Questa ricerca è stata sostenuta da finanziamenti della Fondazione per la Ricerca - Fiandre (FWO, progetto Nr. G.0420.02 e G.0443.11N), l&#39;Ercole Foundation (Grant Nr. AUHA0012), concertate azioni di ricerca (finanziamento GOA) presso l&#39;Università di Anversa, e in parte sponsorizzato dalla CE - FP6 progetto Dimi, LSHB-CT-2005-512146 e CE - FP6 progetto EMIL LSHC-CT-2004-503569 per A.VdL. G.DG e CP sono borsisti post-dottorato della Fondazione di Ricerca - Fiandre (FWO).

1. Preparazione degli stimoli uditivi <ol><li> Prima di registrare il suono-stimolo, mentre in fase di riproduzione all&#39;interno del foro del sistema MR 7T. L&#39;alesaggio è uno spazio limitato che può distorcere gli stimoli uditivi con conseguente valorizzazione di determinate frequenze uditive. Figura 1 mostra le frequenze enfatizzate e repressa come dimostrano le nostre registrazioni di rumore bianco realizzato in corrispondenza della posizione della testa degli stessi all&#39;interno del magnete con un microfono in fibra ottica (Optimic 1160, Optoacoustics). Per compensare questo aumento artificiale, una funzione di equalizzazione viene applicata a ogni stimolo utilizzando il software WaveLab. Per la nostra particolare configurazione, la funzione consiste di un kernel gaussiano con i seguenti parametri: ampiezza massima:-20dB, centrata su 3.750 Hz, larghezza: 0,05 ottave (corrispondente al range 2.500-5.000 Hz per il nostro sistema). </li><li> Gli stimoli brani sono composti da diversi singoli motivi canto di ogni uccello intercalati con periodi di silenzio. Il dfigurazione di questi periodi di silenzio viene regolata per mantenere la quantità totale di suono e silenzio identiche per tutti gli stimoli. Questa costruzione conserva la naturale variabilità intra-individuale e inter-individuale della durata del brano. La lunghezza totale di ogni stimolo è 16 sec. L&#39;intensità di ogni canzone è normalizzato in termini di abbinamento root-mean-square e passa-alto a 400 Hz filtrata prima di essere integrato nel stimolo completo (canto e periodi di silenzio). Queste manipolazioni sono effettuate utilizzando il software Praat. </li><li> L&#39;esperimento è costituito da un ON / OFF di blocco di design si alternano periodi di stimolazione uditiva (su blocchi) con periodi di riposo (OFF blocchi) (Figura 2). Ogni blocco (ON e OFF) dura 16 sec, che corrisponde al tempo di acquisizione di due immagini (vedi sotto per acquisizione). Ogni tipo di stimolo è presentato 25 volte, con la conseguente acquisizione di 50 immagini al stimolo e per ogni soggetto. L&#39;ordine di presentazione delle condizioni dovrebbe essere randomizzati entro e trasoggetti. Questo ordine casuale degli stimoli può essere codificato in un software di presentazione. </li></ol> 2. Oggetto Preparazione 2.1 Oggetto e dimensione del gruppo Qui vi presentiamo un protocollo specificamente adattate per l&#39;uso di (adulti) diamanti mandarini. La scelta della specie dipende dalla domanda scientifica. Tuttavia, altre considerazioni come uccello robustezza per l&#39;anestesia può anche essere presa in considerazione. Zebra fringuelli (Taeniopygia guttata) dovrebbero essere alloggiati in voliere sotto una luce 12 ore: 12 ore fotoperiodo buio e di avere accesso a cibo e acqua ad libitum per tutto lo studio. Il numero minimo di individui per esperimento è 15. Questo numero tiene conto della sensibilità di spin-echo fMRI e la naturale variabilità interindividuale dei fenomeni biologici misurati nell&#39;esperimento. 