Special CCNY BME Seminar Oct 26, 2016 featuring two Neural Engineering Lab researchers.

3 PM in the CCNY BME conference room. Steinman Hall Room 402

Modulating synaptic plasticity with tDCS

Mr. Greg Kronberg

Department of Biomedical Engineering, The City College of New York

Abstract: Synapses allow communication between neurons and guide the flow of information throughout the brain. Modification of synapses in response to experience, or synaptic plasticity, is thought to be a cellular mechanism for learning and memory. Noninvasive tools to alter synaptic plasticity are therefore highly desirable. Recently, transcranial direct current stimulation (tDCS), has received much attention as a such a tool. tDCS is the noninvasive application of weak DC electric current to the brain through electrodes on the scalp. In this talk I will discuss mechanisms by which tDCS may influence synaptic plasticity, and how this can inform tDCS protocols to improve learning and memory

Bio-sketch: Greg Kronberg is currently a PhD student in the Biomedical Engineering department at The City College of New York (CCNY), where he works under Lucas Parra. He received his BS in Biology from the University of Maryland and his MS in Biomedical Engineering from CCNY. His research focuses on the use of electrical brain stimulation to improve learning and memory.

Measurements and models of electric fields in the in vivo human brain during transcranial electric stimulation

Yu (Andy) Huang, Ph.D.

Department of Biomedical Engineering, The City College of New York

Abstract: Transcranial electric stimulation aims to stimulate the brain by applying weak electrical currents at the scalp. However, the magnitude and spatial distribution of electric fields in the human brain are unknown. Here we measure electric potentials intracranially in ten patients and estimate electric fields across the entire brain by leveraging calibrated current-flow models. Electric field magnitudes at the cortical surface reach values of 0.4 V/m, which is at the lower limit of effectiveness in animal studies. When individual anatomy is taken into account, the predicted electric field magnitudes match the recorded values with r=0.77. Modeling white matter anisotropy and different skull compartments does not improve accuracy, but correct magnitude estimates require an adjustment of conductivity values used in the literature. This is the first study to validate and calibrate current-flow models with in vivo intracranial recordings in humans, providing a solid foundation for targeting and interpretation of clinical trials.

Biosketch: Yu (Andy) Huang received his Ph.D. from Department of Biomedical Engineering, City College of New York. His research focuses on neuroimaging, image segmentation and computational modeling of image data. He received his B.S. and M.S. from University of Electronic Science and Technology of China, both in Biomedical Engineering.

Nature Scientific Reports

In-vivo Imaging of Magnetic Fields Induced by Transcranial Direct Current Stimulation (tDCS) in Human Brain using MRI

Mayank V. Jog, Robert X. Smith, Kay Jann, Walter Dunn, Belen Lafon, Dennis Truong, Allan Wu, Lucas Parra, Marom Bikson & Danny J. J. Wang

Transcranial direct current stimulation (tDCS) is an emerging non-invasive neuromodulation technique that applies mA currents at the scalp to modulate cortical excitability. Here, we present a novel magnetic resonance imaging (MRI) technique, which detects magnetic elds induced by tDCS currents. This technique is based on Ampere’s law and exploits the linear relationship between direct current and induced magnetic elds. Following validation on a phantom with a known path of electric current and induced magnetic eld, the proposed MRI technique was applied to a human limb (to demonstrate in- vivo feasibility using simple biological tissue) and human heads (to demonstrate feasibility in standard tDCS applications). The results show that the proposed technique detects tDCS induced magnetic elds as small as a nanotesla at millimeter spatial resolution. Through measurements of magnetic elds linearly proportional to the applied tDCS current, our approach opens a new avenue for direct in-vivo visualization of tDCS target engagement.

