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Mishra A, Yang PF, Manuel TJ, Newton AT, Phipps MA, Luo H, Sigona MK, Reed JL, Gore JC, Grissom WA, Caskey CF, Chen LM. Disrupting nociceptive information processing flow through transcranial focused ultrasound neuromodulation of thalamic nuclei. Brain Stimul 2023; 16:1430-1444. [PMID: 37741439 PMCID: PMC10702144 DOI: 10.1016/j.brs.2023.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 08/25/2023] [Accepted: 09/13/2023] [Indexed: 09/25/2023] Open
Abstract
BACKGROUND MRI-guided transcranial focused ultrasound (MRgFUS) as a next-generation neuromodulation tool can precisely target and stimulate deep brain regions with high spatial selectivity. Combined with MR-ARFI (acoustic radiation force imaging) and using fMRI BOLD signal as functional readouts, our previous studies have shown that low-intensity FUS can excite or suppress neural activity in the somatosensory cortex. OBJECTIVE To investigate whether low-intensity FUS can suppress nociceptive heat stimulation-induced responses in thalamic nuclei during hand stimulation, and to determine how this suppression influences the information processing flow within nociception networks. FINDINGS BOLD fMRI activations evoked by 47.5 °C heat stimulation of hand were detected in 24 cortical regions, which belong to sensory, affective, and cognitive nociceptive networks. Concurrent delivery of low-intensity FUS pulses (650 kHz, 550 kPa) to the predefined heat nociceptive stimulus-responsive thalamic centromedial_parafascicular (CM_para), mediodorsal (MD), ventral_lateral (VL_ and ventral_lateral_posteroventral (VLpv) nuclei suppressed their heat responses. Off-target cortical areas exhibited reduced, enhanced, or no significant fMRI signal changes, depending on the specific areas. Differentiable thalamocortical information flow during the processing of nociceptive heat input was observed, as indicated by the time to reach 10% or 30% of the heat-evoked BOLD signal peak. Suppression of thalamic heat responses significantly altered nociceptive processing flow and direction between the thalamus and cortical areas. Modulation of contralateral versus ipsilateral areas by unilateral thalamic activity differed. Signals detected in high-order cortical areas, such as dorsal frontal (DFC) and ventrolateral prefrontal (vlPFC) cortices, exhibited faster response latencies than sensory areas. CONCLUSIONS The concurrent delivery of FUS suppressed nociceptive heat response in thalamic nuclei and disrupted the nociceptive network. This study offers new insights into the causal functional connections within the thalamocortical networks and demonstrates the modulatory effects of low-intensity FUS on nociceptive information processing.
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Affiliation(s)
- Arabinda Mishra
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Pai-Feng Yang
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Thomas J Manuel
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Allen T Newton
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - M Anthony Phipps
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - Huiwen Luo
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - Michelle K Sigona
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - Jamie L Reed
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - William A Grissom
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Charles F Caskey
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Li Min Chen
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA.
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2
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Liu CS, Herrmann N, Song BX, Ba J, Gallagher D, Oh PI, Marzolini S, Rajji TK, Charles J, Papneja P, Rapoport MJ, Andreazza AC, Vieira D, Kiss A, Lanctôt KL. Exercise priming with transcranial direct current stimulation: a study protocol for a randomized, parallel-design, sham-controlled trial in mild cognitive impairment and Alzheimer's disease. BMC Geriatr 2021; 21:677. [PMID: 34863115 PMCID: PMC8645072 DOI: 10.1186/s12877-021-02636-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/16/2021] [Indexed: 12/14/2022] Open
Abstract
Background Transcranial direct current stimulation (tDCS) is a non-invasive type of brain stimulation that uses electrical currents to modulate neuronal activity. A small number of studies have investigated the effects of tDCS on cognition in patients with Mild Cognitive Impairment (MCI) and Alzheimer’s disease (AD), and have demonstrated variable effects. Emerging evidence suggests that tDCS is most effective when applied to active brain circuits. Aerobic exercise is known to increase cortical excitability and improve brain network connectivity. Exercise may therefore be an effective, yet previously unexplored primer for tDCS to improve cognition in MCI and mild AD. Methods Participants with MCI or AD will be randomized to receive 10 sessions over 2 weeks of either exercise primed tDCS, exercise primed sham tDCS, or tDCS alone in a blinded, parallel-design trial. Those randomized to an exercise intervention will receive individualized 30-min aerobic exercise prescriptions to achieve a moderate-intensity dosage, equivalent to the ventilatory anaerobic threshold determined by cardiopulmonary assessment, to sufficiently increase cortical excitability. The tDCS protocol consists of 20 min sessions at 2 mA, 5 times per week for 2 weeks applied through 35 cm2 bitemporal electrodes. Our primary aim is to assess the efficacy of exercise primed tDCS for improving global cognition using the Montreal Cognitive Assessment (MoCA). Our secondary aims are to evaluate the efficacy of exercise primed tDCS for improving specific cognitive domains using various cognitive tests (n-back, Word Recall and Word Recognition Tasks from the Alzheimer’s Disease Assessment Scale-Cognitive subscale) and neuropsychiatric symptoms (Neuropsychiatric Inventory). We will also explore whether exercise primed tDCS is associated with an increase in markers of neurogenesis, oxidative stress and angiogenesis, and if changes in these markers are correlated with cognitive improvement. Discussion We describe a novel clinical trial to investigate the effects of exercise priming before tDCS in patients with MCI or mild AD. This proof-of-concept study may identify a previously unexplored, non-invasive, non-pharmacological combination intervention that improves cognitive symptoms in patients. Findings from this study may also identify potential mechanistic actions of tDCS in MCI and mild AD. Trial registration Clinicaltrials.gov, NCT03670615. Registered on September 13, 2018.
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Affiliation(s)
- Celina S Liu
- Department of Pharmacology & Toxicology, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 3K1, Canada.,Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada
| | - Nathan Herrmann
- Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Department of Psychiatry, Division of Geriatric Psychiatry, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5, Canada
| | - Bing Xin Song
- Department of Pharmacology & Toxicology, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 3K1, Canada.,Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada
| | - Joycelyn Ba
- Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada.,Department of Biology, Faculty of Science, The University of Western Ontario, London, ON, Canada
| | - Damien Gallagher
- Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Department of Psychiatry, Division of Geriatric Psychiatry, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5, Canada
| | - Paul I Oh
- Cardiovascular Prevention and Rehabilitation Program, KITE - Toronto Rehabilitation Institute, University Health Network, 347 Rumsey Road, Toronto, ON, M5G 1R7, Canada
| | - Susan Marzolini
- Cardiovascular Prevention and Rehabilitation Program, KITE - Toronto Rehabilitation Institute, University Health Network, 347 Rumsey Road, Toronto, ON, M5G 1R7, Canada
| | - Tarek K Rajji
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Adult Neurodevelopment and Geriatric Psychiatry Division, Centre for Addiction & Mental Health, 80 Workman Way, Toronto, ON, M6J 1H4, Canada.,Toronto Dementia Research Alliance, University of Toronto, Toronto, ON, Canada
| | - Jocelyn Charles
- Family & Community Medicine, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada
| | - Purti Papneja
- Family & Community Medicine, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada
| | - Mark J Rapoport
- Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Department of Psychiatry, Division of Geriatric Psychiatry, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5, Canada
| | - Ana C Andreazza
- Department of Pharmacology & Toxicology, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 3K1, Canada
| | - Danielle Vieira
- Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada
| | - Alex Kiss
- Institute for Clinical Evaluative Sciences, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Krista L Lanctôt
- Department of Pharmacology & Toxicology, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 3K1, Canada. .,Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada. .,Department of Psychiatry, University of Toronto, Toronto, ON, Canada. .,Department of Psychiatry, Division of Geriatric Psychiatry, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5, Canada. .,Cardiovascular Prevention and Rehabilitation Program, KITE - Toronto Rehabilitation Institute, University Health Network, 347 Rumsey Road, Toronto, ON, M5G 1R7, Canada.