2.2 Installazione di configurazione e preparazione dell&#39;animale (Per le specifichedelle attrezzature utilizzate, si fa riferimento alla lista di reagenti e attrezzature specifiche alla fine di questo articolo) <ol><li> Installare la maschera becco sul letto risonanza magnetica di un sistema MR 7T e collegarlo al dispositivo di controllo del gas con tubi di plastica. Aprire entrambi ossigeno e bombole di gas di azoto e accendere il dispositivo di controllo del gas (portata di ossigeno: 200 cc / min di azoto: 400 cc / min). </li></ol> Come detto sopra, un sistema RM 7T è utilizzato nella configurazione presentata. Altri sistemi MR con differenti intensità di campo sono possibili, ma a 7T che viene raggiunto un buon compromesso tra rapporto segnale-rumore e grado di artefatti di suscettibilità (vedi la discussione). Ad intensità di campo superiori, il rapporto segnale-rumore aumenta con il grado di artefatti di suscettibilità. <ol start="2"><li> Accendere il sistema di controllo di feedback e dispositivo di flusso d&#39;aria calda. </li><li> Anestetizzare il diamante mandarino con il 3% isoflurano in una miscela di ossigeno e azoto, introducendo il becconella maschera e tenendo la testa verso il basso fino a quando l&#39;uccello è completamente anestetizzati. Questo può essere verificato tirando il piede dolcemente: quando l&#39;uccello è completamente sedato il piede non sarà ritratto dalla uccello. Inoltre, gli occhi dell&#39;uccello saranno parzialmente chiuse. </li><li> Introdurre la sonda di temperatura cloacale per schermare la temperatura corporea e monitorare il tasso di respirazione mettendo un sensore pneumatico sotto il diamante mandarino pancia. Chiudere la giacca per trattenere il corpo dell&#39;uccello (Figura 3). </li><li> Mantenere la frequenza respiratoria nel range di 40 - 100 respiri al minuto e mantenere costante la temperatura corporea in un intervallo ristretto di 40 ± 0,5 ° C. Quando l&#39;intervallo di respirazione è troppo basso / alto, regolare il livello di anestesia (% isoflurano) di conseguenza. Se il problema persiste, l&#39;esperimento deve essere interrotto e l&#39;animale rimosso dalla configurazione al fine di recuperare. </li><li> Posizionare i diffusori dinamici non magnetici su entrambi i lati della testa e del fringuello con zebrali collegare all&#39;amplificatore. Assicurarsi che i cavi degli altoparlanti sono guidati dalla sonda di temperatura, perché può influenzare la lettura della temperatura, quando troppo vicino. </li><li> Disporre la bobina RF superficie sulla parte superiore della testa fringuello e posizionare il diamante mandarino nel centro del magnete (e automaticamente il centro della bobina di trasmissione che si trova al centro del magnete) zebra. </li><li> Ridurre il livello di anestesia al 1,5% isoflurano mescolato con ossigeno e azoto. </li></ol> 3. Acquisizione Dati <ol><li> Acquisire una serie di 1 sagittale, 1 orizzontale e 1 coronale gradiente echo (GE) immagine Scout (tri-pilota sequenza) e set di immagini multi-slice orizzontali, coronale e sagittale (pilotaggio T 2-ponderata rapida acquisizione relax-enhanced ( RARE) sequenza SE) per determinare la posizione del cervello nel magnete (Figura 4). </li><li> Diminuire il rumore dei gradienti, aumentando i loro tempi di rampa a 1.000 ms. </li> &lt;li&gt; Preparare la sequenza fMRI: RARE T sequenza 2-ponderata, efficace TE: 60 msec, TR: 2.000 msec, fattore RARE: 8, FOV: 16 mm, dimensione della matrice: 64 x 32, l&#39;orientamento: sagittale, spessore di taglio: 0,75 mm, Inter-fetta spessore dello spazio: 0,05 millimetri, 15 fette che coprono quasi tutto il cervello (Figura 4). </li><li> Selezionare il protocollo uditivo (stimoli uditivi e tempi di consegna stimolo) nel software di presentazione. Questo protocollo è costituito da una sequenza di comandi - per l&#39;avvio di specifici stimoli uditivi - che vengono eseguiti in una specifica scansione-numero. Ad ogni ripetizione all&#39;interno della sequenza fMRI, il software dello scanner invierà un trigger al software di presentazione uditiva che a sua volta registra il numero di scansione ed esegue il comando corrispondente. </li><li> Per assicurarsi che il software di presentazione uditiva non manca qualsiasi trigger dallo scanner, il protocollo uditivo è iniziato prima. Una volta che il protocollo è completamente caricato, la sequenza fMRI viene avviato. </li><li> Ogni esperimento fMRI è preceduta dalla acquisizione di 12 immagini fittizie per permettere al segnale attribuita al rumore scanner per raggiungere uno stato stabile prima di iniziare la stimolazione uditiva. </li><li> Dopo l&#39;acquisizione zero riempire i dati