Transcranial direct current stimulation (tDCS) neuromodulatory effects on mechanical hyperalgesia and cortical BDNF levels in ovariectomized rats.

Abstract

AIMS:

Epidemiological studies show that painful disorders are more prevalent in women than in men, and the transcranial direct current stimulation (tDCS) technique has been tested in chronic pain states. We explored the effect of tDCS on pain behavior and brain-derived neurotrophic factor (BDNF) levels in ovariectomized rats.

MAIN METHODS:

Forty-five female Wistar adult rats were distributed into five groups: control (CT), ovariectomy + tDCS (OT), ovariectomy + sham tDCS (OS), sham ovariectomy + tDCS (ST), and sham ovariectomy+shamtDCS (SS). The rats were subjected to cathodal tDCS. The vaginal cytology and the estradiol levels confirmed the hormonal status. In addition, nociceptive behavior was evaluated using the tail-flick, von Frey, and hot-plate tests, as well as the BDNF levels in the serum, hypothalamus, hippocampus, spinal cord, and cerebral cortex. One-way analysis of variance (ANOVA) or two-way ANOVA was used for statistical analysis, followed by the Bonferroni, and P-value b 0.05 was considered significant.

KEY FINDINGS:

The ovariectomized animals presented a hypersensitivity response in the hot-plate (P b 0.01) and von Frey (P b 0.05) tests, as well as increased serum BDNF (P b 0.05) and decreased hypothalamic BDNF (P b 0.01) levels. The OT, OS, ST, and SS groups showed decreased hippocampal BDNF levels as compared with the control group (P b 0.001). The interaction between tDCS and ovariectomy on the cortical BDNF levels (P b 0.01) was observed.

SIGNIFICANCE:

The ovariectomy induced nociceptive hypersensitivity and altered serum and hypothalamic BDNF levels. The cathodal tDCS partially reversed nociceptive hypersensitivity.

• Authors: Sônia Fátima da Silva Moreira, Liciane Fernandes Medeiros, Andressa de Souza, Carla de Oliveira, Vanessa Leal Scarabelot, Felipe Fregni, Wolnei Caumo, Iraci L S Torres
• Journal: Life sciences (Life Sci) Vol. 145 Pg. 233-9 (Jan 15 2016) ISSN: 1879-0631 [Electronic] Netherlands
• PMID: 26471218 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Brain-Derived Neurotrophic Factor

Topics

• Animals
• Brain-Derived Neurotrophic Factor (analysis, blood, metabolism)
• Cerebral Cortex (metabolism, pathology)
• Female
• Hippocampus (metabolism, pathology)
• Humans
• Hyperalgesia (blood, etiology, pathology, therapy)
• Male
• Ovariectomy (adverse effects)
• Pain Measurement
• Pain Threshold
• Rats
• Rats, Wistar
• Transcranial Direct Current Stimulation