Questo lavoro è stato supportato dal Neurosciences Research Foundation e sovvenzioni da parte Blasker-Rose-Miah Fondo di The San Diego Foundation e The Harold G. e Leila Y. Mathers Charitable Foundation.

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	<li>Zheng, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Auditory+map+reorganization+and+pitch+discrimination+in+adult+rats+chronically+exposed+to+low-level+ambient+noise.">Auditory map reorganization and pitch discrimination in adult rats chronically exposed to low-level ambient noise.</a> Front. Syst.Neurosci. 6, 65 (2012).</li><li>Talwar, S. K., Gerstein, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Auditory+frequency+discrimination+in+the+white+rat.">Auditory frequency discrimination in the white rat.</a> Hear Res. 126, 135-150 (1998).</li><li>Talwar, S. K., Gerstein, G. 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Neurosci. Methods. , (2011).</li><li>Bieszczad, K. M., Weinberger, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Learning+strategy+trumps+motivational+level+in+determining+learning-induced+auditory+cortical+plasticity.">Learning strategy trumps motivational level in determining learning-induced auditory cortical plasticity.</a> Neurobiology of Learning and Memory. 93, 229-239 (2010).</li><li>Sagvolden, T. I. m. p. u. l. s. i. v. e. n. e. s. s., overactivity, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=poorer+sustained+attention+improve+by+chronic+treatment+with+low+doses+of+l-amphetamine+in+an+animal+model+of+Attention-Deficit/Hyperactivity+Disorder+(ADHD).">poorer sustained attention improve by chronic treatment with low doses of l-amphetamine in an animal model of Attention-Deficit/Hyperactivity Disorder (ADHD).</a> Behav. Brain Funct. 7, 6 (2011).</li><li>Sagvolden, T., Johansen, E. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rat+Models+of+ADHD.">Rat Models of ADHD.</a> Curr. Top Behav. Neurosci. , (2011).</li><li>Brown, D. C., Nichols, J. A., Thomas, F., Dinh, L., Atzori, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nicotinic+modulation+of+auditory+attentional+shift+in+the+rat.">Nicotinic modulation of auditory attentional shift in the rat.</a> Behavioural brain research. 210, 273-279 (2010).</li><li>Johnson, K. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensory+discrimination:+neural+processes+preceding+discrimination+decision.">Sensory discrimination: neural processes preceding discrimination decision.</a> J. Neurophysiol. 43, 1793-1815 (1980).</li><li>Johnson, K. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensory+discrimination:+decision+process.">Sensory discrimination: decision process.</a> J. Neurophysiol. 43, 1771-1792 (1980).</li><li>Fraser, L. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+anxiety-+and+locomotion-related+behaviours+in+mice:+a+new+way+of+using+old+tests.">Measuring anxiety- and locomotion-related behaviours in mice: a new way of using old tests.</a> Psychopharmacology (Berl). 211, 99-112 (2010).</li><li>Hui, G. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conditioned+tone+control+of+brain+reward+behavior+produces+highly+specific+representational+gain+in+the+primary+auditory+cortex.">Conditioned tone control of brain reward behavior produces highly specific representational gain in the primary auditory cortex.</a> Neurobiology of Learning and Memory. 92, 27-34 (2009).</li><li>Feduccia, A. A., Duvauchelle, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Auditory+stimuli+enhance+MDMA-conditioned+reward+and+MDMA-induced+nucleus+accumbens+dopamine,+serotonin+and+locomotor+responses.">Auditory stimuli enhance MDMA-conditioned reward and MDMA-induced nucleus accumbens dopamine, serotonin and locomotor responses.</a> Brain Res. Bull. 77, 189-196 (2008).</li><li>Kudoh, M., Shibuki, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sound+sequence+discrimination+learning+motivated+by+reward+requires+dopaminergic+D2+receptor+activation+in+the+rat+auditory+cortex.">Sound sequence discrimination learning motivated by reward requires dopaminergic D2 receptor activation in the rat auditory cortex.</a> Learning &amp; Memory. 13, 698-69 (2006).</li><li>Shiflett, M. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cue-elicited+reward-seeking+requires+extracellular+signal-regulated+kinase+activation+in+the+nucleus+accumbens.">Cue-elicited reward-seeking requires extracellular signal-regulated kinase activation in the nucleus accumbens.</a> J. Neurosci. 28, 1434-1443 (2008).</li></ol>