a 64 x 64. </li><li> Prendete un primo (preliminare) cerca i risultati utilizzando lo strumento funzionale di Paravision (opzione di elaborazione / Imaging Funzionale). Calcolare la risposta BOLD differenziale tra tutti su blocchi e la linea di base (OFF blocchi). Questa analisi fornisce una prima indicazione della qualità dell&#39;esperimento. Se nessun attivazione è visto nelle aree uditive primarie, in questa fase, l&#39;uccello ha probabilmente non sente / elaborati gli stimoli uditivi a causa di problemi tecnici con la presentazione dello stimolo, il livello di anestesia, ecc L&#39;installazione deve essere verificato e la misurazione ripetuta. </li><li> Eseguire un 3D RARE sequenza pesata in T2 anatomica con lo stesso orientamento come le precedenti scansioni fMRI e con efficace TE: 60 msec, TR: 2.000 msec, fattore RARE: 8, FOV: 16 mm, dimensione della matrice: 256 x 128 x 64. </li><li> Zero riempire i dati di 256 x 256 x 256. </li><li> Prendete il diamante mandarino dal letto MRI e lasciarlo recuperare da anestesia in una gabbia sotto una lampada rossa. Normalmente, il recupero di un diamante mandarino dopo isoflurano va relativamente veloce (massimo 5 min). Dopo pochi minuti, gli uccelli cercheranno di alzarsi in piedi e una volta che l&#39;uccello è completamente recuperato, sarà appollaiarsi su un ramo invece di sedersi sul fondo della gabbia. La durata dell&#39;anestesia è di circa 2 ore per il presente esperimento. Il tempo massimo di isoflurano applicato a diamanti mandarini nel nostro laboratorio è di 6 ore, dopo di che gli uccelli anche recuperato entro 5 min. </li></ol> 4. Elaborazione dati <ol><li> Convertire il MR-dati in formato Analyze o Nifti. </li><li> Perché SPM è stato sviluppato per elaborare dati fMRI acquisiti in esseri umani, che è per voxel di circa 2 millimetri. Numerose impostazioni SPM sono adattati a questa dimensione approssimativa voxel. Se uno non wformica per cambiare tutte queste impostazioni, il modo più semplice di procedere è quello di aumentare artificialmente la dimensione voxel di dati fMRI uccelli. Regolare la dimensione del voxel nell&#39;intestazione moltiplicando la dimensione reale voxel da 10 utilizzando MRIcro. Va notato, che tale rettifica non influenza i dati in sé, nessun ricampionamento o altre modifiche viene applicato l&#39;dati. </li></ol> Un&#39;alternativa a questo è l&#39;uso di &#39;SPMMouse&#39;, che è una cassetta degli attrezzi che consente SPM di aprire e analizzare i file di qualsiasi dimensione voxel. Lo strumento permette SPM &#39;cervelli in vetro &quot;per essere creati da qualsiasi immagine, e regola automaticamente default scale di lunghezza basate sulle intestazioni di file di immagini o dati inseriti dall&#39;utente. Quindi, questo toolbox funziona in modo opposto di quello che noi proponiamo. Invece di cambiare la dimensione del voxel delle immagini per adattarsi in SPM, le impostazioni di default di SPM vengono modificati per utilizzare le immagini con dimensioni diverse voxel. <ol start="3"><li> Riallineare i dati fMRI. Co-registrazione del anatomico set di dati 3D per tegli serie temporali fMRI. Normalizzare i dati 3D (e le serie storiche fMRI co-registrata) per il diamante mandarino cervello MRI atlante. Applicare la matrice di trasformazione per il set di dati fMRI. Tutto questo può essere fatto utilizzando Statistical Parametric Mapping (SPM) del software 8. </li><li> Lisciare i dati con una larghezza di 0,5 mm kernel gaussiano con SPM8. </li><li> Effettuare analisi voxel-based statistici utilizzando SPM8. Modello dei dati come un box-auto (nessuna funzione di risposta emodinamica). Stimare i parametri del modello con l&#39;algoritmo di massima verosimiglianza ristretta classica. Calcola l&#39;effetto medio di ogni stimolo uditivo in ogni materia (analisi a effetti fissi) e quindi calcolare le statistiche come auspicato per le analisi di gruppo (analisi mixed-effect). </li><li> Proiettare la mappa parametrica statistica sul diamante mandarino atlante (Figura 5) 9 in SPM8 di localizzare le attivazioni funzionali (Figura 6). </li></ol>