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3
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Lee S, Cha H. The effect of clinical application of transcranial direct current stimulation combined with non-immersive virtual reality rehabilitation in stroke patients. Technol Health Care 2021; 30:117-127. [PMID: 34250916 DOI: 10.3233/thc-212991] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The ability to manipulate the upper limbs and fingers of stroke patients is very important for independent daily life. Among the latest approaches for upper limb rehabilitation training, transcranial direct current stimulation (tDCS) is a non-invasive stimulation method that stimulates the cranial nerves by attaching electrodes to the scalp. In addition, virtual reality (VR) is an intervention method that provides an environment similar to reality and can help restore function by performing body movements as if playing a game. In addition, VR is an intervention method that provides an environment similar to reality and helps to recover functions by performing body movements as if playing a game. OBJECTIVE This study was conducted to investigate the effect of anodal tDCS applied to the ipsilateral primary motor cortex (M1) during VR training on the upper limb function, cognition, and executive function of stroke patients. METHODS After 20 patients were randomly assigned to the experimental group and the control group, the experimental group received tDCS and VR, and the control group received sham tDCS and VR for 20 minutes a day, 5 days a week, for a total of 4 weeks. Participants were evaluated for upper limb function using Box and Block Test (BBT) and Jebsen-Taylor Hand Function Test (JTHFT), and cognitive and executive function using the Stroop Test (ST) and Trail Making Test (TMT). RESULTS In the experimental group, significant differences were found in the pre- and post-test for the all variance (p< 0.05). Control group is significant differences were found in the pre- and post-test for BBT, ST, TMT (p< 0.05). There were significant differences between the two groups in the post test of BBT and ST (p< 0.05). CONCLUSION The results of this study suggest that anodal tDCS applied to the ipsilateral M1 during VR training is effective for upper limb function, cognitive function, and executive function in stroke patients.
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Affiliation(s)
- SiA Lee
- Department of Physical Therapy, Graduate School, Daegu University, Jillyang, Gyeongsan, Korea
| | - HyunGyu Cha
- Department of Physical Therapy, Joongbu University, Geumsan, Korea
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4
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Yang PF, Phipps MA, Jonathan S, Newton AT, Byun N, Gore JC, Grissom WA, Caskey CF, Chen LM. Bidirectional and state-dependent modulation of brain activity by transcranial focused ultrasound in non-human primates. Brain Stimul 2021; 14:261-272. [PMID: 33460838 PMCID: PMC7988301 DOI: 10.1016/j.brs.2021.01.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 11/19/2020] [Accepted: 01/08/2021] [Indexed: 01/10/2023] Open
Abstract
Transcranial focused ultrasound (FUS) stimulation under MRI guidance, coupled with functional MRI (fMRI) monitoring of effects, offers a precise, noninvasive technology to dissect functional brain circuits and to modulate altered brain functional networks in neurological and psychiatric disorders. Here we show that ultrasound at moderate intensities modulated neural activity bi-directionally. Concurrent sonication of somatosensory areas 3a/3b with 250 kHz FUS suppressed the fMRI signals produced there by peripheral tactile stimulation, while at the same time eliciting fMRI activation at inter-connected, off-target brain regions. Direct FUS stimulation of the cortex resulted in different degrees of BOLD signal changes across all five off-target regions, indicating that its modulatory effects on active and resting neurons differed. This is the first demonstration of the dual suppressive and excitative modulations of FUS on a specific functional circuit and of ability of concurrent FUS and MRI to evaluate causal interactions between functional circuits with neuron-class selectivity.
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Affiliation(s)
- Pai-Feng Yang
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - M Anthony Phipps
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - Sumeeth Jonathan
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - Allen T Newton
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Nellie Byun
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - William A Grissom
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Charles F Caskey
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Li Min Chen
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
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van Dam WO, Chrysikou EG. Effects of unilateral tDCS over left prefrontal cortex on emotion regulation in depression: Evidence from concurrent functional magnetic resonance imaging. COGNITIVE, AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2021; 21:14-34. [PMID: 33432545 PMCID: PMC8572372 DOI: 10.3758/s13415-020-00830-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/03/2020] [Indexed: 12/20/2022]
Abstract
Major depressive disorder (MDD) is the most common mood disorder and a primary cause of disability worldwide. MDD symptomatology entails disturbances in emotion regulation, namely one's ability to modify the intensity and duration of emotional reactions towards affective events. Transcranial direct current stimulation (tDCS) has emerged as a promising treatment for MDD. Yet, positive tDCS outcomes vary across studies, while the precise effects of the procedure for cortical excitability in MDD during emotion regulation remain largely unexplored. Here, we leveraged functional magnetic resonance imaging (fMRI)-compatible tDCS technology to examine the functional consequences of a unilateral anodal tDCS montage at 1.5 mA over left PFC (area F3; with the reference electrode over an extracephalic location) for brain activity during an emotion-regulation task in MDD patients and age-matched healthy control subjects. Our results revealed down-regulation of negative emotions in the right amygdala and visual cortex of healthy controls but not MDD patients prior to stimulation, the degree of which correlated with the magnitude of the participants' reappraisal scores. TDCS did not elicit significant changes in neural activation patterns for either group. These findings contribute to the literature on the pathophysiology of MDD by showing that a key disturbance in the disorder entails the ineffective down-regulation of activity not only within the amygdala, but also within visual cortical areas in response to negative information. Further, these results suggest that relative to bifrontal tDCS montages, unilateral stimulation of moderate intensity over left PFC may not be sufficient to elicit therapeutic effects for MDD.
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Affiliation(s)
- Wessel O van Dam
- Department of Psychology, Drexel University, 3201 Chestnut St., Philadelphia, PA, 19140, USA
| | - Evangelia G Chrysikou
- Department of Psychology, Drexel University, 3201 Chestnut St., Philadelphia, PA, 19140, USA.
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Saldanha JS, Zortea M, Torres ILDS, Fregni F, Caumo W. Age as a Mediator of tDCS Effects on Pain: An Integrative Systematic Review and Meta-Analysis. Front Hum Neurosci 2020; 14:568306. [PMID: 33192397 PMCID: PMC7654216 DOI: 10.3389/fnhum.2020.568306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/22/2020] [Indexed: 12/25/2022] Open
Abstract
Introduction: The transcranial direct current stimulation (tDCS) is a neuromodulatory technique with the potential to decrease pain scores and to improve chronic pain treatment. Although age is an essential factor that might impact the tDCS effect, most studies are solely conducted in adults. Therefore, the age limitation presents a critical research gap in this field and can be shown by only a handful of studies that have included other age groups. To examine the evidence upon the tDCS effect on pain scores on children, adolescents, or elderly, and indirectly, to infer the age-dependent impact on tDCS effects, we conducted a systematic review and meta-analysis. Methods: A systematic review searching the following databases: PubMed, EMBASE, and Science Direct using the following search terms adapted according to MeSh or Entree: [(“Adolescent” OR “Children” OR “Elderly”) AND (“tDCS”) AND (“Pain” OR “Pain threshold”) AND (“dorsolateral prefrontal cortex” OR “Motor cortex)] up to April 20th, 2020. We retrieved 228 articles, 13 were included in the systematic review, and five studies with elderly subjects that had their outcomes assessed by pain score or pain threshold were included in the meta-analysis. Results: For the analysis of pain score, 96 individuals received active stimulation, and we found a favorable effect for active tDCS to reduce pain score compared to sham (P = 0.002). The standardized difference was −0.76 (CI 95% = −1.24 to −0.28). For the pain threshold, the analysis showed no significant difference between active and sham tDCS. We reviewed two studies with adolescents: one study using anodal tDCS over the prefrontal cortex reported a reduction in pain scores. However, the second study reported an increase in pain sensitivity for the dorsolateral prefrontal cortex (DLPFC) stimulation. Conclusion: Our findings suggest tDCS may reduce pain levels in the elderly group. Nevertheless, the small number of studies included in this review—and the considerable heterogeneity for clinical conditions and protocols of stimulation present—limits the support of tDCS use for pain treatment in elderly people. Larger studies on the tDCS effect on pain are needed to be conducted in elderly and adolescents, also evaluating different montages and electrical current intensity.
