1. Preparazione <ol class="lalpha"><li> Per iniziare, ottenere una scansione di base anatomica del soggetto. Questo dovrebbe essere fatto diversi giorni prima che l&#39;esperimento vero e proprio. </li><li> Quindi, caricare la scansione nel pacchetto software senza cornice stereotassica. </li><li> Infine, individuare e indirizzare i tuoi coordinate stimolazione. In questo caso, ci saranno intese a promuovere l&#39;lobo parietale inferiore sinistra. </li></ol> 2. La scansione iniziale <ol class="lalpha"><li> Il giorno dell&#39;esperimento, il soggetto sarà, ancora una volta, inizia nella macchina di risonanza magnetica. </li><li> Inizia con una scansione anatomica. </li><li> Successivamente, condotta tre piste sperimentazione funzionale. Per questo esperimento, il compito è abbastanza semplice: un punto di fissazione è presentato in campo centrale del soggetto della visione, e lui / lei è a fissare semplicemente al passivamente. </li></ol> 3. TMS Preparazione <ol class="lalpha"><li> Poiché gli effetti della rTMS sono transitori, il tempo è essenziale quando si combinano TMS e fMRI. E &#39;indispensabile ottenere il nuovo soggetto nello scanner il più presto possibile dopo la cessazione stimolazione. Per questo motivo, ti consigliamo di utilizzare un dispositivo TMS portatile di stanza in una stanza adiacente o il più vicino possibile alla scansione-bay possibile. In questo caso, stiamo usando un portatile di set-up in una suite di osservazione accanto allo scanner. </li><li> Carico del soggetto pre-mirati RMN basale nel pacchetto software stereotassica. </li><li> Infine, link e calibrare la bobina stimolante con l&#39;attrezzatura stereotassia - in questo caso, ci allineare una serie di sensori a infrarossi per la registrazione centralità della bobina. </li></ol> 4. Determinazione dei parametri TMS <ol class="lalpha"><li> Quando il soggetto arriva, lui si siede / lei comodamente su una sedia. </li><li> Poi, calibrare la testa del soggetto con l&#39;attrezzatura sterotaxy. In questo caso, useremo sensori infrarossi per la registrazione ancoraggi di posizionamento diverse: entrambe le orecchie, il naso, e il nasion. </li><li> Determinare la soglia di riposo motore del soggetto. </li><li> Se vogliamo eccitare corteccia del soggetto, si imposterà la macchina TMS a 20 Hz con una potenza di stimolazione della soglia motoria 110%. Se vogliamo inibire corteccia del soggetto, si imposterà la macchina TMS a 1 Hz al 110% della soglia del motore. Anche se ti consigliamo di visitare entrambi i parametri nel corso di uno studio completo, ci sarà solo guardare una catena 20 eccitatorio rTMS Hz in questo articolo. </li><li> Infine, creare un modello di stimolazione dei 2 treni secondi con 28 periodi di riposo secondo. </li></ol> 5. TMS Stimolazione <ol class="lalpha"><li> Prima di stimolazione, preparare il soggetto ad andare direttamente in TMS dopo lo scanner. Ciò include la rimozione di metalli e di garantire il soggetto ha usato il bagno. </li><li> Tenendo la bobina tangenziale al cuoio capelluto, usare l&#39;apparecchiatura in stereotassia per individuare e target di stimolazione del soggetto. </li><li> Accendere il sistema di bobine della macchina di raffreddamento. </li><li> Iniziare la stimolazione! Per questo protocollo, condurremo 45 treni stimolazione totale. A 2 secondi un treno con 28 rotture secondo, avremo un tempo totale stim di 23 minuti. </li></ol> 6. Torna Scanner <ol class="lalpha"><li> Una volta che la stimolazione è completo, è importante per ottenere il soggetto nello scanner il più presto possibile. Per rendere questa transizione il più semplice possibile, garantire lo scanner è preparato e pronto a partire. Il nostro consiglio è quello di sollevare la piattaforma corpo, e ridurre il numero e la durata delle scansioni localizzatore al minimo. </li></ol> 7. Finale di scansione <ol class="lalpha"><li> Poiché gli effetti della rTMS sono transitori, la sessione di scansione finale dovrebbe iniziare con i percorsi funzionali. Ancora una volta, eseguiamo tre, 6 minuti di piste di fissazione passiva. </li><li> Dopo le prove sperimentali sono completi, finire con una scansione anatomica. </li></ol> 8. Rappresentante Risultati <img src="/files/ftp_upload/2271/2271fig1.jpg" alt="Figura 1" /> Figura 1. I dati suggeriscono che la stimolazione 20 Hz rTMS al lobo parietale inferiore sinistra, pur facilitando eccitabilità locali, atti a diminuire connettività funzionale all&#39;interno della rete di default.