<ol>
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Nessun conflitto di interessi dichiarati.

In questo rapporto, descriviamo un protocollo ottimizzato per la dettagliata caratterizzazione in vivo di substrati neurali della stimolazione uditiva in anestetizzati diamante mandarino. In linea con il protocollo presentato, la maggior parte degli studi di attivazione funzionale del cervello in animali utilizzando fMRI BOLD, anestetizzare gli animali durante l&#39;acquisizione. Animali di addestramento per abituarli all&#39;ambiente magnete e il rumore dello scanner durante i peri...

<table border="1">
 <tbody>
 <tr>
 <td>Name of the reagent/equipment</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments </td>
 </tr>
 <tr>
 <td>Isoflurane anaesthetic</td>
 <td>Isoflo</td>
 <td>05260-05</td>
 <td></td>
 </tr>
 <tr>
 <td>PC-Sam hardware/software</td>
 <td>SA-Instruments</td>
 <td></td>
 <td><a href="http://www.i4sa.com" target="_blank">http://www.i4sa.com</a></td>
 </tr>
 <tr>
 <td>Monitoring and gating system</td>
 <td></td>
 <td>1025</td>
 <td></td>
 </tr>
 <tr>
 <td>MR-compatible small rodent heater system</td>
 <td></td>
 <td></td>
 <td>Model 1025 compatible</td>
 </tr>
 <tr>
 <td>Rectal temperature probe</td>
 <td></td>
 <td>RTP-102B</td>
 <td>7'', 0.044'' </td>
 </tr>
 <tr>
 <td>7T MR scanner</td>
 <td>Bruker Biospin</td>
 <td>PHS 70/16 </td>
 <td></td>
 </tr>
 <tr>
 <td>Paravision software</td>
 <td></td>
 <td>5.1</td>
 <td></td>
 </tr>
 <tr>
 <td>Gradient Insert</td>
 <td></td>
 <td>BGA9S</td>
 <td>400 mT/m, 300A, 500V</td>
 </tr>
 <tr>
 <td>Gradient Amplifiers</td>
 <td>Copley Co., USA</td>
 <td>C256</td>
 <td></td>
 </tr>
 <tr>
 <td>Transmit resonators</td>
 <td></td>
 <td></td>
 <td>Inner diameter: 72 mm, transmit only, active decoupled</td>
 </tr>
 <tr>
 <td>Receiver antenna - 20 mm quadrature Mouse Head</td>
 <td></td>
 <td></td>
 <td>Receive only, active decoupled</td>
 </tr>
 <tr>
 <td>WaveLab software</td>
 <td>Steinberg</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Praat software</td>
 <td>Paul Boersma, University of Amsterdam</td>
 <td></td>
 <td><a href="http://www.praat.org" target="_blank">http://www.praat.org</a></td>
 </tr>
 <tr>
 <td>Non-magnetic dynamic speakers</td>
 <td>Visation, Germany</td>
 <td>HK 150</td>
 <td></td>
 </tr>
 <tr>
 <td>Fiber optic microphone</td>
 <td>Optoacoustics, </td>
 <td>Optimic 1160</td>
 <td></td>
 </tr>
 <tr>
 <td>Sound amplifier</td>
 <td>Phonic corporation</td>
 <td>MM 1002a</td>
 <td></td>
 </tr>
 <tr>
 <td>Presentation software</td>
 <td>Neurobehavioral Systems Inc.</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>MRIcro</td>
 <td>Chris Rorden</td>
 <td></td>
 <td><a href="http://www.cabiatl.com/mricro/mricro/" target="_blank">http://www.cabiatl.com/mricro/mricro/</a></td>
 </tr>
 <tr>
 <td>Statistical Parametric Mapping (SPM)</td>
 <td>Welcome Trust Centre for Neuroimaging</td>
 <td>8</td>
 <td><a href="http://www.fil.ion.ucl.ac.uk/spm/" target="_blank">http://www.fil.ion.ucl.ac.uk/spm/</a></td>
 </tr>
 </tbody>
</table>

functional magnetic resonance imaging (fmri) with auditory stimulation in songbirds

La neurobiologia del canto degli uccelli, come modello per il linguaggio umano, è una zona marcata di ricerca in neuroscienze comportamentali. Considerando che l&#39;elettrofisiologia e molecolare approcci permettono l&#39;indagine sia stimoli differenti su alcuni neuroni, o uno stimolo in grandi parti del cervello, il livello di ossigenazione del sangue dipendente (BOLD), risonanza magnetica funzionale (fMRI) permette di combinare entrambi i vantaggi, cioè confrontare l&#39;attivazione neurale indotta da stimoli differenti in tutto il cervello in una volta. fMRI in uccelli canori è impegnativo a causa delle piccole dimensioni del loro cervello e perché le loro ossa e soprattutto il loro cranio comprendono numerose cavità d&#39;aria, inducendo importanti artefatti di suscettibilità. Gradient-echo (GE) fMRI BOLD è stato applicato con successo per uccelli canori 1-5 (per una rassegna, vedi 6). Questi studi si sono concentrati sulle aree cerebrali uditive primarie e secondarie, che sono le regioni libere di artefatti di suscettibilità. Tuttavia, poiché proccessi di interesse possono verificarsi al di là di queste regioni, è necessaria tutta la fMRI BOLD cervello utilizzando una sequenza MRI meno suscettibile a questi manufatti. Ciò può essere ottenuto utilizzando spin-echo (SE) BOLD fMRI 7,8. In questo articolo, si descrive come utilizzare questa tecnica in diamanti mandarini (Taeniopygia guttata), che sono piccoli uccelli canori, con un peso di 15-25 g ampiamente studiato in neuroscienze comportamentali del canto degli uccelli. Il tema principale di studi fMRI su uccelli canori è percezione canzone e canzone apprendimento. La natura degli stimoli uditivi in ​​combinazione con i deboli sensibilità BOLD di SE (rispetto a GE) sequenze fMRI basati rende l&#39;implementazione di questa tecnica molto impegnativo.

