Congratulations to Belen, Asif, and Natalie
Neuromodulation of Axon Terminals
Cerebral Cortex, 2017; 1–9 doi: 10.1093/cercor/bhx158 Download PDF:NeuromodulationofAxons
Darpan Chakraborty, Dennis Q. Truong, Marom Bikson and Hanoch Kaphzan
Abstract: Understanding which cellular compartments are influenced during neuromodulation underpins any rational effort to explain and optimize outcomes. Axon terminals have long been speculated to be sensitive to polarization, but experimentally informed models for CNS stimulation are lacking. We conducted simultaneous intracellular recording from the neuron soma and axon terminal (blebs) during extracellular stimulation with weak sustained (DC) uniform electric fields in mouse cortical slices. Use of weak direct current stimulation (DCS) allowed isolation and quantification of changes in axon terminal biophysics, relevant to both suprathreshold (e.g., deep brain stimulation, spinal cord stimulation, and transcranial magnetic stimulation) and subthreshold (e.g., transcranial DCS and transcranial alternating current stimulation) neuromodulation approaches. Axon terminals polarized with sensitivity (mV of membrane polarization per V/ m electric field) 4 times than somas. Even weak polarization (<2 mV) of axon terminals significantly changes action potential dynamics (including amplitude, duration, conduction velocity) in response to an intracellular pulse. Regarding a cellular theory of neuromodulation, we explain how suprathreshold CNS stimulation activates the action potential at terminals while subthreshold approaches modulate synaptic efficacy through axon terminal polarization. We demonstrate that by virtue of axon polarization and resulting changes in action potential dynamics, neuromodulation can influence analog– digital information processing.
Friday 6/23 at 3 pm in CDI 3rd floor conference room (3.352)
Laurent Koessler from CNRS and Lorraine University will be speaking
Title: Brain source detection and localization using multi-scale EEG recording.
Abstract: In drug-resistant epilepsy surgery investigations, epileptogenic zone and brain functional areas localization are required. This localization relies on scalp and intracerebral EEG recordings. In Nancy (France) I developed a program concerning simultaneous scalp and intracerebral EEG recordings. Using this methodological approach, 1) in vivo human brain tissue conductivities can be estimated, 2) relationship from brain sources to scalp EEG correlates can be studied and 3) non invasive electrical source localization can be validated.
Tomorrow June 21st at 2pm in CDI 3rd floor conference room (3.352)
Bashar Badran from the Medical Universty of South Carolina and University of New Mexico will be speaking
Title: Development, optimization, and neurophysiological effects of transcutaneous auricular vagus nerve stimulation (taVNS)
Abstract: taVNS is an emerging new form of neuromodulation involving transcutaneous electrical stimulation of the auricular branch of the vagus nerve. Still in its infancy and showing much clinical promise, the optimal human stimulation parameters and direct brain effects are undetermined. This lecture will present the findings of two important studies that aim to solve the taVNS problem of infinite parametric solutions. The first, a taVNS parametric study exploring 9 different combinations of pulse width and frequency and their activation of the vagal tone as measured by physiological recordings. The second is a novel multi-modal imaging study that establishes concurrent taVNS/fMRI and explores the direct brain effect of taVNS on the human brain’s BOLD response. These findings aim to establish an aim and direction of the optimal taVNS parameters to guide future trials.
Neuroimage. 2017 May 31;157:69-80. doi: 10.1016/j.neuroimage.2017.05.059.
Optimal use of EEG recordings to target active brain areas with transcranial electrical stimulation.
Dmochowski JP, Koessler L, Norcia AM, Bikson M, Parra LC.