Produzione e l&#39;accesso gratuito di questo video-articolo è sponsorizzato da Med Associates, Inc.

Un aspetto critico nella progettazione di qualsiasi compito uditivo comportamentale è l&#39;eliminazione di suoni indesiderati derivanti dalla dispersione e la deformazione in ambiente di test. Controllo del suono scadente può avere un effetto significativo sul comportamento in fase di test e produrre risultati fuorvianti o addirittura non interpretabile. La camera comportamentale utilizzato nel sistema qui descritto è progettato specificamente per essere acusticamente trasparente per evitare deflessione suono dalle pareti della camera. Infatti, quando misurata dal centro della camera, deflessione suono era effettivamente rilevabile (dati non mostrati). Sebbene questo sistema sviluppato principalmente per studiare il sistema uditivo, può essere facilmente adattato da altri ricercatori per studiare altri sistemi sensoriali. Le modifiche possono essere effettuate facilmente sia software e hardware per compiti diversi senza modificare la configurazione globale del sistema. Il pannello di controllo modulare rende il sistema particolarmente versatilitàLe consentendo per l&#39;aggiunta e / o sostituzione di dispositivi diversi per i nuovi compiti comportamentali. Per esempio, olfattivi compiti comportamentali possono essere impiantati, fornendo stimolo olfattivo nel dispositivo Poke naso. La scelta illuminata cinque parete Poke naso con stimolo olfattivo dal Associates MED (ENV-115A-OF) può essere facilmente installato sul pannello di comando per complessi compiti olfattivi. Inoltre, tutti i dispositivi operante può essere facilmente sostituito con quelli che sono progettati per topi senza modificare la configurazione del sistema. Preciso controllo temporale di ciascun dispositivo operante, nonché la registrazione ad alta risoluzione di singoli eventi in un processo determinato, consentono la manipolazione accurata dei dispositivi per la personalizzazione del disegno di compiti comportamentali per affrontare diverse funzioni cerebrali cognitive (vedi sotto). Quando combinata con la registrazione dell&#39;attività neuronale, una ricca varietà di temi nel campo delle neuroscienze può essere studiata con questo sistema. Ad esempio, in unouditory compito sopra descritto, alle seguenti domande relative a funzioni cognitive del cervello possono essere studiati in prova unica: (1). Motivazioni: Poiché ogni prova viene iniziata da animale &quot;self-motivated&quot; naso-poke azione (Figura 5A-a e Figura 3), la motivazione può quindi essere valutata quantitativamente misurando il numero totale di prove eseguite da un animale in una data sessione, o il numero di prove consecutive eseguita 6,7. (2). Attenzione: La chiave per ottenere una ricompensa in un processo è quello di riconoscere correttamente i segnali uditivi. In circa il 25% dei ratti che non potevano essere addestrati per eseguire l&#39;operazione, la mancanza di partecipazione ai segnali uditivi fu il fattore principale. Al contrario, nei topi che hanno imparato il compito, una pausa momentanea di comportamenti era evidente durante la presentazione uditiva cue (vedi Figura 5A-b e Figura 3). Utilizzando questo sistema, è quindi possibile (i) ratti schermo per la sindrome da deficit &quot;CITS &quot;e (ii) studiare i meccanismi neurali di attenzione quando combinato con le registrazioni neuronali mentre l&#39;animale sta partecipando alle 8-10 uditivi spunti. (3). Decisione: All&#39;atto della rilevazione dei segnali uditivi, l&#39;animale deve decidere quale direzione girare per avvicinarsi la leva corretta entro una finestra temporale limitata (Figura 5A-c). E &#39;quindi anche un paradigma efficace per lo studio del processo decisionale 11,12. (4). Pazienza: I tempi di estensione della leva può essere controllata in modo tale che l&#39;animale deve attendere per la leva dopo essere arrivato al punto in cui la leva si estenderà (Figura 5A-d). Variando la lunghezza di attesa, la portata di pazienza di un animale può essere testato e quantificati 13. (5). Premi: L&#39;obiettivo finale del compito è quello di ottenere la ricompensa (Figura 5A-e e Figura 3). Compiti comportamentali che utilizzano questo sistema può quindiessere facilmente progettato per studiare molti aspetti della ricompensa-decisione le questioni e la funzione dei sistemi di valore del cervello 14-17.