<html> Siamo qui presentate visivamente una sequenza ottimizzata di procedure per l&#39;imaging di successo di substrati neurali di stimoli uditivi nel cervello fringuello zebra. In primo luogo, la procedura descritta per la preparazione dei stimoli uditivi risultati in stimoli che può essere incorporato in un ON / OFF blocco paradigma (Figura 2) e che sono normalizzati per eliminare potenziali differenze nel livello di pressione sonora che potrebbe evocare una risposta differenziale nel cervello . Dopo...

Watch this Scientific Journal Video about Functional Magnetic Resonance Imaging fMRI with Auditory Stimulation in Songbirds at JoVE.com

Functional Magnetic Resonance Imaging fMRI with Auditory Stimulation in Songbirds

Questo articolo mostra una procedura ottimizzata per l&#39;imaging dei substrati neurali della stimolazione uditiva nel cervello Songbird utilizzando la risonanza magnetica funzionale (fMRI). Esso descrive la preparazione degli stimoli sonori, il posizionamento del soggetto e l&#39;acquisizione e la successiva analisi dei dati fMRI.

Risonanza magnetica funzionale (fMRI) con Auditory Stimulation in uccelli canori

The neurobiology of birdsong, as a model for human speech, is a pronounced area of research in behavioral neuroscience. Whereas electrophysiology and ...

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Functional Magnetic Resonance Imaging (fMRI) with Auditory Stimulation in Songbirds

18.0K Views.  University of Antwerp. Questo articolo mostra una procedura ottimizzata per l'imaging dei substrati neurali della stimolazione uditiva nel cervello Songbird utilizzando la risonanza magnetica funzionale (fMRI). Esso descrive la preparazione degli stimoli sonori, il posizionamento del soggetto e l'acquisizione e la successiva analisi dei dati fMRI.

Video: Functional Magnetic Resonance Imaging fMRI with Auditory Stimulation in Songbirds

Best Current Practice for Obtaining High Quality EEG Data During Simultaneous fMRI

Simultaneous EEG-fMRI allows the excellent temporal resolution of EEG to be combined with the high spatial accuracy of fMRI. The data from these two modalities can be combined in a number of ways, but all rely on the acquisition of high quality EEG and fMRI data. EEG data acquired during simultaneous fMRI are affected by several artifacts, including the gradient artefact (due to the changing magnetic field gradients required for fMRI), the pulse artefact (linked to the cardiac cycle) and movement artifacts (resulting from movements in the strong magnetic field of the scanner, and muscle activity). Post-processing methods for successfully correcting the gradient and pulse artifacts require a number of criteria to be satisfied during data acquisition. Minimizing head motion during EEG-fMRI is also imperative for limiting the generation of artifacts.
Interactions between the radio frequency (RF) pulses required for MRI and the EEG hardware may occur and can cause heating. This is only a significant risk if safety guidelines are not satisfied. Hardware design and set-up, as well as careful selection of which MR sequences are run with the EEG hardware present must therefore be considered.
The above issues highlight the importance of the choice of the experimental protocol employed when performing a simultaneous EEG-fMRI experiment. Based on previous research we describe an optimal experimental set-up. This provides high quality EEG data during simultaneous fMRI when using commercial EEG and fMRI systems, with safety risks to the subject minimized. We demonstrate this set-up in an EEG-fMRI experiment using a simple visual stimulus. However, much more complex stimuli can be used. Here we show the EEG-fMRI set-up using a Brain Products GmbH (Gilching, Germany) MRplus, 32 channel EEG system in conjunction with a Philips Achieva (Best, Netherlands) 3T MR scanner, although many of the techniques are transferable to other systems.

Simultaneous electroencephalography (EEG) and functional Magnetic Resonance imaging (fMRI) is a powerful neuroimaging tool. However, the inside of an MRI scanner forms a difficult environment for EEG data recording and safety must be considered whenever operating EEG equipment inside a scanner. Here, we present an optimised EEG-fMRI data acquisition protocol.

Migliori prassi attuale per ottenere dati di alta qualità durante l&#39;EEG fMRI simultanea

Simultaneous  EEG-fMRI allows the excellent temporal resolution of EEG to be combined with the  high spatial accuracy of fMRI. The data  from these two ...

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Comportamento

Quantitative Assessment of Cortical Auditory-tactile Processing in Children with Disabilities

Objective and easy measurement of sensory processing is extremely difficult in nonverbal or vulnerable pediatric patients. We developed a new methodology to quantitatively assess children&#39;s cortical processing of light touch, speech sounds and the multisensory processing of the 2 stimuli, without requiring active subject participation or causing children discomfort. To accomplish this we developed a dual channel, time and strength calibrated air puff stimulator that allows both tactile stimulation and sham control. We combined this with the use of event-related potential methodology to allow for high temporal resolution of signals from the primary and secondary somatosensory cortices as well as higher order processing. This methodology also allowed us to measure a multisensory response to auditory-tactile stimulation.

