Queremos agradecer a los Dres. Ping Zhu y Koyama Susumu por su ayuda durante la configuración inicial de la técnica, y la Dra. Verónica Alvarez de asistencia en el formato del manuscrito. Este estudio fue financiado por la División de Investigación Intramural clínica y biomédica de NIAAA.

<ol>
	<li>Zhu, P. J., Lovinger, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ethanol+potentiates+gabaergic+synaptic+transmission+in+a+postsynaptic+neuron/synaptic+bouton+preparation+from+basolateral+amygdala.">Ethanol potentiates gabaergic synaptic transmission in a postsynaptic neuron/synaptic bouton preparation from basolateral amygdala.</a> J Neurophysiol. 96, 433-441 (2006).</li><li>Zhu, P. J., Lovinger, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retrograde+endocannabinoid+signaling+in+a+postsynaptic+neuron/synaptic+bouton+preparation+from+basolateral+amygdala.">Retrograde endocannabinoid signaling in a postsynaptic neuron/synaptic bouton preparation from basolateral amygdala.</a> J Neurosci. 25, 6199-6207 (2005).</li><li>Akaike, N., Moorhouse, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Techniques:+Applications+of+the+nerve-bouton+preparation+in+neuropharmacology.">Techniques: Applications of the nerve-bouton preparation in neuropharmacology.</a> Trends Pharmacol Sci. 24, 44-47 (2003).</li><li>Akaike, N., Murakami, N., Katsurabayashi, S., Jin, Y. H., Imazawa, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Focal+stimulation+of+single+gabaergic+presynaptic+boutons+on+the+rat+hippocampal+neuron.">Focal stimulation of single gabaergic presynaptic boutons on the rat hippocampal neuron.</a> Neurosci Res. 42, 187-195 (2002).</li><li>Ye, J. H., Wang, F., Krnjevic, K., Wang, W., Xiong, Z. G., Zhang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Presynaptic+glycine+receptors+on+gabaergic+terminals+facilitate+discharge+of+dopaminergic+neurons+in+ventral+tegmental+area.">Presynaptic glycine receptors on gabaergic terminals facilitate discharge of dopaminergic neurons in ventral tegmental area.</a> J Neurosci. 24, 8961-8974 (2004).</li><li>Koyama, S., Matsumoto, N., Kubo, C., Akaike, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Presynaptic+5-ht3+receptor-mediated+modulation+of+synaptic+gaba+release+in+the+mechanically+dissociated+rat+amygdala+neurons.">Presynaptic 5-ht3 receptor-mediated modulation of synaptic gaba release in the mechanically dissociated rat amygdala neurons.</a> J Physiol. 529, 373-383 (2000).</li><li>Deng, C., Li, K. Y., Zhou, C., Ye, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ethanol+enhances+glutamate+transmission+by+retrograde+dopamine+signaling+in+a+postsynaptic+neuron/synaptic+bouton+preparation+from+the+ventral+tegmental+area.">Ethanol enhances glutamate transmission by retrograde dopamine signaling in a postsynaptic neuron/synaptic bouton preparation from the ventral tegmental area.</a> Neuropsychopharmacology. 34, 1233-1244 (2009).</li><li>Murakami, N., Ishibashi, H., Katsurabayashi, S., Akaike, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+channel+subtypes+on+single+gabaergic+presynaptic+terminal+projecting+to+rat+hippocampal+neurons.">Calcium channel subtypes on single gabaergic presynaptic terminal projecting to rat hippocampal neurons.</a> Brain Res. 951, 121-129 (2002).</li><li>Zhu, P. J., Lovinger, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Persistent+synaptic+activity+produces+long-lasting+enhancement+of+endocannabinoid+modulation+and+alters+long-term+synaptic+plasticity.">Persistent synaptic activity produces long-lasting enhancement of endocannabinoid modulation and alters long-term synaptic plasticity.</a> J Neurophysiol. 97, 4386-4389 (2007).</li><li>Inada, H., Maejima, T., Nakahata, Y., Yamaguchi, J., Nabekura, J., Ishibashi, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endocannabinoids+contribute+to+metabotropic+glutamate+receptor-mediated+inhibition+of+gaba+release+onto+hippocampal+ca3+pyramidal+neurons+in+an+isolated+neuron/bouton+preparation.">Endocannabinoids contribute to metabotropic glutamate receptor-mediated inhibition of gaba release onto hippocampal ca3 pyramidal neurons in an isolated neuron/bouton preparation.</a> Neuroscience. 165, 1377-1389 (2010).</li><li>Miesenbock, G., De Angelis, D. A., Rothman, 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=Visualizing+secretion+and+synaptic+transmission+with+ph-sensitive+green+fluorescent+proteins.">Visualizing secretion and synaptic transmission with ph-sensitive green fluorescent proteins.</a> Nature. 394, 192-195 (1998).</li><li>Li, Z., Burrone, J., Tyler, W. J., Hartman, K. N., Albeanu, D. F., Murthy, V. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synaptic+vesicle+recycling+studied+in+transgenic+mice+expressing+synaptophluorin.">Synaptic vesicle recycling studied in transgenic mice expressing synaptophluorin.</a> Proc Natl Acad Sci U S A. 102, 6131-6136 (2005).</li></ol>