a fully automated and highly versatile system for testing multi-cognitive functions and recording neuronal activities in rodents

Abbiamo sviluppato un sistema completamente automatizzato per testare il comportamento operante e la registrazione dell&#39;attività neuronale attraverso il quale più funzioni cognitive del cervello può essere valutata in una sequenza di attività singola. La caratteristica unica di questo sistema è una custom-made, camera acusticamente trasparente che elimina molti dei problemi legati al controllo di cue uditiva in camere più disponibili in commercio. La facilità con cui i dispositivi operante può essere aggiunto o sostituito rende il sistema molto versatile, consentendo la realizzazione di una varietà di uditivo, visivo, e olfattivi compiti comportamentali. Automazione del sistema consente bel temporale (10 ms) e preciso controllo time-stamping di ogni evento in una sequenza comportamentale predefinito. Quando combinato con un sistema multicanale di registrazione elettrofisiologia, più funzioni cognitive del cervello, come motivazione, attenzione, il processo decisionale, la pazienza, e le ricompense, possono essere esaminate in sequenza o in modo indipendente.

Watch this Scientific Journal Video about A Fully Automated and Highly Versatile System for Testing Multi-cognitive Functions and Recording Neuronal Activities in Rodents at JoVE.com

A Fully Automated and Highly Versatile System for Testing Multi-cognitive Functions and Recording Neuronal Activities in Rodents

In questo rapporto, presentiamo un sistema completamente automatico ed estremamente versatile in grado di testare contemporaneamente multi-cognitive comportamenti e registrare le attività neuronali per i roditori.

Un sistema completamente automatizzato ed altamente versatile per test multi-funzioni cognitive e di registrare le attività neuronali in roditori

We have developed a fully automated system for operant behavior testing and neuronal activity recording by which multiple cognitive brain functions can be ...

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Nanyang Technological University

Research

JoVE Journal

Neuroscience

14.3K Views.  The Neurosciences Institute, San Diego, CA. In questo rapporto, presentiamo un sistema completamente automatico ed estremamente versatile in grado di testare contemporaneamente multi-cognitive comportamenti e registrare le attività neuronali per i roditori.

Video: A Fully Automated and Highly Versatile System for Testing Multi-cognitive Functions and Recording Neuronal Activities in Rodents