Objective and easy measurement of sensory processing is extremely difficult in nonverbal or vulnerable pediatric patients. We developed a new methodology to quantitatively assess infants and children&#39;s cortical processing of light touch, speech sounds, and the multisensory processing of the 2 stimuli, without requiring active subject participation or causing discomfort in vulnerable patients.

La valutazione quantitativa di elaborazione corticale uditivo-tattile nei bambini con disabilità

Objective and easy measurement of sensory processing is extremely difficult in nonverbal or vulnerable pediatric patients. We developed a new methodology ...

Stimulating the Lip Motor Cortex with Transcranial Magnetic Stimulation

Transcranial magnetic stimulation (TMS) has proven to be a useful tool in investigating the role of the articulatory motor cortex in speech perception. Researchers have used single-pulse and repetitive TMS to stimulate the lip representation in the motor cortex. The excitability of the lip motor representation can be investigated by applying single TMS pulses over this cortical area and recording TMS-induced motor evoked potentials (MEPs) via electrodes attached to the lip muscles (electromyography; EMG). Larger MEPs reflect increased cortical excitability. Studies have shown that excitability increases during listening to speech as well as during&#160;viewing speech-related movements. TMS can be used also to disrupt the lip motor representation. A 15-min train of low-frequency sub-threshold repetitive stimulation has been shown to suppress motor excitability for a further 15-20 min. This TMS-induced disruption of the motor lip representation impairs subsequent performance in demanding speech perception tasks and modulates auditory-cortex responses to speech sounds. These findings are consistent with the suggestion that the motor cortex contributes to speech perception. This article describes how to localize the lip representation in the motor cortex and how to define the appropriate stimulation intensity for carrying out both single-pulse and repetitive TMS experiments.

Transcranial magnetic stimulation (TMS) has proven to be a useful tool in investigating the role of the articulatory motor cortex in speech perception.&#160; This article describes how to record motor evoked potentials (MEPs) from the lip muscles and how to disrupt the motor lip representation using repetitive TMS.

Stimolare il Lip Motor Cortex con la Stimolazione Magnetica Transcranica

Transcranial magnetic stimulation (TMS) has proven to be a useful tool in investigating the role of the articulatory motor cortex in speech perception. ...

Transcranial Direct Current Stimulation and Simultaneous  Functional Magnetic Resonance Imaging

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses weak electrical currents administered to the scalp to manipulate cortical excitability and, consequently, behavior and brain function. In the last decade, numerous studies have addressed short-term and long-term effects of tDCS on different measures of behavioral performance during motor and cognitive tasks, both in healthy individuals and in a number of different patient populations. So far, however, little is known about the neural underpinnings of tDCS-action in humans with regard to large-scale brain networks. This issue can be addressed by combining tDCS with functional brain imaging techniques like functional magnetic resonance imaging (fMRI) or electroencephalography (EEG).
In particular, fMRI is the most widely used brain imaging technique to investigate the neural mechanisms underlying cognition and motor functions. Application of tDCS during fMRI allows analysis of the neural mechanisms underlying behavioral tDCS effects with high spatial resolution across the entire brain. Recent studies using this technique identified stimulation induced changes in task-related functional brain activity at the stimulation site&#160;and also in more distant brain regions, which were associated with behavioral improvement. In addition, tDCS administered during resting-state fMRI allowed identification of widespread changes in whole brain functional connectivity.
Future studies using this combined protocol should yield new insights into the mechanisms of tDCS action in health and disease and new options for more targeted application of tDCS in research and clinical settings. The present manuscript describes this novel technique in a step-by-step fashion, with a focus on technical aspects of tDCS administered during fMRI.

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique. It has successfully been used in basic research and clinical settings to modulate brain function in humans. This article describes the implementation of tDCS and simultaneous functional magnetic resonance imaging (fMRI), to investigate the neural basis of tDCS effects.

Transcranica diretta stimolazione corrente e simultanea Magnetic Resonance Imaging funzionale

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses weak electrical currents administered to the scalp ...

Transcranial Magnetic Stimulation for Investigating Causal Brain-behavioral Relationships and their Time Course

Transcranial magnetic stimulation (TMS) is a safe, non-invasive brain stimulation technique that uses a strong electromagnet in order to temporarily disrupt information processing in a brain region, generating a short-lived &#8220;virtual lesion.&#8221; Stimulation that interferes with task performance indicates that the affected brain region is necessary to perform the task normally. In other words, unlike neuroimaging methods such as functional magnetic resonance imaging (fMRI) that indicate correlations between brain and behavior, TMS can be used to demonstrate causal brain-behavior relations. Furthermore, by varying the duration and onset of the virtual lesion, TMS can also reveal the time course of normal processing. As a result, TMS has become an important tool in cognitive neuroscience. Advantages of the technique over lesion-deficit studies include better spatial-temporal precision of the disruption effect, the ability to use participants as their own control subjects, and the accessibility of participants. Limitations include concurrent auditory and somatosensory stimulation that may influence task performance, limited access to structures more than a few centimeters from the surface of the scalp, and the relatively large space of free parameters that need to be optimized in order for the experiment to work. Experimental designs that give careful consideration to appropriate control conditions help to address these concerns. This article illustrates these issues with TMS results that investigate the spatial and temporal contributions of the left supramarginal gyrus (SMG) to reading.

