.g., postsynaptic density 95 (PSD95)). A major caveat to these proxy techniques is that they only identify postsynaptic changes. Yet, a synapse is a connection between a presynaptic terminal and a postsynaptic spine. The gold standard for measuring synapse formation/elimination requires time-consuming electron microscopy or array tomography techniques. These techniques require specialized training and costly equipment. Further, only a limited number of neurons can be assessed and are used to represent changes to an entire brain region. DetectSyn is a rapid fluorescent technique that identifies changes to synapse formation or elimination due to a disease state or drug activity. DetectSyn utilizes a rapid proximity ligation assay to detect juxtaposed pre- and postsynaptic proteins and standard fluorescent microscopy, a technique readily available to most laboratories. Fluorescent detection of the resulting puncta allows for quick and unbiased analysis of experiments. DetectSyn provides more representative results than electron microscopy because larger areas can be analyzed than a limited number of fluorescent neurons. Moreover, DetectSyn works for in vitro cultured neurons and fixed tissue slices. Finally, a method is provided to analyze the data collected from this technique. Overall, DetectSyn offers a procedure for detecting relative changes in synapse density across treatments or disease states and is more accessible than traditional techniques.

DetectSyn is an unbiased, rapid fluorescent assay that measures changes in relative synapse (pre- and postsynaptic engagement) number across treatments or disease states. This technique utilizes a proximity ligation technique that can be used both in cultured neurons and fixed tissue.

DetectSyn: um método fluorescente rápido e imparcial para detectar alterações na densidade da sinapse

Synapses are the site of communication between neurons. Neuronal circuit strength is related to synaptic density, and the breakdown of synapses is ...

Bioquímica

A High Content Imaging Assay for Identification of Botulinum Neurotoxin Inhibitors

Synaptosomal-associated protein-25 (SNAP-25) is a component of the soluble NSF attachment protein receptor (SNARE) complex that is essential for synaptic neurotransmitter release. Botulinum neurotoxin serotype A (BoNT/A) is a zinc metalloprotease that blocks exocytosis of neurotransmitter by cleaving the SNAP-25 component of the SNARE complex. Currently there are no licensed medicines to treat BoNT/A poisoning after internalization of the toxin by motor neurons. The development of effective therapeutic measures to counter BoNT/A intoxication has been limited, due in part to the lack of robust high-throughput assays for screening small molecule libraries. Here we describe a high content imaging (HCI) assay with utility for identification of BoNT/A inhibitors. Initial optimization efforts focused on improving the reproducibility of inter-plate results across multiple, independent experiments. Automation of immunostaining, image acquisition, and image analysis were found to increase assay consistency and minimize variability while enabling the multiparameter evaluation of experimental compounds in a murine motor neuron system.

Botulinum neurotoxin is one of the most potent toxins among Category-A biothreat agents, yet a post-exposure therapeutic is not available. The high content imaging approach is a powerful methodology for identifying novel inhibitors as it enables multiparameter screening using biologically relevant motor neurons, the primary target of this toxin.

A alta Ensaio imagem Conteúdo de Identificação da neurotoxina botulínica Inibidores

Synaptosomal-associated protein-25 (SNAP-25) is a component of the soluble NSF attachment protein receptor (SNARE) complex that is essential for synaptic ...

Qualitative and Quantitative Analysis of the Immune Synapse in the Human System Using Imaging Flow Cytometry

The immune synapse is the area of communication between T cells and antigen-presenting cells (APCs). T cells polarize surface receptors and proteins towards the immune synapse to assure a stable binding and signal exchange. Classical confocal, TIRF, or super-resolution microscopy have been used to study the immune synapse. Since these methods require manual image acquisition and time-consuming quantification, the imaging of rare events is challenging. Here, we describe a workflow that enables the morphological analysis of tens of thousands of cells. Immune synapses are induced between primary human T cells in pan-leukocyte preparations and Staphylococcus aureus enterotoxin B (SEB)-loaded Raji cells as APCs. Image acquisition is performed with imaging flow cytometry, also called In-Flow microscopy, which combines features of a flow cytometer and a fluorescence microscope. A complete gating strategy for identifying T cell/APC couples and analyzing the immune synapses is provided. As this workflow allows the analysis of immune synapses in unpurified pan-leukocyte preparations and hence requires only a small volume of blood (i.e., 1 mL), it can be applied to samples from patients. Importantly, several samples can be prepared, measured, and analyzed in parallel.

Here, we describe a complete workflow for the qualitative and quantitative analysis of immune synapses between primary human T cells and antigen-presenting cells. The method is based on imaging flow cytometry, which allows the acquisition and evaluation of several thousand cell images within a relatively short period of time.