Vibrodissociation requiere que las rebanadas contienen las neuronas sanas y que los espacios intersticiales son lo suficientemente flexibles para permitir a las neuronas para salir de la corte sin daño tóxico. Por lo tanto, la técnica funciona de manera óptima en las primeras edades posnatales (P1-21) cuando rebanadas sano se puede hacer con menos material gliales / interstiatial que se encuentra en rodajas de cerebro de un adulto. En nuestra experiencia, sin embargo, la optimización de la preparación de división para la supervivencia neuronal en el corte en sí mismo puede ser contraproducente para la técnica de vibrodissociation. Mientras que de manera rutinaria para preparar cortes en la grabación in situ utilizando LCRa frío modificada en la que la sacarosa se ​​ha sustituido por la mayor parte del Na + extracelular y Ca 2 +, rebanadas preparado para vibrodissociation se puede preparar (por ejemplo, corte) en nuestro LCRa grabación normal. En la preparación de cortes para la grabación de las neuronas individuales en los mismos cortes que también ponga las rebanadas en ACSF normal a 35 ° C justo después de la sección y se dejan durante 30-60 min a esta temperatura antes de devolverlos a temperatura ambiente. Sin embargo, las rebanadas preparado para vibrodissociation se trasladó inmediatamente a temperatura ambiente justo después de cortar. Estos procedimientos proporcionan un mayor rendimiento de las neuronas sanas después de vibrodissociation, quizás debido a la falta de tejido firme intersticial que permite que las neuronas sean más fácilmente sacudido de la misma rebanada. No hemos examinado exhaustivamente las condiciones de corte de preparación, ya que habitualmente obtienen las neuronas suficientes para nuestra grabación y experimentos de imagen en un día determinado. Es posible que las modificaciones adicionales, tales como cambios en el grosor de corte o procedimientos preincubaton, se podría hacer para aumentar el rendimiento de las neuronas sanas. Tratamientos de la proteasa muy leves han sido probados en un esfuerzo por aumentar el rendimiento celular y obtener la técnica para trabajar en los animales más viejos. Sin embargo, invariablemente, incluso el tratamiento de la proteasa leve parece alterar la función sináptica. Así, mientras que la combinación de la proteasa y la disociación mecánica todavía se pueden encontrar para trabajar, no ha demostrado ser fiable en las neuronas del cerebro anterior a la fecha. También debe tenerse en cuenta el rendimiento relativamente bajo de las neuronas sanas después de vibrodissociation significa que la técnica es especialmente útil para el estudio de abundante subtipos neuronales, principalmente las neuronas de proyección. La disponibilidad de las buenas prácticas agrarias-que expresa los ratones en los que pequeñas subpoblaciones neuronales pueden ser fácilmente identificados aumenta la posibilidad de estudiar estas neuronas más raro. Sin embargo, a menos que el rendimiento neuronal se puede mejorar sustancialmente la acumulación de datos sobre estas neuronas es probable que sea relativamente lenta. Varias medidas han demostrado ser crucial para el éxito de carga de las neuronas sensibles al calcio con colorantes. La exposición a la PM-esterificados tinte se realiza a 37 ° C, y que no han tenido éxito al tratar de colorante de carga a temperaturas más bajas. La concentración de los colorantes deben ser optimizados teniendo en cuenta tanto el tiempo de carga y la temperatura, ya que parece que la mayor concentración de colorante de carga reduce la concentración de calcio en el boutons presináptica. Hemos observado que la carga con una mayor concentración disminuye la frecuencia y la amplitud de sIPSCs. Cuando la carga sensible al calcio en los tintes terminales presinápticas de las neuronas vibrodissociated, se debe tener cuidado, porque la capacidad amortiguadora de la boutons presináptica pequeña puede ser diferente que en el soma y el tamaño de boutons no son consistentes. Las neuronas que contienen los platos se lavan con solución amortiguadora HEPES-externa después de colorante de carga, y el tiempo de recuperación después del lavado es crucial. Además, para lograr un buen sello de células enteras de grabación, las células se deben lavar a fondo para deshacerse de los no internalizan las moléculas del tinte de la membrana celular externa. Además de usar las neuronas vibrodissociated de imágenes de células de electrofisiología y en directo, las técnicas de inmunohistoquímica también se puede aplicar a estas células 11,12. Las células se pueden fijar fácilmente y se tiñeron con una variedad de anticuerpos, y otros marcadores de la célula. El uso de estas células proporciona una preparación de limpieza para la visualización de la expresión de proteínas en GABAérgicas terminales presinápticos. Utilizando ratones que expresan proteínas fluorescentes bajo el control de promotores específicos de las neuronas GABAérgicas permite al investigador para identificar los terminales sinápticos individuales en la preparación de la vibrodissociated (Figura 1). Marcadores fluorescentes de imágenes de este tipo puede permitir mediciones morfológicas en las terminales de uso basada en el láser y nuevas técnicas de microscopía como STED (Emisión Estimulación Microscopía agotamiento). Visualización con tintes que el informe de ciclismo vesículas sinápticas también es posible con esta preparación. Akaike y compañeros de trabajo han etiquetado terminales GABAérgicas con el tinte estirilo, FM1-43 para visualizar las terminales de las células vivas 4. También debería ser posible llevar a cabo una sola célula de la transcriptasa inversa PCR al perfil de la expresión del ARN en vibrodissociatedlas neuronas. Esta técnica se aplica habitualmente a enzimáticamente disociarse las neuronas y las neuronas en cultivos celulares.