Abstract: To demonstrate causal relationships between brain and behavior, investigators would like to guide brain stimulation using measurements of neural activity. Particularly promising in this context are electroencephalography (EEG) and transcranial electrical stimulation (TES), as they are linked by a reciprocity principle which, despite being known for decades, has not led to a formalism for relating EEG recordings to optimal stimulation parameters. Here we derive a closed-form expression for the TES configuration that optimally stimulates (i.e., targets) the sources of recorded EEG, without making assumptions about source location or distribution. We also derive a duality between TES targeting and EEG source localization, and demonstrate that in cases where source localization fails, so does the proposed targeting. Numerical simulations with multiple head models confirm these theoretical predictions and quantify the achieved stimulation in terms of focality and intensity. We show that constraining the stimulation currents automatically selects optimal montages that involve only a few (4-7) electrodes, with only incremental loss in performance when targeting focal activations. The proposed technique allows brain scientists and clinicians to rationally target the sources of observed EEG and thus overcomes a major obstacle to the realization of individualized or closed-loop brain stimulation.
“Noninvasive Neuromodulation Goes Deep” Jacek Dmochowski and Marom Bikson, Cell.http://dx.doi.org/10.1016/j.cell.2017.05.017
Modulating deep regions of the brain with noninvasive technology has challenged researchers for decades. In a new study, Grossman et al. leverage the emergence of a slowly oscillating ‘‘beat’’ from intersecting high-frequency electric fields to stimulate deep brain regions, opening a frontier in the biophysics and technology of brain stimulation. Download PDF: FullPaper
The Science of Consciousness June 5-10, 2017 La Jolla, California
‘The Science of Consciousness’ (‘TSC’) is an interdisciplinary conference on all aspects of the nature of conscious experience, awareness, feelings and existence. How does the brain produce consciousness? Is consciousness intrinsic to the universe, or an epiphenomenal illusion? How can consciousness causally affect brain processes? What are the best empirical theories? Do we have free will? How did life and consciousness originate and evolve? What are the origins of moral and aesthetic values? How can we improve mental, physical and cognitive function? Can consciousness persist after bodily death, e.g. through ‘uploading’ to machines, or via mental processes tied to the natural world?
For registration, hotel and other information see: http://www.consciousness.arizona.edu
Marom Bikson, CCNY/CUNY, ‘Non-Invasive Brain Stimulation Devices to Change Thought and Behavior’
June 6: PL4 2:00 to 4:10 pm Non-Invasive Brain Stimulation
Thursday, May 18, 2017, 12:20PM, NAC 6/113
Basilis Gidas (Brown University), Finding Genes and Towards a Mathematical Framework for Artificial Intelligence and Biological Systems
The first half of the lecture will be on a statistical model for finding genes in the human genome. The model contains two parts: (a) A finite network (graph) which represents the overall architecture of a gene. The vertices in the network represent DNA signals (small patterns) associated with a gene and which are recognized by proteins and enzymes involved in the transcription and translation of genes. The edges of the network correspond to interactions among these signals and represent statistical variability in the architecture across genes; (b) each signal and each part of a gene is a piece of DNA with a random length as well as a random variability of its nucleotide sequence. The second part of the model articulates these variabilities.
The above gene finding procedure is conceptually similar to what is believed to underlie speech recognition whereby recognition involves two types of information: The acoustic signal represented by a concatenation of phonemes, and global regularities articulated by grammars (or syntax). The underpinning process in visual recognition is undoubtedly similar. And so is – many practitioners believe – the functioning of biological processes whereby two principles are at work: physics (biochemistry) and evolution. Physics controls the biochemical interaction of macromolecules, but it is evolution that produced the perfect “code” or “syntactic language” for the collective behavior of genes (Gene Regulatory Networks), or the collective behavior of proteins in Signal Transduction Pathways in cell growth, cell division or immunology. While specific questions and application in speech, vision, and biology have seen impressive advances and have lead to a great deal of mathematical innovation (e.g. modern statistical learning), an underpinning mathematical framework is missing. Though we do not have the framework, we know quite a bit of some of the problems the framework needs to articulate and some of the properties it needs to have. Building on the gene finding process, the second part of the talk will aim at identifying some key sources that makes information processing in cognition and biology difficult, and hint towards a coherent hierarchical/grammatical framework.
The CCNY Neural Engineering group is excited for two important papers on the mechanisms of tDCS published in the same issue of Brain Stimulation journal.