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Affiliation(s)
- Júlia Schirmer Saldanha
- Graduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Laboratory of Pain and Neuromodulation, Clinical Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Maxciel Zortea
- Graduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Laboratory of Pain and Neuromodulation, Clinical Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Iraci Lucena da Silva Torres
- Pharmacology of Pain and Neuromodulation: Pre-Clinical Investigations Research Group, Universidade Federal do Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil
| | - Felipe Fregni
- Laboratory of Neuromodulation and Center for Clinical Research Learning, Physics and Rehabilitation Department, Spaulding Rehabilitation Hospital, Boston, MA, United States
| | - Wolnei Caumo
- Graduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Laboratory of Pain and Neuromodulation, Clinical Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.,Pain and Palliative Care Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
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Gao Y, Cavuoto L, Schwaitzberg S, Norfleet JE, Intes X, De S. The Effects of Transcranial Electrical Stimulation on Human Motor Functions: A Comprehensive Review of Functional Neuroimaging Studies. Front Neurosci 2020; 14:744. [PMID: 32792898 PMCID: PMC7393222 DOI: 10.3389/fnins.2020.00744] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 06/24/2020] [Indexed: 01/05/2023] Open
Abstract
Transcranial electrical stimulation (tES) is a promising tool to enhance human motor skills. However, the underlying physiological mechanisms are not fully understood. On the other hand, neuroimaging modalities provide powerful tools to map some of the neurophysiological biomarkers associated with tES. Here, a comprehensive review was undertaken to summarize the neuroimaging evidence of how tES affects human motor skills. A literature search has been done on the PubMed database, and 46 relative articles were selected. After reviewing these articles, we conclude that neuroimaging techniques are feasible to be coupled with tES and offer valuable information of cortical excitability, connectivity, and oscillations regarding the effects of tES on human motor behavior. The biomarkers derived from neuroimaging could also indicate the motor performance under tES conditions. This approach could advance the understanding of tES effects on motor skill and shed light on a new generation of adaptive stimulation models.
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Affiliation(s)
- Yuanyuan Gao
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Lora Cavuoto
- Department of Industrial and Systems Engineering, University at Buffalo, Buffalo, NY, United States
| | | | - Jack E. Norfleet
- U.S. Army Combat Capabilities Development Command, Soldier Center (CCDC SC), Orlando, FL, United States
- SFC Paul Ray Smith Simulation & Training Technology Center (STTC), Orlando, FL, United States
- Medical Simulation Research Branch (MSRB), Orlando, FL, United States
| | - Xavier Intes
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Suvranu De
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, United States
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Bergmann TO, Hartwigsen G. Inferring Causality from Noninvasive Brain Stimulation in Cognitive Neuroscience. J Cogn Neurosci 2020; 33:195-225. [PMID: 32530381 DOI: 10.1162/jocn_a_01591] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Noninvasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation or transcranial direct and alternating current stimulation, are advocated as measures to enable causal inference in cognitive neuroscience experiments. Transcending the limitations of purely correlative neuroimaging measures and experimental sensory stimulation, they allow to experimentally manipulate brain activity and study its consequences for perception, cognition, and eventually, behavior. Although this is true in principle, particular caution is advised when interpreting brain stimulation experiments in a causal manner. Research hypotheses are often oversimplified, disregarding the underlying (implicitly assumed) complex chain of causation, namely, that the stimulation technique has to generate an electric field in the brain tissue, which then evokes or modulates neuronal activity both locally in the target region and in connected remote sites of the network, which in consequence affects the cognitive function of interest and eventually results in a change of the behavioral measure. Importantly, every link in this causal chain of effects can be confounded by several factors that have to be experimentally eliminated or controlled to attribute the observed results to their assumed cause. This is complicated by the fact that many of the mediating and confounding variables are not directly observable and dose-response relationships are often nonlinear. We will walk the reader through the chain of causation for a generic cognitive neuroscience NIBS study, discuss possible confounds, and advise appropriate control conditions. If crucial assumptions are explicitly tested (where possible) and confounds are experimentally well controlled, NIBS can indeed reveal cause-effect relationships in cognitive neuroscience studies.
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Affiliation(s)
| | - Gesa Hartwigsen
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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Esmaeilpour Z, Shereen AD, Ghobadi‐Azbari P, Datta A, Woods AJ, Ironside M, O'Shea J, Kirk U, Bikson M, Ekhtiari H. Methodology for tDCS integration with fMRI. Hum Brain Mapp 2020; 41:1950-1967. [PMID: 31872943 PMCID: PMC7267907 DOI: 10.1002/hbm.24908] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 11/09/2019] [Accepted: 12/10/2019] [Indexed: 12/28/2022] Open
Abstract
Understanding and reducing variability of response to transcranial direct current stimulation (tDCS) requires measuring what factors predetermine sensitivity to tDCS and tracking individual response to tDCS. Human trials, animal models, and computational models suggest structural traits and functional states of neural systems are the major sources of this variance. There are 118 published tDCS studies (up to October 1, 2018) that used fMRI as a proxy measure of neural activation to answer mechanistic, predictive, and localization questions about how brain activity is modulated by tDCS. FMRI can potentially contribute as: a measure of cognitive state-level variance in baseline brain activation before tDCS; inform the design of stimulation montages that aim to target functional networks during specific tasks; and act as an outcome measure of functional response to tDCS. In this systematic review, we explore methodological parameter space of tDCS integration with fMRI spanning: (a) fMRI timing relative to tDCS (pre, post, concurrent); (b) study design (parallel, crossover); (c) control condition (sham, active control); (d) number of tDCS sessions; (e) number of follow up scans; (f) stimulation dose and combination with task; (g) functional imaging sequence (BOLD, ASL, resting); and (h) additional behavioral (cognitive, clinical) or quantitative (neurophysiological, biomarker) measurements. Existing tDCS-fMRI literature shows little replication across these permutations; few studies used comparable study designs. Here, we use a representative sample study with both task and resting state fMRI before and after tDCS in a crossover design to discuss methodological confounds. We further outline how computational models of current flow should be combined with imaging data to understand sources of variability. Through the representative sample study, we demonstrate how modeling and imaging methodology can be integrated for individualized analysis. Finally, we discuss the importance of conducting tDCS-fMRI with stimulation equipment certified as safe to use inside the MR scanner, and of correcting for image artifacts caused by tDCS. tDCS-fMRI can address important questions on the functional mechanisms of tDCS action (e.g., target engagement) and has the potential to support enhancement of behavioral interventions, provided studies are designed rationally.