<table border="1"><tbody><tr><td> Artículo </td><td> Empresa </td><td> Catálogo # </td><td> Comentarios </td></tr><tr><td> Vibrando Slicer tejido </td><td> Leica Microsystems Inc. </td><td> VT1200S </td><td></td></tr><tr><td> Placa de cultivo celular (35 mm) </td><td> BD Falcon </td><td> 353001 </td><td></td></tr><tr><td> Platos con fondo de cristal </td><td> Willco plato </td><td> GWSB O-5040-3522 GWSB </td><td> 0,16-0,19 mm de espesor de vidrio para la imagen </td></tr><tr><td> Manipulador piezoeléctricos </td><td> EXFO-Burleigh </td><td> LSS-3000 </td><td> También puede utilizar relés, etc </td></tr><tr><td> SD9 Plaza de estimulador de impulsos </td><td> Tecnologías de la hierba </td><td> SD9K </td><td> Para activar manipulador piezoeléctricos </td></tr><tr><td> Disección Estereoscopio </td><td> Salvaje Heerbrugg </td><td> TYP 374590 </td><td> También puede utilizar cualquier estereoscopio </td></tr><tr><td> Flaming / Brown micropipeta extractor </td><td> Sutter Instrumento </td><td> P-97 </td><td></td></tr><tr><td> Pared Delgada capilares de vidrio </td><td> Mundial de Instrumentos de Precisión </td><td> TW-150F-4 </td><td> De la llama de vidrio selladas micropipeta y micropipeta parche </td></tr><tr><td> Seis canales de perfusión sistemas de válvulas de control </td><td> Warner Instrumentos </td><td> VC-6 o VC-6M </td><td></td></tr><tr><td> Perfusión rápida Paso </td><td> Warner Instrumentos </td><td> SF-77B </td><td></td></tr><tr><td> Microscopio invertido con 20-63x objetivos </td><td> Nikon </td><td> TS200 Diaphot </td><td></td></tr><tr><td> EMCCD Cámara </td><td> Andor Technology </td><td> ixon EM + DU-888 </td><td></td></tr><tr><td> Excite iluminación de fluorescencia fuente de luz </td><td> EXFO Fotónica Solutions Inc. </td><td> X-Cite 120PC </td><td></td></tr><tr><td> Fluo-4, AM indicador de calcio </td><td> Las sondas moleculares </td><td> F14201 </td><td></td></tr></tbody></table>

