This work is supported by a Canadian Health Research Institute (CIHR) Team Grant to Dr. Bolduc (co-PI) and Dr. Guy Rouleau (PI). We would like to thank Dr. Oksana Suchowersky, Dr. Kathryn Todd, the members of the University of Alberta fly club and Dr. Clayton Dickson for help in development of the method and statistical analysis.

La investigación sobre Drosophila melanogaster se encontraba en cumplimiento con la Universidad de las pautas de investigación de Alberta. 1. Fly Colección <ol><li> Suma 20 moscas utilizando CO 2 (g) anestesia y colocar en un vial de recogida 25 mm x 95 mm que contiene alimentos. </li><li> Tienda viales que contienen moscas horizontalmente para evitar atrapar moscas en cualquier líquido que pueda acumularse en la parte inferior del vial. </li><li> Incubar las moscas durante al menos 21 horas a 22 ° C a 45% de humedad en una incubadora durante aproximadamente durante 15 horas. Establezca la incubadora con una luz de 12 horas: oscuridad ciclo. </li></ol> Ensayo 2. Escalada <ol><li> A la mañana siguiente, la transferencia de 20 moscas de un solo vial en un vaso de 250 ml cilindro graduado. Marque la posición del cilindro para mantenerla constante todos los días. Utilice un cilindro de vidrio por genotipo para evitar la contaminación cruzada entre los genotipos. Lavar al final de cada experimento y roTate los entre los genotipos. <ol><li> Llevar a cabo los experimentos en la luz ambiental (o luz roja si hay un posible defecto en la visión) a la temperatura y la humedad de 22 ° C y 40% respectivamente. Para evitar confundir ritmo circadiano, siempre realizar experimentos en el mismo momento del día. </li></ol></li><li> Selle la parte superior del cilindro con una película de barrera (película de cera) para evitar cualquier escape de las moscas (Figura 2). </li><li> Configure la cámara de vídeo en un trípode. Cámara Enfoque en la línea de 190 ml de los 250 ml cilindro graduado (17,5 cm). </li><li> Contar el número de moscas muertas en la parte inferior del cilindro y en los viales de alimentos. Anote este número como la mortalidad. </li><li> Muy golpee suavemente el cilindro contra una almohadilla de espuma de célula cerrada en varias ocasiones con la fuerza suficiente para desplazar a las moscas a la superficie inferior interna. Toque 5-10 veces, mientras con la otra mano para presionar registro en la cámara. </li><li> Pulse el botón &quot;Grabar&quot; en la cámara. </li><li> Inicie la video grabación de la cámara y toque el cilindro de seis veces en un patrón no-rítmica distinta. </li><li> Llevar a cabo cada ensayo durante 2 minutos desde el momento en que las moscas están última intervenidos y registre el número de moscas que cruzan la altura de 17,5 cm (190 ml) en cada punto de tiempo elegido (cuantificar cada 10 seg). Nota: La ml marcado en el cilindro variará de un modelo de cilindro a otro dependiendo de diámetro. Para evitar errores, medir la altura de cada cilindro utilizado. </li><li> Una vez que el juicio ha terminado, a disponer de moscas en etanol al 95%. </li><li> Repita los pasos 2.1 a 2.9 hasta que todas las réplicas se han probado con moscas frescos en todo momento. Nota: Aunque 5 repeticiones pueden ser lo suficientemente con una mutación que tiene un fuerte efecto sobre la locomoción, 10 réplicas biológicas de 20 moscas (moscas) 200 se recomienda para detectar diferencias más pequeñas. </li><li> Al finalizar el experimento, lavar los cilindros en el lavavajillas de laboratorio y O seco N para ser reutilizado /. </li></ol> 3. Análisis <ol><li> Analyvídeos ze de cada vuelan juicio. Cada 10 segundos, registra el número total de moscas que pasan la línea de meta. <ol><li> Si una mosca sube de nuevo hacia abajo o se cae, ficha que vuelan como -1 y contar la próxima marcha para cruzar la línea de meta como el mismo número que la mosca que subió de nuevo hacia abajo o cayó. Por ejemplo, si el 15 de mosca cae por debajo de la línea de meta, la próxima marcha para cruzar la línea (los 16 º vuelan) se considera la marcha 15 y no el 16. </li></ol></li><li> Reste la mortalidad por el número total de moscas (20) para obtener el número de moscas que permanecen en el juicio. En cada punto de tiempo, obtener la fracción de moscas por encima de la línea de meta. </li><li> Sinopsis cada porcentaje en cada momento (ver Figura 3). </li><li> Analizar el rendimiento en el punto de datos 120 seg y realice estudiante t-test cuando 2 grupos están presentes o ANOVA y un post-test para comparaciones múltiples (con modificación de Bonferroni para planificarse y Tukey para co no planificadomparisons). La prueba de Kolmogorov-Smirnov 17 también se lleva a cabo para determinar la normalidad y la igualdad de varianza, sino también para comparar las distribuciones del grupo mutante con el control. </li><li> Para presentar los datos sobre el envejecimiento, trazar el porcentaje de moscas subiendo a 120 seg con moscas de diferentes edades (2 días, 1 semana, 2 semanas) para ver si hay un déficit progresivo (Figura 4). </li></ol>