Análise qualitativa e quantitativa de sinapse imunológica no sistema humano usando a imagem latente de citometria de fluxo

The immune synapse is the area of communication between T cells and antigen-presenting cells (APCs). T cells polarize surface receptors and proteins ...

Imunologia e Infecção

Evaluation of Synapse Density in Hippocampal Rodent Brain Slices

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

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

Avaliação da densidade de sinapse em fatias Hippocampal cérebro de roedor

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

An Optical Assay for Synaptic Vesicle Recycling in Cultured Neurons Overexpressing Presynaptic Proteins

At active presynaptic nerve terminals, synaptic vesicles undergo cycles of exo- and endocytosis. During recycling, the luminal domains of SV transmembrane proteins become exposed at the cell surface. One of these proteins is Synaptotagmin-1 (Syt1). An antibody directed against the luminal domain of Syt1, once added to the culture medium, is taken up during the exo-endocytotic cycle. This uptake is proportional to the amount of SV recycling and can be quantified through immunofluorescence. Here, we combine Syt1 antibody uptake with double transfection of cultured hippocampal neurons. This allows us to (1) localize presynaptic sites based on expression of recombinant presynaptic marker Synaptophysin, (2) determine their functionality using Syt1 uptake, and (3) characterize the targeting and effects of a protein of interest, GFP-Rogdi.

We describe an optical assay for synaptic vesicle (SV) recycling in cultured neurons. Combining this protocol with double transfection to express a presynaptic marker and protein of interest allows us to locate presynaptic sites, their synaptic vesicle recycling capacity, and determine the role of the protein of interest.

Um ensaio óptico para vesícula sináptica reciclagem nos neurônios cultivados superexpressão de proteínas pré-sináptica

At active presynaptic nerve terminals, synaptic vesicles undergo cycles of exo- and endocytosis. During recycling, the luminal domains of SV transmembrane ...

Imaging the Human Immunological Synapse

The purpose of the method is to generate an immunological synapse (IS), an example of cell-to-cell conjugation formed by an antigen-presenting cell (APC) and an effector helper T lymphocyte (Th) cell, and to record the images corresponding to the first stages of the IS formation and the subsequent trafficking events (occurring both in the APC and in the Th cell). These events will eventually lead to polarized secretion at the IS. In this protocol, Jurkat cells challenged with Staphylococcus enterotoxin E (SEE)-pulsed Raji cells as a cell synapse model was used, because of the closeness of this experimental system to the biological reality (Th cell-APC synaptic conjugates). The approach presented here involves cell-to-cell conjugation, time-lapse acquisition, wide-field fluorescence microscopy (WFFM) followed by image processing (post-acquisition deconvolution). This improves the signal-to-noise ratio (SNR) of the images, enhances the temporal resolution, allows the synchronized acquisition of several fluorochromes in emerging synaptic conjugates and decreases fluorescence bleaching. In addition, the protocol is well matched with the end point cell fixation protocols (paraformaldehyde, acetone or methanol), which would allow further immunofluorescence staining and analyses. This protocol is also compatible with laser scanning confocal microscopy (LSCM) and other state-of-the-art microscopy techniques. As a main caveat, only those T cell-APC boundaries (called IS interfaces) that were at the right 90&#176; angle to the focus plane along the Z-axis could be properly imaged and analyzed. Other experimental models exist that simplify imaging in the Z dimension and the following image analyses, but these approaches do not emulate the complex, irregular surface of an APC, and may promote non-physiological interactions in the IS. Thus, the experimental approach used here is suitable to reproduce and to confront some biological complexities occurring at the IS.

This protocol images both the immunological synapse formation and the subsequent polarized secretory traffic towards the immunological synapse. Cellular conjugates were formed between a superantigen-pulsed Raji cell (acting as an antigen-presenting cell) and a Jurkat clone (acting as an effector helper T lymphocyte).

Imagem da Sinapse Imunológica Humana

The purpose of the method is to generate an immunological synapse (IS), an example of cell-to-cell conjugation formed by an antigen-presenting cell (APC) ...