vibrodissociation of neurons from rodent brain slices to study synaptic transmission and image presynaptic terminals

Disociación mecánica de las neuronas del sistema nervioso central tiene la ventaja de que boutons presináptica de permanecer unidos a la neurona aislada de interés. Esto permite un examen de la transmisión sináptica en condiciones en los ambientes intracelular extracelular y postsinápticos se puede controlar bien. Una técnica basada en la vibración sin el uso de proteasas, conocidos como vibrodissociation, es la técnica más popular para aislamiento mecánico. Una micropipeta, con la punta pulida al fuego a la forma de una pelota pequeña, se coloca en una rebanada del cerebro a partir de una P1-P21 roedores. La micropipeta se vibra paralelo a la superficie de corte y baja a través del grosor de corte que resulta en la liberación de neuronas aisladas. Las neuronas aisladas están listos para su estudio a pocos minutos de vibrodissociation. Esta técnica tiene ventajas sobre el uso de cultivos primarios de neuronas, las secciones de cerebro y las neuronas aisladas enzimáticamente, incluyendo: una rápida producción de neuronas viables, relativamente maduros adecuados para estudios electrofisiológicos y de imagen, mayor control del medio ambiente extracelular libre de la influencia de las células vecinas; idoneidad para bien controlados experimentos farmacológicos utilizando la aplicación del fármaco y la rápida superfusión total de células, y la mejora del espacio-clamp en células enteras grabaciones en relación con las neuronas en el segmento o preparaciones de cultivo de células. Esta preparación se puede utilizar para examinar la fisiología sináptica, la farmacología, la modulación y plasticidad. Imágenes en tiempo real tanto de los elementos pre-y post-sinápticas en las células vivas y boutons También es posible usar las neuronas vibrodissociated. Caracterización de los componentes moleculares de los elementos pre-y post-sináptica también se puede lograr con los métodos inmunológicos y de imágenes basadas en.

Watch this Scientific Journal Video about Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals at JoVE.com

Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals

Este informe demuestra una técnica para aislamiento mecánico de las neuronas individuales viable mantener unido boutons presináptica. Vibrodissociated neuronas tienen la ventaja de una rápida producción, el control farmacológico excelente y mejora del espacio-clamp sin la influencia de las células vecinas. Este método puede ser utilizado para obtener imágenes de los elementos sináptica y la grabación de patch-clamp.

Vibrodissociation de las neuronas del cerebro de roedores Rodajas para el Estudio de la transmisión sináptica y la imagen terminales presinápticos

Mechanical dissociation of neurons from the central nervous system has the advantage that presynaptic boutons remain attached to the isolated neuron of ...

vibrodissociation-neurons-from-rodent-brain-slices-to-study-synaptic

Research

JoVE Journal

Neuroscience

15.4K vistas.  National Institutes of Health/National Institute on Alcohol Abuse and Alcoholism. Este informe demuestra una técnica para aislamiento mecánico de las neuronas individuales viable mantener unido boutons presináptica. Vibrodissociated neuronas tienen la ventaja de una rápida producción, el control farmacológico excelente y mejora del espacio-clamp sin la influencia de las células vecinas. Este método puede ser utilizado para obtener imágenes de los elementos sináptica y la grabación de patch-clamp.