Transcranial magnetic stimulation (TMS) is a technique for non-invasively disrupting neural information processing and measuring its effect on behavior. When TMS interferes with a task, it indicates that the stimulated brain region is necessary for normal task performance, allowing one to systematically relate brain regions to cognitive functions.

Stimolazione Magnetica Transcranica per indagare le relazioni causali Brain-comportamentali e la loro Corso di Tempo

Transcranial magnetic stimulation (TMS) is a safe, non-invasive brain stimulation technique that uses a strong electromagnet in order to temporarily ...

Transferring Cognitive Tasks Between Brain Imaging Modalities: Implications for Task Design and Results Interpretation in fMRI Studies

As cognitive neuroscience methods develop, established experimental tasks are used with emerging brain imaging modalities. Here transferring a paradigm (the visual oddball task) with a long history of behavioral and electroencephalography (EEG) experiments to a functional magnetic resonance imaging (fMRI) experiment is considered. The aims of this paper are to briefly describe fMRI and when its use is appropriate in cognitive neuroscience; illustrate how task design can influence the results of an fMRI experiment, particularly when that task is borrowed from another imaging modality; explain the practical aspects of performing an fMRI experiment. It is demonstrated that manipulating the task demands in the visual oddball task results in different patterns of blood oxygen level dependent (BOLD) activation. The nature of the fMRI BOLD measure means that many brain regions are found to be active in a particular task. Determining the functions of these areas of activation is very much dependent on task design and analysis. The complex nature of many fMRI tasks means that the details of the task and its requirements need careful consideration when interpreting data. The data show that this is particularly important in those tasks relying on a motor response as well as cognitive elements and that covert and overt responses should be considered where possible. Furthermore, the data show that transferring an EEG paradigm to an fMRI experiment needs careful consideration and it cannot be assumed that the same paradigm will work equally well across imaging modalities. It is therefore recommended that the design of an fMRI study is pilot tested behaviorally to establish the effects of interest and then pilot tested in the fMRI environment to ensure appropriate design, implementation and analysis for the effects of interest.

Transferring a paradigm with a history of use in EEG experiments to an fMRI experiment is considered. It is demonstrated that manipulating the task demands in the visual oddball task resulted in different patterns of BOLD activation and illustrated how task design is crucial in fMRI experiments.

Trasferimento di compiti cognitivi Tra Brain Imaging Modalità: Implicazioni per attività di disegno e interpretazione dei risultati in studi fMRI

As cognitive neuroscience methods develop, established experimental tasks are used with emerging brain imaging modalities. Here transferring a paradigm ...

Design and Implementation of an fMRI Study Examining Thought Suppression in Young Women with, and At-risk, for Depression

Ruminative brooding is associated with increased vulnerability to major depression. Individuals who regularly ruminate will often try to reduce the frequency of their negative thoughts by actively suppressing them. We aim to identify the neural correlates underlying thought suppression in at-risk and depressed individuals. Three groups of women were studied; a major depressive disorder group, an at-risk group (having a first degree relative with depression) and controls. Participants performed a mixed block-event fMRI paradigm involving thought suppression, free thought and motor control periods. Participants identified the re-emergence of &#8220;to-be-suppressed&#8221; thoughts (&#8220;popping&#8221; back into conscious awareness) with a button press. During thought suppression the control group showed the greatest activation of the dorsolateral prefrontal cortex, followed by the at-risk, then depressed group. During the re-emergence of intrusive thoughts compared to successful re-suppression of those thoughts, the control group showed the greatest activation of the anterior cingulate cortices, followed by the at-risk, then depressed group. At-risk participants displayed anomalies in the neural regulation of thought suppression resembling the dysregulation found in depressed individuals. The predictive value of these changes in the onset of depression remains to be determined.

We aim to identify the neural correlates underlying sustained and transient thought suppression, and thought re-emergence in controls, at-risk and depressed individuals. Activation was greatest for controls compared to the at-risk and the depressed group in the dorsolateral prefrontal cortex during thought suppression and anterior cingulate cortex during thought re-emergence.

Progettazione e Realizzazione di uno studio fMRI Esaminare Pensiero Suppression in Donne giovani con e a rischio, per la depressione

Ruminative brooding is associated with increased vulnerability to major depression. Individuals who regularly ruminate will often try to reduce the ...