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The authors have nothing to disclose.

Drosophila ya ha demostrado ser un excelente modelo en la enfermedad 14 y otras condiciones neurodegenerativas 1,2 de Parkinson. Además de las herramientas genéticas disponibles en Drosophila, su genoma está altamente conservada de genes implicados en los trastornos neurológicos 19. El advenimiento de los métodos de detección genética del genoma de ancho (incluyendo la secuenciación del exoma) es probable que continúe para proporcionar una lista más grande de ...

Trastornos neurodegenerativos devastadores como la enfermedad de Parkinson, la esclerosis lateral amiotrófica, y la paraplejía espástica hereditaria se reconocen cada vez más. Desafortunadamente, la mayoría de estos trastornos neurodegenerativos siguen sin tratamientos. El uso clínico generalizado de las pruebas genéticas, imparciales en todo el genoma como la secuenciación del exoma conjunto ha llevado a un creciente número de genes están implicados en los trastornos locomotores humanos. A pesar de este progreso, la progresión patológica desde temprano a las etapas finales de los años, sigue siendo difícil de alcanzar en estos trastornos. Drosophila ofrece uno con las herramientas genéticas para el estudio de requerimiento de genes de una manera espacial y temporal controlada. Además, Drosophila ha demostrado ser útil en el cribado de fármacos para enfermedades neurológicas como el Parkinson 1, 2 Alzheimer, discapacidad intelectual y epilepsia 3,4 5,6 entre otros. Nuestro objetivo era desarrollar un rentabley ensayo fiable que permita análisis de alto rendimiento que todavía sería lo suficientemente sensible para detectar pequeños cambios en el rendimiento del motor. Hay varios ensayos utilizados para cuantificar los efectos de la mutación genética y / o condición ambiental en el comportamiento de escalada Drosophila. La mayoría de los ensayos de sacar provecho de la tendencia natural de las moscas para subir, conocidos como geotaxis negativos, o el ensayo de escalada. Benzer 7 sugirió en 1967 que el aparato de contracorriente utilizado para el estudio de phototaxis también podría ser utilizado para estudiar gravitaxis. Desde entonces, Ganetsky 8 y muchos otros 9 -12 se han basado en el ensayo inicial. El principio es colocar un número conocido de moscas en un vial y toque el vial firmemente contra una superficie dura, haciendo que las moscas que caen al fondo del vial. Como se trata de un comportamiento innato, las moscas se intentan subir a la parte superior del vial, se opuso a la gravedad. Este ensayo es cuantitativo y measures cuántas moscas han subido más allá de un marcador en el vial durante un período de tiempo asignado. Medida de la velocidad en lugar del número total de moscas escalada se ha convertido en un parámetro fiable y se muestra defectos en los casos en que el número de criterios moscas no fue significativa 13. El ensayo de escalada ha demostrado ser útil en el estudio de muchos trastornos neurodegenerativos incluyendo la enfermedad de Parkinson 14. Sin embargo, hemos observado que los defectos de locomotoras pueden no ser detectables en el momento en que la neurodegeneración ya se ve en los estudios patológicos 14. Así, el uso del ensayo tradicional puede limitar la capacidad de estudiar las primeras etapas de la patogénesis de la enfermedad. La aparición de defectos de locomotoras durante las etapas posteriores de la patología puede reflejar una enfermedad cuya progresión es demasiado avanzado para el rescate completo. Esto plantea un problema potencial con la sensibilidad del ensayo tradicional de escalada. La incapacidad potencial de la tradicióncional escalada ensayo para detectar defectos leves de la locomotora se puede atribuir a la altura a la que se requieren las moscas a subir. Los tradicionales ensayo de 15,16 mide el número de moscas que subir con éxito más de una altura de 2 a 5 cm de 10 a 20 seg.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Drosophila stocks</td>
			<td></td>
			<td></td>
			<td>The stocks are selected depending on the experiments. The temperature and humidity in the room and in the incubator must be controled and consistent to avoid flies being too staticky or too wet.</td>
		</tr>
		<tr>
			<td>Video camera</td>
			<td></td>
			<td></td>
			<td>Any digital camcorder will do. Make sure they can focus on close object.</td>
		</tr>
		<tr>
			<td>Graduated cylinder</td>
			<td>Kimble</td>
			<td>20028W</td>
			<td>Different models of graduated cylinder may have different diameter. It is therefore imporant to measure the height.</td>
		</tr>
		<tr>
			<td>computer</td>
			<td></td>
			<td></td>
			<td>Any model will do. We used the computer to monitor the climbing of the flies and record the number of flies at each time point</td>
		</tr>
	</tbody>
</table>