<ol>
	<li>Raichle, M. E., MacLeod, A. M., Snyder, A. Z., Powers, W. J., Gusnard, D. A., Shulman, 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=A+default+mode+of+brain+function.">A default mode of brain function.</a> Proc. Nat. Acad. Sciences. 98 (2), 676-682 (2001).</li><li>Buckner, R. L., Andrews-Hanna, J. R., Schacter, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+brain's+default+network:+anatomy,+function+and+relevance+to+disease.">The brain's default network: anatomy, function and relevance to disease.</a> Ann. N.Y. Acad. Sci. 1124, 1-38 (2008).</li><li>Raichle, M. E., Snyder, A. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+default+mode+of+brain+function:+a+brief+history+of+an+evolving+idea.">A default mode of brain function: a brief history of an evolving idea.</a> Neuroimage. 37 (4), 1083-1090 (2007).</li><li>Whitfield-Gabrieli, S., Thermenos, H. W., Milanovic, S., Tsuang, M. T., Faraone, S. V., McCarley, R. W., Shenton, M. E., Green, A. I., Nieto-Castanon, A., LaViolette, P., Wojcik, J., Gabrieli, J. D., Sidman, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hyperactivity+and+hyperconnectivity+of+the+default+network+in+schizophrenia+and+in+first-degreerelatives+of+persons+with+schizophrenia.">Hyperactivity and hyperconnectivity of the default network in schizophrenia and in first-degreerelatives of persons with schizophrenia.</a> Proc. Nat. Acad. Sciences. 106 (4), 1279-1284 (2009).</li><li>Pomarol-Clotet, E., Salvardor, R., Sarro, S., Gomar, J., Vila, F., Martinez, A., Guerrrero, A., Ortiz-Gil, J., Sans-Sansa, B., Capdevila, A., Cebamanos, J. M., McKenna, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Failure+to+deactivate+the+prefrontal+cortex+in+schizophrenia:+dysfunction+of+the+default+mode+network?.">Failure to deactivate the prefrontal cortex in schizophrenia: dysfunction of the default mode network?.</a> Psychol Med. 38 (8), 1185-1193 (2008).</li><li>Garrity, A. G., Pearlson, G. D., McKiernan, K., Lloyd, D., Kiehl, K. A., Calhoun, V. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aberrant+"default+mode"+functional+connectivity+in+schizophrenia.">Aberrant "default mode" functional connectivity in schizophrenia.</a> American Journal of Psychiatry. 164, 450-457 (2007).</li><li>Kennedy, D. P., Redcay, E., Courchesne, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Failing+to+deactivate:+Resting+functional+abnormalities+in+autism.">Failing to deactivate: Resting functional abnormalities in autism.</a> Proc. Nat. Acad. Sciences. 103 (21), 8275-8280 (2007).</li><li>c Buckner, R. L., Snyder, A. Z., Shannon, B. J., LaRossa, G., Sachs, R., Fotenos, A. F., Sheline, Y. I., Klunk, W. E., Mathis, C. A., Morris, J. C., Mintun, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular,+structural,+and+functional+characterizations+of+Alzheimer's+disease:+evidence+for+a+relationship+between+default+activity,+amyloid,+and+memory.">Molecular, structural, and functional characterizations of Alzheimer's disease: evidence for a relationship between default activity, amyloid, and memory.</a> Journal of Neuroscience. 34, 7709-7717 (2005).</li><li>Pascual-Leone, A., Davey, M., Wassermann, E. M., Rothwell, J., Puri, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Handbook of Transcranial Magnetic Stimulation. , (2002).</li></ol>

Nessun conflitto di interessi dichiarati.