Automated Sholl Analysis of Digitized Neuronal Morphology at Multiple Scales

Neuronal morphology plays a significant role in determining how neurons function and communicate1-3. Specifically, it affects the ability of neurons to receive inputs from other cells2 and contributes to the propagation of action potentials4,5. The morphology of the neurites also affects how information is processed. The diversity of dendrite morphologies facilitate local and long range signaling and allow individual neurons or groups of neurons to carry out specialized functions within the neuronal network6,7. Alterations in dendrite morphology, including fragmentation of dendrites and changes in branching patterns, have been observed in a number of disease states, including Alzheimer's disease8, schizophrenia9,10, and mental retardation11. The ability to both understand the factors that shape dendrite morphologies and to identify changes in dendrite morphologies is essential in the understanding of nervous system function and dysfunction.
Neurite morphology is often analyzed by Sholl analysis and by counting the number of neurites and the number of branch tips. This analysis is generally applied to dendrites, but it can also be applied to axons. Performing this analysis by hand is both time consuming and inevitably introduces variability due to experimenter bias and inconsistency. The Bonfire program is a semi-automated approach to the analysis of dendrite and axon morphology that builds upon available open-source morphological analysis tools. Our program enables the detection of local changes in dendrite and axon branching behaviors by performing Sholl analysis on subregions of the neuritic arbor. For example, Sholl analysis is performed on both the neuron as a whole as well as on each subset of processes (primary, secondary, terminal, root, etc.) Dendrite and axon patterning is influenced by a number of intracellular and extracellular factors, many acting locally. Thus, the resulting arbor morphology is a result of specific processes acting on specific neurites, making it necessary to perform morphological analysis on a smaller scale in order to observe these local variations12.
The Bonfire program requires the use of two open-source analysis tools, the NeuronJ plugin to ImageJ and NeuronStudio. Neurons are traced in ImageJ, and NeuronStudio is used to define the connectivity between neurites. Bonfire contains a number of custom scripts written in MATLAB (MathWorks) that are used to convert the data into the appropriate format for further analysis, check for user errors, and ultimately perform Sholl analysis. Finally, data are exported into Excel for statistical analysis. A flow chart of the Bonfire program is shown in Figure 1.

We have developed a computer program to analyze neuronal morphology. In combination with two existing open source analysis tools, our program performs Sholl analysis and determines the number of neurites, branch points, and neurite tips. The analyses are performed so that local changes in neurite morphology can be observed.

Analisi automatizzata Sholl di Digitized morfologia neuronale a scale multiple

Neuronal morphology plays a significant role in determining how neurons function and communicate1-3.  Specifically, it affects the ability of neurons to ...

Ricerca

Neuroscienze

Cryopreservation of Cortical Tissue Blocks for the Generation of Highly Enriched Neuronal Cultures

In this study, we outline a standardized protocol for the successful cryopreservation and thawing of cortical brain tissue blocks to generate highly enriched neuronal cultures. For this protocol the freezing medium used is 10% dimethyl sulfoxide (DMSO) diluted in Hank's Buffered Salt Solution (HBSS). Blocks of cortical tissue are transferred to cryovials containing the freezing medium and slowly frozen at -1&deg;C/min in a rate-controlled freezing container. Post-thaw processing and dissociation of frozen tissue blocks consistently produced neuronal-enriched cultures which exhibited rapid neuritic growth during the first 5 days in culture and significant expansion of the neuronal network within 10 days. Immunocytochemical staining with the astrocytic marker glial fibrillary acidic protein (GFAP) and the neuronal marker beta-tubulin class III, revealed high numbers of neurons and astrocytes in the cultures. Generation of neural precursor cell cultures after tissue block dissociation resulted in rapidly expanding neurospheres, which produced large numbers of neurons and astrocytes under differentiating conditions. This simple cryopreservation protocol allows for the rapid, efficient, and inexpensive preservation of cortical brain tissue blocks, which grants increased flexibility for later generation of neuronal, astrocyte, and neuronal precursor cell cultures.

Here, we describe a method for efficient cryopreservation and thawing of cortical brain tissue blocks to generate highly enriched neuronal cultures. This simple protocol provides flexibility for later generation of neuronal, astrocyte, and neuronal precursor cell cultures.

Crioconservazione di tessuto corticale blocchi per la generazione di altamente arricchito Culture neuronale

In this study, we outline a standardized protocol for the successful cryopreservation and thawing of cortical brain tissue blocks to generate highly ...