Neuronavigation-guided Repetitive Transcranial Magnetic Stimulation for Aphasia

Repetitive transcranial magnetic stimulation (rTMS) is widely used for several neurological conditions, as it has gained acknowledgement for its potential therapeutic effects. Brain excitability is non-invasively modulated by rTMS, and rTMS to the language areas has proved its potential effects on treatment of aphasia. In our protocol, we aim to artificially induce virtual aphasia in healthy subjects by inhibiting Brodmann area 44 and 45 using neuronavigational TMS (nTMS), and F3 of the International 10-20 EEG system for conventional TMS (cTMS). To measure the degree of aphasia, changes in reaction time to a picture naming task pre- and post-stimulation are measured and compare the delay in reaction time between nTMS and cTMS. Accuracy of the two TMS stimulation methods is compared by averaging the Talairach coordinates of the target and the actual stimulation. Consistency of stimulation is demonstrated by the error range from the target. The purpose of this study is to demonstrate use of nTMS and to describe the benefits and limitations of the nTMS compared to those of cTMS.

This study is designed to test the hypothesis that neuronavigational system-guided transcranial magnetic stimulation has higher accuracy for targeting the intended target as demonstrated by eliciting a greater degree of virtual aphasia in healthy subjects, measured by delay in reaction time to picture naming.

Repetitive stimolazione magnetica transcranica neuronavigazione-guidata per Afasia

Repetitive transcranial magnetic stimulation (rTMS) is widely used for several neurological conditions, as it has gained acknowledgement for its potential ...

Treating Clinical Depression with Repetitive Deep Transcranial Magnetic Stimulation Using the Brainsway H1-coil

Repetitive transcranial magnetic stimulation (rTMS) is an emerging non-pharmacological approach to treating many brain-based disorders. rTMS uses electromagnetic coils to stimulate areas of the brain non-invasively. Deep transcranial magnetic stimulation (dTMS) with the Brainsway H1-coil system specifically is a type of rTMS indicated for treating patients with major depressive disorder (MDD) who are resistant to medication. The unique H1-coil design of this device is able to stimulate neuronal pathways that lie deeper in the targeted brain areas than those reached by conventional rTMS coils. dTMS is considered to be low-risk and well tolerated, making it a viable treatment option for people who have not responded to medication or psychotherapy trials for their depression.
Randomized, sham-control studies have demonstrated that dTMS produces significantly greater improvement in depressive symptoms than sham dTMS treatment in patients with major depression that has not responded to antidepressant medication. In this paper, we will review the methodology for treating major depression with dTMS using an H1-coil.

Here we present a protocol outlining the methodology for treatment of Major Depressive Disorder using the deep Transcranial Magnetic Stimulation (dTMS) system.

Trattamento della depressione clinica con ripetitivo profonda stimolazione magnetica transcranica Utilizzando la Brainsway H1-coil

Repetitive transcranial magnetic stimulation (rTMS) is an emerging non-pharmacological approach to treating many brain-based disorders. rTMS uses ...

Repetitive Transcranial Magnetic Stimulation to the Unilateral Hemisphere of Rat Brain

Previous rodent models of repetitive transcranial magnetic stimulation (rTMS) adopted whole-brain stimulation instead of unilateral hemispheric rTMS, which is unlike the protocols used for human subjects. We report a successful application of rTMS to the unilateral hemisphere of rat brain. The rTMS was delivered with a low-frequency (1 Hz), high-frequency (20 Hz), or sham stimulation protocol to one side of the brain by using a small 25-mm figure-8 coil. We placed the center of the coil 1 cm lateral to the vertex on the biauricular line and angulated the coil 45&#176; to the ground to minimize a potential direct effect of rTMS on the contralateral cortex. We also used an in-house water cooling system to enable repetitive magnetic stimulation for more than 20 min, even at a 20-Hz stimulation frequency. Increases in the transcriptions of immediate early genes (Arc, Junb, and Egr2) were greater after rTMS than after sham stimulation. After 5 consecutive days of 20-min 1-Hz rTMS, bdnf mRNA expression was significantly higher in stimulated cortex than in contralateral side. The model presented herein will elucidate the molecular mechanisms of rTMS by allowing analysis of the inter-hemispheric difference in its effect.

We applied repetitive transcranial magnetic stimulation (rTMS) to the unilateral hemisphere of rat brain, by placing a 25-mm figure-8 coil 1 cm lateral to the vertex on the biauricular line and angulating the coil by 45&#176;. An in-house water cooling system was used for rTMS for more than 20 min.

Repetitive stimolazione magnetica transcranica al unilaterale emisfero del cervello di ratto

Previous rodent models of repetitive transcranial magnetic stimulation (rTMS) adopted whole-brain stimulation instead of unilateral hemispheric rTMS, ...