Evidence map›Paper›PMID 25029273›Full record

Trial reportPloS one2014

Building up analgesia in humans via the endogenous μ-opioid system by combining placebo and active tDCS: a preliminary report.

Marcos F DosSantos, Ilkka K Martikainen, Thiago D Nascimento, Tiffany M Love, Misty D DeBoer, Heidi M Schambra, Marom Bikson, Jon-Kar Zubieta, Alexandre F DaSilva

Open access · goldAbstract readClinical Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in PloS one, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 53 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
53citing papers in PubMed, 3 pooled it
4.2field-weighted citation impact, top 6% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

53 citing papers in PubMed, 3 syntheses or guidelines pooled it, 88 citations in OpenAlex.

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  8. Functional Magnetic Resonance Imaging Signal Variability Is Associated With Neuromodulation in Fibromyalgia.Neuromodulation : journal of the International Neuromodulation Society · 2023
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  9. Active and sham transcranial direct current stimulation (tDCS) improved quality of life in female patients with fibromyalgia.Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation · 2022
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors at 4 institutions in 1 country.

Marcos F DosSantosHeadache & Orofacial Pain Effort (H.O.P.E.), Department of Biologic and Materials Sciences & Michigan Center for Oral Health Research (MCOHR), School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America.
Ilkka K MartikainenHeadache & Orofacial Pain Effort (H.O.P.E.), Department of Biologic and Materials Sciences & Michigan Center for Oral Health Research (MCOHR), School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America; Translational Neuroimaging Laboratory, Molecular and Behavioral Neuroscience Institute (MBNI), University of Michigan, Ann Arbor, Michigan, United States of America.
Thiago D NascimentoHeadache & Orofacial Pain Effort (H.O.P.E.), Department of Biologic and Materials Sciences & Michigan Center for Oral Health Research (MCOHR), School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America.
Tiffany M LoveTranslational Neuroimaging Laboratory, Molecular and Behavioral Neuroscience Institute (MBNI), University of Michigan, Ann Arbor, Michigan, United States of America.
Misty D DeBoerHeadache & Orofacial Pain Effort (H.O.P.E.), Department of Biologic and Materials Sciences & Michigan Center for Oral Health Research (MCOHR), School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America.
Heidi M SchambraDepartments of Neurology and Rehabilitation & Regenerative Medicine, Columbia University, New York, New York, United States of America.
Marom BiksonDepartment of Biomedical Engineering, The City College of New York, New York, New York, United States of America.
Jon-Kar ZubietaTranslational Neuroimaging Laboratory, Molecular and Behavioral Neuroscience Institute (MBNI), University of Michigan, Ann Arbor, Michigan, United States of America.
Alexandre F DaSilvaHeadache & Orofacial Pain Effort (H.O.P.E.), Department of Biologic and Materials Sciences & Michigan Center for Oral Health Research (MCOHR), School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America; Translational Neuroimaging Laboratory, Molecular and Behavioral Neuroscience Institute (MBNI), University of Michigan, Ann Arbor, Michigan, United States of America.
University of Michigan–Ann Arbor · USMichigan United · USCity College of New York · USColumbia University · US

Funding

MICHIGAN INSTITUTE FOR CLINICAL AND HEALTH RESEARCH (MICHR) (UL1): (BPCA)UL1RR024986 · NCRR · UNIVERSITY OF MICHIGAN AT ANN ARBOR · PI SHANLEY, THOMAS P. · 2007 to 2011
$51.2M
NCRR NIH HHS UL1 RR024986NCRR NIH HHS UL1RR024986
6 · The paper itself

Abstract

Transcranial Direct Current Stimulation (tDCS) is a method of non-invasive brain stimulation that has been frequently used in experimental and clinical pain studies. However, the molecular mechanisms underlying tDCS-mediated pain control, and most important its placebo component, are not completely established. In this pilot study, we investigated in vivo the involvement of the endogenous μ-opioid system in the global tDCS-analgesia experience. Nine healthy volunteers went through positron emission tomography (PET) scans with [11C]carfentanil, a selective μ-opioid receptor (MOR) radiotracer, to measure the central MOR activity during tDCS in vivo (non-displaceable binding potential, BPND)--one of the main analgesic mechanisms in the brain. Placebo and real anodal primary motor cortex (M1/2mA) tDCS were delivered sequentially for 20 minutes each during the PET scan. The initial placebo tDCS phase induced a decrease in MOR BPND in the periaqueductal gray matter (PAG), precuneus, and thalamus, indicating activation of endogenous μ-opioid neurotransmission, even before the active tDCS. The subsequent real tDCS also induced MOR activation in the PAG and precuneus, which were positively correlated to the changes observed with placebo tDCS. Nonetheless, real tDCS had an additional MOR activation in the left prefrontal cortex. Although significant changes in the MOR BPND occurred with both placebo and real tDCS, significant analgesic effects, measured by improvements in the heat and cold pain thresholds, were only observed after real tDCS, not the placebo tDCS. This study gives preliminary evidence that the analgesic effects reported with M1-tDCS, can be in part related to the recruitment of the same endogenous MOR mechanisms induced by placebo, and that such effects can be purposely optimized by real tDCS.

Indexed as

AdultAnalgesiaAnalgesics, OpioidAnalysis of VarianceFemaleFentanylHumansMaleMiddle AgedMotor CortexPositron-Emission TomographyReceptors, Opioid, muTranscranial Direct Current StimulationAnalgesics, OpioidcarfentanilFentanylReceptors, Opioid, mu

Identifiers

PMID25029273
PMCPMC4100885
OpenAlexW1969062458

What OpenQuestion holds

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LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.