Direct Current Stimulation Modulates LTP and LTD: Activity Dependence and Dendritic Effects.
Kronberg G, Bridi M, Abel T, Bikson M, Parra LC.
Brain Stimul. 2017 Jan – Feb;10(1):51-58. doi: 10.1016/j.brs.2016.10.001. Epub 2016 Oct 5. PMID: 28104085
Direct Current Stimulation Alters Neuronal Input/Output Function.
Lafon B, Rahman A, Bikson M, Parra LC.
Brain Stimul. 2017 Jan – Feb;10(1):36-45. doi: 10.1016/j.brs.2016.08.014. Epub 2016 Sep 1.PMID: 27717601
The SF Giants Are Zapping Their Brains With Electricity. Will It Help? MAY 8, 2017
“People like to say that electricity is the currency of the brain and that in many ways the brain is a circuit,” says Marom Bikson, a professor of biomedical engineering at City College of New York. “So when we apply electricity to the brain, we interact with that circuit, and we can change how that circuit works.”
Leite J, Goncalves Ó, Pereira P, Khadka N, Bikson M, Fregni F, Carvalho S
Download: PDF published in Neuroscience Research DOI
Abstract
This study examined the effects of bihemispheric and unihemispheric transcranial Direct Current Stimulation (tDCS) over the inferior frontal gyrus (IFG) on proactive control. Sixteen participants were randomized to receive (i) bihemispheric tDCS, with a 35 cm2 anodal electrode of the right IFG and a 35 cm2 cathode electrode of left IFG or (ii) unihemispheric tDCS, with a 35 cm2 anodal electrode of the right IFG and a 100 cm2 electrode of the left IFG or (iii) sham tDCS, while performing a prepotent inhibition task. There were significant speed-accuracy tradeoff effects in terms of switch costs: unihemispheric tDCS significantly decreased the accuracy when compared to bihemispheric, and sham tDCS, while increased response time when comparing to bihemispheric and sham tDCS. The computational model showed a symmetrical field intensity for the bihemispheric tDCS montage, and an asymmetrical for the unihemispheric tDCS montage. This study confirms that unihemispheric tDCS over the rIFG has a significant impact on response inhibition. The lack of results of bihemispheric tDCS brings two important findings for this study: (i) left IFG seems to be also critically associated with inhibitory response control, and (ii) these results highlight the importance of considering the dual effects of tDCS when choosing the electrode montage.
Jackson MP, Truong D, Brownlow ML, Wagner JA, McKinley RA, Bikson M, Jankord R. Safety parameter considerations of anodal transcranial Direct Current Stimulation in rats. Brain, Behavior, and Immunity 2017 pii: S0889-1591(17)30110-1. doi: 10.1016/j.bbi.2017.04.008 PDF
Nitsche M. Bikson M. Extending the parameter range for tDCS: Safety and tolerability of 4 mA stimulation. Brain Stimulation. Editorial, Volume 10, Issue 3, Pages 541–542, 2017 PDF
And don’t forget our seminal 2016 safety review here
Dr. Bikson was interviewed in City College of New York for VICE News Tonight’s Technology segment. The video was aired on HBO on March 30th, 2017. Enter the password tdcsnews to watch the short 7 minutes clip from the VICE News telecast.
Prof. Luca Parra (CCNY Biomedical Engineering), On Brainwaves and Videos and Video Games
Thursday, February 09, 2017, 03:30 PM, NAC 4/156
What are the immediate neural response of the brain to natural stimuli, in particular audiovisual narratives and video games? To answer this question we record EEG while subjects are exposed to the identical audiovisual narratives and measure inter-subject correlation, which captures how similarly and reliably different people respond to the same natural stimulus. We find that inter-subject correlation of EEG is strongly modulated by attention, correlates with long term memory, and provides a quantitative estimate for “audience engagement”. In children and adolescents watching videos we find changes with age and gender that are consistent with an increase in diversity of brain responses as they mature. During video game play, which are unique experiences that preclude correlation across subjects, we measure the strength of stimulus-response correlations instead. We found that correlation with both auditory and visual responses drive the correlation observed between subjects for video and that they are are modulated by attention in video game play. Importantly, the strongest response to visual and auditory features had nearly identical neural origin suggesting that the dominant response of the brain to natural stimuli is supramodal.
