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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Top-Down Effect of Direct Current Stimulation on the Nociceptive Response of Rats

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Author(s):
Dimov, Luiz Fabio [1] ; Franciosi, Adriano Cardozo [1] ; Pinheiro Campos, Ana Carolina [1] ; Brunoni, Andre Russowsky [2, 3, 4] ; Pagano, Rosana Lima [1]
Total Authors: 5
Affiliation:
[1] Hosp Sirio Libanes, Lab Neuromodulat & Expt Pain, Rua Prof Daher Cutait 69, BR-01308060 Sao Paulo, SP - Brazil
[2] Univ Sao Paulo, Fac Med, SIN, Dept & Inst Psychiat, Lab Neurosci LIM27, Rua Doutor Ovidio Pires Campos 785, BR-05403000 Sao Paulo, SP - Brazil
[3] Univ Sao Paulo, Ctr Clin & Epidemiol Res, Univ Hosp, Ave Prof Lineu Prestes 2565, Ext 3, BR-05508000 Sao Paulo, SP - Brazil
[4] Univ Sao Paulo, Interdisciplinary Ctr Appl Neuromodulat CINA, Univ Hosp, Ave Prof Lineu Prestes 2565, Ext 3, BR-05508000 Sao Paulo, SP - Brazil
Total Affiliations: 4
Document type: Journal article
Source: PLoS One; v. 11, n. 4 APR 12 2016.
Web of Science Citations: 4
Abstract

Transcranial direct current stimulation (tDCS) is an emerging, noninvasive technique of neurostimulation for treating pain. However, the mechanisms and pathways involved in its analgesic effects are poorly understood. Therefore, we investigated the effects of direct current stimulation (DCS) on thermal and mechanical nociceptive thresholds and on the activation of the midbrain periaqueductal gray (PAG) and the dorsal horn of the spinal cord (DHSC) in rats; these central nervous system areas are associated with pain processing. Male Wistar rats underwent cathodal DCS of the motor cortex and, while still under stimulation, were evaluated using tail-flick and paw pressure nociceptive tests. Sham stimulation and naive rats were used as controls. We used a randomized design; the assays were not blinded to the experimenter. Immunoreactivity of the early growth response gene 1 (Egr-1), which is a marker of neuronal activation, was evaluated in the PAG and DHSC, and enkephalin immunoreactivity was evaluated in the DHSC. DCS did not change the thermal nociceptive threshold; however, it increased the mechanical nociceptive threshold of both hind paws compared with that of controls, characterizing a topographical effect. DCS decreased the Egr-1 labeling in the PAG and DHSC as well as the immunoreactivity of spinal enkephalin. Altogether, the data suggest that DCS disinhibits the midbrain descending analgesic pathway, consequently inhibiting spinal nociceptive neurons and causing an increase in the nociceptive threshold. This study reinforces the idea that the motor cortex participates in the neurocircuitry that is involved in analgesia and further clarifies the mechanisms of action of tDCS in pain treatment. (AU)

FAPESP's process: 12/20911-5 - Escitalopram and transcranial direct current stimulation in major depressive disorder: a double blind, placebo-controlled, randomized, non-inferiority trial
Grantee:Andre Russowsky Brunoni
Support Opportunities: Research Grants - Young Investigators Grants
FAPESP's process: 09/50772-4 - Parkinson disease and pain: mechanisms involved in the nociceptive neuroplasticity and in the effect of motor cortex stimulation in rats
Grantee:Rosana de Lima Pagano
Support Opportunities: Research Grants - Young Investigators Grants