Prof. Marom Bikson interviewed for IBM thinkLeaders, May 4, 2017
Prof. Marom Bikson interviewed for IBM thinkLeaders, May 4, 2017
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.
Dr. Marom Bikson lectures on “The Promise and Pitfalls of tDCS” at the Department of Clinical Neuroscience, University of Calgary, Jun 30, 2017
Download the slide: 2017_Calgary
2017 Brain Stimulation and Imaging Meeting, Vancouver Canada, June 23-24
Meeting website link
June 24: 1:45 PM
Lucas Parra, Professor of Biomedical Engineering, The City College of the City University of New York Center for Discovery and Innovation, New York, NY, USA
TITLE: CELLULAR MECHANISMS OF TRANSCRANIAL ELECTRICAL STIMULATION
June 24: 2:15 PM
Marom Bikson, Professor of Biomedical Engineering at The City College of New York (CCNY) of the City University of New York (CUNY) and co-Director of the Neural Engineering Group at the New York Center for Biomedical Engineering
TITLE: THE PROBLEM WITH CONCURRENT EEG AND TDCS
Download Bikson slides: BrainStim2017_final
Friday 6/23 at 3 pm in CDI 3rd floor conference room (3.352)
Title: Development, optimization, and neurophysiological effects of transcutaneous auricular vagus nerve stimulation (taVNS)
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.
Full paper: OptimalUseEEG_2016
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
Prof. Marom Bikson gives two invited talk at the International Neuromodulation Society meeting in Edinburgh May 27-30. Conference details link
May 27, 2017 “Toward Markers of Target Engagement in tDCS” in the pre-conference on Non-Invasive Brain Stimulation.
Download slides talk 1: Bikson_INS_2017finalA.compressed
May 29, 2017 “Mechanistic Questions around High-Rate Stimulation and Overview of Methods for Reliable Electrophysiological Recording During High-Rate (10k) Stimulation” in breakout session Mechanisms and Models of High-rate Electrical Stimulation (chaired by Dr. Bikson)
Download slides talk 2:29-1430-BIKSON-BREAKOUT_Fd.compressed
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