Quantifying the Heterogeneous Distribution of a Synaptic Protein in the Mouse Brain Using Immunofluorescence

The presence, absence, or levels of specific synaptic proteins can severely influence synaptic transmission. In addition to elucidating the function of a protein, it is vital to also determine its distribution. Here, we describe a protocol employing immunofluorescence, confocal microscopy, and computer-based analysis to determine the distribution of the synaptic protein Mover (also called TPRGL or SVAP30). We compare the distribution of Mover to that of the synaptic vesicle protein synaptophysin, thereby determining the distribution of Mover in a quantitative manner relative to the abundance of synaptic vesicles. Notably, this method could potentially be implemented to allow for comparison of the distribution of proteins using different antibodies or microscopes or across different studies. Our method circumvents the inherent variability of immunofluorescent stainings by yielding a ratio rather than absolute fluorescence levels. Additionally, the method we describe enables the researcher to analyze the distribution of a protein on different levels: from whole brain slices to brain regions to different subregions in one brain area, such as the different layers of the hippocampus or sensory cortices. Mover is a vertebrate-specific protein that is associated with synaptic vesicles. With this method, we show that Mover is heterogeneously distributed across brain areas, with high levels in the ventral pallidum, the septal nuclei, and the amygdala, and also within single brain areas, such as the different layers of the hippocampus.

Here, we describe a quantitative approach to determining the distribution of a synaptic protein relative to a marker protein using immunofluorescence staining, confocal microscopy, and computer-based analysis.

Quantificar a distribuição heterogênea de uma proteína sináptica no cérebro do rato utilizando imunofluorescência

The presence, absence, or levels of specific synaptic proteins can severely influence synaptic transmission. In addition to elucidating the function of a ...

A Time-Efficient Fluorescence Spectroscopy-Based Assay for Evaluating Actin Polymerization Status in Rodent and Human Brain Tissues

Actin, the major component of cytoskeleton, plays a critical role in the maintenance of neuronal structure and function. Under physiological states, actin occurs in equilibrium in its two forms: monomeric globular (G-actin) and polymerized filamentous (F- actin). At the synaptic terminals, actin cytoskeleton forms the basis for critical pre- and post-synaptic functions. Moreover, dynamic changes in the actin polymerization status (interconversion between globular and filamentous forms of actin) are closely linked to plasticity-related alterations in synaptic structure and function. We report here a modified fluorescence-based methodology to assess polymerization status of actin in ex vivo conditions. The assay employs fluorescently labelled phalloidin, a phallotoxin that specifically binds to actin filaments (F-actin), providing a direct measure of polymerized filamentous actin. As a proof of principle, we provide evidence for the suitability of the assay both in rodent and post-mortem human brain tissue homogenates. Using latrunculin A (a drug that depolymerizes actin filaments), we confirm the utility of the assay in monitoring alterations in F-actin levels. Further, we extend the assay to biochemical fractions of isolated synaptic terminals wherein we confirm increased actin polymerization upon stimulation by depolarization with high extracellular K+.

We report a simple, time-efficient and high-throughput fluorescence spectroscopy-based assay for the quantification of actin filaments in ex vivo biological samples from brain tissues of rodents and human subjects.

Um ensaio baseado em espectroscopia de fluorescência com eficiência temporal para avaliar o status de polimerização de actina em roedores e tecidos cerebrais humanos

Actin, the major component of cytoskeleton, plays a critical role in the maintenance of neuronal structure and function. Under physiological states, actin ...

Ensaios baseados em citometria de fluxo para engolfamento microglial de materiais sinápticos

Quantification of Microglial Engulfment of Synaptic Material Using Flow Cytometry

Microglia play a pivotal role in synaptic refinement in the brain. Analysis of microglial engulfment of synapses is essential for comprehending this process; however, currently available methods for identifying microglial engulfment of synapses, such as immunohistochemistry (IHC) and imaging, are laborious and time-intensive. To address this challenge, herein we present in vitro and in vivo* assays that allow fast and high-throughput quantification of microglial engulfment of synapses using flow cytometry.
In the in vivo* approach, we performed intracellular vGLUT1 staining following fresh cell isolation from adult mouse brains to quantify engulfment of vGLUT1+ synapses by microglia. In the in vitro synaptosome engulfment assay, we used freshly isolated cells from the adult mouse brain to quantify the engulfment of pHrodo&#160;Red-labeled synaptosomes by microglia. These protocols together provide a time-efficient approach to quantifying microglial engulfment of synapses and represent promising alternatives to labor-intensive image analysis-based methods. By streamlining the analysis, these assays can contribute to a better understanding of the role of microglia in synaptic refinement in different disease models.

Autor em destaque: Avançando a compreensão por meio de inovações tecnológicas em psiconeuroimunologia

Here we present two protocols to quantify microglial engulfment of vGLUT1-positive synapses and pHRodo&#160;Red-labeled crude synaptosomes using flow cytometry.

Quantificação do engolfamento microglial de material sináptico usando citometria de fluxo

Microglia play a pivotal role in synaptic refinement in the brain. Analysis of microglial engulfment of synapses is essential for comprehending this ...