quantitative analysis of climbing defects in a drosophila model of neurodegenerative disorders

Defectos locomotores resultantes de trastornos neurodegenerativos pueden ser un síntoma de aparición tardía de la enfermedad, después de años de degeneración subclínica, y por lo tanto las estrategias actuales de tratamiento terapéutico no son curativos. Mediante el uso de toda la secuenciación del exoma, un número creciente de genes han sido identificados para jugar un papel en la locomoción humana. A pesar de la identificación de estos genes, no se sabe cómo estos genes son cruciales para el funcionamiento normal locomotora. Por lo tanto, un ensayo fiable, que utiliza organismos modelo para dilucidar el papel de estos genes con el fin de identificar nuevas dianas de interés terapéutico, se necesita más que nunca. Hemos diseñado una versión sensibilizada del ensayo geotaxis negativas que permite la detección de defectos más leves anteriormente y tiene la capacidad para evaluar estos defectos en el tiempo. El ensayo se realiza en un cilindro de vidrio, que se sella con una película de barrera de cera se graduó. Al aumentar la distancia de umbral para ser subido a 17,5 cm y el aumento de la duración de la prueba a 2 min hemos observado una mayor sensibilidad en la detección de disfunciones de movilidad suaves. El ensayo es rentable y no requiere de una amplia formación para obtener resultados altamente reproducibles. Esto hace que sea una excelente técnica para el cribado de fármacos candidatos en los mutantes de Drosophila con defectos de locomoción.

La escalada es un comportamiento fuerte y reproducible. De hecho, un día de edad de tipo salvaje moscas alcanzan el rendimiento escalada distancia objetivo rápidamente (25-30 seg). Moscas mutantes presentan una gama de rendimiento de leves (o retardada) para completar la imposibilidad de subir a la meta. Ilustramos esta aquí con dos alelos mutantes diferentes. El primero es un alelo severa de la Spastin gen causado por una deleción completa del gen Spastin (balnearios 5,75) 18. En esta línea (balnearios ...

Watch this Scientific Journal Video about Quantitative Analysis of Climbing Defects in a Drosophila Model of Neurodegenerative Disorders at JoVE.com

Quantitative Analysis of Climbing Defects in a Drosophila Model of Neurodegenerative Disorders

We present an optimized inexpensive and reliable negative geotaxis assay in Drosophila melanogaster as a model for neurodegenerative disorders. Being more sensitive to mild locomotor defects, this assay will help screen for potential genetic interactions and drug targets.

Análisis cuantitativo de los Defectos de escalada en un modelo de Drosophila de enfermedades neurodegenerativas

Locomotive defects resulting from neurodegenerative disorders can be a late onset symptom of disease, following years of subclinical degeneration, and ...

quantitative-analysis-climbing-defects-drosophila-model

Research

JoVE Journal

Neuroscience

18.3K vistas.  University of Alberta. We present an optimized inexpensive and reliable negative geotaxis assay in Drosophila melanogaster as a model for neurodegenerative disorders. Being more sensitive to mild locomotor defects, this assay will help screen for potential genetic interactions and drug targets. 