Full PDF: srep34385

Our new review is published:

Jackson MP, Rahman A, Lafon B, Kronberg G, Ling D, Parra LC, Bikson M, Animal Models of transcranial Direct Current Stimulation: Methods and Mechanisms, Clinical Neurophysiology, doi:10.1016/j.clinph.2016.08.016

Full PDF here: animalmodelstdcs_2016

Abstract:  The objective of this review is to summarize the contribution of animal research using direct current stimulation (DCS) to our understanding of the physiological effects of transcranial direct current stimulation (tDCS). We comprehensively address experimental methodology in animal studies, broadly classified as: 1) transcranial stimulation; 2) direct cortical stimulation in vivo and 3) in vitro models. In each case advantages and disadvantages for translational research are discussed including dose translation and the overarching “quasi-uniform” assumption, which underpins translational relevance in all animal models of tDCS. Terminology such as anode, cathode, inward current, outward current, current density, electric field, and uniform are defined. Though we put key animal experiments spanning decades in perspective, our goal is not simply an exhaustive cataloging of relevant animal studies, but rather to put them in context of ongoing efforts to improve tDCS. Cellular targets, including excitatory neuronal somas, dendrites, axons, interneurons, glial cells, and endothelial cells are considered. We emphasize neurons are always depolarized and hyperpolarized such that effects of DCS on neuronal excitability can only be evaluated within subcellular regions of the neuron. Findings from animal studies on the effects of DCS on plasticity (LTP/LTD) and network oscillations are reviewed extensively. Any endogenous phenomena dependent on membrane potential changes are, in theory, susceptible to modulation by DCS. The relevance of morphological changes (galvanotropy) to tDCS is also considered, as we suggest microscopic migration of axon terminals or dendritic spines may be relevant during tDCS. A majority of clinical studies using tDCS employ a simplistic dose strategy where excitability is singularly increased or decreased under the anode and cathode, respectively. We discuss how this strategy, itself based on classic animal studies, cannot account for the complexity of normal and pathological brain function, and how recent studies have already indicated more sophisticated approaches are necessary. One tDCS theory regarding “functional targeting” suggests the specificity of tDCS effects are possible by modulating ongoing function (plasticity). Use of animal models of disease are summarized including pain, movement disorders, stroke, and epilepsy.

D.Q. Truong. D. Adair, M. Bikson. Computer-based models of tDCS of tACS in Transcranial Direct Current Stimulation in Neuropsychiatric Disorders: Clinical Principles ed. M.Nitsche, C. Loo and A. Brunoni 2016 10.1007/978-3-319-33967-2_5 p.47-66 . PDF

D. Ling, A. Rahman, M. Jackson M. Bikson Animal studies in the field of transcranial electric stimulation in Transcranial Direct Current Stimulation in Neuropsychiatric Disorders: Clinical Principles M.Nitsche, C. Loo and A. Brunoni 2016 10.1007/978-3-319-33967-2_5 p.67-83 PDF

Bikson M,Paneri B, Giordano J. The off-label use, utility and potential value of tDCS in the clinical care of particular neuropsychiatric conditions. Journal of Law and the Biosciences, 1–5 doi:10.1093/jlb/lsw044

PDF

Olympic Athletes Are Electrifying Their Brains, and You Can Too

If a brain-stimulation gadget catches on, expect controversy over “brain doping”

IEEE Spectrum, August 21, 2916 Link

Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016
Marom Bikson, Pnina Grossman, Chris Thomas, Adantchede Louis Zannou, Jimmy Jiang, Tatheer Adnan, Antonios P. Mourdoukoutas, Greg Kronberg, Dennis Truong, Paulo Boggio, André R. Brunoni, Leigh Charvet, Felipe Fregni, Brita Fritsch, Bernadette Gillick, Roy H. Hamilton, Benjamin M. Hampstead, Ryan Jankord, Adam Kirton, Helena Knotkova, David Liebetanz, Anli Liu, Colleen Loo, Michael A. Nitsche, Janine Reis, Jessica D. Richardson, Alexander Rotenberg, Peter E. Turkeltaub, Adam J. Woods
Brain Stimulation 2016, Vol. 9, Issue 5

Full PDF

Actually, just a fun image as we pilot the new headgear.

Since our lab is multidisciplinary, we have members from other fields than engineering. Selin Unal, is a medical student from Turkey that joined our lab for the summer and she is going to continue her research from Turkey remotely! See you soon Selin!

The “Non-invasive neuromodulation technology and regulation meeting” is a national meeting covering topics on the commercialization and regulation of non-invasive neuromodulation technology intended for medical and wellness use. This intensive one-day event is in direct response to the proliferation of clinical trials, popular press coverage, and now consumer-directed devices. The meeting is focused on transcranial Direct Current Stimulation (tDCS) but spans any investigational techniques or marketed technologies that apply electrical energy to the head. Ample time will be allowed for discussion with speakers.