Video: Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals

Preparation of Oligomeric &beta;-amyloid1-42 and Induction of Synaptic Plasticity Impairment on Hippocampal Slices

Impairment of synaptic connections is likely to underlie the subtle amnesic changes occurring at the early stages of Alzheimer s Disease (AD). &beta;-amyloid (A&beta;), a peptide produced in high amounts in AD, is known to reduce Long-Term Potentiation (LTP), a cellular correlate of learning and memory. Indeed, LTP impairment caused by A&beta; is a useful experimental paradigm for studying synaptic dysfunctions in AD models and for screening drugs capable of mitigating or reverting such synaptic impairments. Studies have shown that A&beta; produces the LTP disruption preferentially via its oligomeric form. Here we provide a detailed protocol for impairing LTP by perfusion of oligomerized synthetic A&beta;1-42 peptide onto acute hippocampal slices. In this video, we outline a step-by-step procedure for the preparation of oligomeric A&beta;1-42. Then, we follow an individual experiment in which LTP is reduced in hippocampal slices exposed to oligomerized A&beta;1-42 compared to slices in a control experiment where no A&beta;1-42 exposure had occurred.

Preparation of Oligomeric &amp;#946;-amyloid1-42 and Induction of Synaptic Plasticity Impairment on Hippocampal Slices

One feature of Alzheimer's Disease is the elevation of A&beta;1-42 peptide. Here we provide a protocol for preparing synthetic A&beta;1-42 oligomers, which impairs hippocampal Long-Term Potentiation, a cellular correlate of memory. This procedure is useful for investigating mechanisms of A&beta;-induced pathology and drug screening.

Preparación de oligómeros β-amiloide 1-42 Y la inducción del deterioro de plasticidad sináptica en rodajas de hipocampo

Impairment of synaptic connections is likely to underlie the subtle amnesic changes occurring at the early stages of Alzheimer s Disease (AD). ...

Investigación

Neurociencias

DiOLISTIC Labeling of Neurons from Rodent and Non-human Primate Brain Slices

DiOLISTIC staining uses the gene gun to introduce fluorescent dyes, such as DiI, into neurons of brain slices (Gan et al., 2009; O'Brien and Lummis, 2007; Gan et al., 2000). Here we provide a detailed description of each step required together with exemplary images of good and bad outcomes that will help when setting up the technique. In our experience, a few steps proved critical for the successful application of DiOLISTICS. These considerations include the quality of the DiI-coated bullets, the extent of fixative exposure, and the concentration of detergent used in the incubation solutions. Tips and solutions for common problems are provided. This is a versatile labeling technique that can be applied to multiple animal species at a wide range of ages. Unlike other fluorescent labeling techniques that are limited to preparations from young animals or restricted to mice because they rely on the expression of a fluorescent transgene, DiOLISTIC labeling can be applied to animals of all ages, species and genotypes and it can be used in combination with immunostaining to identify a specific subpopulation of cells. Here we demonstrate the use of DiOLISTICS to label neurons in brain slices from adult mice and adult non-human primates with the purpose of quantifying dendrite branching and dendritic spine morphology.

We demonstrate the use of the gene gun to introduce fluorescent dyes, such as DiI, into neurons in brain slices from rodents and non-human primates of different ages. In this particular case, we use adult mice (3-6 months old) and adult cynomologus monkeys (9-15 years old). This technique, originally described by the laboratory of Dr. Lichtman (Gan et al., 2000), is well suited for the study of dendritic branching and dendritic spine morphology and can be combined with traditional immunostaining, if detergents are kept at a low concentration.

Etiquetado DiOLISTIC de las neuronas de los roedores y no humanos rodajas de cerebro de los primates

DiOLISTIC staining uses the gene gun to introduce fluorescent dyes, such as DiI, into neurons of brain slices (Gan et al., 2009; O'Brien and Lummis, 2007; ...

Presynaptic Dopamine Dynamics in Striatal Brain Slices with Fast-scan Cyclic Voltammetry

Extensive research has focused on the neurotransmitter dopamine because of its importance in the mechanism of action of drugs of abuse (e.g. cocaine and amphetamine), the role it plays in psychiatric illnesses (e.g. schizophrenia and Attention Deficit Hyperactivity Disorder), and its involvement in degenerative disorders like Parkinson's and Huntington's disease. Under normal physiological conditions, dopamine is known to regulate locomotor activity, cognition, learning, emotional affect, and neuroendocrine hormone secretion. One of the largest densities of dopamine neurons is within the striatum, which can be divided in two distinct neuroanatomical regions known as the nucleus accumbens and the caudate-putamen. The objective is to illustrate a general protocol for slice fast-scan cyclic voltammetry (FSCV) within the mouse striatum. FSCV is a well-defined electrochemical technique providing the opportunity to measure dopamine release and uptake in real time in discrete brain regions. Carbon fiber microelectrodes (diameter of ~ 7 &mu;m) are used in FSCV to detect dopamine oxidation. The analytical advantage of using FSCV to detect dopamine is its enhanced temporal resolution of 100 milliseconds and spatial resolution of less than ten microns, providing complementary information to in vivo microdialysis.