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Affiliation(s)
- Zeinab Esmaeilpour
- Neural Engineering Laboratory, Department of Biomedical EngineeringThe City College of the City University of New York, City College Center for Discovery and InnovationNew YorkNew York
| | - A. Duke Shereen
- Advanced Science Research Center, The Graduate CenterCity University of New YorkNew YorkNew York
| | | | | | - Adam J. Woods
- Center for Cognitive Aging and Memory, McKnight Brain Institute, Department of Clinical and Health PsychologyUniversity of FloridaGainesvilleFlorida
| | - Maria Ironside
- Center for Depression, Anxiety and Stress Research, McLean HospitalBelmontMassachusetts
- Department of PsychiatryHarvard Medical SchoolBostonMassachusetts
| | - Jacinta O'Shea
- Nuffield Department of Clinical Neuroscience, Medical Science DivisionUniversity of OxfordOxfordEnglandUK
| | - Ulrich Kirk
- Department of PsychologyUniversity of Southern DenmarkOdenseDenmark
| | - Marom Bikson
- Neural Engineering Laboratory, Department of Biomedical EngineeringThe City College of the City University of New York, City College Center for Discovery and InnovationNew YorkNew York
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10
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Chrysikou EG, Wing EK, van Dam WO. Transcranial Direct Current Stimulation Over the Prefrontal Cortex in Depression Modulates Cortical Excitability in Emotion Regulation Regions as Measured by Concurrent Functional Magnetic Resonance Imaging: An Exploratory Study. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2019; 7:85-94. [PMID: 32111579 DOI: 10.1016/j.bpsc.2019.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/27/2019] [Accepted: 12/03/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND A well-established impaired top-down network for effortful emotion regulation (ER) in major depressive disorder (MDD) includes the dorsal and ventromedial prefrontal cortex (PFC) and the amygdala. Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation method that has been used successfully to induce mood changes in MDD. Despite reliable findings, little is known regarding the precise effects of tDCS on cortical excitability in vivo in depression and how such changes relate to ER. Here, we addressed this question by combining-for the first time in a psychiatric sample-tDCS with functional magnetic resonance imaging in a single-blind randomized design. METHODS We applied anodal tDCS over the left PFC (area F3 per the 10/20 system) together with cathodal tDCS over the right PFC (F4) or sham tDCS during functional magnetic resonance imaging in patients with moderate to severe MDD (n = 20) and gender- and age-matched control subjects (n = 20). Participants performed 2 runs of an ER task prior to tDCS and 2 runs of the task during tDCS, which was administered at 1.5 mA with 5-cm × 5-cm electrodes. RESULTS Whole-brain, region of interest, and connectivity analyses revealed an impaired ER network in patients with MDD prior to stimulation. Active anodal tDCS over the left (with concurrent cathodal stimulation of the right) PFC during reappraisal of negative stimuli upregulated activity in ventromedial PFC, which was predictive of gains in reappraisal performance during stimulation for the patients with MDD. CONCLUSIONS The results of this study offer insights into the mechanisms of action of tDCS and support its potential as a treatment for depression.
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Affiliation(s)
| | - Erik K Wing
- Department of Psychology, University of Kansas, Lawrence, Kansas
| | - Wessel O van Dam
- Department of Psychology, Drexel University, Philadelphia, Pennsylvania
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11
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Di Rosa E, Brigadoi S, Cutini S, Tarantino V, Dell'Acqua R, Mapelli D, Braver TS, Vallesi A. Reward motivation and neurostimulation interact to improve working memory performance in healthy older adults: A simultaneous tDCS-fNIRS study. Neuroimage 2019; 202:116062. [PMID: 31369810 DOI: 10.1016/j.neuroimage.2019.116062] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 07/25/2019] [Accepted: 07/27/2019] [Indexed: 01/12/2023] Open
Abstract
Several studies have evaluated the effect of anodal transcranial direct current stimulation (tDCS) over the prefrontal cortex (PFC) for the enhancement of working memory (WM) performance in healthy older adults. However, the mixed results obtained so far suggest the need for concurrent brain imaging, in order to more directly examine tDCS effects. The present study adopted a continuous multimodal approach utilizing functional near-infrared spectroscopy (fNIRS) to examine the interactive effects of tDCS combined with manipulations of reward motivation. Twenty-one older adults (mean age = 69.7 years; SD = 5.05) performed an experimental visuo-spatial WM task before, during and after the delivery of 1.5 mA anodal tDCS/sham over the left prefrontal cortex (PFC). During stimulation, participants received performance-contingent reward for every fast and correct response during the WM task. In both sessions, hemodynamic activity of the bilateral frontal, motor and parietal areas was recorded across the entire duration of the WM task. Cognitive functions and reward sensitivity were also assessed with standard measures. Results demonstrated a significant impact of tDCS on both WM performance and hemodynamic activity. Specifically, faster responses in the WM task were observed both during and after anodal tDCS, while no differences were found under sham control conditions. However, these effects emerged only when taking into account individual visuo-spatial WM capacity. Additionally, during and after the anodal tDCS, increased hemodynamic activity relative to sham was observed in the bilateral PFC, while no effects of tDCS were detected in the motor and parietal areas. These results provide the first evidence of tDCS-dependent functional changes in PFC activity in healthy older adults during the execution of a WM task. Moreover, they highlight the utility of combining reward motivation with prefrontal anodal tDCS, as a potential strategy to improve WM efficiency in low performing healthy older adults.
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Affiliation(s)
- Elisa Di Rosa
- Department of Neuroscience & Padova Neuroscience Center, University of Padova, Padova, Italy; Department of Psychological & Brain Sciences, Washington University in St. Louis, St. Louis, USA.
| | - Sabrina Brigadoi
- Department of Developmental Psychology, University of Padova, Padova, Italy; Department of Information Engineering, University of Padova, Padova, Italy
| | - Simone Cutini
- Department of Developmental Psychology, University of Padova, Padova, Italy; Padova Neuroscience Center, University of Padova, Padova, Italy
| | - Vincenza Tarantino
- Department of Neuroscience & Padova Neuroscience Center, University of Padova, Padova, Italy; Department of Psychology, Educational Science and Human Movement, University of Palermo, Palermo, Italy
| | - Roberto Dell'Acqua
- Department of Developmental Psychology, University of Padova, Padova, Italy; Padova Neuroscience Center, University of Padova, Padova, Italy
| | - Daniela Mapelli
- Department of General Psychology, University of Padova, Padova, Italy
| | - Todd S Braver
- Department of Psychological & Brain Sciences, Washington University in St. Louis, St. Louis, USA
| | - Antonino Vallesi
- Department of Neuroscience & Padova Neuroscience Center, University of Padova, Padova, Italy; Brain Imaging and Neural Dynamics Research Group, IRCCS San Camillo Hospital, Venice, Italy
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12
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Steinberg F, Pixa NH, Fregni F. A Review of Acute Aerobic Exercise and Transcranial Direct Current Stimulation Effects on Cognitive Functions and Their Potential Synergies. Front Hum Neurosci 2019; 12:534. [PMID: 30687048 PMCID: PMC6336823 DOI: 10.3389/fnhum.2018.00534] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 12/18/2018] [Indexed: 01/18/2023] Open
Abstract
Today, several pharmaceutic and non-pharmaceutic approaches exist to treat psychiatric and neurological diseases. Because of the lack of treatment procedures that are medication free and without severe side effects, transcranial direct current stimulation (tDCS) and aerobic exercise (AE) have been tested to explore the potential for initiating and modulating neuroplasticity in the human brain. Both tDCS and AE could support cognition and behavior in the clinical and non-clinical context to improve the recovery process within neurological or psychiatric conditions or to increase performance. As these techniques still lack meaningful effects, although they provide multiple beneficial opportunities within disease and health applications, there is emerging interest to find improved tDCS and AE protocols. Since multimodal approaches could provoke synergetic effects, a few recent studies have begun to combine tDCS and AE within different settings such as in cognitive training in health or for treatment purposes within clinical settings, all of which show superior effects compared to single technique applications. The beneficial outcomes of both techniques depend on several parameters and the understanding of neural mechanisms that are not yet fully understood. Recent studies have begun to directly combine tDCS and AE within one session, although their interactions on the behavioral, neurophysiological and neurochemical levels are entirely unclear. Therefore, this review: (a) provides an overview of acute behavioral, neurophysiological, and neurochemical effects that both techniques provoke within only one single application in isolation; (b) gives an overview regarding the mechanistic pathways; and (c) discusses potential interactions and synergies between tDCS and AE that might be provoked when directly combining both techniques. From this literature review focusing primarily on the cognitive domain in term of specific executive functions (EFs; inhibition, updating, and switching), it is concluded that a direct combination of tDCS and AE provides multiple beneficial opportunities for synergistic effects. A combination could be useful within non-clinical settings in health and for treating several psychiatric and neurologic conditions. However, there is a lack of research and there are several possibly interacting moderating parameters that must be considered and more importantly must be systematically investigated in the future.