<p class="jove_content"&gt; Quando si esegue uno TMS offline / esperimento di risonanza magnetica, forse la considerazione più importante riguarda il passaggio rapido e senza sforzo dal sito di stimolazione alla baia risonanza magnetica. Come tale, essa varrebbe la pena di rivisitare molte delle idee di cui sopra suggerito di aiuto in questa transizione. Primo: utilizzare una macchina portatile TMS istituita in un luogo più vicino alla baia MRI possibile. Due: eludere qualsiasi meccanismo automatico di stand-by o equivalente programmato le ap...

<ul><li> MRI Dotato di fMRI (nella foto in video è un Philips) </li><li> Dispositivo TMS grado di stimolazione ripetitiva (nella foto in video è un Magstim) </li><li> Stereotassi apparecchiature senza telaio (nella foto in video è Brainsight) </li><li> Tappi per le orecchie </li><li> Sedia per soggetto durante la stimolazione </li><li> Indietro schermo di proiezione o la RMN Goggles compatibile </li><li> Stimoli schermo vuoto </li></ul>

combining transcranial magnetic stimulation and fmri to examine the default mode network

La rete di modalità di default è un gruppo di regioni del cervello che si attiva quando un individuo non è focalizzata sul mondo esterno e il cervello è in &quot;riposo vigile.&quot; 1,2,3 Si pensa alla rete in modalità di default corrisponde alla auto-referenziale o &quot;attuazione interna&quot;. 2,3 E &#39;stato ipotizzato che, negli esseri umani, l&#39;attività all&#39;interno della rete modalità di default è correlata con alcune patologie (per esempio, iper-attivazione è stato collegato alla schizofrenia 4,5,6 e disturbi dello spettro autistico 7 mentre ipo-attivazione della rete ha stati collegati al morbo di Alzheimer e altre malattie neurodegenerative 8). Come tale, la modulazione non invasiva di questa rete può rappresentare un intervento terapeutico potenziale per un certo numero di patologie neurologiche e psichiatriche legate alla attivazione della rete anormale. Uno strumento possibile per effetto di questa modulazione è Stimolazione Magnetica Transcranica: un non-invasiva e tecnica neurostimulatory neuromodulatori che possono transitoriamente o durevolmente modulare l&#39;eccitabilità corticale (sia aumentando o diminuendo esso) attraverso l&#39;applicazione localizzata di impulsi di campo magnetico 9. Al fine di esplorare la propensione alla rete in modalità di default e la tolleranza nei confronti di modulazione, saremo combinando TMS (al lobo parietale inferiore sinistra) con la risonanza magnetica funzionale (fMRI). Attraverso questo articolo prenderemo in esame il protocollo e le considerazioni necessarie per coniugare con successo questi due strumenti neuroscientifiche.

Watch this Scientific Journal Video about Combining Transcranial Magnetic Stimulation and fMRI to Examine the Default Mode Network at JoVE.com

Combining Transcranial Magnetic Stimulation and fMRI to Examine the Default Mode Network

In questo articolo prendiamo in esame la metodologia e le considerazioni rilevanti per la combinazione di TMS e fMRI per esaminare gli effetti della stimolazione cerebrale sulla rete di default.

La combinazione di stimolazione magnetica transcranica e fMRI per esaminare il modo predefinito della rete

The default mode network is a group of brain regions that are active when an individual is not focused on the outside world and the brain is at "wakeful ...

combining-transcranial-magnetic-stimulation-fmri-to-examine-default

Research

JoVE Journal

Neuroscience

12.8K Views.  Beth Israel Deaconess Medical Center. In questo articolo prendiamo in esame la metodologia e le considerazioni rilevanti per la combinazione di TMS e fMRI per esaminare gli effetti della stimolazione cerebrale sulla rete di default.

Video: Combining Transcranial Magnetic Stimulation and fMRI to Examine the Default Mode Network

A Novel Approach for Documenting Phosphenes Induced by Transcranial Magnetic Stimulation

Stimulation of the human visual cortex produces a transient perception of light, known as a phosphene. Phosphenes are induced by invasive electrical stimulation of the occipital cortex, but also by non-invasive Transcranial Magnetic Stimulation (TMS)1 of the same cortical regions. The intensity at which a phosphene is induced (phosphene threshold) is a well established measure of visual cortical excitability and is used to study cortico-cortical interactions, functional organization 2, susceptibility to pathology 3,4 and visual processing 5-7. Phosphenes are typically defined by three characteristics: they are observed in the visual hemifield contralateral to stimulation; they are induced when the subject s eyes are open or closed, and their spatial location changes with the direction of gaze 2. Various methods have been used to document phosphenes, but a standardized methodology is lacking. We demonstrate a reliable procedure to obtain phosphene threshold values and introduce a novel system for the documentation and analysis of phosphenes. We developed the Laser Tracking and Painting system (LTaP), a low cost, easily built and operated system that records the location and size of perceived phosphenes in real-time. The LTaP system provides a stable and customizable environment for quantification and analysis of phosphenes.