Using fast-scan cyclic voltammetry to measure electrically evoked presynaptic dopamine dynamics in striatal brain slices.

Dinámica presináptica de dopamina estriatal en rodajas de cerebro de voltametría cíclica rápida de exploración

Extensive research has focused on the neurotransmitter dopamine because of its importance in the mechanism of action of drugs of abuse (e.g. cocaine and ...

Voltage-sensitive Dye Recording from Axons, Dendrites and Dendritic Spines of Individual Neurons in Brain Slices

Understanding the biophysical properties and functional organization of single neurons and how they process information is fundamental for understanding how the brain works. The primary function of any nerve cell is to process electrical signals, usually from multiple sources. Electrical properties of neuronal processes are extraordinarily complex, dynamic, and, in the general case, impossible to predict in the absence of detailed measurements. To obtain such a measurement one would, ideally, like to be able to monitor, at multiple sites, subthreshold events as they travel from the sites of origin on neuronal processes and summate at particular locations to influence action potential initiation. This goal has not been achieved in any neuron due to technical limitations of measurements that employ electrodes. To overcome this drawback, it is highly desirable to complement the patch-electrode approach with imaging techniques that permit extensive parallel recordings from all parts of a neuron. Here, we describe such a technique - optical recording of membrane potential transients with organic voltage-sensitive dyes (Vm-imaging) - characterized by sub-millisecond and sub-micrometer resolution. Our method is based on pioneering work on voltage-sensitive molecular probes 2. Many aspects of the initial technology have been continuously improved over several decades 3, 5, 11. Additionally, previous work documented two essential characteristics of Vm-imaging. Firstly, fluorescence signals are linearly proportional to membrane potential over the entire physiological range (-100 mV to +100 mV; 10, 14, 16). Secondly, loading neurons with the voltage-sensitive dye used here (JPW 3028) does not have detectable pharmacological effects. The recorded broadening of the spike during dye loading is completely reversible 4, 7. Additionally, experimental evidence shows that it is possible to obtain a significant number (up to hundreds) of recordings prior to any detectable phototoxic effects 4, 6, 12, 13. At present, we take advantage of the superb brightness and stability of a laser light source at near-optimal wavelength to maximize the sensitivity of the Vm-imaging technique. The current sensitivity permits multiple site optical recordings of Vm transients from all parts of a neuron, including axons and axon collaterals, terminal dendritic branches, and individual dendritic spines. The acquired information on signal interactions can be analyzed quantitatively as well as directly visualized in the form of a movie.

An imaging technique for monitoring of membrane potential changes with sub-micrometer spatial and sub-millisecond temporal resolution is described. The technique, based on laser excitation of voltage-sensitive dyes, allows measurements of signals in axons and axon collaterals, terminal dendritic branches, and individual dendritic spines.

Sensibles al voltaje Dye grabación de axones, dendritas y espinas dendríticas de las neuronas individuales en rodajas de cerebro

Understanding the biophysical properties and functional organization of single neurons and how they process information is fundamental for understanding ...

Acute Dissociation of Lamprey Reticulospinal Axons to Enable Recording from the Release Face Membrane of Individual Functional Presynaptic Terminals