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Affiliation(s)
- Fabian Steinberg
- Institute of Sport Science, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Nils Henrik Pixa
- Sport Psychology, Institute of Human Movement Science and Health, Faculty of Behavioral and Social Sciences, Chemnitz University of Technology, Chemnitz, Germany
| | - Felipe Fregni
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
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Pixa NH, Berger A, Steinberg F, Doppelmayr M. Parietal, but Not Motor Cortex, HD-atDCS Deteriorates Learning Transfer of a Complex Bimanual Coordination Task. JOURNAL OF COGNITIVE ENHANCEMENT 2018. [DOI: 10.1007/s41465-018-0088-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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14
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Yang PF, Phipps MA, Newton AT, Chaplin V, Gore JC, Caskey CF, Chen LM. Neuromodulation of sensory networks in monkey brain by focused ultrasound with MRI guidance and detection. Sci Rep 2018; 8:7993. [PMID: 29789605 PMCID: PMC5964220 DOI: 10.1038/s41598-018-26287-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 05/08/2018] [Indexed: 01/16/2023] Open
Abstract
Focused ultrasound (FUS) has gained recognition as a technique for non-invasive neuromodulation with high spatial precision and the ability to both excite and inhibit neural activity. Here we demonstrate that MRI-guided FUS is capable of exciting precise targets within areas 3a/3b in the monkey brain, causing downstream activations in off-target somatosensory and associated brain regions which are simultaneously detected by functional MRI. The similarity between natural tactile stimulation-and FUS- evoked fMRI activation patterns suggests that FUS likely can excite populations of neurons and produce associated spiking activities that may be subsequently transmitted to other functionally related touch regions. The across-region differences in fMRI signal changes relative to area 3a/3b between tactile and FUS conditions also indicate that FUS modulated the tactile network differently. The significantly faster rising (>1 sec) fMRI signals elicited by direct FUS stimulation at the targeted cortical region suggest that a different neural hemodynamic coupling mechanism may be involved in generating fMRI signals. This is the first demonstration of imaging neural excitation effects of FUS with BOLD fMRI on a specific functional circuit in non-human primates.
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Affiliation(s)
- Pai-Feng Yang
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - M Anthony Phipps
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Allen T Newton
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Vandiver Chaplin
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - John C Gore
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Charles F Caskey
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA.
| | - Li Min Chen
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA.
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15
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Albouy P, Baillet S, Zatorre RJ. Driving working memory with frequency-tuned noninvasive brain stimulation. Ann N Y Acad Sci 2018; 1423:126-137. [PMID: 29707781 DOI: 10.1111/nyas.13664] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 02/05/2018] [Accepted: 02/13/2018] [Indexed: 12/21/2022]
Abstract
Frequency-tuned noninvasive brain stimulation is a recent approach in cognitive neuroscience that involves matching the frequency of transcranially applied electromagnetic fields to that of specific oscillatory components of the underlying neurophysiology. The objective of this method is to modulate ongoing/intrinsic brain oscillations, which correspond to rhythmic fluctuations of neural excitability, to causally change behavior. We review the impact of frequency-tuned noninvasive brain stimulation on the research field of human working memory. We argue that this is a powerful method to probe and understand the mechanisms of memory functions, targeting specifically task-related oscillatory dynamics, neuronal representations, and brain networks. We report the main behavioral and neurophysiological outcomes published to date, in particular, how functionally relevant oscillatory signatures in signal power and interregional connectivity yield causal changes of working memory abilities. We also present recent developments of the technique that aim to modulate cross-frequency coupling in polyrhythmic neural activity. Overall, the method has led to significant advances in our understanding of the mechanisms of systems neuroscience, and the role of brain oscillations in cognition and behavior. We also emphasize the translational impact of noninvasive brain stimulation techniques in the development of therapeutic approaches.
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Affiliation(s)
- Philippe Albouy
- Montreal Neurological Institute, McGill University, Montreal, Canada
- International Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Canada
| | - Sylvain Baillet
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Robert J Zatorre
- Montreal Neurological Institute, McGill University, Montreal, Canada
- International Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Canada
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16
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Younger JW, Booth JR. Parietotemporal Stimulation Affects Acquisition of Novel Grapheme-Phoneme Mappings in Adult Readers. Front Hum Neurosci 2018; 12:109. [PMID: 29628882 PMCID: PMC5876236 DOI: 10.3389/fnhum.2018.00109] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 03/06/2018] [Indexed: 11/13/2022] Open
Abstract
Neuroimaging work from developmental and reading intervention research has suggested a cause of reading failure may be lack of engagement of parietotemporal cortex during initial acquisition of grapheme-phoneme (letter-sound) mappings. Parietotemporal activation increases following grapheme-phoneme learning and successful reading intervention. Further, stimulation of parietotemporal cortex improves reading skill in lower ability adults. However, it is unclear whether these improvements following stimulation are due to enhanced grapheme-phoneme mapping abilities. To test this hypothesis, we used transcranial direct current stimulation (tDCS) to manipulate parietotemporal function in adult readers as they learned a novel artificial orthography with new grapheme-phoneme mappings. Participants received real or sham stimulation to the left inferior parietal lobe (L IPL) for 20 min before training. They received explicit training over the course of 3 days on 10 novel words each day. Learning of the artificial orthography was assessed at a pre-training baseline session, the end of each of the three training sessions, an immediate post-training session and a delayed post-training session about 4 weeks after training. Stimulation interacted with baseline reading skill to affect learning of trained words and transfer to untrained words. Lower skill readers showed better acquisition, whereas higher skill readers showed worse acquisition, when training was paired with real stimulation, as compared to readers who received sham stimulation. However, readers of all skill levels showed better maintenance of trained material following parietotemporal stimulation, indicating a differential effect of stimulation on initial learning and consolidation. Overall, these results indicate that parietotemporal stimulation can enhance learning of new grapheme-phoneme relationships in readers with lower reading skill. Yet, while parietotemporal function is critical to new learning, its role in continued reading improvement likely changes as readers progress in skill.