Efficient Derivation of Human Neuronal Progenitors and Neurons from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system (CNS) structure and circuitry in today's healthcare industry. Cell-based therapies hold great promise to restore the lost nerve tissue and function for CNS disorders. However, cell therapies based on CNS-derived neural stem cells have encountered supply restriction and difficulty to use in the clinical setting due to their limited expansion ability in culture and failing plasticity after extensive passaging1-3. Despite some beneficial outcomes, the CNS-derived human neural stem cells (hNSCs) appear to exert their therapeutic effects primarily by their non-neuronal progenies through producing trophic and neuroprotective molecules to rescue the endogenous cells1-3. Alternatively, pluripotent human embryonic stem cells (hESCs) proffer cures for a wide range of neurological disorders by supplying the diversity of human neuronal cell types in the developing CNS for regeneration1,4-7. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity7-10. In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic11-13. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules14 (please see a schematic in Fig. 1). Retinoic acid (RA) does not induce neuronal differentiation of undifferentiated hESCs maintained on feeders1, 14. And unlike mouse ESCs, treating hESC-differentiated embryoid bodies (EBs) only slightly increases the low yield of neurons1, 14, 15. However, after screening a variety of small molecules and growth factors, we found that such defined conditions rendered retinoic acid (RA) sufficient to induce the specification of neuroectoderm direct from pluripotent hESCs that further progressed to neuroblasts that generated human neuronal progenitors and neurons in the developing CNS with high efficiency (Fig. 2). We defined conditions for induction of neuroblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human neuronal cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of neuroblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human neuronal progenitors and neuronal cell types in the developing CNS for neural repair.

Derivazione efficiente di progenitori neuronali umane e Neuroni pluripotenti da cellule staminali embrionali umane con induzione piccole molecole

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system ...

Large-scale Recording of Neurons by Movable Silicon Probes in Behaving Rodents

A major challenge in neuroscience is linking behavior to the collective activity of neural assemblies. Understanding of input-output relationships of neurons and circuits requires methods with the spatial selectivity and temporal resolution appropriate for mechanistic analysis of neural ensembles in the behaving animal, i.e. recording of representatively large samples of isolated single neurons. Ensemble monitoring of neuronal activity has progressed remarkably in the past decade in both small and large-brained animals, including human subjects1-11. Multiple-site recording with silicon-based devices are particularly effective because of their scalability, small volume and geometric design.
Here, we describe methods for recording multiple single neurons and local field potential in behaving rodents, using commercially available micro-machined silicon probes with custom-made accessory components. There are two basic options for interfacing silicon probes to preamplifiers: printed circuit boards and flexible cables. Probe supplying companies (<a href="http://www.neuronexustech.com/" >http://www.neuronexustech.com/</a>; <a href="http://www.sbmicrosystems.com/">http://www.sbmicrosystems.com/</a>; <a href="http://www.acreo.se/">http://www.acreo.se/</a>) usually provide the bonding service and deliver probes bonded to printed circuit boards or flexible cables. Here, we describe the implantation of a 4-shank, 32-site probe attached to flexible polyimide cable, and mounted on a movable microdrive. Each step of the probe preparation, microdrive construction and surgery is illustrated so that the end user can easily replicate the process.

We describe methods for large-scale recording of multiple single units and local field potential in behaving rodents with silicon probes. Drive fabrication, probe attachment to the drive and probe implantation processes are illustrated in sufficient details for easy replication.

Su larga scala di registrazione dei neuroni da sonde mobili in silicio Comportarsi Roditori

A major challenge in neuroscience is linking behavior to the collective activity of neural assemblies. Understanding of input-output relationships of ...