Phosphenes are transient percepts of light that can be induced by applying Transcranial Magnetic Stimulation (TMS) to visually sensitive regions of cortex. We demonstrate a standard protocol for determining the phosphene threshold value and introduce a novel method for quantifying and analyzing perceived phosphenes.

Un nuovo approccio per documentare Fosfeni indotta dalla Stimolazione Magnetica Transcranica

Stimulation of the human visual cortex produces a transient perception of light, known as a phosphene. Phosphenes are induced by invasive electrical ...

Ricerca

Neuroscienze

Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation

Transcranial Magnetic Stimulation (TMS) is an effective method for establishing a causal link between a cortical area and cognitive/neurophysiological effects. Specifically, by creating a transient interference with the normal activity of a target region and measuring changes in an electrophysiological signal, we can establish a causal link between the stimulated brain area or network and the electrophysiological signal that we record. If target brain areas are functionally defined with prior fMRI scan, TMS could be used to link the fMRI activations with evoked potentials recorded. However, conducting such experiments presents significant technical challenges given the high amplitude artifacts introduced into the EEG signal by the magnetic pulse, and the difficulty to successfully target areas that were functionally defined by fMRI. Here we describe a methodology for combining these three common tools: TMS, EEG, and fMRI. We explain how to guide the stimulator&#39;s coil to the desired target area using anatomical or functional MRI data, how to record EEG during concurrent TMS, how to design an ERP study suitable for EEG-TMS combination and how to extract reliable ERP from the recorded data. We will provide representative results from a previously published study, in which fMRI-guided TMS was used concurrently with EEG to show that the face-selective N1 and the body-selective N1 component of the ERP are associated with distinct neural networks in extrastriate cortex. This method allows us to combine the high spatial resolution of fMRI with the high temporal resolution of TMS and EEG and therefore obtain a comprehensive understanding of the neural basis of various cognitive processes.

This paper describes a method for collecting and analyzing electroencephalography (EEG) data during concurrent transcranial magnetic stimulation (TMS) guided by activations revealed with functional magnetic resonance imaging (fMRI). A method for TMS artifact removal and extraction of event related potentials is described as well as considerations in paradigm design and experimental setup.

Estrazione Potenziali visivi evocati da EEG dati registrati durante fMRI-guidata Stimolazione Magnetica Transcranica

Transcranial Magnetic Stimulation (TMS) is an effective method for establishing a causal link between a cortical area and cognitive/neurophysiological ...

The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of neurological and psychiatric disorders such as stroke and depression. Yet, the mechanisms underlying its ability to modulate brain excitability to improve clinical symptoms remains poorly understood 33. To help improve this understanding, proton magnetic resonance spectroscopy (1H-MRS) can be used as it allows the in vivo quantification of brain metabolites such as &#947;-aminobutyric acid (GABA) and glutamate in a region-specific manner 41. In fact, a recent study demonstrated that 1H-MRS is indeed a powerful means to better understand the effects of tDCS on neurotransmitter concentration 34. This article aims to describe the complete protocol for combining tDCS (NeuroConn MR compatible stimulator) with 1H-MRS at 3 T using a MEGA-PRESS sequence. We will describe the impact of a protocol that has shown great promise for the treatment of motor dysfunctions after stroke, which consists of bilateral stimulation of primary motor cortices 27,30,31. Methodological factors to consider and possible modifications to the protocol are also discussed.

This article aims to describe a basic protocol for combining transcranial direct current stimulation (tDCS) with proton magnetic resonance spectroscopy (1H-MRS) measurements to investigate the effects of bilateral stimulation on primary motor cortex metabolism.

L&#39;uso di Spettroscopia di Risonanza Magnetica come uno strumento per la misura della Bi-emisferici transcraniali elettrici effetti di stimolazione sul motore principale Cortex Metabolismo

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of ...

Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific frequency and in turn modulate ongoing cortical oscillatory activity. This neurotool allows the establishment of a causal link between endogenous oscillatory activity and behavior. Most of the tACS studies have shown online effects of tACS. However, little is known about the underlying action mechanisms of this technique because of the AC-induced artifacts on Electroencephalography (EEG) signals. Here we show a unique approach to investigate online physiological frequency-specific effects of tACS of the primary motor cortex (M1) by using single pulse Transcranial Magnetic Stimulation (TMS) to probe cortical excitability changes. In our setup, the TMS coil is placed over the tACS electrode while Motor Evoked Potentials (MEPs) are collected to test the effects of the ongoing M1-tACS. So far, this approach has mainly been used to study the visual and motor systems. However, the current tACS-TMS setup can pave the way for future investigations of cognitive functions. Therefore, we provide a step-by-step manual and video guidelines for the procedure.

Transcranial Alternating Current Stimulation (tACS) allows the modulation of cortical excitability in a frequency-specific fashion. Here we show a unique approach which combines online tACS with single pulse Transcranial Magnetic Stimulation (TMS) in order to "probe" cortical excitability by means of Motor Evoked Potentials.

Effetti della stimolazione transcranica con corrente alternata la corteccia motoria primaria di approccio combinato Online con stimolazione magnetica transcranica

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific ...

Combined Transcranial Magnetic Stimulation and Electroencephalography of the Dorsolateral Prefrontal Cortex

Transcranial magnetic stimulation (TMS) is a non-invasive method that produces neural excitation in the cortex by means of brief, time-varying magnetic field pulses. The initiation of cortical activation or its modulation depends on the background activation of the neurons of the cortical region activated, the characteristics of the coil, its position and its orientation with respect to the head. TMS combined with simultaneous electrocephalography (EEG) and neuronavigation (nTMS-EEG) allows for the assessment of cortico-cortical excitability and connectivity in almost all cortical areas in a reproducible manner. This advance makes nTMS-EEG a powerful tool that can accurately assess brain dynamics and neurophysiology in test-retest paradigms that are required for clinical trials. Limitations of this method include artifacts that cover the initial brain reactivity to stimulation. Thus, the process of removing artifacts may also extract valuable information. Moreover, the optimal parameters for dorsolateral prefrontal (DLPFC) stimulation are not fully known and current protocols utilize variations from the motor cortex (M1) stimulation paradigms. However, evolving nTMS-EEG designs hope to address these issues. The protocol presented here introduces some standard practices for assessing neurophysiological functioning from stimulation to the DLPFC that can be applied in patients with treatment resistant psychiatric disorders that receive treatment such as transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), magnetic seizure therapy (MST) or electroconvulsive therapy (ECT).

The protocol presented here is for TMS-EEG studies utilizing intracortical excitability test-retest design paradigms. The intent of the protocol is to produce reliable and reproducible cortical excitability measures for assessing neurophysiological functioning related to therapeutic interventions in the treatment of neuropsychiatric diseases such as major depression.

Stimolazione magnetica transcranica combinata e l'elettroencefalografia della corteccia prefrontale dorsolaterale

Transcranial magnetic stimulation (TMS) is a non-invasive method that produces neural excitation in the cortex by means of brief, time-varying magnetic ...

Bilateral Assessment of the Corticospinal Pathways of the Ankle Muscles Using Navigated Transcranial Magnetic Stimulation

Distal leg muscles receive neural input from motor cortical areas via the corticospinal tract, which is one of the main motor descending pathway in humans and can be assessed using transcranial magnetic stimulation (TMS). Given the role of distal leg muscles in upright postural and dynamic tasks, such as walking, a growing research interest in the assessment and modulation of the corticospinal tracts relative to the function of these muscles has emerged in the last decade. However, methodological parameters used in previous work have varied across studies making the interpretation of results from cross-sectional and longitudinal studies less robust. Therefore, use of a standardized TMS protocol specific to the assessment of leg muscles&#39; corticomotor response (CMR) will allow for direct comparison of results across studies and cohorts. The objective of this paper is to present a protocol that provides the flexibility to simultaneously assess the bilateral CMR of two main ankle antagonistic muscles, the tibialis anterior and soleus, using single pulse TMS with a neuronavigation system. The present protocol is applicable while the examined muscle is either fully relaxed or isometrically contracted at a defined percentage of maximum isometric voluntary contraction. Using each subject&#39;s structural MRI with the neuronavigation system ensures accurate and precise positioning of the coil over the leg cortical representations during assessment. Given the inconsistency in CMR derived measures, this protocol also describes a standardized calculation of these measures using automated algorithms. Though this protocol is not conducted during upright postural or dynamic tasks, it&#160;can be used to assess bilaterally any pair of leg muscles, either antagonistic or synergistic, in both neurologically intact and impaired subjects.