Video: Quantitative Analysis of Climbing Defects in a Drosophila Model of Neurodegenerative Disorders

Ex vivo Culturing of Whole, Developing Drosophila Brains

We describe a method for ex vivo culturing of whole Drosophila brains. This can be used as a counterpoint to chronic genetic manipulations for investigating the cell biology and development of central brain structures by allowing acute pharmacological interventions and live imaging of cellular processes. As an example of the technique, prior work from our lab1 has shown that a previously unrecognized subcellular compartment lies between the axonal and somatodendritic compartments of axons of the Drosophila central brain. The development of this compartment, referred to as the axon initial segment (AIS)2, was shown genetically to depend on the neuron-specific cyclin-dependent kinase, Cdk5. We show here that ex vivo treatment of wild-type Drosophila larval brains with the Cdk5-specific pharmacological inhibitors roscovitine and olomoucine3 causes acute changes in actin organization, and in localization of the cell-surface protein Fasciclin 2, that mimic the changes seen in mutants that lack Cdk5 activity genetically.
A second example of the ex vivo culture technique is provided for remodeling of the connections of embryonic mushroom body (MB) gamma neurons during metamorphosis from larva to adult. The mushroom body is the center of olfactory learning and memory in the fly4, and these gamma neurons prune their axonal and dendritic branches during pupal development and then re-extend branches at a later timepoint to establish the adult innervation pattern5. Pruning of these neurons of the MB has been shown to occur via local degeneration of neurite branches6, by a mechanism that is triggered by ecdysone, a steroid hormone, acting at the ecdysone receptor B17, and that is dependent on the activity of the ubiquitin-proteasome system6. Our method of ex vivo culturing can be used to interrogate further the mechanism of developmental remodeling. We found that in the ex vivo culture setting, gamma neurons of the MB recapitulated the process of developmental pruning with a time course similar to that in vivo. It was essential, however, to wait until 1.5 hours after puparium formation before explanting the tissue in order for the cells to commit irreversibly to metamorphosis; dissection of animals at the onset of pupariation led to little or no metamorphosis in culture. Thus, with appropriate modification, the ex vivo culture approach can be applied to study dynamic as well as steady state aspects of central brain biology.

Ex vivo Culturing of Whole, Developing Drosophila Brains

This article describes a method by which one can mimic in vivo development of the Drosophila mushroom body in an ex vivo culture system.

Ex cultivo in vivo de la Plenaria, los cerebros en desarrollo de Drosophila

We describe a method for ex vivo culturing of whole Drosophila brains. This can be used as a counterpoint to chronic genetic manipulations for ...

Investigación

Neurociencias

Assessing Neurodegenerative Phenotypes in Drosophila Dopaminergic Neurons by Climbing Assays and Whole Brain Immunostaining

Drosophila melanogaster is a valuable model organism to study aging and pathological degenerative processes in the nervous system. The advantages of the fly as an experimental system include its genetic tractability, short life span and the possibility to observe and quantitatively analyze complex behaviors. The expression of disease-linked genes in specific neuronal populations of the Drosophila brain, can be used to model human neurodegenerative diseases such as Parkinson's and Alzheimer's 5.
Dopaminergic (DA) neurons are among the most vulnerable neuronal populations in the aging human brain. In Parkinson's disease (PD), the most common neurodegenerative movement disorder, the accelerated loss of DA neurons leads to a progressive and irreversible decline in locomotor function. In addition to age and exposure to environmental toxins, loss of DA neurons is exacerbated by specific mutations in the coding or promoter regions of several genes. The identification of such PD-associated alleles provides the experimental basis for the use of Drosophila as a model to study neurodegeneration of DA neurons in vivo. For example, the expression of the PD-linked human &alpha;-synuclein gene in Drosophila DA neurons recapitulates some features of the human disease, e.g. progressive loss of DA neurons and declining locomotor function 2. Accordingly, this model has been successfully used to identify potential therapeutic targets in PD 8.
Here we describe two assays that have commonly been used to study age-dependent neurodegeneration of DA neurons in Drosophila: a climbing assay based on the startle-induced negative geotaxis response and tyrosine hydroxylase immunostaining of whole adult brain mounts to monitor the number of DA neurons at different ages. In both cases, in vivo expression of UAS transgenes specifically in DA neurons can be achieved by using a tyrosine hydroxylase (TH) promoter-Gal4 driver line 3, 10.