Recording and Analysis of Circadian Rhythms in Running-wheel Activity in Rodents

When rodents have free access to a running wheel in their home cage, voluntary use of this wheel will depend on the time of day1-5. Nocturnal rodents, including rats, hamsters, and mice, are active during the night and relatively inactive during the day. Many other behavioral and physiological measures also exhibit daily rhythms, but in rodents, running-wheel activity serves as a particularly reliable and convenient measure of the output of the master circadian clock, the suprachiasmatic nucleus (SCN) of the hypothalamus. In general, through a process called entrainment, the daily pattern of running-wheel activity will naturally align with the environmental light-dark cycle (LD cycle; e.g. 12 hr-light:12 hr-dark). However circadian rhythms are endogenously generated patterns in behavior that exhibit a ~24 hr period, and persist in constant darkness. Thus, in the absence of an LD cycle, the recording and analysis of running-wheel activity can be used to determine the subjective time-of-day. Because these rhythms are directed by the circadian clock the subjective time-of-day is referred to as the circadian time (CT). In contrast, when an LD cycle is present, the time-of-day that is determined by the environmental LD cycle is called the zeitgeber time (ZT).
Although circadian rhythms in running-wheel activity are typically linked to the SCN clock6-8, circadian oscillators in many other regions of the brain and body9-14 could also be involved in the regulation of daily activity rhythms. For instance, daily rhythms in food-anticipatory activity do not require the SCN15,16 and instead, are correlated with changes in the activity of extra-SCN oscillators17-20. Thus, running-wheel activity recordings can provide important behavioral information not only about the output of the master SCN clock, but also on the activity of extra-SCN oscillators. Below we describe the equipment and methods used to record, analyze and display circadian locomotor activity rhythms in laboratory rodents.

Circadian rhythms in voluntary wheel-running activity in mammals are tightly coupled to the molecular oscillations of a master clock in the brain. As such, these daily rhythms in behavior can be used to study the influence of genetic, pharmacological, and environmental factors on the functioning of this circadian clock.

Registrazione e analisi dei ritmi circadiani in Running-ruota Attività nei roditori

When rodents have free access to a running wheel in their home cage, voluntary use of this wheel will depend on the time of day1-5. Nocturnal rodents, ...

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.

Veloce micro-ionoforesi di glutammato e GABA: un utile strumento per indagare l&#39;integrazione Synaptic

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

Inducing Plasticity of Astrocytic Receptors by Manipulation of Neuronal Firing Rates

Close to two decades of research has established that astrocytes in situ and in vivo express numerous G protein-coupled receptors (GPCRs) that can be stimulated by neuronally-released transmitter. However, the ability of astrocytic receptors to exhibit plasticity in response to changes in neuronal activity has received little attention. Here we describe a model system that can be used to globally scale up or down astrocytic group I metabotropic glutamate receptors (mGluRs) in acute brain slices. Included are methods on how to prepare parasagittal hippocampal slices, construct chambers suitable for long-term slice incubation, bidirectionally manipulate neuronal action potential frequency, load astrocytes and astrocyte processes with fluorescent Ca2+ indicator, and measure changes in astrocytic Gq GPCR activity by recording spontaneous and evoked astrocyte Ca2+ events using confocal microscopy. In essence, a &#8220;calcium roadmap&#8221; is provided for how to measure plasticity of astrocytic Gq GPCRs. Applications of the technique for study of astrocytes are discussed. Having an understanding of how astrocytic receptor signaling is affected by changes in neuronal activity has important implications for both normal synaptic function as well as processes underlying neurological disorders and neurodegenerative disease.

Here we describe an adaptation of protocols used to induce homeostatic plasticity in neurons for the study of plasticity of astrocytic G protein-coupled receptors. Recently used to examine changes in astrocytic group I mGluRs in juvenile mice, the method can be applied to measure scaling of various astrocytic GPCRs, in tissue from adult mice in situ and in vivo, and to gain a better appreciation of the sensitivity of astrocytic receptors to changes in neuronal activity.

Indurre Plasticità di astrociti recettori per manipolazione del neuronali di cottura Prezzi

Close to two decades of research has established that astrocytes in situ and in vivo express numerous G protein-coupled receptors (GPCRs) that can be ...

Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System

An In vivo electroretinogram (ERG) signal is composed of several overlapping components originating from different retinal cell types, as well as noise from extra-retinal sources. Ex vivo ERG provides an efficient method to dissect the function of retinal cells directly from an intact isolated retina of animals or donor eyes. In addition, ex vivo ERG can be used to test the efficacy and safety of potential therapeutic agents on retina tissue from animals or humans. We show here how commercially available in vivo ERG systems can be used to conduct ex vivo ERG recordings from isolated mouse retinas. We combine the light stimulation, electronic and heating units of a standard in vivo system with custom-designed specimen holder, gravity-controlled perfusion system and electromagnetic noise shielding to record low-noise ex vivo ERG signals simultaneously from two retinas with the acquisition software included in commercial in vivo systems. Further, we demonstrate how to use this method in combination with pharmacological treatments that remove specific ERG components in order to dissect the function of certain retinal cell types.

Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System

Ex vivo ERG can be used to record electrical activity of retinal cells directly from isolated intact retinas of animals or humans. We demonstrate here how common in vivo ERG systems can be adapted for ex vivo ERG recordings in order to dissect the electrical activity of retinal cells.

Simultaneo<em&gt; Ex vivo</em&gt; Test funzionale di due retine per<em&gt; In vivo</em&gt; Sistema Elettroretinogramma

An In vivo electroretinogram (ERG) signal is composed of several overlapping components originating from different retinal cell types, as well as noise ...

Chronic Transcranial Electrical Stimulation and Intracortical Recording in Rats

Transcranial electrical stimulation (TES) is a powerful and relatively simple approach to diffusely influence brain activity either randomly or in a closed-loop event-triggered manner. Although many studies are focusing on the possible benefits and side-effects of TES in healthy and pathologic brains, there are still many fundamental open questions regarding the mechanism of action of the stimulation. Therefore, there is a clear need for a robust and reproducible method to test the acute and the chronic effects of TES in rodents. TES can be combined with regular behavioral, electrophysiological, and imaging techniques to investigate neuronal networks in vivo. The implantation of transcranial stimulation electrodes does not impose extra constraints on the experimental design while it offers a versatile, flexible tool to manipulate brain activity. Here we provide a detailed, step-by-step protocol to fabricate and implant transcranial stimulation electrodes to influence brain activity in a temporally constrained manner for months.

This detailed protocol describes transcranial stimulation electrode placement on the temporal bone in order to investigate the short- and long-term effects of transcranial electrical stimulation in freely moving rats.

Stimolazione elettrica transcranica cronica e registrazione intracorticale in ratti

Transcranial electrical stimulation (TES) is a powerful and relatively simple approach to diffusely influence brain activity either randomly or in a ...

Ablation of a Neuronal Population Using a Two-photon Laser and Its Assessment Using Calcium Imaging and Behavioral Recording in Zebrafish Larvae

To identify the role of a subpopulation of neurons in behavior, it is essential to test the consequences of blocking its activity in living animals. Laser ablation of neurons is an effective method for this purpose when neurons are selectively labeled with fluorescent probes. In the present study, protocols for laser ablating a subpopulation of neurons using a two-photon microscope and testing of its functional and behavioral consequences are described. In this study, prey capture behavior in zebrafish larvae is used as a study model. The pretecto-hypothalamic circuit is known to underlie this visually-driven prey catching behavior. Zebrafish pretectum were laser-ablated, and neuronal activity in the inferior lobe of the hypothalamus (ILH; the target of the pretectal projection) was examined. Prey capture behavior after pretectal ablation was also tested.

Here, we present a protocol to ablate a genetically labeled subpopulation of neurons by a two-photon laser from Zebrafish larvae.

Ablazione di una popolazione neuronale utilizzando un Laser del due-fotone e sua valutazione usando formazione immagine del calcio e registrazione del comportamento nelle larve di Zebrafish

To identify the role of a subpopulation of neurons in behavior, it is essential to test the consequences of blocking its activity in living animals. Laser ...

Un sistema completamente automatizzato ed altamente versatile per test multi-funzioni cognitive e di registrare le attività neuronali in roditori

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