Monthly Archives: March 2016

Anna Wexler – DIY tDCS Podcast #6 – Regulating tDCS

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annaWexlerGlacier

Anna Wexler is a Ph.D. candidate in the HASTS Program (History, Anthropology, Science, Technology, and Society) at MIT. Her dissertation focuses on the ethical, social and regulatory implications of consumer non-invasive brain stimulation. She is currently a 2015-2016 visiting scholar at the Center for Neuroscience and Society at the University of Pennsylvania. In 2007, Anna graduated from MIT with two Bachelors’ of Science degrees, one in Brain and Cognitive Science and the other in Humanities and Science with a focus in Writing.

AnnaWexler.com

Papers of Anna’s we discuss.
A pragmatic analysis of the regulation of consumer transcranial direct current stimulation (TDCS) devices in the United States
The practices of do-it-yourself brain stimulation: implications for ethical considerations and regulatory proposals (Paywall)

“Medical Batteries”
The Practice of Medical Electricity: Showing the Most Approved Apparatus, Their Methods of Use, and Rules for the Treatment of Nervous Diseases, More Especially Paralysis and Neuralgia

Front Cover
Fannin & Company, 1869

Harvard Law Professor Peter Barton Hutt

Sally Adee Better Living Through Electrochemistry 2/9/2012 Her blog version of the New Scientist article (now paywalled).
GoFlow FlowStateEngaged.com (2012 Archive.org)
Radiolab 9-Volt Nirvana 6/26/2014
Elif Batuman Electrified 4/6/2015 New Yorker

The challenge of crafting policy for do-it-yourself brain stimulation
Nicholas S Fitz, Peter B Reiner

FDA Proposed Rule Neurological Devices; Reclassification of Cranial Electrotherapy Stimulator Intended To Treat Insomnia and/or Anxiety; Effective Date of Requirement for Premarket Approval for Cranial Electrotherapy Stimulator Intended To Treat Depression

General Wellness: Policy for Low Risk Devices – Draft Guidance for Industry and Food and Drug Administration Staff (PDF – 550KB)

The FDA doesn’t want to regulate wearables, and device makers want to keep it that way (The Verge)

CDPH Warns Consumers Not to Use TDCS Home Device Kit

Understanding The Mechanism Underlying The Effects of tDCS

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The paper, Calcium imaging reveals glial involvement in transcranial direct current stimulation-induced plasticity in mouse brain, is being lauded as a major discovery among tDCS researchers. It is however, extremely hard to follow. Fortunately RIKEN also issued a press release describing the study in a way most tDCS-curious will understand. Read the full press release here.

Researchers at the RIKEN Brain Science Institute in Japan have discovered that the benefits of stimulating the brain with direct current come from its effects on astrocytes — not neurons — in the mouse brain. Published in Nature Communications, the work shows that applying direct current to the head releases synchronized waves of calcium from astrocytes that can reduce depressive symptoms and lead to a general increase in neural plasticity — the ability of neuronal connections to change when we try to learn or form memories.


(top) Low spontaneous calcium activity in a normal mouse followed by tDCS-induced calcium surges. (bottom) tDCS-induced calcium surges are absent in IP3 Receptor 2 knockout mice, indicating that the calcium surges originate in astrocytes, not neurons.
Note: The upper. ‘normal’ mouse brain vs. modified mouse brain, bottom. Watch near ticking clock when ‘spontaneous’ switches to ‘tDCS’.

Let’s put this in some context by having a quick look at astrocytes and glial cells. From 2-Minute Neuroscience

Electrical brain stimulation can help recovery from stroke | CTV

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Watch the CTV news story.tdcsCtvStrokeStudy

Dr. Alexander Thiel, director of the Comprehensive Stroke Centre at Montreal’s Jewish General Hospital, said the TDCS treatments have been studied before, but what’s special about the study out of Oxford is that it suggests the treatment may be causing structural changes in the brain that contribute to the patient’s recovery.

“This is important because it could either indicate that some parts of these nerve cells are able to regenerate, or these nerve cells try to form alternative pathways  to reroute the traffic in the brain to a different route  from the one that has been destroyed by the stroke,” he told CTV News.

Stroke patients in Canada can’t get TDCS therapy outside of a research study. But with several studies underway around the world, scientists hope they’ll be able to quickly confirm that brain stimulation has the power to accelerate stroke recovery.

Full article: Electrical brain stimulation can help recovery from stroke: study
Study: Ipsilesional anodal tDCS enhances the functional benefits of rehabilitation in patients after stroke
Study author: Charlotte Stagg

tDCS Depression Montage

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Marom Bikson (no less!) demonstrating depression montage using the Soterix EasyStrap.

From a recent Marom Bikson slide deck.

From a recent Marom Bikson slide deck (pdf).

Prefrontal Electrical Stimulation in Non-depressed Reduces Levels of Reported Negative Affects from Daily Stressors

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Prefrontal Electrical Stimulation in Non-depressed Reduces Levels of Reported Negative Affects from Daily Stressors

In two sham-controlled experiments, we found that repeated daily prefrontal tDCS sessions over 5 several days could effectively modulate how non-depressed individuals self-assess their mood states. Results show that participants experienced less psychological distress from daily stressors, a well established cause in the establishment of a negative emotional state. We replicated this finding in an independent, randomized, double-blind experiment applying similar protocol and stimulation on 3 consecutive days.

anode over the left F3 10–20 position, cathode over the contralateral F4 position

anode over the left F3 10–20 position, cathode over the contralateral F4 position

tDCS Boosts Synaptic Plasticity and Memory In Mice via Epigenetic Regulation of Bdnf Expression

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Wait! There’s a Science Daily version.
Brain boost: Research to improve memory through electricity?

More important, the researchers identified the actual molecular trigger behind the bolstered memory and plasticity–increased production of BDNF, a protein essential to brain growth. BDNF, which stands for “brain-derived neurotrophic factor,” is synthesized naturally by neurons and is crucial to neuronal development and specialization.

“While the technique and behavioral effects of tDCS are not new,” said ONR Global Associate Director Dr. Monique Beaudoin, “Dr. Grassi’s work is the first to describe BDNF as a mechanism for the behavioral changes that occur after tDCS treatment. This is an exciting and growing research area of great interest to ONR.”

The research is sponsored by the Office of Naval Research!
What he said!

Podda, M. V. et al. Anodal transcranial direct current stimulation boosts synaptic plasticity and memory in mice via epigenetic regulation of Bdnf expression. Sci. Rep. 6, 22180; doi: 10.1038/srep22180 (2016).

I won’t even pretend to understand this paper at this point, but it’s unique enough that I want to encourage people to have a look. That said… what I think it’s saying is that (in mice) hippocampal tDCS creates a chain reaction that results in increased brain plasticity, i.e. increased neuronal connection which in this case is responsible for increased performance in a memory task. (Not more neurotransmitters.)

But this paper suggests the actual mechanism for how this is happening.

We hypothesized that anodal tDCS induced membrane depolarization mimicking neuronal activation and triggered epigenetic changes at Bdnf, thus favoring its transcription.

All together these results indicate that Bdnf expression in the hippocampus is induced by anodal tDCS and that enhanced acetylation at Bdnf promoter I is likely responsible for such effect.

Collectively, these data suggest that anodal tDCS induced epigenetic changes at Bdnf promoters likely relying on a mechanism involving CREB activation, CBP recruitment and H3K9 acetylation.

These results strongly support our hypothesis that increased histone acetylation promoting Bdnf transcription plays a major role in anodal tDCS-induced enhancement of synaptic plasticity.

tDCS-Model of anodal tDCS-induced chromatin remodeling