Assessing Neurodegenerative Phenotypes in Drosophila Dopaminergic Neurons by Climbing Assays and Whole Brain Immunostaining

Here we describe two assays that have been established to study age-dependent neurodegeneration of dopaminergic (DA) neurons in Drosophila: the climbing/startle-induced negative geotaxis assay which allows to study the functional effects of DA neurons degeneration and the tyrosine hydroxylase immunostaining which is used to identify and count DA neurons in whole brain mounts.

La evaluación de fenotipos neurodegenerativas en<em&gt; Drosophila</em&gt; Las neuronas dopaminérgicas mediante ensayos de Escalada y inmunotinción de todo el cerebro

Drosophila melanogaster is a valuable model organism to study aging and pathological degenerative processes in the nervous system. The advantages of the ...

Fast Micro-iontophoresis of Glutamate and GABA: A Useful Tool to Investigate Synaptic Integration

One of the fundamental interests in neuroscience is to understand the integration of excitatory and inhibitory inputs along the very complex structure of the dendritic tree, which eventually leads to neuronal output of action potentials at the axon. The influence of diverse spatial and temporal parameters of specific synaptic input on neuronal output is currently under investigation, e.g. the distance-dependent attenuation of dendritic inputs, the location-dependent interaction of spatially segregated inputs, the influence of GABAergig inhibition on excitatory integration, linear and non-linear integration modes, and many more.
With fast micro-iontophoresis of glutamate and GABA it is possible to precisely investigate the spatial and temporal integration of glutamatergic excitation and GABAergic inhibition. Critical technical requirements are either a triggered fluorescent lamp, light-emitting diode (LED), or a two-photon scanning microscope to visualize dendritic branches without introducing significant photo-damage of the tissue. Furthermore, it is very important to have a micro-iontophoresis amplifier that allows for fast capacitance compensation of high resistance pipettes. Another crucial point is that no transmitter is involuntarily released by the pipette during the experiment.
Once established, this technique will give reliable and reproducible signals with a high neurotransmitter and location specificity. Compared to glutamate and GABA uncaging, fast iontophoresis allows using both transmitters at the same time but at very distant locations without limitation to the field of view. There are also advantages compared to focal electrical stimulation of axons: with micro-iontophoresis the location of the input site is definitely known and it is sure that only the neurotransmitter of interest is released. However it has to be considered that with micro-iontophoresis only the postsynapse is activated and presynaptic aspects of neurotransmitter release are not resolved. In this article we demonstrate how to set up micro-iontophoresis in brain slice experiments.

In this article we introduce fast micro-iontophoresis of neurotransmitters as a technique to investigate integration of postsynaptic signals with high spatial and temporal precision.

Fast Micro-iontoforesis de glutamato y GABA: una herramienta útil para investigar la integración sináptica

One of the fundamental interests in neuroscience is to understand the integration of excitatory and inhibitory inputs along the very complex structure of ...

High-Resolution Quantitative Immunogold Analysis of Membrane Receptors at Retinal Ribbon Synapses

Retinal ganglion cells (RGCs) receive excitatory glutamatergic input from bipolar cells. Synaptic excitation of RGCs is mediated postsynaptically by NMDA receptors (NMDARs) and AMPA receptors (AMPARs). Physiological data have indicated that glutamate receptors at RGCs are expressed not only in postsynaptic but also in perisynaptic or extrasynaptic membrane compartments. However, precise anatomical locations for glutamate receptors at RGC synapses have not been determined. Although a high-resolution quantitative analysis of glutamate receptors at central synapses is widely employed, this approach has had only limited success in the retina. We developed a postembedding immunogold method for analysis of membrane receptors, making it possible to estimate the number, density and variability of these receptors at retinal ribbon synapses. Here we describe the tools, reagents, and the practical steps that are needed for: 1) successful preparation of retinal fixation, 2) freeze-substitution, 3) postembedding immunogold electron microscope (EM) immunocytochemistry and, 4) quantitative visualization of glutamate receptors at ribbon synapses.

The postembedding immunogold method is one of the most effective ways to provide high-resolution analyses of the subcellular localization of specific molecules. Here we describe a protocol to quantitatively analyze glutamate receptors at retinal ribbon synapses.

Resolución de alta Análisis Cuantitativo Inmunoelectrónica de Receptores de Membrana en la retina cinta sinapsis

Retinal ganglion cells (RGCs) receive excitatory glutamatergic input from bipolar cells. Synaptic excitation of RGCs is mediated postsynaptically by NMDA ...