Date: August 28, 2016
Location Center for Discovery and Innovation (CDI) Room Number – 4352

For more information visit the links below:
About this Meeting
Location
Speakers
Registration and Tickets
Program

Neural Engineering Lab members can ask for free registraton code from Dr. Marom Bikson or Bhaskar Paneri

Center of Pressure Speed Changes with tDCS Versus GVS in Patients with Lateropulsion after Stroke

Brain Stimul. 2016 Jun 21. pii: S1935-861X(16)30190-5. doi: 10.1016/j.brs.2016.06.053.

PDF

Marom Bikson speak “Brain Stimulation” at Mount Sinai for the Brain Imaging Center symposium on October 19th

Details and Registration here 

Transcranial direct current stimulation modulates pattern separation

Neuroreport 2016 DOI: 10.1097/WNR.0000000000000621

Full paper PDF

Marcus Cappiello, Weizhen Xie, Alexander David, Marom Bikson and Weiwei Zhang

Abstract: Maintaining similar memories in a distinct and nonoverlapping manner, known as pattern separation, is an important mnemonic process. The medial temporal lobe, especially the hippocampus, has been implicated in this crucial memory function. The present study thus examines whether it is possible to modulate pattern separation using bilateral transcranial direct current stimulation (tDCS) over the temporal lobes. Specifically, in this study, pattern separation was assessed using the Mnemonic Similarity Task following 15-min offline bilateral temporal lobe tDCS (left cathode and right anode or left anode and right cathode) or sham stimulation. In the Mnemonic Similarity Task, participants studied a series of sequentially presented visual objects. In the subsequent recognition memory test, participants viewed a series of sequentially presented objects that could be old images from study, novel foils, or lures that were visually similar to the studied images. Participants reported whether these images were exactly the same as, similar to, or different from the studied images. Following both active tDCS conditions, participants were less likely to identify lures as ‘similar’ compared with the sham condition, indicating a reduction in pattern separation resulting from temporal lobe tDCS. In contrast, no significant difference in overall accuracy was found for participants’ discrimination of old and new images. Together, these results suggest that temporal lobe tDCS can selectively modulate the pattern separation function without changing participants’ baseline recognition memory performance.

Dr. Marom Bikson lectures at the National Institutes of Health (NIH) National Cancer Institute (NCI)

6/13/2016 NCI Shady Grove Campus Room TE406 9:30 AM

Medical Device Device for Innovative Cancer Therapies: Preclinical Evaluation, Clinical Trial Preparation, and a Prospective Clinical Trial of Intraoperative Real-Time Tissue Oxygenation Monitoring by Wireless Pulse Oximetry

Gozde Unal MS in Biomedical Engineering 2016 (mentor Marom Bikson)

Asif Rahman PhD in Biomedical Engineering 2016 (mentor Marom Bikson)

Alam M, Truong DQ, Khadka N , Bikson M
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Download: PDF Published in Physics in Medicine & Biology DOI 

Abstract:

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that applies low amplitude current via electrodes placed on the scalp. Rather than directly eliciting a neuronal response, tDCS is believed to modulate excitability—enhancing or suppressing neuronal activity in regions of the brain depending on the polarity of stimulation. The specificity of tDCS to any therapeutic application derives in part from how electrode configuration determines the brain regions that are stimulated. Conventional tDCS uses two relatively large pads (>25 cm2) whereas high-definition tDCS (HD-tDCS) uses arrays of smaller electrodes to enhance brain targeting. The 4  ×  1 concentric ring HD-tDCS (one center electrode surrounded by four returns) has been explored in application where focal targeting of cortex is desired. Here, we considered optimization of concentric ring HD-tDCS for targeting: the role of electrodes in the ring and the ring’s diameter. Finite element models predicted cortical electric field generated during tDCS. High resolution MRIs were segmented into seven tissue/material masks of varying conductivities. Computer aided design (CAD) model of electrodes, gel, and sponge pads were incorporated into the segmentation. Volume meshes were generated and the Laplace equation (  (σ  V)  =  0) was solved for cortical electric field, which was interpreted using physiological assumptions to correlate with stimulation and modulation. Cortical field intensity was predicted to increase with increasing ring diameter at the cost of focality while uni-directionality decreased. Additional surrounding ring electrodes increased uni-directionality while lowering cortical field intensity and increasing focality; though, this effect saturated and more than 4 surround electrode would not be justified. Using a range of concentric HD-tDCS montages, we showed that cortical region of influence can be controlled while balancing other design factors such as intensity at the target and uni-directionality. Furthermore, the evaluated concentric HD-tDCS approaches can provide categorical improvements in targeting compared to conventional tDCS. Hypothesis driven clinical trials, based on specific target engagement, would benefit by this more precise method of stimulation that could avoid potentially confounding brain regions.