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Affiliation(s)
- Jessica W Younger
- Department of Communication Sciences and Disorders, University of Texas at Austin, Austin, TX, United States
| | - James R Booth
- Department of Communication Sciences and Disorders, University of Texas at Austin, Austin, TX, United States.,Department of Psychology and Human Development, Vanderbilt University, Nashville, TN, United States
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17
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Miyagishi Y, Ikeda T, Takahashi T, Kudo K, Morise H, Minabe Y, Kikuchi M. Gamma-band auditory steady-state response after frontal tDCS: A double-blind, randomized, crossover study. PLoS One 2018; 13:e0193422. [PMID: 29489895 PMCID: PMC5830999 DOI: 10.1371/journal.pone.0193422] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 02/10/2018] [Indexed: 11/19/2022] Open
Abstract
The effects of transcranial direct current stimulation (tDCS) likely depend on cortical N-methyl-D-aspartic acid (NMDA) neurotransmission; however, no previous studies have reported tDCS-mediated modulation of cortical NMDA neurotransmission in humans. The gamma-band auditory steady-state response (ASSR) to a 40 Hz stimulation likely reflects the integrity of cortical NMDA neurotransmission. The present study tested whether the effect of tDCS is reflected in gamma-band ASSRs during a 40 Hz stimulation. Using a double-blind, randomized, crossover study, we performed magnetoencephalography (MEG) and measured the ASSR in 24 healthy participants during 40 Hz of auditory stimulation after prefrontal tDCS (2 mA) or sham (i.e., placebo) treatment. Our results failed to reveal significant differences in any brain between the two conditions after the application of a frequency of approximately 40 Hz. Based on these results, the ASSR is an insufficient method to detect the effect of tDCS on cortical NMDA neurotransmission. Unexpectedly, the results revealed an enhanced beta-band event-related spectral perturbation (ERSP) in the left motor cortex after tDCS compared with that observed after the sham stimuli. Given that beta-band oscillations reflect many functions in motor cortices, the tDCS for the frontal areas had some effect on the left motor cortex while the participants were focusing on not pressing the button with their right index finger. An additional study with an adequate psychological task is necessary to draw a conclusion regarding this unexpected result.
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Affiliation(s)
- Yoshiaki Miyagishi
- Department of Psychiatry and Neurobiology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
| | - Takashi Ikeda
- Research Center for Child Mental Development, Kanazawa University, Kanazawa, Japan
- * E-mail:
| | | | - Kiwamu Kudo
- Ricoh Institute of Future Technology, Research and Development Division, Ricoh Company, Ltd., Kanazawa, Japan
| | - Hirofumi Morise
- Ricoh Institute of Future Technology, Research and Development Division, Ricoh Company, Ltd., Kanazawa, Japan
| | - Yoshio Minabe
- Department of Psychiatry and Neurobiology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
- Research Center for Child Mental Development, Kanazawa University, Kanazawa, Japan
| | - Mitsuru Kikuchi
- Research Center for Child Mental Development, Kanazawa University, Kanazawa, Japan
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18
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Muthalib M, Besson P, Rothwell J, Perrey S. Focal Hemodynamic Responses in the Stimulated Hemisphere During High-Definition Transcranial Direct Current Stimulation. Neuromodulation 2017; 21:348-354. [PMID: 28714545 DOI: 10.1111/ner.12632] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/01/2017] [Accepted: 05/25/2017] [Indexed: 12/01/2022]
Abstract
OBJECTIVE High-definition transcranial direct current stimulation (HD-tDCS) using a 4 × 1 electrode montage has been previously shown using modeling and physiological studies to constrain the electric field within the spatial extent of the electrodes. The aim of this proof-of-concept study was to determine if functional near-infrared spectroscopy (fNIRS) neuroimaging can be used to determine a hemodynamic correlate of this 4 × 1 HD-tDCS electric field on the brain. MATERIALS AND METHODS In a three session cross-over study design, 13 healthy males received one sham (2 mA, 30 sec) and two real (HD-tDCS-1 and HD-tDCS-2, 2 mA, 10 min) anodal HD-tDCS targeting the left M1 via a 4 × 1 electrode montage (anode on C3 and 4 return electrodes 3.5 cm from anode). The two real HD-tDCS sessions afforded a within-subject replication of the findings. fNIRS was used to measure changes in brain hemodynamics (oxygenated hemoglobin integral-O2 Hbint ) during each 10 min session from two regions of interest (ROIs) in the stimulated left hemisphere that corresponded to "within" (Lin ) and "outside" (Lout ) the spatial extent of the 4 × 1 electrode montage, and two corresponding ROIs (Rin and Rout ) in the right hemisphere. RESULTS The ANOVA showed that both real anodal HD-tDCS compared to sham induced a significantly greater O2 Hbint in the Lin than Lout ROIs of the stimulated left hemisphere; while there were no significant differences between the real and sham sessions for the right hemisphere ROIs. Intra-class correlation coefficients showed "fair-to-good" reproducibility for the left stimulated hemisphere ROIs. CONCLUSIONS The greater O2 Hbint "within" than "outside" the spatial extent of the 4 × 1 electrode montage represents a hemodynamic correlate of the electrical field distribution, and thus provides a prospective reliable method to determine the dose of stimulation that is necessary to optimize HD-tDCS parameters in various applications.
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Affiliation(s)
| | - Pierre Besson
- EuroMov, University of Montpellier, Montpellier, France
| | - John Rothwell
- Institute of Neurology, University College London, London, UK
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19
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Nasehi M, Khani-Abyaneh M, Ebrahimi-Ghiri M, Zarrindast MR. The effect of left frontal transcranial direct-current stimulation on propranolol-induced fear memory acquisition and consolidation deficits. Behav Brain Res 2017; 331:76-83. [PMID: 28472633 DOI: 10.1016/j.bbr.2017.04.055] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 04/20/2017] [Accepted: 04/26/2017] [Indexed: 12/25/2022]
Abstract
Accumulating evidence supports the efficacy of transcranial direct current stimulation (tDCS) in modulating numerous cognitive functions. Despite the fact that tDCS has been used for the enhancement of memory and cognition, very few animal studies have addressed its impact on the modulation of fear memory. This study was designed to determine whether pre/post-training frontal tDCS application would alter fear memory acquisition and/or consolidation deficits induced by propranolol in NMRI mice. Results indicated that administration of β1-adrenoceptor blocker propranolol (0.1mg/kg) impaired fear memory retrieval. Pre/post-training application of anodal tDCS when propranolol was administered prior to training reversed contextual memory retrieval whereas only the anodal application prior to training could induce the same result in the auditory test. Meanwhile, anodal stimulation had no effect on fear memories by itself. Moreover, regardless of when cathode was applied and propranolol administered, their combination restored contextual memory retrieval, while only cathodal stimulation prior to training facilitated the contextual memory retrieval. Also, auditory memory retrieval was restored when cathodal stimulation and propranolol occurred prior to training but it was abolished when stimulation occurred after training and propranolol was administered prior to training. Collectively, our findings show that tDCS applied on the left frontal cortex of mice affects fear memory performance. This alteration seems to be task-dependent and varies depending on the nature and timing of the stimulation. In certain conditions, tDCS reverses the effect of propranolol. These results provide initial evidence to support the timely use of tDCS for the modulation of fear-related memories.
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Affiliation(s)
- Mohammad Nasehi
- Cognitive and Neuroscience Research Center (CNRC), Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran.
| | - Mozhgan Khani-Abyaneh
- Department of Psychology, Faculty of Education, Islamic Azad University, Garmsar Branch, Garmsar, Iran
| | | | - Mohammad-Reza Zarrindast
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran; School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran; Medical Genomics Research Center, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran; Institute for Cognitive Science Studies (ICSS), Tehran, Iran.