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 ...

The Use of Trace Eyeblink Classical Conditioning to Assess Hippocampal Dysfunction in a Rat Model of Fetal Alcohol Spectrum Disorders

Neonatal rats were administered a relatively high concentration of ethyl alcohol (11.9% v/v) during postnatal days 4-9, a time when the fetal brain undergoes rapid organizational change and is similar to accelerated brain changes that occur during the third trimester in humans. This model of fetal alcohol spectrum disorders (FASDs) produces severe brain damage, mimicking the amount and pattern of binge-drinking that occurs in some pregnant alcoholic mothers. We describe the use of trace eyeblink classical conditioning (ECC), a higher-order variant of associative learning, to assess long-term hippocampal dysfunction that is typically seen in alcohol-exposed adult offspring. At 90 days of age, rodents were surgically prepared with recording and stimulating electrodes, which measured electromyographic (EMG) blink activity from the left eyelid muscle and delivered mild shock posterior to the left eye, respectively. After a 5 day recovery period, they underwent 6 sessions of trace ECC to determine associative learning differences between alcohol-exposed and control rats. Trace ECC is one of many possible ECC procedures that can be easily modified using the same equipment and software, so that different neural systems can be assessed. ECC procedures in general, can be used as diagnostic tools for detecting neural pathology in different brain systems and different conditions that insult the brain.

Trace eyeblink classical conditioning (ECC) was used to assess hippocampal-dependent associative learning in adult rats that were administered a high concentration (11.9% v/v) of alcohol during early neonatal brain development. In general, ECC procedures are sound diagnostic tools for detecting brain dysfunction across many psychological and biomedical settings.

El uso de condicionamiento de clásico de Eyeblink rastro para evaluar disfunción hipocampal en un modelo de rata de trastornos del espectro alcohólico Fetal

Neonatal rats were administered a relatively high concentration of ethyl alcohol (11.9% v/v) during postnatal days 4-9, a time when the fetal brain ...

Assessment of Blood-brain Barrier Permeability by Intravenous Infusion of FITC-labeled Albumin in a Mouse Model of Neurodegenerative Disease

Disruption of blood-brain barrier (BBB) integrity is a common feature for different neurological and neurodegenerative diseases. Although the interplay between perturbed BBB homeostasis and the pathogenesis of brain disorders needs further investigation, the development and validation of a reliable procedure to accurately detect BBB alterations may be crucial and represent a useful tool for potentially predicting disease progression and developing targeted therapeutic strategies.
Here, we present an easy and efficient procedure for evaluating BBB leakage in a neurodegenerative condition like that occurring in a preclinical mouse model of Huntington disease, in which defects in the permeability of BBB are clearly detectable precociously in the disease. Specifically, the high molecular weight fluorescein isothiocyanate labelled (FITC)-albumin, which is able to cross the BBB only when the latter is impaired, is acutely infused into a mouse jugular vein and its distribution in the vascular or parenchymal districts is then determined by fluorescence microscopy.
Accumulation of green fluorescent-albumin in the brain parenchyma functions as an index of aberrant BBB permeability and, when quantitated by using Image J processing software, is reported as Green Fluorescence Intensity.

In this study, we present an easy and efficient procedure for evaluating the disruption of the blood-brain barrier under neurodegenerative conditions. To achieve our objective, we infused high molecular weight fluorescein isothiocyanate labelled (FITC)-albumin into mouse jugular vein and evaluated its leakage into the brain parenchyma by fluorescence microscopy.

Evaluación de la permeabilidad de la barrera hemato - encefálica por infusión intravenosa de albúmina marcado con FITC en un modelo murino de enfermedad neurodegenerativa

Disruption of blood-brain barrier (BBB) integrity is a common feature for different neurological and neurodegenerative diseases. Although the interplay ...

Quantitative Analysis of Neuronal Dendritic Arborization Complexity in Drosophila

Dendrites are the branched projections of a neuron, and dendritic morphology reflects synaptic organization during the development of the nervous system. Drosophila larval neuronal dendritic arborization (da) is an ideal model for studying morphogenesis of neural dendrites and gene function in the development of nervous system. There are four classes of da neurons. Class IV is the most complex with a branching pattern that covers almost the entire area of the larval body wall. We have previously characterized the effect of silencing the Drosophila ortholog of SOX5 on class IV neuronal dendritic arborization complexity (NDAC) using four parameters: the length of dendrites, the surface area of dendrite coverage, the total number of branches, and the branching structure. This protocol presents the workflow of NDAC quantitative analysis, consisting of larval dissection, confocal microscopy, and image analysis procedures using ImageJ software. Further insight into da neuronal development and its underlying mechanisms will improve the understanding of neuronal function and provide clues about the fundamental causes of neurological and neurodevelopmental disorders.