The present protocol describes the simultaneous, bilateral assessment of the corticomotor response of the tibialis anterior and soleus during rest and tonic voluntary activation using a single pulse transcranial magnetic stimulation and neuronavigation system.

Valutazione bilaterale delle vie Corticospinal dei muscoli della caviglia utilizzando navigato la stimolazione magnetica transcranica

Distal leg muscles receive neural input from motor cortical areas via the corticospinal tract, which is one of the main motor descending pathway in humans ...

Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation

Understanding interactions between brain areas is important for the study of goal-directed behavior. Functional neuroimaging of brain connectivity has provided important insights into fundamental processes of the brain like cognition, learning, and motor control. However, this approach cannot provide causal evidence for the involvement of brain areas of interest. Transcranial magnetic stimulation (TMS) is a powerful, noninvasive tool for studying the human brain that can overcome this limitation by transiently modifying brain activity. Here, we highlight recent advances using a paired-pulse, dual-site TMS method with two coils that causally probes cortico-cortical interactions in the human motor system during different task contexts. Additionally, we describe a dual-site TMS protocol based on cortical paired associative stimulation (cPAS) that transiently enhances synaptic efficiency in two interconnected brain areas by applying repeated pairs of cortical stimuli with two coils. These methods can provide a better understanding of the mechanisms underlying cognitive-motor function as well as a new perspective on manipulating specific neural pathways in a targeted fashion to modulate brain circuits and improve behavior. This approach may prove to be an effective tool to develop more sophisticated models of brain-behavior relations and improve diagnosis and treatment of many neurological and psychiatric disorders.

This article describes new approaches to measure and strengthen functionally specific neural pathways with transcranial magnetic stimulation. These advanced noninvasive brain stimulation methodologies can provide new opportunities for the understanding of brain-behavior relations and development of new therapies to treat brain disorders.

Misurazione e manipolazione dei percorsi neurali funzionalmente specifici nel sistema motorio umano con stimolazione magnetica transcranica

Understanding interactions between brain areas is important for the study of goal-directed behavior. Functional neuroimaging of brain connectivity has ...

Employing Transcranial Magnetic Stimulation in a Resource Limited Environment to Establish Brain-Behavior Relationships

Neuroimaging is typically perceived as a resource demanding discipline. While this is the case in certain circumstances, institutions with limited resources have historically contributed significantly to the field of neuroscience, including neuroimaging. In the study of self-deception, we have successfully employed single-pulse TMS to determine the brain correlates of abilities including overclaiming and self-enhancement. Even without the use of neuro-navigation, methods provided here lead to successful outcomes. For example, it was discovered that decreases in self-deceptive responding lead to a decrease in affect. These methods provide data that are reliable and valid, and such methods provide research opportunities otherwise unavailable.&#160;Through the use of these methods, the overall knowledge base in the field of neuroscience is expanded, providing research opportunities to students such as those at our institution&#160;(Montclair State University is a Hispanic-Serving Institute) who are often denied such research experiences.

Transcranial Magnetic Stimulation (TMS) and low-frequency TMS (lfTMS) have&#160;been demonstrated to be major contributors to brain literature. Here we highlight the methods for investigating the cortical correlates of self-deception using TMS.

Impiegare la stimolazione magnetica transcranica in un ambiente con risorse limitate per stabilire relazioni cervello-comportamento

Neuroimaging is typically perceived as a resource demanding discipline. While this is the case in certain circumstances, institutions with limited ...