Congrats on Yu (Andy) Huang, Marom Bikson, and Lucas Parra’s paper on TES model validation accepted to be published on eLife. Also thank Anli Liu’s team from NYU School of Medicine for all the experimental recordings.
Measurements and models of electric fields in the in vivo human brain during transcranial electric stimulation
Here is the link to the paper, and a summary video.
OR Download the PDF here
CORRECTION NOTICE: Published on February 15, 2018
“Whats wrong with tDCS”?
Thursday March 16th at 9:30 AM at Alexandria East 901
Remotely Supervised Transcranial Direct Current Stimulation Increases the Benefit of At-Home Cognitive Training in Multiple Sclerosis
Neuromodulation. 2017 Feb 22. doi: 10.1111/ner.12583. [Epub ahead of print]
PMID: 28225155
Leigh Charvet, PhD; Michael Shaw, BS; Bryan Dobbs, MS; Ariana Frontario, BS; Kathleen Sherman, MS; Marom Bikson, PhD; Abhishek Datta, PhD; Lauren Krupp, MD; Esmail Zeinapour, MS; Margaret Kasschau, BS
Full paper PDF
Objective: To explore the efficacy of remotely-supervised transcranial direct current stimulation (RS-tDCS) paired with cognitive training (CT) exercise in participants with multiple sclerosis (MS). Methods: In a feasibility study of RS-tDCS in MS, participants completed ten sessions of tDCS paired with CT (1.5 mA 3 20 min, dorsolateral prefrontal cortex montage). RS-tDCS participants were compared to a control group of adults with MS who underwent ten 20-min CT sessions through the same remotely supervised procedures. Cognitive outcomes were tested by composite scores measuring change in performance on standard tests (Brief International Cognitive Assessment in MS or BICAMS), basic attention (ANT-I Orienting and Attention Networks, Cogstate Detection), complex attention (ANT-I Executive Network, Cogstate Identification and One-Back), and intra-individual response variability (ANT-I and Cogstate identification; sensitive markers of disease status). Results: After ten sessions, the tDCS group (n 5 25) compared to the CT only group (n 5 20) had significantly greater improvement in complex attention (p 5 0.01) and response variability (p 5 0.01) composites. The groups did not differ in measures of basic attention (p 5 0.95) or standard cognitive measures (p 5 0.99). Conclusions: These initial findings indicate benefit for RS-tDCS paired with CT in MS. Exploratory analyses indicate that the earliest tDCS cognitive benefit is seen in complex attention and response variability. Telerehabilitation using RS-tDCS combined with CT may lead to improved outcomes in MS.
Chen CF, Bikson M, Chou LW, Shan C, Khadka N, Chen WS, Fregni F.
Download: PDF Published in Nature, Scientific Reports DOI
Abstract
It is well established that electrical-stimulation frequency is crucial to determining the scale of induced neuromodulation, particularly when attempting to modulate corticospinal excitability. However, the modulatory effects of stimulation frequency are not only determined by its absolute value but also by other parameters such as power at harmonics. The stimulus pulse shape further influences parameters such as excitation threshold and fiber selectivity. The explicit role of the power in these harmonics in determining the outcome of stimulation has not previously been analyzed. In this study, we adopted an animal model of peripheral electrical stimulation that includes an amplitude-adapted pulse train which induces force enhancements with a corticospinal contribution. We report that the electrical-stimulation-induced force enhancements were correlated with the amplitude of stimulation power harmonics during the amplitude-adapted pulse train. This is a pilot, but important first demonstration that power at high order harmonics in the frequency spectrum of electrical stimulation pulses may contribute to neuromodulation, thus warrant explicit attention in therapy design and analysis.