Neuromodulation: Technology at the Neural Interface doi: 10.1111/ner.12430

Transcranial Direct Current Stimulation Is Feasible for Remotely Supervised Home Delivery in Multiple Sclerosis

Read the full paper

Margaret Kasschau; Jesse Reisner; Kathleen Sherman; Marom Bikson; Abhishek Datta; Leigh E. Charvet

Objectives: Transcranial direct current stimulation (tDCS) has potential clinical application for symptomatic management in mul- tiple sclerosis (MS). Repeated sessions are necessary in order to adequately evaluate a therapeutic effect. However, it is not feasible for many individuals with MS to visit clinic for treatment on a daily basis, and clinic delivery is also associated with sub- stantial cost. We developed a research protocol to remotely supervise self- or proxy-administration for home delivery of tDCS using specially designed equipment and a telemedicine platform.

Materials and Methods: We targeted ten treatment sessions across two weeks. Twenty participants (n 5 20) diagnosed with MS (any subtype), ages 30 to 69 years with a range of disability (Expanded Disability Status Scale or EDSS scores of 1.0 to 8.0) were enrolled to test the feasibility of the remotely supervised protocol.

Results: Protocol adherence exceeded what has been observed in studies with clinic-based treatment delivery, with all but one participant (95%) completing at least eight of the ten sessions. Across a total of 192 supervised treatment sessions, no session required discontinuation and no adverse events were reported. The most common side effects were itching/tingling at the elec- trode site.

Conclusions: This remotely supervised tDCS protocol provides a method for safe and reliable delivery of tDCS for clinical studies in MS and expands patient access to tDCS.

Effects of High-Definition and Conventional tDCS on Response Inhibition

Brain Stimulation doi:10.1016/j.brs.2016.04.015.    Read the full PDF

J. Hogeveen , J. Grafman  , M. Aboseria , A. David , M. Bikson , K.K. Hauner

ABSTRACT Background: Response inhibition is a critical executive function, enabling the adaptive control of behavior in a changing environment. The inferior frontal cortex (IFC) is considered to be critical for response inhibition, leading researchers to develop transcranial direct current stimulation (tDCS) montages attempting to target the IFC and improve inhibitory performance. However, conventional tDCS montages produce diffuse current through the brain, making it difficult to establish causality between stimulation of any one given brain region and resulting behavioral changes. Recently, high-definition tDCS (HDtDCS) methods have been developed to target brain regions with increased focality relative to conventional tDCS. Objective: Remarkably few studies have utilized HD-tDCS to improve cognitive task performance, however, and no study has directly compared the behavioral effects of HD-tDCS to conventional tDCS. Methods: In the present study, participants received either HD-tDCS or conventional tDCS to the IFC during performance of a response inhibition task (stop-signal task, SST) or a control task (choice reaction time task, CRT). A third group of participants completed the same behavioral protocols, but received tDCS to a control site (mid-occipital cortex). Post-stimulation improvement in SST performance was analyzed as a function of tDCS group and the task performed during stimulation using both conventional and Bayesian parameter estimation analyses. Results: Bayesian estimation of the effects of HD- and conventional tDCS to IFC relative to control site stimulation demonstrated enhanced response inhibition for both conditions. No improvements were found after control task (CRT) training in any tDCS condition. Conclusion: Results support the use of both HD- and conventional tDCS to the IFC for improving response inhibition, providing empirical evidence that HD-tDCS can be used to facilitate performance on an executive function task.