Conventional and Threshold-Tracking Transcranial Magnetic Stimulation Tests for Single-handed Operation

Most single-pulse transcranial magnetic stimulation (TMS) parameters (e.g., motor threshold, stimulus-response function, cortical silent period) are used to examine corticospinal excitability. Paired-pulse TMS paradigms (e.g., short- and long-interval intracortical inhibition (SICI/LICI), short-interval intracortical facilitation (SICF), and short- and long-latency afferent inhibition (SAI/LAI)) provide information about intracortical inhibitory and facilitatory networks. This has long been done by the conventional TMS method of measuring changes in the size of the motor-evoked potentials (MEPs) in response to stimuli of constant intensity. An alternative threshold-tracking approach has recently been introduced whereby the stimulus intensity for a target amplitude is tracked. The diagnostic utility of threshold-tracking SICI in amyotrophic lateral sclerosis (ALS) has been shown in previous studies. However, threshold-tracking TMS has only been used in a few centers, in part due to the lack of readily available software but also perhaps due to uncertainty over its relationship to conventional single- and paired-pulse TMS measurements.
A menu-driven suite of semi-automatic programs has been developed to facilitate the broader use of threshold-tracking TMS techniques and to enable direct comparisons with conventional amplitude measurements. These have been designed to control three types of magnetic stimulators and allow recording by a single operator of the common single- and paired-pulse TMS protocols.
This paper shows how to record a number of single- and paired-pulse TMS protocols on healthy subjects and analyze the recordings. These TMS protocols are fast and easy to perform and can provide useful biomarkers in different neurological disorders, particularly neurodegenerative diseases such as ALS.

We present a suite of standardized single- and paired-pulse transcranial magnetic stimulation (TMS) recording protocols, with options for conventional amplitude measurements and threshold-tracking. This program can control three different types of magnetic stimulators and is designed to enable all tests to be performed conveniently by a single operator.

Test di stimolazione magnetica transcranica convenzionali e con tracciamento delle soglie per il funzionamento con una sola mano

Most single-pulse transcranial magnetic stimulation (TMS) parameters (e.g., motor threshold, stimulus-response function, cortical silent period) are used ...

Stimolazione combinata dei nervi periferici e TMS con parametri di impulso controllabili

Combined Peripheral Nerve Stimulation and Controllable Pulse Parameter Transcranial Magnetic Stimulation to Probe Sensorimotor Control and Learning

Skilled motor ability depends on efficiently integrating sensory afference into the appropriate motor commands. Afferent inhibition provides a valuable tool to probe the procedural and declarative influence over sensorimotor integration during skilled motor actions. This manuscript describes the methodology and contributions of short-latency afferent inhibition (SAI) for understanding sensorimotor integration. SAI quantifies the effect of a convergent afferent volley on the corticospinal motor output evoked by transcranial magnetic stimulation (TMS). The afferent volley is triggered by the electrical stimulation of a peripheral nerve. The TMS stimulus is delivered to a location over the primary motor cortex that elicits a reliable motor-evoked response in a muscle served by that afferent nerve. The extent of inhibition in the motor-evoked response reflects the magnitude of the afferent volley converging on the motor cortex and involves central GABAergic and cholinergic contributions. The cholinergic involvement in SAI makes SAI a possible marker of declarative-procedural interactions in sensorimotor performance and learning. More recently, studies have begun manipulating the TMS current direction in SAI to tease apart the functional significance of distinct sensorimotor circuits in the primary motor cortex for skilled motor actions. The ability to control additional pulse parameters (e.g., the pulse width) with state-of-the-art controllable pulse parameter TMS (cTMS) has enhanced the selectivity of the sensorimotor circuits probed by the TMS stimulus and provided an opportunity to create more refined models of sensorimotor control and learning. Therefore, the current manuscript focuses on SAI assessment using cTMS. However, the principles outlined here also apply to SAI assessed using conventional fixed pulse width TMS stimulators and other forms of afferent inhibition, such as long-latency afferent inhibition (LAI).

Autore in primo piano: Stimolazione combinata del nervo periferico e stimolazione magnetica transcranica con parametri di impulso controllabili per sondare il controllo sensomotorio e l'apprendimento 

Short-latency afferent inhibition (SAI) is a transcranial magnetic stimulation protocol to probe sensorimotor integration. This article describes how SAI can be used to study the convergent sensorimotor loops in the motor cortex during sensorimotor behavior.

Stimolazione combinata dei nervi periferici e dei parametri di impulso controllabili Stimolazione magnetica transcranica per sondare il controllo e l'apprendimento sensomotorio

Skilled motor ability depends on efficiently integrating sensory afference into the appropriate motor commands. Afferent inhibition provides a valuable ...