Quantitative Analysis of Neuronal Dendritic Arborization Complexity in Drosophila

This protocol focuses on quantitative analysis of neuronal dendritic arborization complexity (NDAC) in Drosophila, which can be used for studies of dendritic morphogenesis.

Análisis cuantitativo de la complejidad de la arborización dendrítica Neuronal en Drosophila

Dendrites are the branched projections of a neuron, and dendritic morphology reflects synaptic organization during the development of the nervous system. ...

Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ

With the rising prevalence of neurodegenerative diseases, it is increasingly important to understand the underlying pathophysiology that leads to neuronal dysfunction and loss. Fluorescence-based imaging tools and technologies enable unprecedented analysis of subcellular neurobiological processes, yet there is still a need for unbiased, reproducible, and accessible approaches for extracting quantifiable data from imaging studies. We have developed a simple and adaptable workflow to extract quantitative data from fluorescence-based imaging studies using Drosophila models of neurodegeneration. Specifically, we describe an easy-to-follow, semi-automated approach using Fiji/ImageJ to analyze two cellular processes: first, we quantify protein aggregate content and profile in the Drosophila optic lobe using fluorescent-tagged mutant huntingtin proteins; and second, we assess autophagy-lysosome flux in the Drosophila visual system with ratiometric-based quantification of a tandem fluorescent reporter of autophagy. Importantly, the protocol outlined here includes a semi-automated segmentation step to ensure all fluorescent structures are analyzed to minimize selection bias and to increase resolution of subtle comparisons. This approach can be extended for the analysis of other cell biological structures and processes implicated in neurodegeneration, such as proteinaceous puncta (stress granules and synaptic complexes), as well as membrane-bound compartments (mitochondria and membrane trafficking vesicles). This method provides a standardized, yet adaptable reference point for image analysis and quantification, and could facilitate reliability and reproducibility across the field, and ultimately enhance mechanistic understanding of neurodegeneration.

Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ

We have developed a simple and adaptable workflow to extract quantitative data from fluorescence-imaging-based cell biological studies of protein aggregation and autophagic flux in the central nervous system of Drosophila models of neurodegeneration.

Biología celular cuantitativa de neurodegeneración en Drosophila mediante análisis imparcial de fluorescencia etiquetas proteínas con ImageJ

With the rising prevalence of neurodegenerative diseases, it is increasingly important to understand the underlying pathophysiology that leads to neuronal ...

Isolation of Adult Spinal Cord Nuclei for Massively Parallel Single-nucleus RNA Sequencing

Probing an individual cell&#39;s gene expression enables the identification of cell type and cell state. Single-cell RNA sequencing has emerged as a powerful tool for studying transcriptional profiles of cells, particularly in heterogeneous tissues such as the central nervous system. However, dissociation methods required for single cell sequencing can lead to experimental changes in the gene expression and cell death. Furthermore, these methods are generally restricted to fresh tissue, thus limiting studies on archival and bio-bank material. Single nucleus RNA sequencing (snRNA-Seq) is an appealing alternative for transcriptional studies, given that it accurately identifies cell types, permits the study of tissue that is frozen or difficult to dissociate, and reduces dissociation-induced transcription. Here, we present a high-throughput protocol for rapid isolation of nuclei for downstream snRNA-Seq. This method enables isolation of nuclei from fresh or frozen spinal cord samples and can be combined with two massively parallel droplet encapsulation platforms.

Here, we present a protocol to rapidly isolate high-quality nuclei from the fresh or frozen tissue for downstream massively parallel RNA sequencing. We include detergent-mechanical and hypotonic-mechanical tissue disruption and cell lysis options, both of which can be used for isolation of nuclei.

Aislamiento de núcleos de adultos de la médula espinal para secuenciación masivamente paralela solo núcleo ARN

Probing an individual cell&#39;s gene expression enables the identification of cell type and cell state. Single-cell RNA sequencing has emerged as a ...