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20
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Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives. Neuroimage 2016; 140:4-19. [DOI: 10.1016/j.neuroimage.2016.02.012] [Citation(s) in RCA: 197] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 01/26/2016] [Accepted: 02/07/2016] [Indexed: 12/23/2022] Open
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21
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Transcranial electrical stimulation of the occipital cortex during visual perception modifies the magnitude of BOLD activity: A combined tES-fMRI approach. Neuroimage 2015; 140:110-7. [PMID: 26608246 DOI: 10.1016/j.neuroimage.2015.11.034] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 11/05/2015] [Accepted: 11/13/2015] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to investigate if the blood oxygenation level-dependent (BOLD) changes in the visual cortex can be used as biomarkers reflecting the online and offline effects of transcranial electrical stimulation (tES). Anodal transcranial direct current stimulation (tDCS) and 10Hz transcranial alternating current stimulation (tACS) were applied for 10min duration over the occipital cortex of healthy adults during the presentation of different visual stimuli, using a crossover, double-blinded design. Control experiments were also performed, in which sham stimulation as well as another electrode montage were used. Anodal tDCS over the visual cortex induced a small but significant further increase in BOLD response evoked by a visual stimulus; however, no aftereffect was observed. Ten hertz of tACS did not result in an online effect, but in a widespread offline BOLD decrease over the occipital, temporal, and frontal areas. These findings demonstrate that tES during visual perception affects the neuronal metabolism, which can be detected with functional magnetic resonance imaging (fMRI).
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22
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Vosskuhl J, Huster RJ, Herrmann CS. BOLD signal effects of transcranial alternating current stimulation (tACS) in the alpha range: A concurrent tACS-fMRI study. Neuroimage 2015; 140:118-25. [PMID: 26458516 DOI: 10.1016/j.neuroimage.2015.10.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 09/30/2015] [Accepted: 10/01/2015] [Indexed: 02/01/2023] Open
Abstract
Many studies have proven transcranial alternating current stimulation (tACS) to manipulate brain activity. Until now it is not known, however, how these manipulations in brain activity are represented in brain metabolism or how spatially specific these changes are. Alpha-tACS has been shown to enhance the amplitude of the individual alpha frequency (IAF) and a negative correlation between alpha amplitude and occipital BOLD signal was reported in numerous EEG/fMRI experiments. Thus, alpha-tACS was chosen to test the effects of tACS on the BOLD signal. A reduction thereof was expected during alpha-tACS which shows the spatial extent of tACS effects beyond modeling studies. Three groups of subjects were measured in an MRI scanner, receiving tACS at either their IAF (N=11), 1Hz (control; N=12) or sham (i.e., no stimulation - a second control; N=11) while responding to a visual vigilance task. Stimulation was administered in an interleaved pattern of tACS-on runs and tACS-free baseline periods. The BOLD signal was analyzed in response to tACS-onset during resting state and in response to seldom target stimuli. Alpha-tACS at 1.0mA reduced the task-related BOLD response to visual targets in the occipital cortex as compared to tACS-free baseline periods. The deactivation was strongest in an area where the BOLD signal was shown to correlate negatively with alpha amplitude. A direct effect of tACS on resting state BOLD signal levels could not be shown. Our findings suggest that tACS-related changes in BOLD activity occur only as a modulation of an existing BOLD response.
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Affiliation(s)
- Johannes Vosskuhl
- Experimental Psychology Lab, Department of Psychology, Cluster for Excellence "Hearing4all", European Medical School, Faculty for Medicine and Health Sciences, University of Oldenburg, 26129 Oldenburg, Germany
| | - René J Huster
- Experimental Psychology Lab, Department of Psychology, Cluster for Excellence "Hearing4all", European Medical School, Faculty for Medicine and Health Sciences, University of Oldenburg, 26129 Oldenburg, Germany; Research Center Neurosensory Science, University of Oldenburg, 26111 Oldenburg, Germany; Department of Psychology, University of Oslo, 0373 Oslo, Norway; The Mind Research Network, Albuquerque, NM 87106, USA
| | - Christoph S Herrmann
- Experimental Psychology Lab, Department of Psychology, Cluster for Excellence "Hearing4all", European Medical School, Faculty for Medicine and Health Sciences, University of Oldenburg, 26129 Oldenburg, Germany; Research Center Neurosensory Science, University of Oldenburg, 26111 Oldenburg, Germany.
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23
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Sale MV, Mattingley JB, Zalesky A, Cocchi L. Imaging human brain networks to improve the clinical efficacy of non-invasive brain stimulation. Neurosci Biobehav Rev 2015; 57:187-98. [DOI: 10.1016/j.neubiorev.2015.09.010] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 09/03/2015] [Accepted: 09/22/2015] [Indexed: 01/28/2023]
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Abstract
Do neuronal oscillations play a causal role in brain function? In a study in this issue of PLOS Biology, Helfrich and colleagues address this long-standing question by attempting to drive brain oscillations using transcranial electrical current stimulation. Remarkably, they were able to manipulate visual perception by forcing brain oscillations of the left and right visual hemispheres into synchrony using oscillatory currents over both hemispheres. Under this condition, human observers more often perceived an inherently ambiguous visual stimulus in one of its perceptual instantiations. These findings shed light on the mechanisms underlying neuronal computation. They show that it is the neuronal oscillations that drive the visual experience, not the experience driving the oscillations. And they indicate that synchronized oscillatory activity groups brain areas into functional networks. This points to new ways for controlled experimental and possibly also clinical interventions for the study and modulation of brain oscillations and associated functions.
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Affiliation(s)
- Gregor Thut
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
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25
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Filmer HL, Dux PE, Mattingley JB. Applications of transcranial direct current stimulation for understanding brain function. Trends Neurosci 2014; 37:742-53. [PMID: 25189102 DOI: 10.1016/j.tins.2014.08.003] [Citation(s) in RCA: 309] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 08/08/2014] [Accepted: 08/12/2014] [Indexed: 12/29/2022]
Affiliation(s)
- Hannah L Filmer
- School of Psychology, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - Paul E Dux
- School of Psychology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Jason B Mattingley
- School of Psychology, The University of Queensland, St Lucia, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, St Lucia QLD 4072 Australia
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26
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Meinzer M, Lindenberg R, Darkow R, Ulm L, Copland D, Flöel A. Transcranial direct current stimulation and simultaneous functional magnetic resonance imaging. J Vis Exp 2014. [PMID: 24796646 DOI: 10.3791/51730] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
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 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.