Synaptic transmission is an extremely rapid process. Action potential driven influx of Ca2+&#160;into the presynaptic terminal, through voltage-gated calcium channels (VGCCs) located in the release face membrane, is the trigger for vesicle fusion and neurotransmitter release. Crucial to the rapidity of synaptic transmission is the spatial and temporal synchrony between the arrival of the action potential, VGCCs and the neurotransmitter release machinery. The ability to directly record Ca2+&#160;currents from the release face membrane of individual presynaptic terminals is imperative for a precise understanding of the relationship between presynaptic Ca2+&#160;and neurotransmitter release. Access to the presynaptic release face membrane for electrophysiological recording is not available in most preparations and presynaptic Ca2+&#160;entry has been characterized using imaging techniques and macroscopic current measurements &#8211; techniques that do not have sufficient temporal resolution to visualize Ca2+ entry. The characterization of VGCCs directly at single presynaptic terminals has not been possible in central synapses and has thus far been successfully achieved only in the calyx-type synapse of the chick ciliary ganglion and in rat calyces. We have successfully addressed this problem in the giant reticulospinal synapse of the lamprey spinal cord by developing an acutely dissociated preparation of the spinal cord that yields isolated reticulospinal axons with functional presynaptic terminals devoid of postsynaptic structures. We can fluorescently label and identify individual presynaptic terminals and target them for recording. Using this preparation, we have characterized VGCCs directly at the release face of individual presynaptic terminals using immunohistochemistry and electrophysiology approaches. Ca2+ currents have been recorded directly at the release face membrane of individual presynaptic terminals, the first such recording to be carried out at central synapses.

Recording Ca2+ currents at the presynaptic release face membrane is key to a precise understanding of Ca2+ entry and neurotransmitter release. We present an acute dissociation of the lamprey spinal cord that yields functional isolated reticulospinal axons, permitting recording directly from the release face membrane of individual presynaptic terminals.

Agudo Disociación de lamprea reticuloespinal axones para permitir la grabación del estreno de la cara de la membrana de individuales Terminales presinápticos funcionales

Synaptic transmission is an extremely rapid process. Action potential driven influx of Ca2+&#160;into the presynaptic terminal, through voltage-gated ...

Isolation, Culture and Long-Term Maintenance of Primary Mesencephalic Dopaminergic Neurons From Embryonic Rodent Brains

Degeneration of mesencephalic dopaminergic (mesDA) neurons is the pathological hallmark of Parkinson&#8217;s diseae. Study of the biological processes involved in physiological functions and vulnerability and death of these neurons is imparative to understanding the underlying causes and unraveling the cure for this common neurodegenerative disorder. Primary cultures of mesDA neurons provide a tool for investigation of the molecular, biochemical and electrophysiological properties, in order to understand the development, long-term survival and degeneration of these neurons during the course of disease. Here we present a detailed method for the isolation, culturing and maintenance of midbrain dopaminergic neurons from E12.5 mouse (or E14.5 rat) embryos. Optimized cell culture conditions in this protocol result in presence of axonal and dendritic projections, synaptic connections and other neuronal morphological properties, which make the cultures suitable for study of the physiological, cell biological and molecular characteristics of this neuronal population.

The causes of degeneration of midbrain dopaminergic neurons during Parkinson&#8217;s disease are not fully understood. Cellular culture systems provide an essential tool for study of the neurophysiological properties of these neurons. Here we present an optimized protocol, which can be utilized for in vitro modeling of neurodegeneration.

Aislamiento, cultivo y mantenimiento a largo plazo de Primaria mesencefálico neuronas dopaminérgicas a partir de cerebros de embriones de roedores

Degeneration of mesencephalic dopaminergic (mesDA) neurons is the pathological hallmark of Parkinson&#8217;s diseae. Study of the biological processes ...

Analyzing Synaptic Modulation of Drosophila melanogaster Photoreceptors after Exposure to Prolonged Light

The nervous system has the remarkable ability to adapt and respond to various stimuli. This neural adjustment is largely achieved through plasticity at the synaptic level. The Active Zone (AZ) is the region at the presynaptic membrane that mediates neurotransmitter release and is composed of a dense collection of scaffold proteins. AZs of Drosophila melanogaster (Drosophila) photoreceptors undergo molecular remodeling after prolonged exposure to natural ambient light. Thus the level of neuronal activity can rearrange the molecular composition of the AZ and contribute to the regulation of the functional output.
Starting from the light exposure set-up preparation to the immunohistochemistry, this protocol details how to quantify the number, the spatial distribution, and the delocalization level of synaptic molecules at AZs in Drosophila photoreceptors. Using image analysis software, clusters of the GFP-fused AZ component Bruchpilot were identified for each R8 photoreceptor (R8) axon terminal. Detected Bruchpilot spots were automatically assigned to individual R8 axons. To calculate the distribution of spot frequency along the axon, we implemented a customized software plugin. Each axon&#39;s start-point and end-point were manually defined and the position of each Bruchpilot spot was projected onto the connecting line between start and end-point. Besides the number of Bruchpilot clusters, we also quantified the delocalization level of Bruchpilot-GFP within the clusters. These measurements reflect in detail the spatially resolved synaptic dynamics in a single neuron under different environmental conditions to stimuli.