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Affiliation(s)
- Marcus Meinzer
- Centre for Clinical Research, University of Queensland; Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin;
| | - Robert Lindenberg
- Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin
| | - Robert Darkow
- Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin
| | - Lena Ulm
- Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin
| | - David Copland
- Centre for Clinical Research, University of Queensland
| | - Agnes Flöel
- Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin
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27
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Meinzer M, Jähnigen S, Copland DA, Darkow R, Grittner U, Avirame K, Rodriguez AD, Lindenberg R, Flöel A. Transcranial direct current stimulation over multiple days improves learning and maintenance of a novel vocabulary. Cortex 2014; 50:137-47. [PMID: 23988131 DOI: 10.1016/j.cortex.2013.07.013] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 07/23/2013] [Accepted: 07/23/2013] [Indexed: 11/18/2022]
Affiliation(s)
- Marcus Meinzer
- Department of Neurology, Charité University Medicine, Berlin, Germany; Center for Stroke Research, Charité University Medicine, Berlin, Germany; Center for Clinical Research, University of Queensland, Brisbane, Australia.
| | - Sophia Jähnigen
- Department of Neurology, Charité University Medicine, Berlin, Germany
| | - David A Copland
- Center for Clinical Research, University of Queensland, Brisbane, Australia; CCRE in Aphasia Rehabilitation, University of Queensland, Brisbane, Australia
| | - Robert Darkow
- Department of Neurology, Charité University Medicine, Berlin, Germany
| | - Ulrike Grittner
- Center for Stroke Research, Charité University Medicine, Berlin, Germany; Department for Biostatistics and Clinical Epidemiology, Charité University Medicine, Berlin, Germany
| | - Keren Avirame
- Department of Neurology, Charité University Medicine, Berlin, Germany
| | - Amy D Rodriguez
- Center for Clinical Research, University of Queensland, Brisbane, Australia; CCRE in Aphasia Rehabilitation, University of Queensland, Brisbane, Australia
| | - Robert Lindenberg
- Department of Neurology, Charité University Medicine, Berlin, Germany
| | - Agnes Flöel
- Department of Neurology, Charité University Medicine, Berlin, Germany; Center for Stroke Research, Charité University Medicine, Berlin, Germany; NeuroCure Cluster of Excellence, Charité University Medicine, Berlin, Germany.
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28
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Anodal transcranial direct current stimulation temporarily reverses age-associated cognitive decline and functional brain activity changes. J Neurosci 2013; 33:12470-8. [PMID: 23884951 DOI: 10.1523/jneurosci.5743-12.2013] [Citation(s) in RCA: 195] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The rising proportion of elderly people worldwide will yield an increased incidence of age-associated cognitive impairments, imposing major burdens on societies. Consequently, growing interest emerged to evaluate new strategies to delay or counteract cognitive decline in aging. Here, we assessed immediate effects of anodal transcranial direct current stimulation (atDCS) on cognition and previously described detrimental changes in brain activity attributable to aging. Twenty healthy elderly adults were assessed in a crossover sham-controlled design using functional magnetic resonance imaging (fMRI) and concurrent transcranial DCS administered to the left inferior frontal gyrus. Effects on performance and task-related brain activity were evaluated during overt semantic word generation, a task that is negatively affected by advanced age. Task-absent resting-state fMRI (RS-fMRI) assessed atDCS-induced changes at the network level independent of performance. Twenty matched younger adults served as controls. During sham stimulation, task-related fMRI demonstrated that enhanced bilateral prefrontal activity in older adults was associated with reduced performance. RS-fMRI revealed enhanced anterior and reduced posterior functional brain connectivity. atDCS significantly improved performance in older adults up to the level of younger controls; significantly reduced task-related hyperactivity in bilateral prefrontal cortices, the anterior cingulate gyrus, and the precuneus; and induced a more "youth-like" connectivity pattern during RS-fMRI. Our results provide converging evidence from behavioral analysis and two independent functional imaging paradigms that a single session of atDCS can temporarily reverse nonbeneficial effects of aging on cognition and brain activity and connectivity. These findings may translate into novel treatments to ameliorate cognitive decline in normal aging in the future.
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29
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Antonenko D, Flöel A. Healthy aging by staying selectively connected: a mini-review. Gerontology 2013; 60:3-9. [PMID: 24080587 DOI: 10.1159/000354376] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 07/15/2013] [Indexed: 11/19/2022] Open
Abstract
Cognitive neuroscience of the healthy aging human brain has thus far addressed age-related changes of local functional and structural properties of gray and white matter and their association with declining or preserved cognitive functions. In addition to these localized changes, recent neuroimaging research has attributed an important role to neural networks with a stronger focus on interacting rather than isolated brain regions. The analysis of functional connectivity encompasses task-dependent and -independent synchronous activity in the brain, and thus reflects the organization of the brain in distinct performance-relevant networks. Structural connectivity in white matter pathways, representing the integrity of anatomical connections, underlies the communication between the nodes of these functional networks. Both functional and structural connectivity within these networks have been demonstrated to change with aging, and to have different predictive values for cognitive abilities in older compared to young adults. Structural degeneration has been found in the entire cerebral white matter with greatest deterioration in frontal areas, affecting whole brain structural network efficiency. With regard to functional connectivity, both higher and lower functional coupling has been observed in the aging compared to the young brain. Here, high connectivity within the nodes of specific functional networks on the one hand, and low connectivity to regions outside this network on the other hand, were associated with preserved cognitive functions in aging in most cases. For example, in the language domain, connections between left-hemisphere language-related prefrontal, posterior temporal and parietal areas were described as beneficial, whereas connections between the left and right hemisphere were detrimental for language task performance. Of note, interactions between structural and functional network properties may change in the course of aging and differentially impact behavioral performance in older versus young adults. Finally, studies using noninvasive brain stimulation techniques like transcranial direct current stimulation (tDCS) to simultaneously modulate behavior and functional connectivity support the importance of 'selective connectivity' of aging brain networks for preserved cognitive functions. These studies demonstrate that enhancing task performance by tDCS is paralleled by increased connectivity within functional networks. In this review, we outline the network perspective on healthy brain aging and discuss recent developments in this field.
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Affiliation(s)
- Daria Antonenko
- Department of Neurology, NeuroCure Cluster of Excellence, and Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany
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30
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Hunter MA, Coffman BA, Trumbo MC, Clark VP. Tracking the neuroplastic changes associated with transcranial direct current stimulation: a push for multimodal imaging. Front Hum Neurosci 2013; 7:495. [PMID: 23986681 PMCID: PMC3753560 DOI: 10.3389/fnhum.2013.00495] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 08/04/2013] [Indexed: 11/15/2022] Open
Affiliation(s)
- Michael A Hunter
- Psychology Clinical Neuroscience Center, The University of New Mexico Albuquerque, NM, USA ; Department of Psychology, The University of New Mexico Albuquerque, NM, USA ; Department of Psychiatry, The University of New Mexico School of Medicine Albuquerque, NM, USA ; The Mind Research Network and Lovelace Biomedical and Environmental Research Institute Albuquerque, NM, USA ; Psychiatry Research, New Mexico Raymond G. Murphy VA Healthcare System Albuquerque, NM, USA
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31
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Bestmann S, Feredoes E. Combined neurostimulation and neuroimaging in cognitive neuroscience: past, present, and future. Ann N Y Acad Sci 2013; 1296:11-30. [PMID: 23631540 PMCID: PMC3760762 DOI: 10.1111/nyas.12110] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Modern neurostimulation approaches in humans provide controlled inputs into the operations of cortical regions, with highly specific behavioral consequences. This enables causal structure–function inferences, and in combination with neuroimaging, has provided novel insights into the basic mechanisms of action of neurostimulation on distributed networks. For example, more recent work has established the capacity of transcranial magnetic stimulation (TMS) to probe causal interregional influences, and their interaction with cognitive state changes. Combinations of neurostimulation and neuroimaging now face the challenge of integrating the known physiological effects of neurostimulation with theoretical and biological models of cognition, for example, when theoretical stalemates between opposing cognitive theories need to be resolved. This will be driven by novel developments, including biologically informed computational network analyses for predicting the impact of neurostimulation on brain networks, as well as novel neuroimaging and neurostimulation techniques. Such future developments may offer an expanded set of tools with which to investigate structure–function relationships, and to formulate and reconceptualize testable hypotheses about complex neural network interactions and their causal roles in cognition.
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Affiliation(s)
- Sven Bestmann
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, United Kingdom.
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