Analyzing Synaptic Modulation of Drosophila melanogaster Photoreceptors after Exposure to Prolonged Light

Here we show how to quantify the number and spatial distribution of synaptic active zones in Drosophila melanogaster&#160;photoreceptors, highlighted with a genetically encoded molecular marker, and their modulation after prolonged exposure to light.

Analizando Synaptic Modulación de<em&gt; Drosophila melanogaster</em&gt; Los fotorreceptores después de la exposición prolongada a la luz

The nervous system has the remarkable ability to adapt and respond to various stimuli. This neural adjustment is largely achieved through plasticity at ...

Application of Automated Image-guided Patch Clamp for the Study of Neurons in Brain Slices

Whole-cell patch clamp is the gold-standard method to measure the electrical properties of single cells. However, the in vitro patch clamp remains a challenging and low-throughput technique due to its complexity and high reliance on user operation and control. This manuscript demonstrates an image-guided automatic patch clamp system for in vitro whole-cell patch clamp experiments in acute brain slices. Our system implements a computer vision-based algorithm to detect fluorescently labeled cells and to target them for fully automatic patching using a micromanipulator and internal pipette pressure control. The entire process is highly automated, with minimal requirements for human intervention. Real-time experimental information, including electrical resistance and internal pipette pressure, are documented electronically for future analysis and for optimization to different cell types. Although our system is described in the context of acute brain slice recordings, it can also be applied to the automated image-guided patch clamp of dissociated neurons, organotypic slice cultures, and other non-neuronal cell types.

This protocol describes how to conduct automatic image-guided patch-clamp experiments using a system recently developed for standard in vitro electrophysiology equipment.

Aplicación de la abrazadera de parche guiada por imágenes automatizada para el estudio de neuronas en cortes cerebrales

Whole-cell patch clamp is the gold-standard method to measure the electrical properties of single cells. However, the in vitro patch clamp remains a ...

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.

Evaluación de la densidad de sinapsis en rebanadas de hipocampo cerebral de roedor

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

Combining Optogenetics with Artificial microRNAs to Characterize the Effects of Gene Knockdown on Presynaptic Function within Intact Neuronal Circuits

The purpose of this protocol is to characterize the effect of gene knockdown on presynaptic function within intact neuronal circuits. We describe a workflow on how to combine artificial microRNA (miR)-mediated RNA interference with optogenetics to achieve selective stimulation of manipulated presynaptic boutons in acute brain slices. The experimental approach involves the use of a single viral construct and a single neuron-specific promoter to drive the expression of both an optogenetic probe and artificial miR(s) against presynaptic gene(s). When stereotactically injected in the brain region of interest, the expressed construct makes it possible to stimulate with light exclusively the neurons with reduced expression of the gene(s) under investigation. This strategy does not require the development and maintenance of genetically modified mouse lines and can in principle be applied to other organisms and to any neuronal gene of choice. We have recently applied it to investigate how the knockdown of alternative splice isoforms of presynaptic P/Q-type voltage-gated calcium channels (VGCCs) regulates short-term synaptic plasticity at CA3 to CA1 excitatory synapses in acute hippocampal slices. A similar approach could also be used to manipulate and probe the neuronal circuitry in vivo.

This protocol provides a workflow on how to combine artificial microRNA-mediated RNA interference with optogenetics to stimulate specifically presynaptic boutons with reduced expression of selective gene(s) within intact neuronal circuits.

Combinando Optogenetics con microRNAs artificiales para caracterizar los efectos de Gene caída en la función presináptica en circuitos neuronales intactas

The purpose of this protocol is to characterize the effect of gene knockdown on presynaptic function within intact neuronal circuits. We describe a ...